Aim: To assess the properties of 3D biodegradable scaffolds fabricated from novel star-shaped poly(D,L-lactide) (SSL) materials for bone tissue regeneration. Materials & methods: The SSL polymer was synthesized using an optimized synthetic procedure and applied for scaffold fabrication by the two-photon polymerization technique. The osteogenic differentiation was controlled using human adipose-derived stem cells cultured for 28 days. The SSL scaffolds with or without murine MSCs were implanted into the cranial bone of C57/Bl6 mice. Results: The SSL scaffolds supported differentiation of human adipose-derived stem cells toward the osteogenic lineage in vitro. The SSL scaffolds with murine MSCs enhanced the mineralized tissue formation. Conclusion: The SSL scaffolds provide a beneficial microenvironment for the osteogenic MSCs’ differentiation in vitro and support de novo bone formation in vivo.

Chitosan-g-oligolactide copolymers with relatively long oligolactide grafted chains of various stereochemical compositions have been synthetized via a solvent-free mechanochemical technique and tailored to fabricate three-dimensional hydrogels using two-photon induced microstereolithography. An effect of the characteristics of chitosan and oligolactide used for the synthesis on the grafting yield and copolymer’s behavior were evaluated using fractional analysis, FTIR-spectroscopy, dynamic light scattering, and UV-spectrophotometry. The lowest copolymer yield was found for the system based on chitosan with higher molecular weight, while the samples consisting of low-molecular weight chitosan showed higher grafting degrees, which were comparable in both the cases of l,l- or l,d-oligolactide grafting. The copolymer processability in the course of two-photon stereolithography was evaluated as a function of the copolymer’s characteristics and stereolithography conditions. The structure and mechanical properties of the model film samples and fabricated 3D hydrogels were studied using optical and scanning electron microscopy, as well as by using tensile and nanoindenter devices. The application of copolymer with oligo(l,d-lactide) side chains led to higher processability during two-photon stereolithography in terms of the response to the laser beam, reproduction of the digital model, and the mechanical properties of the fabricated hydrogels.