Cell-matrix and cell-cell interactions on 3D nanofibrous gelatin scaffolds

Tissue engineering is the latest biomedical technology which aims towards the repair and regeneration of deficient and injured tissues. It combines the principles from the fields of materials science, cell biology, transplantation, and engineering. There are three major components involved in tissue engineering including biomaterials, cell sources, and growth factors. It is essential to understand the interactions among these components, especially between biomaterials and the interacting cells. These two components are mutually responsive to each other and thus a change in one significantly alters the other. This dissertation is a comprehensive effort to outline cell behavior during the use of three dimensional (3D) matrices in general and 3D nanofibrous gelatin scaffolds (3D-NF-GS) with two different cell types in particular. These gelatin matrices have nanofibrous architecture comparable to that of natural collagen, thus making their physical and chemical composition very similar to natural extracellular matrix (ECM). The first and second parts of this study analyzed the behavior of human gingival fibroblasts and mouse primary osteoblasts on 3D-NF-GS in vitro. The study focused on adhesion, migration and proliferation of the cells on the scaffolds leading to the secretion of new matrix. The study using mouse primary osteoblasts on 3D-NF-GS also demonstrated in vitro mineralization in 14 days. The third part of the study analyzed the behavior of 3D-NF-GS in vivo as an implantation in a mouse calvarial critical sized defect. The scaffolds were either pre-seeded with osteoblasts, contained no cells or the wound was closed without a scaffold. This study used confocal microscopy to evaluate and analyze the behavior and interactions of cells on the non-translucent, rigid three dimensional matrices to great depths (∼400um). This included the assessment of new matrix production in vitro and in vivo. The present investigation demonstrated the generation of numerical and analytical data using confocal microscopy and associated software for comparison of various parameters. In conclusion, this comprehensive overview demonstrated that fibroblast and osteoblasts adhered, migrated, proliferated and mineralized (with osteoblasts) the 3D-NF-GS rapidly and may be beneficial for their future experimental and clinical applications.