Functional copolymer coatings on electrospun fibers via photo-initiated chemical vapor deposition

With the increasing use of implantable patches in biomedical applications, the significance of surface modification techniques in improving biocompatibility, enhancing adhesion, and regulating drug release has grown. A significant challenge that these methods must address is ensuring that the process does not harm the delicate fibers or therapeutic agents they contain. Here, we report surface functionalization of implantable, curcumin loaded Polycaprolactone (PCL) patches with pH-responsive poly(2-hydroxyethyl methacrylate-co-4-vinylpyridine), p(HEMA-co-4VP) polymer thin film. The polymer was coated on the patch surface via photo-initiated chemical vapor deposition (piCVD) where the polymerization was initiated by the UV degradation of the initiator tert-butyl peroxide (TBPO) and the monomer HEMA. Additionally, the piCVD method was utilized to crosslink the HEMA without the use of additional crosslinkers. The pH-responsiveness of the coating was achieved by incorporating 4VP into the copolymer structure. The effect of the coating was demonstrated through degradation and drug release studies. The presence of the polymer coating decelerated the fiber degradation and the pH-dependent swelling of the coating allowed for the control of drug release rates from the patches. The innovative use of piCVD as a coating method provides a platform for advancing tailored surface modifications in various biomedical applications.