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Physical vapor deposition (PVD) sputtering is a promising technique for the generation of electrically conductive coatings on complex structured biomaterials, such as nonwovens, that can be used in implants. The ultra-thin coatings can fulfil a variety of purposes, such as drug depot or biosensor. The aim of our studies was to determine the feasibility of generating thin silver (Ag) coatings on complex structured poly-L-lactide (PLLA) nonwovens by sputtering and their morphological characterization. PVD sputter process was performed using a customized plasma chamber and a complex rotation of the tender electrospun PLLA nonwovens. Morphological analysis revealed a promising homogenous Ag coating, representing the structure of the nonwovens.

Electrospun fibers based on synthetic and natural polymers represent a promising approach in order to mimic the mechanical stability and the required cell-polymer interaction of the natural extracellular matrix (ECM), . In this biomedical context, the biodegradable medical grade poly-llactide (PLLA) and the natural gelatin are already well established. However, to obtain a stabilized structured PLLA/gelatin blend, crosslinking of gelatin is required. In this study, the influence of the post processed crosslinking via Glutaraldehyde (GTA) vapor and GTA solution on the morphological and physicochemical properties of the blend, as well as on the in vitrorelease of previously incorporated dexamethasone (DMS), was investigated. The addition of gelatin decreased the fiber diameter and increased the surface hydrophilicity, which is furthermore unaffected by the crosslinking process. The in vitrorelease of DMS was decisively changed by both, the addition of gelatin and the subsequent crosslinking processes. For all modified samples, a very rapid burst release of DMS was detected within the first 24 h, which is crucial for biomedical applications such as tumor therapy.

Biomaterial research efforts focus on the development of biomaterials that mimic the natural extracellular environment. In addition, different strategies are applied to render materials for blood-contacting devices nonthrombogenic through surface modifications that would suppress activation of platelets, coagulation and the complement system. A confluent thin layer of endothelial cells lines all blood vessels and produces factors responsible for inhibition of coagulation, thrombosis and neointimal hyperplasia. Thus, the ability to rapidly form a healthy endothelium upon implantation represents a desired property of biomaterials used for cardiovascular devices. In this study we used advanced in vitro methods to investigate the biocompatibility of a biodegradable and a permanent electrospun nanofiber fabric, poly-L-lactic acid and polycarbonate-based silicone elastomer respectively, with the focus on endothelialization and hemocompatibility.

For the generation of tailor-made polymer coatings on nanofibrous nonwovens plasma enhanced chemical vapor (PECVD) is a promising process, even for complex geometries. The plasma coatings can greatly improve their suitability for biomedical applications by optimising biocompatibility to the local needs, especially for cardiovascular disease treatments. Therein, wound healing and endothelialisation are important steps which are connected by a complex interaction. The monomers allylamine and hexamethyldisiloxane, as well as different process conditions were studied for the coating of nanofibrous thermoplastic silicone polycarbonate polyurethane (TSPCU) nonwovens. Aim of this study was to investigate the feasibility of plasma polymer coating under preservation of the nanofibrous morphological structure. Beside characterization of the nonwoven, biological evaluation with endothelial and fibroblast cells was performed. The prepared nonwoven samples support the feasibility of plasma coating under preservation of the nanofibrous structure. Also, different effects of the surfaces in contact with fibroblasts and endothelial cells could be observed.