Nanofilm Protective and Release Matrices
A modified atomic plasma deposition (APD) procedure is used to produce amorphous, nonconformal thin metal film coatings on a variety of substrates. The films are porous, mesh-like lattices with imperfections such as pinholes and pores, which are useful as scaffolds for cell attachment, controlled release of bioactive agents and protective coatings.
1 . A method for preparing a nonconformal, amorphous metal oxide surface film, comprising:
(a) evacuating a heated reaction chamber housing a substrate;
(b) rapidly introducing an oxygen source into the evacuated chamber;
(c) releasing the vacuum;
(d) introducing a volatile metal based precursor into the closed reaction chamber; and repeating steps (a)-(d) a sufficient number of times for the oxygen source and metal precursor to react on the substrate surface to form a nonconformal, amorphous metal oxide surface film.
2 . The method of claim 1 wherein the oxygen source is water or hydrogen peroxide.
3 . The method of claim 1 wherein the film is formed to a subnanometer thickness up to 500 nm.
4 . The method of claim 1 wherein the substrate is a metal, polymer, silicon, ceramic metal, stainless steel, titanium, titanium alloy, magnesium alloy or cobalt alloy polycarbonate, polyvinyl chloride (PVC) or 316L stainless steel, titanium grade 1, titanium grade 2 titanium grade 1, titanium grade 2, a biodegradable or biocompatible polymer or copolymer.
5 . The method of claim 1 wherein the metal-based precursor is titanium isopropoxide or trimethyl aluminum.
6 . The method of claim 5 wherein the reaction chamber temperature is at or below 165° C. for formation of a titania film from a titanium isoproproxide precursor.
7 . The method of claim 5 wherein the reaction chamber temperature is at or below 600° C. for formation of an alumina film from a trimethyl aluminum precursor.
8 . The method of claim 5 wherein the reaction chamber temperature is at or below 165° C. for formation of a titania film from the trimethyl aluminum precursor.
9 . An atomic plasma deposited (APD) amorphous, porous, nonconformal, thin titania or alumina surface film produced by the method of claim 1 .
10 . The APD film of claim 9 which comprises the surface of a medical device.
11 . The APD film of claim 9 which is a controlled release surface over a biomolecule attached to an underlying substrate, wherein the biomolecule elutes in a time-dependent manner.
12 . A controlled release surface, comprising,
A biomolecule deposited on or attached to a substrate surface; and
an atomic plasma deposited (APD) nonconformal, porous titania or alumina film over the attached biomolecule;
optionally multilayer deposited biomolecules each coated with said titania or alumina film wherein the biomolecule elutes from the nonconformal, porous titanium or alumina film in a time-dependent manner.
13 . An atomic plasma deposited (APD) nanorough amorphous nonconforming deposited thin titania or alumina surface film 100-500 nm thick prepared by the method of claim 1 by introduction of each precursor in 0.2-10 second input to the reaction chamber.
14 . The APD film of claim 13 which comprises the surface of a stent, catheter, implantable guidewire, implantable medical device, orthopedic device, pouch or mesh sack .
15 . An artificial skin comprising an atomic layer deposited (APD) amorphous, nonconformal, porous titania or alumina coating 40-60 nm thick on a physiologically compatible dissolvable substrate prepared by the method of claim 1 .
16 . The (APD) amorphous titania film of claim 13 which attracts any one or more of a cell selected from the group consisting of osteoblast, endothelial, gingival fibroblast and periodontal fibroblast cells.
17 . An atomic plasma deposited (APD) amorphous, thin porous titania film on a stainless steel substrate which attaches osteoblast, endothelial, gingival fibroblast and cells compared to said surface on a or polycarbonate substrate.