Medical devices having activated surfaces

Abstract

Implantable biocompatible polymeric medical devices include a substrate with a plasma-modified surface which is subsequently modified to include click reactive members.

Description

BACKGROUND

1. Technical Field

The present disclosure relates to medical devices having an activated surface.

2. Related Art

Biocompatible and biodegradable materials have been used for the manufacture of prosthetic implants, suture threads, and the like. A relative advantage of these materials is that of eliminating the need for a second surgical intervention to remove the implant. The gradual biodegradability of such materials favors regeneration of the pre-existing tissues. There has been recent interest in using such devices for delivery of bioactive agents.

It would be advantageous to provide reactive functional groups on the surface of such biodegradable medical devices for a variety of purposes.

SUMMARY

Implantable biocompatible polymeric medical devices in accordance with the present disclosure include a substrate with a plasma-modified surface which is subsequently modified to include click reactive members. The substrate of the medical devices described herein may be made from any biocompatible polymer and can be part of any medical device of being implanted at a target location. Plasma treatment of the substrate may result in chemical modification of the material from which the substrate is made or in the deposition of a coating of a linking material to which click reactive members may be covalently attached thereby.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiments given below, serve to explain the principles of the disclosure.

FIG. 1 is a schematic illustration of an apparatus which is suitable for carrying out plasma treatment of a substrate in accordance with the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Implantable biocompatible polymeric medical devices in accordance with the present disclosure include a substrate with a plasma-modified surface which is subsequently modified to include click reactive members.

The Polymeric Substrate

The substrate of the medical devices described herein may be made from any biocompatible polymer. The biocompatible polymer may be a homopolymer or a copolymer, including random copolymer, block copolymer, or graft copolymer. The biocompatible polymer may be a linear polymer, a branched polymer, or a dendrimer. The biocompatible polymer may be bioabsorbable or non-absorbable and may be of natural or synthetic origin.

Examples of suitable biodegradable polymers from which the substrate of the medical devices described herein may be made include, but are not limited to polymers such as those made from lactide, glycolide, ε-caprolactone, δ-valerolactone, carbonates (e.g., trimethylene carbonate, tetramethylene carbonate, and the like), dioxanones (e.g., 1,4-dioxanone), 1,dioxepanones (e.g., 1,4-dioxepan-2-one and 1,5-dioxepan-2-one), ethylene glycol, ethylene oxide, esteramides, hydroxy alkanoates (e.g., γ-hydroxyvalerate, β-hydroxypropionate, hydroxybuterates), poly (ortho esters), tyrosine carbonates, polyimide carbonates, polyimino carbonates such as poly (bisphenol A-iminocarbonate) and poly (hydroquinone-iminocarbonate), polyurethanes, polyanhydrides, polymer drugs (e.g., polydiflunisol, polyaspirin, and protein therapeutics) and copolymers and combinations thereof. Suitable natural biodegradable polymers include collagen, cellulose, poly (amino acids), polysaccharides, hyaluronic acid, gut, copolymers and combinations thereof.

Examples of suitable non-degradable polymers from which the substrate of the medical devices described herein may be made include, but are not limited to fluorinated polymers (e.g. fluoroethylenes, propylenes, fluoroPEGs), polyolefins such as polyethylene, polyesters such as poly ethylene terephthalate (PET), nylons, polyamides, polyurethanes, silicones, ultra high molecular weight polyethylene (UHMWPE), polybutesters, polyaryletherketone, copolymers and combinations thereof.

The biocompatible polymeric substrate may be fabricated into any desired physical form. The polymeric substrate may be fabricated for example, by spinning, casting, molding or any other fabrication technique known to those skilled in the art. The polymeric substrate may be made into any shape, such as, for example, a fiber, sheet, rod, staple, clip, needle, tube, foam, or any other configuration suitable for a medical device. Where the polymeric substrate is in the form of a fiber, the fiber may be formed into a textile using any known technique including, but not limited to, knitting, weaving, tatting and the like. It is further contemplated that the polymeric substrate may be a non-woven fibrous structure.

The present biocompatible polymeric substrate can be part of any medical device of being implanted at a target location. Some non-limiting examples include monofilaments, multifilaments, surgical meshes, ligatures, sutures, staples, patches, slings, foams, pellicles, films, barriers, stents, catheters, shunts, grafts, coil, inflatable balloon, and the like. The implantable device can be intended for permanent or temporary implantation.

Plasma Treatment of the Substrate

Plasma treatment of the substrate may result in chemical modification of the material from which the substrate is made, thereby producing sites for the covalent attachment of click reactive members. Alternatively, plasma treatment may result in the deposition of a coating of a linking material to which click reactive members may be covalently attached.

The term “plasma” refers to a thermodynamically non-equilibrium gaseous complex, composed of electrons, ions, gas atoms, free radicals, and molecules in an excited state, known as the plasma state. Plasma may be generated in a process known as plasma discharge by a number of methods including combustion, flames, electric discharges, controlled nuclear reactions and shocks. The most commonly used is electric discharge.

An illustrative plasma treatment apparatus is shown in FIG. 1. Positioned in chamber 21 are rack 22, preferably made of stainless steel and a pair of parallel electrode plates 24 and 26 between which the plasma is formed. Radio frequency generator 23 is provided as a source of potential, the output terminal of generator 23 being connected to plate 24, plate 26 being grounded, thereby providing means for generating an electrical field between the plates, in which field a plasma can be created and sustained. To provide the desired gas from which the plasma is formed, the apparatus includes gas source 30 (typically a standard gas cylinder) connected through gas inlet system 32 to chamber 21. System 32 is typically formed of supply line 34 connected to source 30, valve 36 for controlling the flow of gas through line 34, and valve 38. The apparatus also includes vacuum pump 40 connected to chamber 21 for reducing the gas pressure therein. A source 42 of purge gas such as helium is connected through line 44 to valve 38 of valve system 32.

In a typical reaction, the substrate is mounted in chamber 21 on steel rack 22, the latter then being positioned between electrodes 24 and 26. Vacuum pump 40 is operated to reduce the pressure in chamber 21 to below 0.1 torr. Valve system 32 is operated to permit reacting gas monomer from source 30 to flow into chamber 21 through line 34 for approximately 10 minutes before generating a plasma.

The plasma is created by applying the output of radio frequency generator 23, operating typically at 13.56 MHz, to electrode plate 24. The power supplied by generator 23 is controlled at the minimum required to sustain the plasma, generally 50 to 100 watts. Higher powered plasma will only degrade the surface of the substrate. The reaction between the plasma and the substrate surface is allowed to proceed for a period of time determined by the desired thickness and surface energy on the substrates and the concentration of gas monomers in the reacting vapor. Typical reaction times are 15 seconds to 60 minutes. The thickness of the treated surface layer of the substrate should be between about 100 to 1500 Angstroms, in embodiments between about 200 and 1000 Angstroms. The pressure in chamber 21, as measured by capacitance nanometers 46 coupled to chamber 21 is maintained at 50 millitorrs throughout the reaction period.

Finally, all flow of gas from source 30 is terminated, the power from generator 23 sustaining the plasma is turned off, and valve 38 is opened to permit purge gas to flow into chamber 21 from source 42 to purge the substrate surface of highly reactive radicals which could cause premature contamination of the substrate surface. Valve 38 is then closed, the door to reactor chamber 21 is opened so that chamber 21 is returned to atmospheric pressure, and the plasma treated substrate is removed.

In embodiments, the substrate is made from a bioabsorbable polyester which, when plasma treated, contains reactive members. Plasma treatment of bioabsorbable polyester substrates can be carried out both in the presence of a reactive gas, for example air, Ar, O₂ with the formation of surface activation of oxygenate type, such as —OH, —CHO, —COOH.

In other embodiments, the plasma is produced using a nitrogen-containing molecule, an oxygen-containing molecule or mixtures thereof. In embodiments, mixtures of oxygen plus any one of ammonia, nitrous oxide (dinitrogen oxide), nitrogen dioxide, nitrogen tetroxide, ammonium hydroxide, nitrous acid, mixtures thereof, or sequential use of two or more of the materials within a plasma. Ozone may also be used in place of oxygen. It is also contemplated that mixtures of oxygen and nitrogen can be used. When a gas mixture is used, the ratio of the component gases may be varied to obtain an optimal concentration of each gas. Also, the gases may be used serially. For example, ammonia plasma may be generated first, followed by a plasma of oxygen. Typically, the plasma treatment is for less than about five minutes, in embodiments for less than about two minutes, in other embodiments for less than about one minute, and in yet other embodiments for between about thirty seconds and about one minute.

In embodiments, the substrate is treated with a plasma that utilizes a reactant gas mixture of ammonia and oxygen (hereafter an NH₃/O₂ plasma) at a plasma treatment temperature of less than 100° C., and, in embodiments, at ambient temperature. The reactant gas mixture is introduced into the plasma chamber through a gas inlet manifold. The gas inlet manifold may also be an electrode. The gas inlet manifold is one plate of a parallel plate plasma chamber for introducing the gas mixture into the chamber. The plate has a plurality of apertures, each comprising an outlet at a chamber or processing side of the plate and an inlet spaced from the processing side, with the entire plate complex being removable for ease of cleaning. The gas inlet manifold enhances the mixing of the gases.

In embodiments, the plasma treatment is of a plasma wherein the nitrogen-containing molecules are NH₃ and the oxygen-containing molecules are O₂. The mass flow rate during plasma treatment with each of NH₃ and of O₂ is between a ratio of about 1.5:1 and about 1:1.5. In alternative embodiments, the plasma treatment is of a plasma wherein the nitrogen-containing molecules are N₂O and the oxygen-containing molecules are O₂. The mass flow rate during plasma treatment with each of N₂O and of O₂ is between a ratio of about 1.5:1 and about 1:1.5.

In other embodiments, the substrate is treated in accordance with the present disclosure are subjected to a plasma polymerization process to form a polymer coating on at least a portion of the surface of the substrate. Plasma coating methods are disclosed, for example in U.S. Pat. No. 7,294,357, the entire disclosure of which is incorporated herein by this reference.

The monomers used to form the polymer coating are polymerized directly on the substrate surface using plasma-state polymerization techniques generally known to those skilled in the art. See, Yasuda, Plasma Polymerization, Academic Press Inc., New York (1985), the entire disclosure of which is incorporated herein by reference.

In brief, the monomers are polymerized onto the suture surface by activating the monomer in a plasma state. The plasma state generates highly reactive species, which form the characteristically highly cross-linked and highly-branched, ultra-thin polymer coating, which is deposited on the suture surface as it moves through the area of the reactor having the most intense energy density, known as the plasma glow zone.

For plasma polymerization to produce a coating on a substrate, which may also be called “plasma grafting”, a suitable organic monomer or a mixture of monomers having polymerizable unsaturated groups is introduced into the plasma glow zone of the reactor where it is fragmented and/or activated forming further excited species in addition to the complex mixture of the activated plasma gases. The excited species and fragments of the monomer recombine upon contact with the substrate surface to form a largely undefined structure which contains a complex variety of different groups and chemical bonds and forms a highly cross-linked polymer coating on the suture surface. If O₂, N₂, or oxygen or nitrogen containing molecules are present, either within the plasma reactor during the polymer coating process, or on exposure of the polymer coated suture to oxygen or air subsequent to the plasma process, the polymeric deposit will include a variety of polar groups.

The amount and relative position of polymer deposition on the substrates are influenced by at least three geometric factors: (1) location of the electrodes and distribution of charge; (2) monomer flow; and (3) substrate position within the reactor relative to the glow region. In the case of substrates which can be pulled continuously through the plasma chamber (e.g., suture fibers), the influence of the suture position is averaged over the length of the fibers.

In practice, an electric discharge from an RF generator is applied to the “hot” electrodes of a plasma reactor. The selected monomers are introduced into the reactor and energized into a plasma, saturating the plasma glow zone with an abundance of energetic free radicals and lesser amounts of ions and free electrons produced by the monomers. As the substrate passes through or remains in the plasma glow zone, the surface of the substrate is continually bombarded with free radicals, resulting in the formation of the polymer coating.

In embodiments, the plasma chamber used for plasma polymerization has capacitively coupled plate-type electrodes. The substrate is exposed to monomers having a mass flow rate of from about 50 to about 100 standard cubic centimeters per minute (sccm), at an absolute pressure of from about 40 mTorr to about 70 mTorr. The exposure time can be from about 45 seconds to about 9 minutes, in embodiments from about 2 minutes to about 6 minutes. A radio frequency of 13.56 MHz with from about 25 watts to about 100 watts generates sufficient energy to activate the monomers.

It will be appreciated by those skilled in the art that in a differently configured plasma chamber, the monomer flow rate, power, chamber pressure, and exposure time may be outside the ranges of that set forth for the embodiment discussed above.

In embodiments, siloxane monomers are used in the plasma polymerization process to produce polymer coatings on the substrate surfaces. One preferred polymer coating which can be deposited on the substrate surface through the plasma state polymerization process of the present disclosure uses aliphatic hydrocyclosiloxane monomers of the general formula:

where R is an aliphatic group and n is an integer from 2 to about 10, in embodiments 4 to 6.

Examples of suitable aliphatic hydrocyclosiloxane monomers include: 1,3,5,7-tetramethylhydrocycltetrasiloxane (“TMCTS”); 1,3,5,7,9-pentamethylhydrocyclo pentasiloxane (“PMCTS”); 1,3,5,7,9,11-hexamethylhydrocyclohexasiloxane (“HMCHS”) and a mixture of 1,3,5,7,9-pentamethylcyclosiloxane and 1,3,5,6,9,11-hexamethylcyclohexasiloxane monomers (“XMCXS”).

The aliphatic hydrocyclosiloxane monomers noted above may be used to create a homogeneous coating on the substrate surface. In embodiments, the aliphatic hydrocyclosiloxane monomers may be mixed with co-monomers to give polymer coatings having properties different from the properties of the homogenous coating. For example, by introducing reactive functionalizing monomers, or organo-based monomers, or fluorocarbon monomers together with the aliphatic hydrocyclosiloxane monomers in the plasma polymerization system, physical pore size and chemical affinity of the plasma copolymerized aliphatic hydrocyclosiloxane coating with selective monomers can be controlled. This allows the use of the copolymerized plasma polymer coating for applications which require the coating to differentiate between certain types of gases, ions, and molecules and it also may be utilized to introduce functional groups to the polymer coating which, in turn, can help link other compounds or compositions to the polymer coating.

In embodiments, the polymer coatings may be produced by a plasma co-polymerization process of mixtures of the same aliphatic hydrocyclosiloxane monomers noted above with organo-based monomers that introduce amine groups onto the polymer coating and form amine grafted polymer coatings. These organo-based monomers can be introduced onto the polymer coating in a second plasma grafting process which occurs after the plasma polymerization of the aliphatic hydrocyclosiloxane monomers. Suitable organo-based monomers include allylamine, N-trimethylsilylallylamine, unsaturated amines (both N-protected and N-unprotected), and cyclic aliphatic amines (both N-protected and N-unprotected). As used herein, the term “amine grafted polymer coatings” refers to a polymer coating containing amine groups, which can be obtained either by co-polymerization of the organo-based monomer with the hydrocyclosiloxane monomer or by plasma grafting the organo-based monomer onto a previously formed siloxane polymer coating.

In yet another embodiment, these plasma treated substrates, possessing amine grafted polymer coatings, are then reacted with carbonate-based polyoxyalkylene compounds to produce polyoxyalkylene modified polymer coatings. In a preferred embodiment, the carbonate-based polyalkylene oxide is of the general formula:

wherein R₁ is an N-benzotriazole group, an N-2-pyrrolidinone group, or a 2-oxypyrimidine group; R₂, R₃ and R₄ are independently selected alkylene groups of about 2 to about 3 carbon atoms and may be the same or different; R₅ is selected from hydrogen, methyl, a carbonyloxy-N-benzotriazole group, a carbonyloxy-N-2-pyrrolidinone group, and a carbonyl-2-oxypyrimidine group; a is an integer from 1 to 1000 and each of b and c is an integer from 0 to 1000, where a+b+c is an integer from 3 to 1000. Suitable lower alkylene groups include those having about 2 to about 3 carbon atoms.

In embodiments, compounds of the above formula, R₂, R₃ and R₄ is —(CH₂CH₂)— or —CH₂CH(CH₃)— or any combination thereof. In embodiments, R₂, R₃ and R₄ are ethylene. According to certain embodiments a, b, and c are selected so as to give a molecular weight for the PEG moiety of about 500 to about 20,000, in embodiments from 3000 to 4000. Suitable polyoxyalkylene carbonates include, but are not limited to, polyoxyethylene bis-(2-hydroxypyrimidyl) carbonate, polyoxyethylene bis-(N-hydroxybenzotriazolyl) carbonate and polyoxyethylene bis-(N-hydroxy-2-pyrrolidinonyl) carbonate.

These polyoxyalkylene modified polymer coatings possess a polyoxyalkylene tether capable being functionalized with a click reactive functional group as described hereinbelow.

The resulting coating on the substrate can be between about 0.01 to about 10 percent by weight based upon the weight of the substrate to which the coating is applied. In embodiments, the coating is applied in an amount of from about 0.05 to about 7.5 weight percent, in other embodiments, the amount of coating is between about 0.1 and about 5 weight percent. The amount of coating applied to the substrate may be adequate to coat all surfaces of the substrate. The term coating as used herein is intended to embrace both full and partial coatings.

The amount of coating composition may be varied depending on the construction of the substrate. In embodiments, the depth of cross-linking of the silicone coating with the surface of the suture is less than about 100 Å. The coatings may optionally contain other materials including colorants, such as pigments or dyes, fillers or therapeutic agents, such as antibiotics, growth factors, antimicrobials, wound-healing agents, etc. Depending on the amount of coating present, these optional ingredients may constitute up to about 25 percent by weight of the coating.

Addition of Reactive Members to the Plasma Treated Substrate

Once a surface of the substrate is plasma treated (either to provide active sites or a coating of a material containing active sites), click reactive functional groups are provided on the surface.

Click chemistry refers to a collection of reactive members having a high chemical potential energy capable of producing highly selective, high yield reactions. The reactive members react to form extremely reliable molecular connections in most solvents, including physiologic fluids, and often do not interfere with other reagents and reactions. Examples of click chemistry reactions include Huisgen cycloaddition, Diels-Alder reactions, thiol-alkene reactions, and maleimide-thiol reactions.

Huisgen cycloaddition is the reaction of a dipolarophile with a 1,3-dipolar compound that leads to 5-membered (hetero)cycles. Examples of dipolarophiles are alkenes and alkynes and molecules that possess related heteroatom functional groups (such as carbonyls and nitriles). 1,3-Dipolar compounds contain one or more heteroatoms and can be described as having at least one mesomeric structure that represents a charged dipole. They include nitril oxides, azides, and diazoalkanes. Metal catalyzed click chemistry is an extremely efficient variant of the Huisgen 1,3-dipolar cycloaddition reaction between alkyl-aryl-sulfonyl azides, C—N triple bonds and C—C triple bonds which is well-suited herein. The results of these reactions are 1,2 oxazoles, 1,2,3 triazoles or tetrazoles. For example, 1,2,3 triazoles are formed by a copper catalyzed Huisgen reaction between alkynes and alkly/laryl azides. Metal catalyzed Huisgen reactions proceed at ambient temperature, are not sensitive to solvents, i.e., nonpolar, polar, semipolar, and are highly tolerant of functional groups. Non-metal Huisgen reactions (also referred to as strain promoted cycloaddition) involving use of a substituted cyclooctyne, which possesses ring strain and electron-withdrawing substituents such as fluorine, that together promote a [3+2] dipolar cycloaddition with azides are especially well-suited for use herein due to low toxicity as compared to the metal catalyzed reactions. Examples include DIFO and DIMAC. Reaction of the alkynes and azides is very specific and essentially inert against the chemical environment of biological tissues. One reaction scheme may be represented as:

where R and R′ are a polymeric material or a component of a biologic tissue.

The Diels-Alder reaction combines a diene (a molecule with two alternating double bonds) and a dienophile (an alkene) to make rings and bicyclic compounds. Examples include:

The thiol-alkene (thiol-ene) reaction is a hydrothiolation, i.e., addition of RS—H across a C═C bond. The thiol-ene reaction proceeds via a free-radical chain mechanism. Initiation occurs by radical formation upon UV excitation of a photoinitiator or the thiol itself. Thiol-ene systems form ground state charge transfer complexes and therefore photopolymerize even in the absence of initiators in reasonable polymerization times. However, the addition of UV light increases the speed at which the reaction proceeds. The wavelength of the light can be modulated as needed, depending upon the size and nature of the constituents attached to the thiol or alkene. A general thiol-ene coupling reaction mechanism is represented below:

Thus, suitable reactive members that may be applied to the plasma treated substrate include, for example, an amine, sulfate, thiol, hydroxyl, azide, alkyne, alkene, carboxyl groups aldehyde groups, sulfone groups, vinylsulfone groups, isocyanate groups, acid anhydride groups, epoxide groups, aziridine groups, episulfide groups, groups such as —CO₂N(COCH₂)₂, —CO₂N(COCH₂)₂, —CO₂H, —CHO, —CHOCH₂, —N═C═O, —SO₂CH═CH₂, —N(COCH)₂, —S—S—(C₅H₄N) and groups of the following structures wherein X is halogen and R is hydrogen or C₁ to C₄ alkyl:

The plasma treated substrate can be provided with click reactive members using any variety of suitable chemical processes. Those skilled in the art reading this disclosure will readily envision chemical reactions for activating plasma treated substrate to render them suitable for use in the presently described devices/methods.

For example, in embodiments, the plasma treated substrate is functionalized with a halogen group to provide a reactive site at which a click reactive member can be attached. The halogenated sites on the surface of the plasma treated substrate can be functionalized with a click reactive member, for example, by converting pendant chlorides on the core into an azide by reacting it with sodium azide. See, R. Riva et al., Polymer 49 pages 2023-2028 (2008) for a description of suitable reaction conditions. The halogenated polymer or copolymer backbone may be converted to the alkyne by reacting it with an alcoholic alkyne such as propargyl alcohol. These functionalities may be used to crosslink the substrate or tether drugs, therapeutics, polymers, biomolecules or even cells of interest to the substrate.

Uses of Medical Devices Having an Activated Surface

Medical devices having an activated surface in accordance with the present disclosure can be used for a variety of purposes. For example, in embodiments they may be used for drug delivery. In such embodiments, the drug to be delivered is functionalized with one or more reactive member that are complementary to the reactive members provided on the surface of the substrate. By “complementary” it is meant that the reactive members on the drug to be delivered are able to interact with the reactive members provided on the surface of the substrate to covalently bond the drug to be delivered to the surface activated substrate.

In other embodiments, the medical device having an activated surface in accordance with the present disclosure can be attached to biological tissue by functionalizing tissue with one or more reactive member that are complementary to the reactive members provided on the surface of the substrate. Biological tissue can be provided with reactive member that are complementary to the reactive members provided on the surface of the substrate by conjugation of such groups to various components of tissue such as proteins, lipids, oligosaccharides, oligonucleotides, glycans, including glycosaminoglycans. In embodiments, the complementary groups are attached directly to components of the tissue. In other embodiments, the complementary groups are attached to components of the tissue via a linker. In either case, situating the complementary groups on the tissue can be accomplished by suspending the reactive member in a solution or suspension and applying the solution or suspension to the tissue such that the reactive member binds to a target. The solution or suspension may be poured, sprayed or painted onto the tissue, whereupon the reactive members are incorporated into the tissue.

Those skilled in the art reading this disclosure will readily envision other uses for the activated medical devices described herein.

It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications within the scope and spirit of the claims appended hereto.

Claims

1. A medical device having a plasma-treated surface that is functionalized with a click reactive member to provide an activated surface on the medical device.

2. The medical device of claim 1, wherein the medical device comprises a biodegradable polymer selected from collagen, cellulose, poly (amino acids), polysaccharides, hyaluronic acid, gut, copolymers and combinations thereof.

3. The method of claim 1, wherein the medical device comprises a non-degradable polymer selected from fluorinated polymers, polyolefins, nylons, polyamides, polyurethanes, silicones, ultra high molecular weight polyethylene, polybutesters, polyaryletherketone, copolymers and combinations thereof.

4. The medical device of claim 1, wherein the click reactive member is selected from the group consisting of thiols, azides, alkynes and alkenes.

5. The medical device of claim 1, wherein the click reactive member comprises a thiol.

6. The medical device claim 1, wherein the click reactive member comprises an azide.

7. The medical device of claim 1, wherein the click reactive member comprises an alkyne.

8. The medical device of claim 1, wherein the click reactive member comprises an alkene.

9. The medical device of claim 1, wherein the medical device is selected from the group consisting of monofilament sutures, multifilament sutures, surgical meshes, ligatures, sutures, staples, slings, patches, foams, pellicles, films, barriers, stents, catheters, and inflatable balloons.

10. A method of preparing a medical device having an activated surface, the method comprising: plasma treating at least a portion of a surface of an absorbable polymeric medical device; andattaching one or more click reactive members to the plasma treated surface of the absorbable polymeric medical device.

11. The method according to claim 10, wherein the plasma treating provides reactive members on the surface of the medical device.

12. The method according to claim 10, wherein the plasma treating provides a coating on the device, the coating including reactive members on the surface of the medical device.

13. The method according to claim 10, wherein the medical device comprises a natural polymer selected from collagen, cellulose, poly (amino acids), polysaccharides, hyaluronic acid, gut, copolymers and combinations thereof.

14. The method according to claim 10, wherein the click reactive member is selected from the group consisting of thiols, azides, alkynes and alkenes.

15. The method according to claim 10, wherein the click reactive member comprises a thiol.

16. The method according to claim 10, wherein the click reactive member comprises an azide.

17. The method according to claim 10, wherein the click reactive member comprises an alkyne.

18. The method according to claim 10, wherein the click reactive member comprises an alkene.

19. The method according to claim 10, wherein the medical device is selected from the group consisting of monofilament sutures, multifilament sutures, surgical meshes, ligatures, sutures, staples, slings, patches, foams, pellicles, films, barriers, stents, catheters, and inflatable balloons.

20. The method according to claim 10, wherein the medical device comprises a synthetic polymer.

21. The method according to claim 10 wherein the plasma treatment lasts less than 5 minutes.

22. The method according to claim 10 further comprising the step of combining the absorbable polymeric medical device with a drug functionalized with one or more complimentary click reactive members to covalently bond the drug to the surface of the absorbable polymeric substrate for drug delivery.