Drug Delivered Poly(ethylene glycol) Diacrylate (PEGDA) Hydrogels and Their Mechanical Characterization Tests for Tissue Engineering Applications

Tissue Engineering has been studied to develop tissues as an alternative approach to the organ regeneration. Successful artificial tissue growth in regenerative medicine depends on the precise scaffold fabrication as well as the cell-cell and cell-scaffold interaction. Scaffolds are extracellular matrices that guide cells to grow in 3D to regenerate the tissues. Cell-seeded scaffolds must be implanted to the damaged tissues to do the tissue regeneration. Scaffolds' mechanical properties and porosities are the two main scaffold fabrication parameters as the scaffolds must be able to hold the pressure due to the surrounding tissues after the implantation process. In this research, scaffolds were fabricated by photolithography and Poly(ethylene glycol) Diacrylate (PEGDA) which is a biocompatible and biodegradable material was used as a fabrication material. In order to compare the compressive properties of PEGDA only with the compressive properties of drug delivered PEGDA, firstly, PEGDA only solutions were prepared. Then, PEGDA was mixed with Meloxicam 15 mg, Hydrochlorothiazide 12.5 mg, Cyclobenzaprine 10 mg and Spironolactone-hctz 25-25 mg respectively and they were placed under the UV light for about 15 minutes to solidify the cylindrical shaped hydrogels. 5 samples from each group were fabricated under the same conditions. Laboratory temperature, photoinitiator concentration and UV light intensity was kept constant during the fabrication process. After the fabrication was completed, Instron 3369 universal mechanical testing machine with the 5 mm/min compression rate was used to do the compression tests to compare the drug effects on PEGDA hydrogels. Our results indicate that average ultimate strength of PEGDA only samples was 3.820 MPa. Also, due to the fact that Meloxicam 15 mg and PEGDA mixture did not solidify under the UV light at all, compression test could not be performed for PEGDA-Meloxicam 15 mg mixture. However, Hydrochlorothiazide 12.5 mg, Cyclobenzaprine 10 mg and Spironolactone-hctz 25-25 mg dissolved within the PEGDA completely and our compression results show that average ultimate strengths were 3.372 MPa, 1.602 MPa, 1.999 MPa respectively. This preliminary research showcases that compressive properties of the PEGDA-based photopolymerized scaffolds can be altered with the control of the drug type and drug concentration.