Electrospinning Auricular Shaped Scaffolds for Tissue Engineering

Poly(ɛ)caprolactone scaffolds have been electrospun directly into an auricular shaped conductive mould. Bovine chondrocytes were harvested from articular cartilage and seeded onto 16 of the produced scaffolds, which received either an ethanol (group A) or a plasma treatment (group B) for sterilisation before seeding. The seeded scaffolds were cultured for 3 weeks in vitro and analysed with regard to total DNA and GAG content as well as the expression of AGG, COL1, COL2, MMP3 and MMP13. Rapid cell proliferation and GAG accumulation was observed until week 2. However, total DNA and GAG content decreased again in week 3. qPCR data shows a slight increase in the expression of anabolic genes and a slight decrease for the catabolic genes, with a significant difference between the groups A and B only for COL2 and MMP13.

Micro- and nanostructured polymer substrates for biomedical applications

Polymer implants are interesting alternatives to the contemporary load-bearing implants made from metals. Polyetheretherketone (PEEK), a well-established biomaterial for example, is not only iso-elastic to bone but also permits investigating the surrounding soft tissues using magnetic resonance imaging or computed tomography, which is particularly important for cancer patients. The commercially available PEEK bone implants, however, require costly coatings, which restricts their usage. As an alternative to coatings, plasma activation can be applied. The present paper shows the plasma-induced preparation of nanostructures on polymer films and on injection-molded micro-cantilever arrays and the associated chemical modifications of the surface. In vitro cell experiments indicate the suitability of the activation process. In addition, we show that microstructures such as micro-grooves 1 μm deep and 20 μm wide cause cell alignment. The combination of micro-injection molding, simultaneous microstructuring using inserts/bioreplica and plasma treatments permits the preparation of polymer implants with nature-analogue, anisotropic micro- and nanostructures.