Claims:WE CLAIM
1. A biodegradable jacket 20 disposed on at least one of an inner surface or outer surface of a medical implant, the biodegradable jacket 20 comprising:
a. a first layer 22 including a first upper end 22a and a first lower end 22b to entrap embolic particles of size greater than 100 microns; and
b. a second layer 24 including a second upper end 24a and a second lower end 24b to provide support to the medical implant at an annulus;
wherein the first lower end 22b of the first layer 22 is attached with the second upper end 24aof the second layer 24,
wherein the first layer 22 includes a plurality of consecutive interlocking loops 22c,
wherein the first layer 22 and the second layer 24 are made of a biodegradable polymers.
2. The biodegradable jacket 20 as claimed in claim 1 wherein the first layer 22 is made via knitting.
3. The biodegradable jacket 20 as claimed in claim 1 wherein the first layer 22 is made of Poly L-lactide co-glycolic acid (PLGA).
4. The biodegradable jacket 20 as claimed in claim 1 wherein the second layer 24 is made via weaving.
5. The biodegradable jacket 20 as claimed in claim 1 wherein the second layer 24 is made of poly (L-lactic acid) (PLLA).
6. The biodegradable jacket 20 as claimed in claim 1 wherein the first layer 22 includes a thickness ‘t1’ in a range of 20 microns to 160 microns.
7. The biodegradable jacket 20 as claimed in claim 1 wherein the second layer 24 includes a thickness t2 in a range of 20 micron to 200 microns.
8. The biodegradable jacket 20 as claimed in claim 1 wherein the first layer and second layer is attached by means of heat sealing at a predefined temperature and pre-defined time.
9. The biodegradable jacket 20 as claimed in claim 8 wherein the pre-defined temperature and predefined time is in a range of 60 °C to 120 °C and 10 minutes to 60 minutes respectively.
10. The biodegradable jacket 20 as claimed in claim 1 wherein the first layer 22 is attached on a medical implant by means of a surgical knot 11.
11. The biodegradable jacket 20 as claimed in claim 1 wherein the first layer 22 and the second layer 24 are coated with an elastomeric coating and a drug coating.
12. A process of manufacturing of a jacket 20, the process comprising:
a. preparing a first layer 22,wherein the first layer 22 is prepared by a process of knitting using a plurality of monofilaments;
b. preparing a second layer 24,wherein the second layer 24 is prepared by a process of weaving using a plurality of fiber yarns;
c. cutting and cleaning the first layer 22 and the second layer 24;
d. attaching the first layer 22 with the second layer 24 at their predefined ends to form a jacket 20, wherein the first layer 22 is attached with the second layer 24 at a pre-defined temperature and pre-defined time; and
e. coating the jacket 20 formed at step d, wherein the jacket 20 is coated with an elastomeric coating followed by a drug coating.
13. The process of manufacturing of a jacket 20 as claimed in claim 12 wherein the cleaning is performed by via one of air spray or saline spray.
14. The process of manufacturing of a jacket 20 as claimed in claim 12 wherein the elastomeric coating and drug coating is performed by means of spray coating method.
15. The process of manufacturing of a jacket 20 as claimed in claim 12 wherein the pre-defined temperature and pre-defined time is in a range of 60 °C to 120 °C and 10 minutes to 60 minutes respectively. , Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(Section 10 and Rule 13)

1. TITLE OF THE INVENTION:
BIODEGRADABLE JACKET FOR MEDICAL IMPLANTS
2. APPLICANT:
Meril Life Sciences Pvt. Ltd., an Indian company of the address Survey No. 135/139 Bilakhia House, Muktanand Marg, Chala, Vapi- 396191, Gujarat, India

The following specification particularly describes the invention and particularly the method in which it is to be performed:

FIELD OF INVENTION
[1] The present invention relates to a biodegradable jacket. More specifically, the present invention relates to the biodegradable jacket provided on a medical device.
BACKGROUND OF INVENTION
[2] Heart valve failure is a major cause of death worldwide. The valves of a human heart can suffer from various diseases which result in malfunctioning of the heart causing serious cardiovascular compromise or death. A heart valve disease occurs when one or more of the four heart valves (the aortic, pulmonary, tricuspid and mitral valves) can no longer perform their function adequately as gateways in circulation, failing to maintain a competent unidirectional flow of blood through the heart.
[3] One of the major conditions related with valve impairment may include valvular stenosis. Valvular stenosis is characterized by a marked narrowing of the valve opening, resulting in restriction of blood flow. The other type of condition may be valvular insufficiency. Valvular insufficiency may occur when the valve does not form a tight seal upon closure, resulting in regurgitation of blood. Both the conditions may burden the heart with an increased work rate to maintain stroke volume, leading to heart muscle dysfunction and eventually heart failure. In such a medical condition, a prosthetic implant has been used for many years to replace the diseased valve.
[4] The conditions as mentioned above have been treated by replacement of a native tissue with a prosthetic implant. However, the problem of paravalvular leakage has been the most common challenge associated with such transplantations. The paravalvular leakage may occur due to loosening of the prosthetic implants with the surrounding native tissue. Such problems have been occurring in various implants such as occluder, heart stent etc. Further, conventional methods, for example, a skirt on an outer wall of a stent do not properly address the aforesaid problems.
[5] Therefore, there exists a continuous need to develop a mechanism which can minimize paravalvular leakage and avoid regurgitation of the medical implant at the implantation site.
SUMMARY
[6] The present invention relates to a biodegradable jacket disposed on one of an inner surface or outer surfaces of a medical implant is disclosed. The biodegradable jacket includes a first layer including a first upper end and a first lower end to entrap embolic particles of size greater than microns and a second layer including a second upper end and a second lower end to provide support to the medical implant at an annulus. The first lower end of the first layer is attached with the second upper end of the second layer and the first layer includes a plurality of consecutive interlocking loops. Further, the first layer and the second layer are made of biodegradable material.
[7] The foregoing features and other features as well as the advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF DRAWINGS
[8] The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale.
[9] Fig.1 depicts a front view of a jacket 20 in accordance with an embodiment of the present invention.
[10] Fig. 1a depicts a peripheral view of a heart valve 100 in accordance with an embodiment of the present invention.
[11] Fig.1b depicts an enlarged view of a stent 10 attached with the jacket 20 in accordance with an embodiment of the present invention.
[12] Fig.2 depicts a flow chart of process involved in fabrication the jacket 20 in accordance with an embodiment of the present invention.
[13] Fig.3a depicts an intrahepatic implant 30 provided with the jacket 20 in accordance with an embodiment of the present invention.
[14] Fig.3b depicts a peripheral view of a left atrial appendage provided with the jacket 20 in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF DRAWINGS
[15] Prior to describing the invention in detail, definitions of certain words or phrases used throughout this patent document will be defined: the terms "include" and "comprise", as well as derivatives thereof, mean inclusion without limitation; the term "or" is inclusive, meaning and/or; the phrases "coupled with" and "associated therewith", as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have a property of, or the like; Definitions of certain words and phrases are provided throughout this patent document, and those of ordinary skill in the art will understand that such definitions apply in many, if not most, instances to prior as well as future uses of such defined words and phrases.
[16] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.
[17] Although the operations of exemplary embodiments of the disclosed method may be described in a particular, sequential order for convenient presentation, it should be understood that the disclosed embodiments can encompass an order of operations other than the particular, sequential order disclosed. For example, operations described sequentially may in some cases be rearranged or performed concurrently. Further, descriptions and disclosures provided in association with one particular embodiment are not limited to that embodiment, and may be applied to any embodiment disclosed herein. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed system, method, and apparatus can be used in combination with other systems, methods, and apparatuses.
[18] Furthermore, the described features, advantages, and characteristics of the embodiments may be combined in any suitable manner. One skilled in the relevant art will recognize that the embodiments may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments. These features and advantages of the embodiments will become more fully apparent from the following description and appended claims, or may be learned by the practice of embodiments as set forth hereinafter.
[19] It should be noted that the term bio-resorbable, biodegradable or bio-absorbable are having same meaning and used either one in this submission. The terms "yarn" and "fiber", mean primary component of fabric without limitation. The term “filament” mean initial component of fabric or knitted mesh without limitation. The term “array” mean pattern of fabric without limitation. The term “fabric” means skirt material without limitation.
[20] In accordance with the present invention, a jacket configured to be mounted on a medical implant is disclosed. The medical implant may include without limitation, a stent, a frame, a filter, an occluder, etc. The jacket may include at least two layers, namely, a first layer and a second layer. The first layer and the second layer may be attached to each other at one of their predefined ends.
[21] The jacket may be mounted on at least an inner surface or outer surface of the medical implant. The jacket may or may not cover the entire surface of the medical implant depending upon the geometry of the implant. The jacket may provide enhanced prevention of paravalvular leakage and resistance against regurgitation. The jacket may prevent generation of embolic particles of size more than 100 micron during expansion of the implant at the implantation site which may be responsible for blockage of arteries. In addition to above, the jacket may minimize the space between medical implant and the native heart tissue.
[22] Now moving specifically to drawings, FIG.1 depicts a front view of a jacket 20. The jacket 20 may be provided on a medical implant (or implant).
[23] The jacket 20 may be a composite of at least two layers. In an exemplary embodiment, the jacket 20 is made of a first layer 22 and a second layer 24. The first layer 22 may be a knitted layer. The first layer 22 may be manufactured by a process of weft knitting, warp kitting, braiding etc. The knitting may be performed with the help of a circular knitting machine using a plurality of needles ranging from 48 to 120. The needle used for knitting may be a thin needle having density ranging from 016” - .018”. The density may be varied depending upon the artery to be treated such as without limitation coronary, peripheral, intracranial, carotid, etc. The weft machine may run at around 40 to 55mm/min. The braiding maybe performed manually where filaments are twisted and turned to form a porous structure of the first layer 22.
[24] In an embodiment, the first layer 22 is prepared by a process of knitting using a plurality of monofilaments. The monofilaments of the first layer 22 may be extruded from granules/billets/pellets of biodegradable polymer. The biodegradable polymer may be selected from a group having, without limitation, poly-L-lactide-co-caprolactone (PLC), polycaprolactone (PCL), poly-dl-lactic acid (PDLLA), polyglycerol sebacate (PGS), Poly L-lactide (PLLA), Poly (glycolic acid) (PGA), Poly L-lactide co-glycolic acid (PLGA) or a mixture thereof. In an embodiment, the first layer 22 is made of Poly L-lactide co-glycolic acid (PLGA).The melting point of the PLGA granules may be in a range of 126.7 to 144.8 °C.
[25] The first layer 22 may be prepared by PLGA monofilaments having diameter ranging from 10 to 80 micron. The PLGA monofilaments may be extracted from PLGA granules by a process of extrusion. The PLGA granules may be made of L-lactide and Glycolide in a ratio ranging from 85:15, 75:25 and 50:50. Each of the aforesaid ratio may have different degradation time in a range of 5-6 months, 4-5 months and 1-2 months respectively. The PLGA monofilaments are used owing to its high strength, modulus and are able to degrade completely in body within a maximum time span of 05-06 months.
[26] The first layer 22 may be a porous structure including a plurality of consecutive interlocking loops 22c.The interlocking loops 22c of the first layer 22 may provide seamless expansion of the first layer 22 along with the implant. Further, the interlocking loops 22c of the first layer 22 may restrict plague from dislodging and/or entrap the plague on the first layer 22 thereby preventing thrombosis.
[27] The interlocking loops 22c may have a predefined length ranging from 100 microns to 500 microns and width ranging from 80 to 140 microns. In an embodiment, the length of the interlocking loops 22c is 300 microns and width is 110 microns. The interlocking loops 22c may have a predefined aperture diameter. The aperture diameter may be in a range of 50 microns to 200 microns. In an embodiment, the aperture diameter is 120micron. The interlocking loops 22c are dimensioned such that the jacket 20 does not release embolic particles above 100 micron which travel and block the nearby arteries. The dimensions of the interlocking loops 22c may be controlled by monofilament tension and stitch value varying between 0 to 40.
[28] The first layer 22 may include a first upper end 22a and a first lower end 22b. The first layer 22 may have a predefined length ‘L1’ extending between the first upper end 22a and the first lower end 22b. The length L1 may be in a range of 14mm to 28mm. The length L1 may vary depending upon dimension of the implant.
[29] The first layer 22 may include a thickness t1 in a range of 20 micron to 160micron. In an embodiment, the thickness t1 of the first layer 22 is 60 microns. The thickness t1 of the first layer 22 is low such that it does not impact crimping profile of the implant.
[30] The second layer 24 may have a predefined shape and dimension depending upon the implant. The second layer 24 may be a weaved layer. The second layer 24 may facilitate fixing and/or provide support to the implant at the annulus. The second layer 24 may be prepared by using a plurality of fiber yarns made of one or more filaments. The filaments may be made of similar and/or different polymers. The polymers may include a biodegradable and/or a non-biodegradable polymer. The biodegradable polymers may be selected from the group consisting of poly-L-lactide-co-caprolactone (PLC), polycaprolactone (PCL), poly-dl-lactic acid (PDLLA), polyglycerol sebacate (PGS), Poly L-lactide (PLLA), Poly (glycolic acid) (PGA), Poly L-lactide co-glycolic acid (PLGA) or a mixture thereof. The non-biodegradable polymers may be selected from a group having polyester, PTFE, Nylon, etc. In an embodiment, the biodegradable polymer is poly (L-lactic acid) (PLLA). The poly (L-lactic acid) (PLLA) may be degraded in a predefined time and/or tissue in-growth may take place on a stent upon deployment of the prosthetic valve 100. The predefined time may be in a range of 6 months to 24 months. In an embodiment, the second layer 24 can be degraded in a time period of approximately 24months.
[31] The second layer 24 may be prepared by a process of weaving of a plurality of filaments. The plurality of filaments may be in a range of 60 to 120 filaments per thread. The diameter of the filaments may be in a range of 01 micron to 100 microns. In an embodiment, the diameter of the filaments is in a range of 20 micron to 40 microns. Alternatively, the second layer 24 may be prepared by braiding followed by coating with polytetrafluoroethylene (PTFE) by electrospinning method.
[32] The filaments may have a predefined thickness in a range of 100 to 200 deniers. In an embodiment, the thickness is in a range of 140 deniers to 180 deniers.
[33] The process of weaving may be performed using a circular weft knitting machine. The process of circular weft knitting may be performed at predefined parameters configured in the circular weft knitting machine. The multi-filament strands may be arranged in a weft woven and/or warp woven pattern to create a flexible array of fibers as depicted in Fig.1. In an embodiment, the multi-filament strands are arranged in the weft woven pattern.
[34] The weft woven pattern of the multi-filament strands impart high degree of flexibility and/or minimize porosity of the second layer 24. The porosity of the second layer 24 plays a crucial role in cellular and tissue in-growth in order to avoid regurgitation and paravalvular leakages. The second layer 24 has a predefined porosity in a range of 01 micron to 200 microns. The porosity of fabric depends on the arrangement and spacing between two fibers.The spacing between the fibers of the textile lies from about 25 microns to about 150 microns. In an embodiment, the porosity of the second layer is 100 microns.
[35] The second layer 24 may include a second upper end 24a and a second lower end 22b. The second layer 24 has a predefined length L2 extending between the second upper end 24a and the second lower end 24b. The length L2 may be in a range of 5mm to 20mm. In an embodiment, the length L2 is 10mm.
[36] The second layer 24 includes a thickness t2 in a range of 20 micron to 200 micron. In an embodiment, the thickness t2 of the second layer 24 is 100 microns.
[37] The first layer 22 and the second layer 24 may be attached with each other at one their ends to form the jacket 20. In an embodiment, the first lower end 22b of the first layer 22 is attached with the second upper end 24a of the second layer 24 as depicted in Fig.1. The first layer 22 and the second layer 24 may be attached with each other by means of without limitation, stitching, annealing, heat sealing, ultrasonic fabric sealing, adhesive bonding/fusing or any other possible ways. In an embodiment, the first layer 22 is attached with the second layer 24 by means of heat sealing.
[38] In accordance with an exemplary embodiment, the medical implant over which the jacket 20 is provided on a prosthetic heart valve 100 as depicted in Fig. 1a. The prosthetic heart valve 100 includes a stent 10 and one or more leaflets 12. The stent 10 may include an inflow end 10a and an outflow end 10b. The stent 10 may have a predefined length ‘L’ extending between the inflow end 10a and the outflow end 10b. The predefined length ‘L’ of the stent 10 may be in the range of 14mm to 28mm.
[39] The stent 10 of the present invention may be made of any metallic material, without limitation, stainless steel (316LVM), cobalt chromium alloy (L605), etc. In an embodiment, the stent 10 is fabricated from a cobalt-chromium alloy which is widely used for manufacturing implants in the medical industry due to its shape memory and bio-compatibility property. Further, the use of cobalt-chromium alloy offers various advantages over other materials which include, without limitation, kink resistance, crush resistance, flexibility and high amount of recoverable deformation.
[40] Alternately, the stent 10 may be fabricated from conventional bioresorbable polymers or biodegradable metals known in the art. The bioresorbable polymers may be selected from, without limitation, poly-L-lactide, poly-DL-lactide, poly-L-lactide-co-glycolide, poly-L-lactide-co-caprolactone or combination thereof. The biodegradable metals used for the present invention may be magnesium, iron or alloys thereof.
[41] The stent 10 of the present invention includes features such as flexibility, vessel wall coverage, and deployment accuracy to ensure lesion coverage, etc.
[42] The stent 10 may have an inner surface and an outer surface. The inner surface of the stent 10 may be attached with the one or more leaflets 12. In an embodiment, the inner surface of the stent 10 is attached with three leaflets 12.
[43] The leaflets 12 may be obtained from any animal derived tissue known in the art depending upon the application. The selected animal tissue must be strong, flexible and compatible for being utilized as a xenograft. In an embodiment, the leaflet 12 is made of bovine pericardium tissue.
[44] The leaflets 12 are attached to the inner surface of the stent 10 by means of suturing, adhesion etc. In an embodiment, the leaflet 12 is sutured to the one or more commissure posts (not shown) of the stent 10. The leaflets 12 may expand or collapse in order to mimic functions of the native heart valve.
[45] The jacket 20 may be provided a predefined surface of the stent 10. The predefined surface may be at least one of the inner surface or the outer surface of the stent 10. In an embodiment, the jacket 20 is provided on the outer surface of the stent 10. The jacket 20 is provided on a predefined portion of the outer surface of the stent 10. In an embodiment, the jacket 20 is provided over the length ‘L’ extending from the inflow end 10a to the outflow end 10b of the stent. Presence of the jacket 20 on the length ‘L’ of the stent 10 helps in reduction of paravalvular leakage by acting as a seal between the prosthetic valve 100 and the surrounding tissue of native leaflets/aortic annulus in which the prosthetic valve 100 is implanted. Moreover, the jacket 20 facilitates strong grip with the surrounding tissue of native annulus and prevents slippage of the valve 100 during and/or after expansion.
[46] The jacket 20 is attached to the stent 10 in a predefined manner at predefined positions. In an embodiment, the first upper end 22a of the first layer 22 is attached to the primary row of the stent 10. The first upper end 22a may be attached by means of without limitation stitching, adhesion, heat fusion, knot etc. In an embodiment, the jacket 20 is attached to the medical implant by means of surgical knot 11 as depicted in Fig.1b. In an embodiment, the first upper end 22a is attached by means of surgical knot 11 as depicted in Fig. 1b. The second layer 24 is in the form of a flared skirt attached to a lower row (not shown) of the stent 10. The second lower end 24b of the second layer 24 may be kept free and not attached to the stent 10. Alternatively, the second lower end 24b of the second layer 24 may be sutured with a lower end of an internal cover (not shown). The second lower end 24b of second layer 24 is kept loose by providing extra length. The fabric of the second layer 24 may form a bulge or take any similar pattern which may result in prevention of paravalvular leakage and/or facilitate proper fixation of the stent 10 at the implantation site. Post attachment of the jacket 20, the prosthetic heart valve is sterilized is packed and sealed in a multi-layer protective pouch. It should be noted that the foregoing description of attachment of the jacket 20 to the stent 10 is an exemplary embodiment and other embodiments of the same are also within the scope of the present invention.
[47] In another exemplary embodiment in accordance with the present invention, the jacket 20 is disposed on an intrahepatic implant 30 as depicted in Fig.3a. The jacket 20 is disposed on the intrahepatic implant 30 in a way such that the first layer 22 of the jacket 20 covers flexible proximal part of the intrahepatic implant 30 which is placed in the hepatic vein. The second layer 24 covers the rest of the intrahepatic implant 30 by creating the membrane like structure which prevents the blood leakage between the hepatic & portal vein.
[48] In yet another exemplary embodiment in accordance with the present invention, the jacket 20 is disposed on a left atrial appendage 40 as depicted in Fig. 3b. The jacket 20 is disposed in such a way that a top portion of the left atrial appendage 40 is covered with the second layer 24 for preventing entry of blood inside the left atrial appendage 40 and the first layer 22 cover rest of the left atrial appendage 40 body in order to effectively hold the appendage 40 at the implantation site.
[49] Fig.2 depicts a flow chart of a process involved in fabrication of the jacket 20. The process of manufacturing of the jacket 20 commences at a step 201. At this step, the first layer 22 and the second layer 24 are prepared by a process of knitting using a plurality of monofilaments and a process of weaving using a plurality of fiber yarns made of one or more filaments respectively as mentioned in description of Fig.1.
[50] Further, post manufacturing at the step 203, the first layer 22 and the second layer 24 are subjected to a process of cutting and cleaning. The first layer 22 and the second layer 24 may be cut in accordance with the structure of the stent 10. The first layer 22 may be cut with the help of scissors. Further, the second layer 24 may be cut using one of a scissor, laser cutting or any other known method. In an embodiment, the second layer 24 is cut by means of laser cutting in order to maintain specific shape of the second layer 24. Post cutting, the first layer 22 and the second layer 24 are subjected to a process of cleaning. The process of cleaning is performed by means of air spray or saline spray. The process of cleaning is performed in order to remove debris or contaminants present on the surface of the first layer 22 and the second layer 24.
[51] At step 205, the first layer 22 is attached with the second layer 24 to form the jacket 20. The first layer 22 and the second layer 24 may be attached with each other at their predefined ends at a predefined temperature. The first layer 22 and the second layer 24 may be attached by means of without limitation, stitching, annealing, heat sealing, ultrasonic fabric sealing, adhesive bonding/fusing etc. In an embodiment, the first layer 22 and the second layer 24 are attached with each other by means of heat sealing at a predefined temperature and pre-defined time.
[52] The process of heat sealing may be performed by exposing the first layer 22 and the second layer 24 to a predefined temperature for a predefined period of time. The two layers 22, 24 are pressed and cooled in order to stick the first layer 22 and the second layer 24 together. The predefined temperature may be varied as per the polymer melting temperature. The predefined temperature may be in a range of 60 °C to 120 °C. In an embodiment, the predefined temperature is 90 °C. The predefined period of time may be in a range of 10 minutes to 60 minutes. In an embodiment, the predefined period of time is 30 minutes.
[53] At step 207, the first layer 22 and the second layer 24 of the jacket 20 are subjected to a process of elastomeric coating followed by drug coating at step 209. The first layer 22 and the second layer 24 may be subjected to similar and/or different elastomeric coating. In an embodiment, a similar elastomeric coating is applied on both the first layer 22 and the second layer 24. The elastomeric coating may be performed by means of without limitation spray coating, dip coating etc. In an embodiment, the elastomeric coating is performed by means of spray method. The elastomeric coating may be an ultrathin coating such that it does not affect overall crimping profile of the prosthetic valve 100.
[54] The elastomeric coating includes a predefined formulation. The elastomeric coating formulation may include a degradable and/or non-degradable polymer. In an embodiment, the elastomeric coating formulation is made of the degradable polymer.
[55] The degradable polymer is selected from a group consisting of without limitation, Poly-L-lactide-co-caprolactone (PLC), Polycaprolactone (PCL), Poly-dl-lactic acid (PDLLA), Polyglycerol sebacate (PGS), Poly L - lactide (PLLA), Poly(glycolic acid) (PGA), Polydioxane (PDO), Poly L-lactide co-glycolic acid (PLGA) or a mixture thereof. In an embodiment, the elastomeric coating formulation includes Poly-L-lactide-co-caprolactone PLC or PLCL (a co-polymer of L-lactide and ?-caprolactone).
[56] Alternatively, the elastomeric coating formulation may include one or more polymers with or without cross-linkers. The cross-linkers may enhance mechanical strength and elasticity of the second layer 24.
[57] The cross-linkers are selected from a group consisting of polyurethanes derived from diisocynates includes Butane Diisocyanate (BDI), Hexamethylene Diisocyanate (HDI), Isophorone Diisocyanate (IPD), Lysine Diisocyanate (LDI) or a mixture thereof.
[58] The elastomeric material is selected from a group of polymers such as without limitation, Poly-L-lactide-co-caprolactone (PLC), Polycaprolactone (PCL), Poly-dl-lactic acid (PDLLA), Polyglycerol sebacate (PGS), Poly L - lactide (PLLA), Poly(glycolic acid) (PGA), Polydioxane (PDO), Poly L-lactide co-glycolic acid (PLGA) or a mixture thereof. Cross-linkers like polyurethanes derived from diisocynates includes Butane Diisocyanate (BDI), Hexamethylene Diisocyanate (HDI), Isophorone Diisocyanate (IPD), Lysine Diisocyanate (LDI) and the like can also be used in the elastomer coating formulation. Cross-linkers enhance the mechanical strength and elasticity of the prosthetic heart valve fabric.
[59] At step 209, post elastomeric coating, the first layer 22 and the second layer 24 are subjected to a process of drug coating. The drug coating may be performed by means of without limitation, spray coating, dip coating or any other available methods. In an embodiment, the drug coating is performed by means of spray coating.
[60] The drug coating may include a predefined formulation. The formulation may include an anti-proliferative agent and/ anti-inflammatory agent. The anti-proliferative agent may include without limitation Sirolimus, Everolimus, paclitaxel, Tacrolimus, Cyclosporine, Prednisone or other compounds of the limus group etc.
[61] The scope of the invention is only limited by the appended patent claims. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present invention is/are used.