Three‐dimensional microstructured scaffolds provide a means for cells to be cultured in vitro in a way that resembles natural conditions more closely than flat tissue culture polystyrene. In the presented work, two‐photon polymerization (2PP) is applied as a tool for the engineering of high‐resolution 3D scaffold structures with a well defined microarchitecture made of biocompatible photo resins. 2PP is a novel photolithographic technique using femtosecond laser pulses which enables free 3D microstructuring of liquid photo resins due to the relationship of the axial and lateral spatial confinement of the photoreaction to the focal volume of a focused laser beam. A set of photo resins were tested with regard to 2PP processability and three different classes of methacrylated photopolymerizable monomers (methacrylated oligolactones, urethane dimethacrylate, poly(ethylene glycol diacrylate)) were found to be efficient 2PP materials. 3D microstructures based on computer models were produced and tested for biocompatibility. The initial cell adhesion and the viability of bovine chondrocytes on the polymeric scaffolds were evaluated morphologically by confocal laser scanning microscopy (CLSM) after three‐day culture on 2PP derived microstructures. 2PP derived scaffolds were fabricated in different sizes and geometries, starting from the 100 µm‐range reaching out to the cm‐range showing the actual possibilities to produce large volume scaffolds even for implantation purposes.

No abstract

An irreversible loss of subcutaneous adipose tissue in patients after tumor removal or deep dermal burns makes soft tissue engineering one of the most important challenges in biomedical research. The ideal scaffold for adipose tissue engineering has yet not been identified though biodegradable polymers gained an increasing interest during the last years. In the present study we synthesized two novel biodegradable polymers, poly(ε-caprolactone-co-urethane-co-urea) (PEUU) and poly[(L-lactide-co-ε-caprolactone)-co-(L-lysine ethyl ester diisocyanate)-block-oligo(ethylene glycol)-urethane] (PEU), containing different types of hydrolytically cleavable bondings. Solutions of the polymers at appropriate concentrations were used to fabricate fleeces by electrospinning. Ultrastructure, tensile properties, and degradation of the produced fleeces were evaluated. Adipose-derived stem cells (ASCs) were seeded on fleeces and morphology, viability, proliferation and differentiation were assessed. The biomaterials show fine micro- and nanostructures composed of fibers with diameters of about 0.5 to 1.3 µm. PEUU fleeces were more elastic, which might be favourable in soft tissue engineering, and degraded significantly slower compared to PEU. ASCs were able to adhere, proliferate and differentiate on both scaffolds. Morphology of the cells was slightly better on PEUU than on PEU showing a more physiological appearance. ASCs differentiated into the adipogenic lineage. Gene analysis of differentiated ASCs showed typical expression of adipogenetic markers such as PPARgamma and FABP4. Based on these results, PEUU and PEU meshes show a promising potential as scaffold materials in adipose tissue engineering.

No abstract

No abstract