CELLULOSE SUBSTRATES, COMPOSITIONS AND METHODS FOR STORAGE AND
ANALYSIS OF BIOLOGICAL MATERIALS
BACKGROUND
[0001] FTA®paper (GE Healthcare, Whatman Inc., Piscataway, NJ) has proven to be a
reliable means of collecting, transporting, storing, and archiving genetic material, such as DNA,
from a variety of biological samples. Simple procedures have been developed and widely used
for purification and amplification of samples stored on FTA. Newer procedures have also been
developed using FTA molecular procedures, such as drug metabolism and pharmacokinetic
(DMPK) analysis including toxicokinetics (TK) studies. In many cases analysis may be
performed directly on the paper containing the immobilized DNA sample. In other cases, the
DNA may first be eluded from the paper, whereby the DNA is released into solution (FTA
Elute®) . Elution may occur through various washing cycles using solutions capable of
solubilizing the DNA and may also include applying heat, vacuum, or centrifugation to the
process.
[0002] Although current FTA paper provides attractive properties, such as stabilization of
components of interest and antibacterial features that enable lower safety guidelines, one
disadvantage of the current FTA paper, as applied to DMPK and TK type studies, is leachable
components on the paper, which may interfere with the downstream analysis of drugs and
metabolites, or other analytes.
[0003] In order to expand the use of FTA paper technology, a method of preserving the
biological sample on paper is needed, without the problem of interfering leachables, and while
maintaining other desirable features such as antibacterial properties and hydrophilic/wicking
properties of the paper are maintained.
[0004] EP1534269A1 describes oxime conjugates to e.g. polysaccharides, but does not
disclose any paper formulations useful as substrates for storage and analysis of biological
materials.
BRIEF DESCRIPTION
[0005] In one embodiment, the invention provides a method of storing genetic material or
analytes from a biological sample by contacting said biological sample with a cellulose substrate
said cellulose substrate comprising structural units of Formula I(I)
wherein X and Y are independently N-O-L-A or 0 „ with the proviso that when Y is O, then X
is N-O-L-A, and when X is O, then Y is N-O-L-A; L is a direct bond, an aliphatic radical, an
aromatic radical, a cycloaliphatic radical, or a combination thereof; and A= COOH, SO3H, or a
combination thereof.
[0006] In one embodiment, the invention provides an article for storing genetic material or
analytes from a biological sample comprising a cellulose substrate comprising the structural
units of Formula I .
[0007] In another embodiment, the invention provides a cellulose substrate comprising
structural units of Formula I and a method of manufacturing the same.
DRAWINGS
[0008] These and other features, aspects, and advantages of the present invention will
become better understood when the following detailed description is read with reference to the
accompanying drawings in which like characters represent like parts throughout the drawings.
[0009] FIG. 1 is LC-MS trace of extractables from papers treated using different surface
chemistries and formulations, including both positive (current FTA paper) and negative controls
(unmodified paper).
[0010] FIG 2 is a graphical representation of wicking performance of a variety of papers
treated with different chemistries and families of molecules; for the aminooxy/amine family, the
corresponding oxidized paper is included as a control, in addition to the standard positive and
negative control papers.
[001 1] FIG.3 shows analyte recovery of multiple model drugs represented in terms of
percent recovery for different paper formulations.[0012] FIG.4 shows phospholipid retention represented in terms of mean LPC
(lysophosphatidylcholine) quantified in extracts for different paper formulations.
DETAILED DESCRIPTION
DEFINITIONS
[0013] To more clearly and concisely describe and point out the subject matter of the
claimed invention, the following definitions are provided for specific terms that are used in the
following description and the claims appended hereto.
[0014] Aliphatic radical is an organic radical having at least one carbon atom, a valence of at
least one and may be a linear or branched array of atoms. Aliphatic radicals may include
heteroatoms such as nitrogen, sulfur, silicon, selenium and oxygen or may be composed
exclusively of carbon and hydrogen. Aliphatic radical may include a wide range of functional
groups such as alkyl groups, alkenyl groups, alkynyl groups, halo alkyl groups, conjugated
dienyl groups, alcohol groups, ether groups, aldehyde groups, ketone groups, carboxylic acid
groups, acyl groups (for example, carboxylic acid derivatives such as esters and amides), amine
groups, nitro groups and the like. For example, the 4-methylpent-l-yl radical is a C aliphatic
radical comprising a methyl group, the methyl group being a functional group, which is an alkyl
group. Similarly, the 4-nitrobut-l-yl group is a C4 aliphatic radical comprising a nitro group, the
nitro group being a functional group. An aliphatic radical may be a haloalkyl group that
includes one or more halogen atoms, which may be the same or different. Halogen atoms
include, for example; fluorine, chlorine, bromine, and iodine. Aliphatic radicals having one or
more halogen atoms include the alkyl halides: trifluoromethyl, bromodifluoromethyl,
chlorodifluoromethyl, hexafluoroisopropylidene, chloromethyl, difluorovinylidene,
trichloromethyl, bromodichloromethyl, bromoethyl, 2-bromotrimethylene (e.g., -CH2CHBrCH2-
), and the like. Further examples of aliphatic radicals include allyl, aminocarbonyl (-CONH 2),
carbonyl, dicyanoisopropylidene -CH2C(CN)
2CH2-), methyl (-CH3), methylene (-CH 2-), ethyl,
ethylene, formyl (-CHO), hexyl, hexamethylene, hydroxymethyl (-CH2OH), mercaptomethyl (-
CH2SH), methylthio (-SCH 3), methylthiomethyl (-CH 2SCH3), methoxy, methoxycarbonyl
(CH3OCO-), nitromethyl (-CH2N0 2), thiocarbonyl, trimethylsilyl ((CH3)
3Si-), t-
butyldimethylsilyl, trimethoxysilylpropyl ((CH30 )
3SiCH2CH2CH2-), vinyl, vinylidene, and the
like. By way of further example, a "Ci - C3o aliphatic radical" contains at least one but no morethan 30 carbon atoms. A methyl group (CH3-) is an example of a Ci aliphatic radical. A decyl
group (CH3(CH2)cr) is an example of a C10
aliphatic radical.
[0015] A cycloaliphatic radical is a radical having a valence of at least one, and having an
array of atoms, which is cyclic but which is not aromatic. A cycloaliphatic radical may include
one or more non-cyclic components. For example, a cyclohexylmethyl group (C6HnCH 2-) is a
cycloaliphatic radical, which includes a cyclohexyl ring (the array of atoms, which is cyclic but
which is not aromatic) and a methylene group (the noncyclic component). The cycloaliphatic
radical may include heteroatoms such as nitrogen, sulfur, selenium, silicon and oxygen, or may
be composed exclusively of carbon and hydrogen. A cycloaliphatic radical may include one or
more functional groups, such as alkyl groups, alkenyl groups, alkynyl groups, halo alkyl groups,
conjugated dienyl groups, alcohol groups, ether groups, aldehyde groups, ketone groups,
carboxylic acid groups, acyl groups (for example carboxylic acid derivatives such as esters and
amides), amine groups, nitro groups and the like. For example, the 4-methylcyclopent-l-yl
radical is a C cycloaliphatic radical comprising a methyl group, the methyl group being a
functional group, which is an alkyl group. Similarly, the 2-nitrocyclobut-l-yl radical is a C4
cycloaliphatic radical comprising a nitro group, the nitro group being a functional group. A
cycloaliphatic radical may include one or more halogen atoms, which may be the same or
different. Halogen atoms include, for example, fluorine, chlorine, bromine, and iodine.
Cycloaliphatic radicals having one or more halogen atoms include 2-trifluoromethylcyclohex-l-
yl, 4-bromodifluoromethylcyclooct-l-yl, 2-chlorodifluoromethylcyclohex-l-yl,
hexafluoroisopropylidene 2,2-bis (cyclohex-4-yl) (-C6HioC (CF3) 2C6Hi
0-), 2-
chloromethylcyclohex-l-yl; 3- difluoromethylenecyclohex-l-yl; 4-trichloromethylcyclohex-l-
yloxy, 4-bromodichloromethylcyclohex-l-ylthio, 2-bromoethylcyclopent-l-yl, 2-
bromopropylcyclohex-l-yloxy (e.g. CH3CHBrCH2C6Hio-), and the like. Further examples of
cycloaliphatic radicals include 4-allyloxycyclohex-l-yl, 4-aminocyclohex-l-yl (H2NCeHio-), 4-
aminocarbonylcyclopent-l-yl (NH2COC H8-), 4-acetyloxycyclohex-l-yl, 2,2-
dicyanoisopropylidenebis(cyclohex-4-yloxy) (-OC6Hi
0C(CN)2C6Hi
0O-), 3-methylcyclohex- 1-
yl, methylenebis(cyclohex-4-yloxy) (-OC6Hi
0CH2C6Hi
0O-), 1-ethylcyclobut-l-yl,
cyclopropylethenyl, 3-formyl-2-terahydrofuranyl, 2-hexyl-5-tetrahydrofuranyl; hexamethylene-
1,6-bis(cyclohex-4-yloxy) 4-hydroxymethylcyclohex- 1-yl (4-
HOCH2C6Hio-), 4-mercaptomethylcyclohex-l-yl (4-HSCH2C6Hi
0-), 4-methylthiocyclohex-l-yl
(4-CH3SCeHio-), 4-methoxycyclohex-l-yl, 2-methoxycarbonylcyclohex-l-yloxy (2-
CH3OCOC6HioO-), 4-nitromethylcyclohex-l-yl (NO2CH2C6Hi
0-), 3-trimethylsilylcyclohex-l-
yl, 2-t-butyldimethylsilylcyclopent-l-yl, 4-trimethoxysilylethylcyclohex-l-yl (e.g.(CH30)3SiCH2CH2C Hio-), 4-vinylcyclohexen-l-yl, vinylidenebis(cyclohexyl), and the like.
The term "a C3 - C3o cycloaliphatic radical" includes cycloaliphatic radicals containing at least
three but no more than 10 carbon atoms. The cycloaliphatic radical 2-tetrahydrofuranyl
(C4H7O-) represents a C4 cycloaliphatic radical. The cyclohexylmethyl radical (C HiiCH2-)
represents a C cycloaliphatic radical.
[0016] An aromatic radical is an array of atoms having a valence of at least one and having at
least one aromatic group. This may include heteroatoms such as nitrogen, sulfur, selenium,
silicon and oxygen, or may be composed exclusively of carbon and hydrogen. Suitable aromatic
radicals may include phenyl, pyridyl, furanyl, thienyl, naphthyl, phenylene, and biphenyl
radicals. The aromatic group may be a cyclic structure having 4n+2 "delocalized" electrons
where "n" is an integer equal to 1 or greater, as illustrated by phenyl groups (n = 1), thienyl
groups (n = 1), furanyl groups (n = 1), naphthyl groups (n = 2), azulenyl groups (n = 2),
anthracenyl groups (n = 3) and the like. The aromatic radical also may include non-aromatic
components. For example, a benzyl group may be an aromatic radical, which includes a phenyl
ring (the aromatic group) and a methylene group (the non-aromatic component). Similarly a
tetrahydronaphthyl radical is an aromatic radical comprising an aromatic group (C H3) fused to
a non-aromatic component -(CH 2)
4- . An aromatic radical may include one or more functional
groups, such as alkyl groups, alkenyl groups, alkynyl groups, haloalkyl groups, haloaromatic
groups, conjugated dienyl groups, alcohol groups, ether groups, thio groups, aldehyde groups,
ketone groups, carboxylic acid groups, acyl groups (for example carboxylic acid derivatives
such as esters and amides), amine groups, nitro groups, and the like. For example, the 4-
methylphenyl radical is a C7 aromatic radical comprising a methyl group, the methyl group
being a functional group, which is an alkyl group. Similarly, the 2-nitrophenyl group is a C6
aromatic radical comprising a nitro group, the nitro group being a functional group. Aromatic
radicals include halogenated aromatic radicals such as trifluoromethylphenyl,
hexafluoroisopropylidenebis(4-phen-l-yloxy) (-OPhC(CF 3)
2PhO-), chloromethylphenyl, 3-
trifluorovinyl-2-thienyl, 3-trichloromethylphen-l-yl (3-CCl
3Ph-), 4-(3-bromoprop-l-yl)phen-l-
yl (BrCH2CH2CH2Ph-), and the like. Further examples of aromatic radicals include 4-
allyloxyphen-l-oxy, 4-aminophen-l-yl (H2NPh-), 3-aminocarbonylphen-l-yl (NH2COPh-), 4-
benzoylphen-l-yl, dicyanoisopropylidenebis(4-phen-l-yloxy) (-OPhC(CN)
2PhO-), 3-
methylphen-l-yl, methylenebis(phen-4-yloxy) (-OPhCH 2PhO-), 2-ethylphen-l-yl,
phenylethenyl, 3-formyl-2-thienyl, 2-hexyl-5-furanyl; hexamethylene-l,6-bis(phen-4-yloxy) (-
OPh(CH2)
6PhO-), 4-hydroxymethylphen-l-yl (4-HOCH2Ph-), 4-mercaptomethylphen-l-yl (4-
HSCH2Ph-), 4-thiophenyl (-S-Ph), 4-methylthiophen-l-yl (4-CH3SPh-), 3-methoxyphen-l-yl, 2-methoxycarbonylphen-l-yloxy (e.g., methyl salicyl), 2-nitromethylphen-l-yl (-PhCH2N0 2), 3-
trimethylsilylphen- 1-yl, 4-t-butyldimethylsilylphenl- 1-yl, 4-vinylphen- 1-yl,
vinylidenebis(phenyl), and the like. The term "a C3 - C3o aromatic radical" includes aromatic
radicals containing at least three but no more than 30 carbon atoms. The aromatic radical 1-
imidazolyl (C3H2N2-) represents a C3 aromatic radical. The benzyl radical (C7H7-) represents a
C aromatic radical.
[0017] Many of the compounds described herein may contain one or more asymmetric
centers and may thus give rise to enantiomers, diastereomers, and other stereoisomeric forms
that may be defined, in terms of absolute stereochemistry, as (R)- or (S)-. The present invention
is meant to include all such possible isomers, as well as, their racemic and optically pure forms.
Optically active (R)- and (S)- isomers may be prepared using chiral synthons or chiral reagents,
or resolved using conventional techniques. When the compounds described herein contain
olefmic double bonds or other centers of geometric asymmetry, and unless specified otherwise,
it is intended that the compounds include both E and Z geometric isomers. Likewise, all
tautomeric forms are also intended to be included.
[0018] FTA paper is cellulose-based matrix impregnated with chemicals that lyse cells and
preserve nucleic acid. The chemicals are activated when a biological fluid contacts the surface.
Additional features of the chemical treatment are bacterial and viral inactivation. This protects
the biosample from microbial growth contamination and may also protect the user from
potential biohazards present in the biosample. As such FTA paper is a preferred medium that
protects and stabilizes DNA for collection, transport, storage, and archival from a variety of
biological samples. The biological sample may then subsequently be analyzed. The analysis
may include, but is not limited to genetic analysis or qualitative or quantitative determination of
analytes present within the biological sample.
[0019] Biological samples, also refer to as genetic samples, may include both plant and
animal tissue samples including, but not limited to, buccal (cheek) samples, cerebrospinal fluid,
feces, plasma, blood, lymph, urine, , seminal fluid, vaginal fluid, gland secretion, suspension of
cells or viruses, viral plaques, or serum sample that contains nucleic acid. The sample may be in
a purified state or from crude preparations such as a cell extract or culture, or directly obtained
as a sample transfer such as a surface swabbing or spotting. The nucleic acids may include
DNA and RNA, ribosomal RNA and messenger RNA, and nucleic acid primers and aptamers.Once a genetic sample is stored on the FTA paper, or a similar cellulose based material, it may
be submitted for analysis using a number of protocols.
[0020] Analytes refers to one or more substances being measured in the biological sample.
Analytes being measured in dried blood samples (DBS) may include quantitative or qualitative
determination of circulating chemicals, drugs or metabolites. This may include, but is not
limited to metabolites screening relating to the detection of a variety of metabolic diseases, drug
metabolites relating to pharmacokinetic (DMPK) analysis for example with drug screening
candidates, or chemical and drug exposure in toxicokinetics (TK) studies.
[0021] Analysis involving amplification or restriction enzyme digestion of the genetic
material may be performed directly on the FTA paper, or a similar cellulose based material
without the need for extraction procedures. In other instances extraction and purification of the
genetic material from the paper may occur prior to analysis. This may be accomplished by
washing a portion of the paper, such as a punch sample, with an extraction reagent.
[0022] However, regardless of the analysis, leachable components on the paper may be
present which may interfere with the downstream analysis of the targeted analytes from the
biological sample such as, but not limited to, compositional testing, drug discovery, and
metabolites.
[0023] The structure of cellulose consists of parallel D-glucose chains. The structure is
stabilized by hydrogen bonds giving it fibrous properties. The cellulose substrate may be in paper
sheet, pulp form, tablet, or a cellulose powder prepared by either mechanical or chemical
disintegration of alpha-cellulose, hard or soft wood pulp, purified wood pulp, cotton linter sheet,
cotton pulp, or the like. Other sources of cellulose include low crystallinity celluloses and
commercially available cellulose excipients, such as microfibrillated cellulose, powdered
cellulose, regenerated cellulose, and microcrystalline cellulose. In certain embodiments the
cellulose substrate may include nitrocellulose or carboxymethylcellulose papers. It is preferred
that the cellulose substrate be of a porous nature to facilitate immobilization of genetic material,
storage, elution, and subsequent analysis.
[0024] In accordance with one embodiment, a method is described in which a cellulose
substrate undergoes ring opening oxidation to form aldehyde groups at the C2-C3 position. In
certain embodiments, in addition to ring opening oxidation at the C2-C3 position, oxidation of
one or more hydroxyl groups present on the surface of the cellulose may also occur.[0025] In certain embodiments ring opening oxidation of the cellulose substrate may occur
through contact of the substrate with an oxidant such, but not limited to, gaseous chlorine,
aqueous solutions of periodic acid and sodium hydroxide, persulfates, and permanganates. In
other embodiments oxidation consists of consecutive oxidation with sodium periodate, and
sodium chlorite. In other embodiments oxidation may involve enzymes. The oxidized cellulose
may contain carboxylic acid groups, aldehyde groups, ketone groups, or a combination thereof
in addition to hydroxyl groups of the untreated substrate. The amount of oxidation depends on
the nature of the oxidant and the reaction conditions.
[0026] The cellulose substrate may be oxidized just prior to subsequent reaction with the
aminooxy reagents. In other embodiments, a cellulose substrate having a certain degree of
oxidation may be used available and stored from a prior oxidation treatment or from a
commercial source.
[0027] In certain embodiments, the oxidized cellulose substrate is subsequently treated with
an aminooxy reagent having a terminal sulfate group (-OSO 3H), sulfonate group (-SO 3H) or a
carboxylic acid group (-COOH). Aminooxylation of one or more of the aldehyde groups occur
to form pendent alpha-oximocarboxamide groups on the cellulose surface. Aminooxylation
occurs at the C2 position, C 3 position or both. In certain embodiments, aminooxylation may also
occur at surface aldehyde groups, which resulted from oxidation of pendent hydroxyl groups on
the cellulose surface.
[0028] Scheme 1 illustrates aminooxylation at both the C2 and C 3 position.Scheme 1:Aminooxylation at the ring opened C2 and C3 and positions.
[0029] This results in a modified cellulose substrate comprising structural units of Formula I
(I)
wherein X and Y are independently N-O-L-A or O, with the proviso that when Y is O, then X is
N-O-L-A, and when X is O, then Y is N-O-L-A; L is a direct bond, an aliphatic radical, an
aromatic radical, a cycloaliphatic radical, or a combination thereof; and A= COOH, SO3H, or
a combination thereof
[0030] In certain embodiments, the aminooxy reagent may comprise
a substituted aminooxy of Formula II wherein;
H2N-0-L-A
(II)
L is a direct bond, an aliphatic radical, an aromatic radical, a cycloaliphatic radical,
or a mixture thereof; and
A= COOH, SO3H, or a mixture thereof.
[0031] In certain embodiment, L may be a disubstituted (CH2) aliphatic radical wherein , n
is an integer between 1 and 20. The aliphatic radical may be a linear or branched array of atoms.[0032] In certain embodiments L may be heteroatom substituted. In certain embodiments L
may be equal to -(CH2) -Z-(CH2)
m - wherein n is an integer between 0 and 20, m is an integer
between 0 and 20, and X is a heteroatom containing moiety. In certain embodiments, Z may
equal, but not limited to; O, NH, C(0)NH, NHC(O), N(CO)N, 0(CO)0, N(CS)N, 0(CS)0, or
a combination thereof. In each embodiment L links a sulfonate group (- SO3H), a carboxylic
acid group (-COOH), or, when L is a direct link, a terminal sulfate group to the
oximocarboxamide moiety. For example, Z is O, n is 0, m is 1 and A is COOH.
[0033] The aminooxy reagent may be used as an aqueous solution of its salts. Salts include,
but are not limited to, sulfates, nitrates, hydrohalides, and phosphates. In certain embodiments
the aqueous solutions range from 0.05 to 0.5 mol % aminooxy. In certain embodiments, alcohol
co-solvents may be used. In another embodiments, the aqueous solution may also contain a
buffer solution. In other embodiments the aqueous solution may also contain a stabilizer.
[0034] A method of applying the aminooxy reagent may include contacting the aminooxy
reagent with the oxidized cellulose substrate such that a chemical reaction occurs, involving
binding of the aminooxy reagent to the oxidized cellulose. In one embodiment, an aminooxy
reagent may be contacted with the oxidized cellulose substrate by dipping the oxidized cellulose
substrate in a solution of the aminooxy reagent. In another embodiment the aminooxy reagent
may be applied to the oxidized cellulose by spraying, wetting, or printing onto the surface.
Solutions of aminooxy reagent, if employed may include solvents having sufficient volatility to
allow for evaporation of the solvent.
[0035] In one embodiment, the oxidized cellulose substrate may be in a powder form. A
slurry containing both the aminooxy reagent and the oxidized cellulose may be used to allow
contact and binding. The slurry may be decanted, pressed, and dried to yield an oxidized
powder.
[0036] In one embodiment, the binding may be initiated at room temperature. In another
embodiment, binding may be initiated by applying heat. In certain embodiment the temperature
ranges from about 40°C to about 90°C.
[0037] The binding of the reagent is conducted for a time sufficient to react the aminooxy
compound of Formula I with the aldehyde groups on the oxidized cellulose substrate. In one
embodiment, the reaction is conducted for a time period ranging from about 1min to about 30.In another embodiment, the time period ranges from about 1min to about 10 min. The reaction
may be carried out under ordinary pressure or pressurized conditions.
[0038] An article may be fabricated employing the compositions and methods described
hereinabove. In one embodiment, an article is provided. An article includes reaction product of
oxidized cellulose having binding sites and an aminooxy reagent. In one embodiment, an article
fabricated employing the compositions and methods disclosed herein may have a thickness that
is greater than about 0.1 millimeters, greater than about 0.5 millimeters, greater than about 1
millimeters, or greater than about 0.5 centimeter. In one embodiment, the article may be in
powder form and contained in an appropriate sized sample vial. In still another embodiment, the
article may be in the shape of a tablet. In still other embodiments the article may be in a gel or
solution.
[0039] In other embodiments, additional treatment of the oxidized cellulose substrate may
occur, including but not limited to applying chemical coating solutions such as protein
denaturing agents and a free radical trap. The denaturing agents can be a surfactant or anionic
detergents that will denature proteins and pathogenic organisms in the genetic sample. The
denaturing agents also act to lyse the genetic material and allow the genetic material to be
immobilized and preserved. In certain embodiments the denaturing agent acts to lyse the cells
containing the genetic material to release analytes of interest. The chemical solution may
include a weak base, chelating agents, and an anionic surfactant or detergent. Uric acids and
urate salts may also be used. A weak base may be a Tris, trishydroxymethyl methane, either as
a free base or as the carbonate, and the chelating agent may be EDTA. The anionic detergent
may be sodium dodecyl sulfate or sodium lauryl sulfate. Other coatings having similar functions
may also be used. For example in certain embodiments a coating may be used that is capable of
lysing the cells but does not denature proteins In other embodiments, the coating may act to
deactivate enzymes without denaturing for instance, by chelating metals that act of cofactors for
enzymes function.
[0040] In certain embodiments, the coating solutions may be applied to the substrate in such
a matter that the coatings are disposed, sorbed, or otherwise associated with the oxidized
cellulose. In certain embodiments the coatings may adhere to the substrate through chemical
bonding while in other embodiments, adherence may be physical such as through impregnation.
[0041] In certain embodiments, the aminooxy reagent is applied prior to other chemical
treatments. In other embodiments, the aminooxy reagent is applied subsequent to the otherchemical treatments. In still other embodiments the aminooxy reagent is applied as an
intermediate step.
[0042] The modified oxidized cellulose substrate may be used as a method for storage of a
genetic material that is contacted with the substrate. In certain embodiments, the method
involves contacting the genetic material to the substrate. The genetic material may include both
plant and animal tissue samples including, but not limited to, buccal (cheek) samples,
cerebrospinal fluid, feces, plasma, blood, lymph, urine, suspension of cells or viruses, viral
plaques, or serum sample that contains nucleic acid.
[0043] The modified cellulose substrate may also be used as or in a method for storage of,
but not limited to, small drugs and metabolites that could be incorporated in applications, such
as DMPK. In a preclinical setting, the ability to store analyte samples contained in biological
media for example using a dried blood spot (DBS) approach, may simplify the experimental
workflow. This may be accomplished by decreasing the volume of biological samples needed
and consequently minimizes the number and size of animal subjects used, while the analytes are
being preserved for later analytes. Simplification in experimental workflow may also reduce the
possibility of human error.
[0044] In certain embodiments the storage method also comprises a step of drying a biological
sample on the cellulose substrate and a step of storing the cellulose substrate with the dried
biological sample for at least 24 h, such as for at least one week. The drying can be active, e.g.
by application of a stream of dry air to the substrate or by subjecting the substrate to moderately
elevated temperatures, e.g. 25-40°C. It can also be passive, where the substrate with the sample
is left to dry on e.g. a bench surface. The storage can be performed under dry conditions, such as
in the presence of a desiccant, and can be at room temperature (e.g. 20-35°C), under
refrigeration (e.g. 0-1 0°C) or under freezing conditions.
[0045] In some embodiments the storage method further comprises a step of extracting genetic
material or at least one analyte from said cellulose substrate. The extraction can be made with
either aqueous (e.g. buffers) or non-aqueous liquids (e.g. solvents) or even with supercritical
gases such as carbon dioxide. The extract produced may be subjected to further separation steps,
such as e.g. chromatography.
[0046] In certain embodiments the storage method also comprises a step of analyzing the
analyte(s), e.g. by mass spectrometry.[0047] The analyte can be a drug or drug candidate or a metabolite of a drug or drug candidate.
In particular, the method can be used in DMPK studies where e.g. small blood samples are
applied to and stored on the substrate and analyzed with respect to concentration of drugs/drug
candidates and/or metabolites of the drugs/drug candidates.
[0048] The genetic sample may be in a purified state or from crude preparations such as a
cell extract or culture, or directly obtained as a sample transfer such as a surface swabbing or
spotting. The nucleic acids may include, but is not limited to, DNA and RNA, ribosomal R A
and messenger RNA, or nucleic acid primers and aptamers.
[0049] In certain embodiments, the modified oxidized cellulose substrate is shaped into an
article, which will facilitate the storage of the genetic material. The article may be in the form
of a paper, tablet, or powder. In certain embodiments, a paper form may be used which may be
such as a card stock wherein samples contacted with the form may be subsequently removed for
example by punching through the card stock. In other embodiments, the article may be in the
form of a powder contained within a sample tube or vial. The sample tube or vial may be sized
to match the size of the genetic sample or analyte and allow subsequent reagents or extraction
techniques to be added directly to the article to allow for genetic incubation, amplification, or
other testing. In another embodiment, the article may be in form of a tablet wherein the tablet,
based on different compaction pressures, may have different physical properties, such as pore
size distribution and surface area.
[0050] As an article, desirable properties of the cellulose substrate useful for collecting,
storing, and preserving a biological sample may include low leachable components, antibacterial
properties, antiviral properties, and efficient wicking properties.
[005 1] In certain embodiments, the modified oxidized cellulose substrate may have lower
levels of leachables as compared to other similarly formed cellulose articles. Leachables are
defined as residual chemicals that may be present on or within the cellulose substrate that may
be leached or extracted from the substrate during subsequent processing of the genetic sample,
such that the residual may be present in the isolated genetic sample and interfere with
downstream analysis. The level of leachables may be measured as extractables from the
cellulose substrate using a solvent washing wherein the solvent dissolves or extracts materials
from the cellulose substrate. In certain embodiments, the leachable- free substrate may be
defined as having less than 200 ppm, preferably less than 100 ppm, and more preferable less
than 25 ppm of extractables in the wash solution. As such a leachable- free composition orarticle formed from a leachable-free composition means that the composition is relatively free of
residuals such that the residuals do not have a potential for contaminating the genetic sample.
In the case of DMPK application, leachables and extractables that can interfere with the analysis
of metabolites or analytes of interest are not desired.
[0052] The various chemistries and formulations used to modify the cellulose substrate are
shown in TABLE 1. Whatman 3IETF is a smooth cellulose paper that has not been treated,
[0]ETF is 3IETF subjected to C2 and C3 and ring opening surface oxidation by treatment with
NaI0 4. FTA® is a commercially available paper used for genetic sampling and treated with
TRIS, EDTA, uric acid, and sodium dodecyl sulfate.
TABLE 1; Chemical Modificationlb; w = 0.02, x = 0.45,y = 0.33, z = 0.2
Id; w= 0.02, x = 0.38, y = 0.33, z = 0.27
2; w =0.02, x =0.28, y=0.54, z = 0.16
3a= 26 wt% add on, e-beam initiation
3b= 9% wt% add on, eerie ammonium nitrate initiation
[0053] The degree of leachability for the different chemistries and formulations tested on
cellulose paper or oxidized cellulose, was determined by subjecting the various papers to
extraction with 70% aqueous tetrahydrofuran. The extracts where identified and quantified
using LC-MS methodology. Extractables analyses showed that in contrast to other chemistries,
the cellulose that was derivatized by means of aminooxy chemistry shows relatively no
extractables from the cellulose paper. This result is comparable to the negative control (3 IETF)
shown in FIG. 1 as a liquid chromatographic trace. As shown, 3IETF shows no extractables, in
contrast to the positive control (FTA paper) that contains a mixture of molecules impregnated on
the surface and shows extractables that may interfere with metabolite analysis. The formulation
involving the use of a combination of aminooxy "S" and amine molecule "D" (S-D) showed that
the aminooxy molecule, that forms an oxime linkage with the oxidized cellulose paper, does not
have extractables (non leaching), whereas the amine molecule that forms a Schiff base, from a
quaternary amine salt, with the oxidized cellulose paper does. Further, the samples having only
aminooxy molecules present in the formulation (S, C, T) do not show extractables.
[0054] These results may be explained in part by the non-reversible character of an oxime
linkage as compared to the reversible character of a Schiff base. In the formulations involving
quaternary amines, extractables were corresponding both to the monomeric unit used andhydrolysis products. Hence, these results suggest that the oxime modification chemistry may
be a preferred method to render non-leachable properties.
[0055] In certain embodiments, the modified oxidized cellulose may have antibacterial
and antiviral properties, comparable or better than commercial FTA paper. These properties
minimize the need for highly regulated safety classifications and guidelines in procedures
involving the handling of biological samples. This may translates into lower cost, simplified
processes that may involve the use, storage and transportation of biological samples. In
addition, antibacterial properties of the paper may minimize the potential growth of bacteria that
may damage the biological samples upon storage.
[0056] The antibacterial properties of various modified oxidized cellulose formulations were
evaluated against three different strains that represent both gram positive and gram-negative
strains, as well multidrug resistant strains. Table 2 summarizes the results from a replica plating
assay and show that the oxidized paper modified with aminooxy/amine moieties show the
highest antibacterial activity, as compared against non-modified cellulose substrates and
representative examples of formulations prepared using a radical chemical approach to
immobilize polymeric or quaternary amine-based formulations. Hence, the antibacterial
character is a result of the modification step, not the preceding oxidation step. The polymeric
molecules showed no antibacterial activity, while the family of quaternary amines showed
strain-dependant results, but still rather mild. As depicted in Table 2 no antibacterial activity is
indicated as (-), minimal inhibition of bacterial grown (+), partial inhibition of bacterial growth
(++), and complete inhibition of bacterial growth as (+++).TABLE 2 :Antibacterial property results
[0057] In applications involving the collection of biological samples, the ability of the paper
to wick, or to flow the biological sample through the paper in a wetting type of action, rapidly
and homogeneously is important in order to ensure a reliable and reproducible sample reading.
In certain embodiments, the modified oxidized cellulose has the desired wicking properties
whereby the wicking properties are comparable to commercial FTA paper.
[0058] FIG 2. is a graphical representation of how quickly the different samples of modified
paper can absorb 10 uL of whole blood. The control cellulose papers (3 IETF, FTA and
[0]3 IETF) were shown to absorb 10 uL of whole blood in the range of 3-4 seconds. 3IETF
and [0]31ETF papers were modified using different families of molecules and formulations as
shown previously in TABLE 1. Formulations involving the use of polymeric (SDS-like)
molecules rendered a rather hydrophobic surface despite the hydrophilic and water soluble
character of the molecules prior to their immobilization onto the cellulose paper using an
approach involving radical chemistry. Nevertheless, the oxidized cellulose paper that was
reacted with the aminooxy and amine molecules, as well as the quaternary amine formulationsinvolving radical chemistry on the non-oxidized cellulose paper (3 IETF), showed results
comparable to the controls.
[0059] As demonstrated, the aminooxy chemistry rendered substrates with wicking,
antibacterial, and non-leachable properties amenable for improved use in the field of storage and
analysis of biological materials. It minimizes or eliminates the sources of leachables that can
inhibit downstream analysis, while retaining some desired properties in products currently
available in the market (e.g. FTA).
[0060] Internal testing has demonstrated that the cellulosic substrate may brown and become
embrittled when exposed to extremes of pH and temperature. This wouldn't be practical for
large scale manufacturing applications. The aminooxysulfonic acids (S and T) would be
expected to generate a solution greater than 5 pH units lower than that of aminooxyacetic acid
(C) at equivalent concentrations. Although optimization of formulation and process conditions
could circumvent this problem with the non-leachable and antibacterial formulations S and T,
formulation C was selected to be tested against performance testing more closely associated to
DMPK application.
[0061] In the DMPK application, the ability to store and analyze small drug molecules and its
metabolites present in very low concentration is critical. The ability to adsorb phospholipids
present in body fluids, such as blood in DBS applications, is also of interest since these
molecules may also interfere with the analysis the same way surfactants do, leading to lower
sensitivity and high variability. These properties were tested experimentally, showing that
formulation C had the ability to extract model drug molecules that ranged from only about 25-40
% lower than commercially available DMPK standard paper while retaining ca. 40-50% more
phospholipid on the paper. Such significant retention of interfering molecules can significantly
enhance the ability to better detect the analytes of interest, not only more reproducibly, but at
lower concentrations. These results, in addition to the other properties previously described
suggest formulation C to be a suitable formulation for specifically DMPK applications, or other
applications that may require comparable combination of performance properties.
[0062] The invention includes embodiments that relate generally to methods applicable in
analytical, diagnostic, or prognostic applications such as, but not limited to, forensics, transgenic
identification, transfusion medicine/HLA typing, plasmid screening, food and agriculture
testing, drug discovery, genomics, STR analysis, animal identification, whole genomeamplification, and molecular biology. In some embodiments, the methods disclosed herein may
be particularly applicable in DMPK analysis. It is to be noted that features of different
embodiments can be combined to form further embodiments.
EXPERIMENTAL
General Procedure for Oxidizing Cellulose
[0063] Whatman grade 3IETF cellulose supplied by GE Healthcare was submerged in an
aqueous solution of NaI0 4 and allowed to react at a given temperature for a predetermined time.
Temperature varied but typically varied from 1 to 5 minutes at 50 to 90°C. The fully wetted out
membranes were then washed in deionized water until the conductivity of the aqueous washes
were less than 3 . Samples were then dried at room temperature overnight.
General Procedure for Reacting Aminooxy Compounds (AO) with Oxidized Cellulose
[0064] Oxidized 3IETF cellulose samples were pre-weighed and then submerged in an
aqueous solution of the aminooxy compound at room temperature. Following complete wet-out,
the samples were removed from the solution with tweezers, and excess solution was allowed to
drain from the saturated membrane. The samples were then partially dried with a heat gun, and
placed in crystallization dishes to be dried at a predetermined temperature and time. Typically
samples were dried at room temperature or in a warm circulating air oven between 50° and 70
C for a period of 12 to 24 hours. The samples were weighed following drying, washed with
deionized water, and solution conductivity was recorded. The samples were redried at the same
predetermined oven temperature for approximately 1 hour, and rewashed with deionized water.
This process was repeated until the ion conductivity was less than 3 . The samples were
redried at the same predetermined temperature, and a final weight was recorded. Weight
percent add-ons were determined by the following equation:
Weight percent add-on = (Final weight - initial weight)/initial weight * 100%
[0065] Samples were also characterized by elemental analysis. Either elemental sulfur or
nitrogen content was determined to deduce the extent of aminooxy (AO) functionalization.
Procedure for Sample 4a in AO-C02H DOE
[0066] A 14 cm x 14 cm 3IETF cellulose sheet was submerged in a 1.0 M aqueous solution
of NaI0 4 at 80 °C and allowed to react for 5 minutes. The fully wetted out membranes were thenwashed in deionized water until the conductivity of the aqueous washes were less than 3 .
The oxidized 3 IETF cellulose was then dried at room temperature overnight. The 14 cm x 14
cm sheet was then cut up into multiple 6 cm x 4 cm sheets for the subsequent treatment with the
aminooxy reagents. A 6 cm x 4 cm sheet was submerged in an aqueous 0.2 M aminooxy
reagents solution at room temperature. Following complete wet-out, the samples were removed
from the solution with tweezers, and excess solution was allowed to drain from the saturated
membrane. The samples were then partially dried with a heat gun, and placed in crystallization
dishes to be dried at 60°C overnight. The sample turned a brown color upon heating overnight.
The dried sample was weighed, washed with deionized water, and solution conductivity was
recorded. The sample was redried at 60 °C for one hour, and rewashed with deionized water.
This process was repeated until the ion conductivity was less than 3 . The sample was
submitted for nitrogen elemental analysis to determine the extent of covalently attached
aminooxy moieties. Elemental Nitrogen Analysis, results are expressed as N% in the sample as
submitted ± the 95% confidence intervals (CI).
Sample Preparation
[0067] Samples were submitted as approx. ¾" squares, two squares per sample type. A razor
blade, pre-cleaned with IPA, cut the samples into tiny squares. Using a microbalance, each
sample replicate was weighed into a tared 5x9mm tin capsule, which was then squeezed into a
small, capsule-enclosed ball, and weighed again. The weight of each sample type varied
dependent upon approx. nitrogen concentration. Two tin capsule blanks were carried through
the analysis.
Standards
[0068] A CFIN calibration was performed on an EA1 108 Elemental Analyzer (Thermo
Scientific, Waltham, MA) using THAB (1.407% N) as standard material. An 8pt calibration
(0.068mg, 0.187mg, 0.416mg, 0.826mg, 1.552mg, 2.404mg, 3.450mg, 6.323mg) produced a
nitrogen curve with a R2 = 99.98%. A second standard material (atropine, 4.84% N) was
analyzed, in addition to the THAB, as unknowns to verify the accuracy of the calibration curve.
THAB nitrogen recovery: 97% - 109%. Atropine nitrogen recovery: 96% - 106%.
Experimental Technique
[0069] The samples were analyzed 4x's on the Carlo Erba EA1 108 Analyzer for N. The
technique is based on a quantitative flash combustion of the sample at lOOOC in an oxygen-enriched atmosphere to form C0 2, H20 , and NOx, from nitrogen, carbon, hydrogen, and sulfur
respectively. The combustion gases are passed through heated elemental copper to reduce all
forms of NOx to N2. They are then carried through a chromatographic column by the carrier gas
where they are separated and detected by a thermal conductivity detector for quantification. The
analyte concentration is calculated by comparison with a series of known standards. The
calibration is prepared as total mg analyte, which is converted to % based on the weight of
sample analyzed. (Instrumental Parameters: Helium flow set to 150 mL/min, Oxygen flow set to
60 mL/min, 540 seconds per sample. Elemental Sulfur Analysis results were determined
measuring wt% metals in cellulose paper at a 95% confidence intervals (CI) to verify surface
modification. . Sample Preparation
[0070] Microwave vessels were pre-cleaned once with 10 mL HNO 3 acid using one
microwave cycle. One replicates of 0.06-0.09g samples (the entire sample submitted was used
for one replicate) were weighed by difference and placed into Teflon XP1500 microwave liners.
10 ml HNO 3 acid was added, washing down the liner walls. The liners were capped, placed into
microwave, and run with "paper" program (10-minute ramp to 100 °C; hold at 100 °C for 10
minutes; pressure control to lOOpsi, 10 minute ramp to 150 °C; hold at 150 °C for 10 minutes;
pressure control to 200psi, minute ramp to 180 °C; hold at 180 °C for 10 minutes; pressure
control to 300psi, minute ramp to 200 °C; hold at 200 °C for 10 minutes; pressure control to
400psi, 10 minute ramp to 220 °C; hold at 220 °C for 10 minutes; pressure control to 600psi,).
After heating cycle samples were allowed to cool completely to room temperature before
opening. Vessel contents transferred to orange cap tube, 5 mL of 10 ppm Sc was added, and the
solution diluted to 50 mL with deionized water (DIW). A blank and a sample spike were
carried throughout the procedure. Acid Spike Recovery: S: 110%. Spex QC Recovery: S:
102% . Standards : S: 0.05ppm - lOppm in 50 ml orange-cap plastic tubes with 20%> HNO 3
with 1 ppm Sc. QC1 : lppm Spex4. Rinse: 20% HN0 3.
Technique: Spectra Arcos ICP-AES
[0071] High temperature plasma is produced by inductively coupling radio frequency power
into a stream of argon gas. The samples are introduced as a solution aerosol into the plasma by a
nebulizer where the respective elements emit their characteristic radiation. In the optics, the
Arcos utilizes 32 linear CCD detectors in an optimized Paschen-Runge mount ORCA
(Optimized Rowland Circle Alignment) (SPECTRO Analytical Instruments GmbH, Germany)
for the simultaneous recording of the wavelengths between 130 and 770 nm. The magnitude ofthe signal is directly proportional to the concentration of an element in a sample. Comparing
sample signal intensities to those generated by calibration standards produces quantitative
results.
Replica Plating Assay (Antibacterial assay) experimental
[0072] Anti-bacterial properties were evaluated using the Gram-negative bacterium
Pseudomonas aeruginosa (infecting isolate 09-010, Brooke Army Medical Center Molecular
Biology Lab and US Army Institute of Surgical Research), the Gram-positive bacterium MRSA
USA300 (methicillin-resistant Staphylococcus aureus infecting isolate NRS384, Network on
Antimicrobial Resistance in Staphylococcus aureus), and lab-strain Escherichia coli (HB101).
Inoculates were cultured in Luria Broth for >6 hours until mid- late log phase (0.6-1 .2 OD600),
at which time culture density was estimated using a 0.5 McFarland standard. Approximately 1-
2 xl07 cells (14-20 of culture) were applied) to a 7mm punch of grafted 31-ETF as well as
positive (FTA) and negative (31-ETF) control paper, and samples were air-dried for 30 minutes
(clinical isolates) or 60-90 minutes (lab-strain E. coli). Using sterile forceps, samples were
replica-plated to fresh trypticase soy agar (TSA) by inverting each punch onto the agar surface
and gently pressing. Punch samples were removed prior to incubating the plate overnight at
37°C, and bacterial growth was assessed after 12-24 hours.
Analysis of Extractable Reagents from 31-ETF Oxidized Substrates by HPLC-Electro Spray
ToFMS:
[0073] Paper circular punches, 7 mm in diameter, were extracted with 500 uL of 70 THF in
water, using vortex for 1min. The chromatographic analysis of extractables was achieved using
an Agilent 1200 Series HPLC system equipped with a 1200 Series Photo-Diode Array detector
in-line to an AB Sciex Q Star Elite® Quadropole Time of Flight Mass Spectrometer equipped
with an Electro Spray ionization accessory. The separation was carried out using a Cadenza CL
CI8 1 x 50mm reverse phase column consisting of 3um particle media. Electro spray ionization
mass spectra were acquired in positive ionization mode. The quantitative analysis was obtained
from the integrated peak area of extracted mass chromatograms of known masses of the
respective reference materials. The method parameters were as follows: Mobile Phase: Solvent
A, 2mM Ammonium Formate (pH = 4); Solvent B, 100% acetonitrile containing 0.1% formic
acid; Flow Rate: 0.2 ml min-1; Photodiode Array Detector Acquisition: 200-800nm; Column:
Cadenza CL C18 3um ( 1 x 50mm);Injection Volume: 50ul;ESI Conditions: Neb Gas: 40,Drying
Gas: 40,Applied Needle Voltage: 3000V,Temperature: 400°C.[0074] The invention may be embodied in other specific forms without departing from the
spirit or essential characteristics thereof. The foregoing embodiments are therefore to be
considered in all respects as illustrative rather than limiting on the invention described herein.
The scope of the invention is thus indicated by the appended claims rather than by the foregoing
description, and all changes that come within the meaning and range of equivalency of the
claims are therefore intended to be embraced therein.
[0075] Analyte Recovery & Phospholipid Retention
[0076] Stocks of model drug molecules were prepared in methanol. The model molecules
represented different chemical groups: base, quaternary amine, neutral and acid. These were
proguanil, hyamine, simvastatin and 2,4,6-Triisopropyl benzoic acid, respectively. The first 3
were prepared at 100 ug/mL concentration and the latter to 200 ug/mL. Whole human blood
was spiked with these drug solutions so that the final drug concentration is a 1/10 of the original
concentration and no more than 10% methanol was present in the blood. Each formulated paper
was spotted with 10 uL of each of the drug-blood mixtures. Papers were dried overnight in
drying chamber. The whole blood spot was punched and collected using 7mm hole puncher and
spot was extracted in 500 ul of 70 % methanol. The theoretical 100% final recovery would be
200 ng/niL for the first three drugs and 400 ng/mL for the latter. For analyte recovery, each
component was quantitated using LC-MS, compared against calibrated standards of the same
components. Internal standards of dinonylamine (positive ion) and triisopropyl benzoic acid
(negative ion) were used to ensure constant signal throughout the runs. The system and
conditions used for chromatographic analysis were done using reverse phase HPLC-ToF MS
used are as follows. The instrument used was an AB Sciex Q Star Elite® Quadropole Time of
Flight Mass Spectrometer equipped with an Electro Spray ionization accessory. The separation
was carried out using a Cadenza CL CI8 1 x 50mm reverse phase column consisting of 3um
particle media. Electro spray ionization mass spectra were acquired in positive ionization mode.
The quantitative analysis was obtained from the integrated peak area of extracted mass
chromatograms of known masses of the respective reference materials. The method parameters
were as follows: Mobile Phase: Solvent A, 2mM Ammonium Formate (pH = 4); Solvent B,
100% acetonitrile containing 0.1% formic acid; Flow Rate: 0.2 ml min-1; Gradient Profile:
95%-0 A over 10 min, hold at 100% B for 2 min, Re-equilibrate at initial condition for 10 min.
Photodiode Array Detector Acquisition: 200-800nm; Column: Cadenza CL C18 3um ( 1 x
50mm); Injection Volume: 5 ul; ESI Conditions: Gl 40, G2 30, CG 25, Applied Needle
Voltage: 3000V, Temperature: 400°C.[0077] The system and conditions used for chromatographic analysis of phospholipid
populations was accomplished using reverse phase HPLC-ToF MS and method conditions were
as follows: The instrument used was an AB Sciex Q Star Elite® Quadropole Time of Flight
Mass Spectrometer equipped with an Electro Spray ionization accessory. The separation was
carried out using a Cadenza CW CI8 1 x 50mm reverse phase column consisting of 3um
particle media. Electro spray ionization mass spectra were acquired in positive ionization mode.
The quantitative analysis was obtained from the integrated peak area of extracted mass
chromatograms of known masses of the respective reference materials
(Lysophosphatidylcholine -LPC, Sphingomyelin, Phosphatidylcholine and
Phosphatidylethanolamine, dissolved in acetonitrile and isopropyl alcohol 50:50). The method
parameters were as follows: Mobile Phase: Solvent A, 2mM Ammonium Formate (pH = 4) +
10% Isopropyl Alcohol; Solvent B, 100% acetonitrile containing 0.1% formic acid and 10%
Isopropyl Alcohol; Flow Rate: 0.25 ml min-1; Gradient Profile: 95%-0 A over 10 min, hold at
100% B for 10 min, Re-equilibrate at initial condition for 10 min. Photodiode Array Detector
Acquisition: 200-800nm; Column: Cadenza CW C18 3um ( 1 x 50mm); Injection Volume: 5 ul;
ESI Conditions: Gl 40, G2 30, CG 25, Applied Needle Voltage: 3000V, Temperature: 450°C.Claims
1. A method of storing genetic material or analytes from a biological sample by contacting
said biological sample with a cellulose substrate said cellulose substrate comprising structural
units of Formula I
(I)
wherein
X and Y are independently N-O-L-A or O, with the proviso that when Y is O, then X is
N-O-L-A, and when X is O, then Y is N-O-L-A; and
L is a direct bond, an aliphatic radical, an aromatic radical, a cycloaliphatic radical,
or a combination thereof; and
A= COOH, SO3H, or a combination thereof.
2. The method of claim 1wherein L is -(CH2) -wherein n is an integer between 1 and 20.
3. The method of claim 1wherein L is a direct bond and A is SO3H.
4. The method of any one of claims 1 - 3 wherein L is heteroatom substituted.
5. The method of claim 4 wherein:
L is -(CH2) -Z-(CH2)
m - ;
n is an integer between 0 and 20;
m is an integer between 0 and 20; andZ is equal to O, NH, C(0)NH, NHC(O), N(CO)N, 0(CO)0, N(CS)N, 0(CS)0 or a
combination thereof.
6. The method of claim 5 wherein Z is O, n is 0, m is 1 and A is COOH.
7. The method of any one of claims 1 - 6 wherein the cellulose substrate is a paper, tablet,
or cellulose powder.
8. The method of claim 7 wherein the cellulose substrate is a paper.
9. The method of any one of claims 1 - 8 wherein the biological sample is a buccal sample,
cerebrospinal fluid, feces, plasma, blood, lymph, urine, seminal fluid, vaginal fluid, gland
secretion, suspension of cells or viruses, viral plaques, serum sample, or a combination thereof.
10. The method of claim 9 wherein the biological sample is blood.
11. The method of any preceding claim, further comprising a step of drying said biological
sample on said cellulose substrate and a step of storing said cellulose substrate with the dried
biological sample for at least 24 h, such as for at least one week.
12. The method of any preceding claim, further comprising a step of extracting genetic
material or at least one analyte from said cellulose substrate.
13. The method of claim 12, further comprising a step of analyzing said at least one analyte,
e.g. by mass spectrometry.
14. The method of claim 13, wherein said at least one analyte is a drug or drug candidate or
a metabolite of a drug or drug candidate.
15. An article for storing genetic material or analytes from a biological sample comprising:
a cellulose substrate comprising structural units of Formula I(I)
wherein;
X and Y are independently N-O-L-A or O, with the proviso that when Y is O,
then X is N-O-L-A, and when X is O, then Y is N-O-L-A; and
L is a direct bond, an aliphatic radical, an aromatic radical, a cycloaliphatic
radical, or a combination thereof; and
A= COOH, S03H, or a combination thereof.
16. The article of claim 15 wherein L is equal to (CH2) and n is an integer between 1 and
20.
17. The article of claim 15 wherein L is a direct bond and A is SO3H.
18. The article of claim 15 wherein L is heteroatom substituted.
19. The article of claim 18 wherein:
L is -(CH2) -Z-(CH2)
m - ;
n is an integer between 0 and 20;
m is an integer between 0 and 20; and
Z is equal to O, NH, C(0)NH, NHC(O), N(CO)N, 0(CO)0, N(CS)N, 0(CS)0 or a
combination thereof.
20. The article of claim 18 wherein Z is O, n is 0, m is 1 and A is COOH.21. The article of any one of claims 15 - 20 further comprising a chemical coating adhered to
the cellulose substrate, said coating capable of denaturing proteins, deactivating enzymes, or a
combination thereof.
22. The article of claim 2 1 wherein the chemical coating comprises a surfactant, anionic
detergent, a weak base, a chelating agent, a free radical trap, uric acid, urate salts, and
combinations thereof.
23. The article of any one of claims 15 - 22 wherein the article is a paper, tablet, or powder.
24. A cellulose substrate comprising structural units of Formula I
(I)
wherein;
X and Y are independently N-O-L-A or O, with the proviso that when Y is O,
then X is -N-O-L-A, and when X is O, then Y is -N-O-L-A; and
L is a direct bond, an aliphatic radical, an aromatic radical, a cycloaliphatic
radical, or a combination thereof; and
A= COOH, S03H, or a combination thereof.
25. The substrate of claim 24 wherein L is -(CH2) - and n is an integer between 1 and 20.
26. The substrate of claim 24 wherein L is a direct bond and A is SO3H.
27. The substrate of claim 24 wherein L is heteroatom substituted.
28. The substrate of claim 27 wherein:
L is -(CH2) -Z-(CH2)
m - ;
n is an integer between 0 and 20;m is an integer between 0 and 20; and
Z is equal to O, NH, C(0)NH, NHC(O), N(CO)N, 0(CO)0, N(CS)N, 0(CS)0 or a
combination thereof.
29. The substrate of claim 28 wherein Z is O, n is 0, m is 1 and A is COOH.
30. The substrate of any one of claims 24 - 29 wherein the cellulose substrate is a paper,
tablet, or cellulose powder.
31. The substrate of claim 30 wherein the cellulose substrate is a paper.
32. A method of making of making a cellulose substrate comprising:
contacting an oxidized C2-C3 ring opened cellulose with a substituted aminooxy of
Formula II
H2N-0-L-A
(II)
at a time and temperature effective to bind said formula I to the cellulose
substrate wherein;
L is a direct bond, an aliphatic radical, an aromatic radical, a
cycloaliphatic radical, or a combination thereof; and
A= -COOH, -S03H, or a combination thereof; and
washing the oxidized C2-C3 ring opened cellulose to remove unreacted substituted
aminooxy of formula II.
33. The method according to claim 32 wherein L is equal to (CH2) and n is an integer
between 1 and 20.
34. The method of claim 32 wherein L is a direct bond and A is S0 3H.
35. The method of claim 32 wherein L is heteroatom substituted.
36. The method of claim 35 wherein;L is -(CH2) -Z-(CH2)
m - ;
n is an integer between 0 and 20;
m is an integer between 0 and 20; and
Z is equal to O, NH, C(0)NH, NHC(O), N(CO)N, 0(CO)0, N(CS)N, 0(CS)0 or a
combination thereof.
37. The method of claim 36 wherein Z is O, n is 0, m is 1 and A is COOH.
38. The method of any one of claims 32 - 37 further comprising the steps of contacting
the oxidized C2-C3 ring opened cellulose with one or more chemical coating solutions capable of
denaturing proteins, deactivating enzymes, or a combination thereof.
39. The method of claim 38 wherein the chemical coating solution comprises a
surfactant, anionic detergent, a weak base, a chelating agent, a free radical trap, uric acid, urate
salts, and combinations thereof.