Abstract
Purpose :
To develop a degradable bioink for fabricating ophthalmic devices using 3D printing.
Methods :
The bioink formulation consisted of 10% gelatin methacrylate (GelMA), 0.6% lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP), and 5% yellow dye as a light absorbing agent to improve print resolution. The bioink was used to 3D print square sheets (7x7x1 mm) using a commercial masked-stereolithography (mSLA) 3D printer at 95% humidity and 37°C temperature. The degradation of printed sheets was evaluated with different concentrations (0,25,50,100 µg/ml) of matrix metalloproteinase (MMP9) enzyme 37°C. MMP9s are naturally found in the tear film and elevated in various diseased states such as in corneal wounds and dry eye disease. The weights of the sheets were measured at t = 0,4,6,8,12,16,24 hrs. Another set of cubes (1x1x1 cm) was autoclaved and kept sealed in storage at different temperatures (4°C, 25°C, and 37°C) in phosphate buffered saline (PBS) and their weight was measured on day 10. An attempt was made to fabricate a contact lens using this bioink.
Results :
Samples that were exposed to MMP9 enzymes showed a time-dependent degradation with increasing enzyme concentration. The samples incubated with 100 and 50 µg/ml of MMP9 were completely degraded by the end of 12 and 16 hrs, respectively. At the end of 24 hrs, the samples incubated at 25 µg/ml enzyme showed 72.8% degradation whereas the control samples did not show any signs of degradation. Interestingly, samples that were autoclaved and kept in storage also did not show any signs of degradation at all temperatures. A 3D-printed CL with overall diameter 14mm and thickness 1mm was printed without any support structures within 1 hour.
Conclusions :
This study showed GelMA-based bioink can be used to fabricate biodegradable devices such as contact lenses. The biomaterials degrade in the presence of MMP-9 and future work will work on tuning the degradation kinetics of these materials, as well as incorporating ocular drugs.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.