Biomimetic Designer Scaffolds Made of D,L-Lactide-ɛ-Caprolactone Polymers by 2-Photon Polymerization

Traditionally tissue engineering (TE) strategy relies on three components: cells, signaling systems (e.g., growth factors), and extracellular matrix (ECM). Nowadays the combination of cells, signaling systems, an artificial ECM, and appropriate bioreactor systems has recently been defined as the “Tissue Engineering Quadriad”1 taking into consideration the fundamental role of the dynamic physiological environment. Not surprisingly, the establishment of an artificial ECM with the necessary flexibility seems to be a mission impossible without advanced materials and fabrication techniques. This claim applies to therapeutic (regeneration) as well as diagnostic (disease-modeling) approaches. To meet the challenge to mimic the hierarchical structured and complex milieu of the natural ECM it was tried in this study to combine a flexible photosensitive polymer platform based on (D,L)-lactide-ɛ-caprolactone methacrylate (LCM) with a nanoscale rapid prototyping technique based on two-photon polymerization (2-PP). Polyesters, such as poly-ɛ-caprolactone or poly-(D, L)-lactide, are very popular candidates for mimicking the ECM, because of their adjustable biophysical and biochemical properties. 2-PP represents a versatile lithographic method for the generation of scaffolds with defined size and shape, due to a spatial resolution