Fabrication and evaluation of PEGDA hydrogel by stereo-lithography for cartilage tissue engineering

The stereo-lithography technique for fabricating biocompatible polyethyleneglycol diacrylate (PEGDA) hydrogel with a controlled accurate architecture is developed for cartilage tissue engineering application, and the different laser scanning parameters for single-line hydrogel or 2-D layer hydrogel are comparatively investigated, The cure parameters of the single-line and 2-D layer of hydrogel scaffold are affected by PEG(400)DA content of the solution, the laser scanning speed and hatch space. Hydrogel scaffold properties, such as structure accuracy, composition, and water absorption and compression modulus are experimentally confirmed. The results showed that: Cure depth and width increase positively with the energy dosage of laser and the PEG(400)DA content of solution; Cure depth scales inversely with the hatch space; Water absorption decreases and the compression modulus increases as the PEG(400)DA content of solution varies from 30% to 60%. The optimal laser process parameters include: 0.1 W laser power, 1800 mm/s laser scanning speed, 0.15 mm hatch space and 30% content of φ(PEG(400)DA) solution, customized hydrogel scaffold of knee cartilage was obtained with 191.67% water absorption rate and 0.75 MPa average compression modulus. The stereo-lithographic PEGDA hydrogel technique perfectly meets the requirements for cartilage tissue engineering.