OP6: Gelatin Methacryloyl is a Slow Degrading Material Allowing Vascularization and Long-Term Use In Vivo

Abstract

INTRODUCTION: Vascularization of bioartificial tissues can be surgically enhanced by means of prefabrication. In this context, the use of arteriovenous loops (AVL) is a powerful tool to enhance vascularization. Besides surgical vascularization, the choice of the appropriate biomaterial has to be considered as an important factor for tissue engineering applications. Therefore, we investigated vascularization and biocompatibility of Gelatin methacryloyl (GelMA) scaffolds in the rat AVL model. MATERIALS AND METHODS: Hydrogels consisting of GelMA (10%) were transferred into an inert chambers and vascularized by AVL in the groin of Lewis rats. After 2 and 4 weeks, the constructs were explanted and further analyzed. Immune response was analyzed based on CD68 and CD163 staining. Vascularization was visualized by α-smooth muscle actin staining and multiphoton microscopy. Moreover, proteome analysis of 53 angiogenesis-related proteins was performed to gain more insight into AVL-induced vascularization. RESULTS: We were able to show that GelMA hydrogels are stable for at least 4 weeks in the rat AVL model. Furthermore, our data indicate that GelMA hydrogels are biocompatible. Finally, we provide evidence that GelMA hydrogels in the AVL model allow connective tissue formation as well as vascularization. In addition, proteomic analysis revealed the upregulation of proangiogenic molecules. CONCLUSION: GelMA has proven to be a stable matrix in the AVL model. Investigations such as multiphoton microscopy and proteome analysis, as well as histological examinations, demonstrated the angiogenic potential of the material in vivo. GelMA is, therefore, a promising material for further applications in vivo.