Two-photon polymerization technique for microfabrication of CAD-designed 3D scaffolds from commercially available photosensitive materials

Abstract

We report on recent advances in the fabrication of three-dimensional (3D) scaffolds for tissue engineering and regenerative medicine constructs using a two-photon polymerization technique (2PP). 2PP is a novel CAD/CAM technology allowing the fabrication of any computer-designed 3D structure from a photosensitive polymeric material. The flexibility of this technology and the ability to precisely define 3D construct geometry allows issues associated with vascularization and patient-specific tissue fabrication to be directly addressed. The fabrication of reproducible scaffold structures by 2PP is important for systematic studies of cellular processes and better understanding of in vitro tissue formation. In this study, 2PP was applied for the generation of 3D scaffold-like structures, using the photosensitive organic-inorganic hybrid polymer ORMOCER (ORganically MOdified CERamics) and epoxy-based SU8 materials. By comparing the proliferation rates of cells grown on flat material surfaces and under control conditions, it was demonstrated that ORMOCER and SU8 are not cytotoxic. Additional tests show that the DNA strand breaking of GFSHR-17 granulosa cells was not affected by the presence of ORMOCER. Furthermore, gap junction conductance measurements revealed that ORMOCER did not alter the formation of cell-cell junctions, critical for functional tissue growth. The possibilities of seeding 3D structures with cells were analysed. These studies demonstrate the great potential of 2PP technique for the manufacturing of scaffolds with controlled topology and properties.

Optical microassembly platform for constructing reconfigurable microenvironments for biomedical studies

“…These feature-rich building blocks can then be optically manipulated in a fluidic environment using multiple, real-time reconfigurable counterpropagating trapping beams to construct user-defined configurations or reconfigurable scaffolds. This approach complements the allied technique of directly fabricating 3D scaffolds by photopolymerization [11], which has been applied, very recently, to fabricate biodegradable structures [12]. Moreover, reconfigurable assembly has the added flexibility for utilizing building blocks made from different materials, which allows for selective chemical functionalization [13].…”

Direct laser writing-mediated generation of standardized topographies for dental implant surface optimization

“…23 Direct laser writing has already been successfully employed for the controlled generation and functionalization of 3D structures for biological applications at the submicrometer scale. Photoresists such as ORMOCER and SU8 have been proven for their biocompatibility, 24 and 3D structures generated have been demonstrated to support the development of characteristic phenotypes for a variety of cell types, among them granulosa cells, fibroblasts, chondrocytes as well as endothelial, epithelial, and cancer cells. [25][26][27] Recent research of our lab addressed the impact of structure flexibility and scaffold functionalization on cellular properties.…”

Synthesis of new photoactive urethane carbohydrates and their behavior in UV or femtosecond laser-induced two-photon polymerization

“…Because a variety of photosensitive materials were successfully processed by two-photon polymerization, [49][50][51] we decided to investigate the visible light-curing behavior of binary mixtures of monomers based on CMA-1, CMA-2, or CMA-3 and BP-UDMA (B1-B3 formulations) by this procedure, the possibility of their later employment in the development of 3D scaffolds was evaluated. The two-photon polymerization experiments were performed with a femtosecond Ti-sapphire laser pulses, using different average power laser values (10-30 mW) and different scanning velocities (0.5-2 mm s −1 ).…”