Rapid prototyping of polymeric hydrogels for biomedical applications

Rapid prototyping techniques have been in-vestigated for the production of biomedical devices that perfectly fit the patient‟s tissue defect (e.g. for bone and dental applications) and/or reproduce the microstructure of the tissue or organ of interest. The possibility to create patient-specific devices has been recently exploited for the creation of tissue engineer-ing scaffolds, i.e. porous, resorbable matrices, which stimulate cell functions and induce tissue regenera-tion by providing cells with appropriate physical, me-chanical and biochemical cues. Poly(ethylene glycol) (PEG)-based hydrogels, although intrinsically non-biodegradable and non-bioactive, show great promise as tissue engineering scaffolds, due to their ability to be covalently linked to bioactive and/or degradable moieties, that elicit specific cell responses, and to their fast and biocompatible formation under ultra-violet (UV) exposure. In this work, poly(ethylene glycol)-based hydrogels, containing bioactive moie-ties, were photopolymerized and characterized in terms of mechanical, swelling and degradation prop-erties. The production of hydrogels possessing a complex shape was finally investigated by means of stereolithography, a rapid prototyping technique which is able to build a three-dimensional object, starting from the CAD model, by guiding an ultravio-let laser beam on the surface of a photosensitive solu-tion. The results demonstrated that the developed hy-drogel formulations allow the creation of biomimetic constructs with complex shapes, which might be use-ful as platforms for tissue engineering or as tissue mimicking phantoms.