Molecular Plasma Deposition of Bioactive Small Molecules
Substrates coated with several classes of bioactive agents, including antimicrobial agents, are described. The coating technique is based on a molecular plasma discharge deposition method such that the deposited materials retain biological activity and/or structure. The deposited biomaterials can be selected for a variety of medical uses, including coated implants for in situ release of pharmaceuticals.
1 . A method for depositing an organic molecule on a substrate surface, comprising:
ejecting a solution comprising at least one organic molecule from a conductive point source held at a high potential gradient under atmospheric or reduced partial pressure conditions to form a corona discharge plasma;
directing the discharge plasma through an orifice into an evacuated chamber housing to deposit an organic coating onto a substrate wherein structural integrity of the at least one organic molecule is preserved.
2 . The method of claim 1 wherein the at least one organic molecule is selected from the group consisting of penicillin, streptomycin, retinol, thiamine, riboflavin, thiophene and combinations thereof.
3 . The method of claim 2 wherein the at least one organic molecule is retinol.
4 . The method of claim 2 wherein the at least one organic molecule is riboflavin.
5 . The method of claim 2 wherein the at least one organic molecule is thiamine.
6 . The method of claim 1 wherein the at least one organic molecule is a vitamin, antimicrobial agent, a heterocyclic organic molecule or combinations thereof.
7 . The method of claim 6 wherein the heterocyclic organic molecule is thiophene.
8 . The method of claim 6 wherein the antimicrobial agent is penicillin or streptomycin.
9 . The method of claim 6 wherein the antimicrobial is streptomycin and penicillin
10 . The method of claim 1 wherein the substrate surface comprises titanium, polyethylene or cotton.
11 . A metal, plastic, natural fiber or ceramic substrate coated with a molecular plasma deposited film selected from the group of biomaterials consisting of an antimicrobial agent, a vitamin, a heterocyclic organic molecule and combinations thereof.
12 . The substrate of claim 11 wherein the deposited film comprises streptomycin or penicillin.
13 . The substrate of claim 11 wherein the deposited file comprises thiamine or riboflavin.
14 . The substrate of claim 11 wherein the deposited film comprises at least one antimicrobial agent.
15 . The substrate of claim 14 wherein the antimicrobial agent comprises penicillin and streptomycin.
16 . The substrate of claim 11 wherein the heterocyclic organic molecule is thiophene.
17 . The substrate of claim 11 comprising a penicillin coated titanium wherein the penicillin inhibits growth at least of Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Pseudomonas aeruginosa.
18 . The substrate of claim 11 comprising a streptomycin-coated titanium or fiber substrate wherein the streptomycin inhibits growth at least of Candida albicans.
19 . A penicillin/streptomycin molecular plasma deposited woven fiber or titanium substrate wherein antimicrobial activity is substantially unchanged compared with a penicillin/streptomycin composition.
20 . The penicillin/streptomycin surface coated woven fiber substrate of claim 19 wherein the fiber is cotton, nylon, wool, silk or rayon.