Synthetic Cellular Scaffolds with Biomimetic Properties Interact Favorably with Osteoblastic Cells
There has been a push to discover new synthetic polymers with biomimetic properties that support the proliferation and migration of osteoblastlbone cells. By fabricating polymers into cellular scaffolds that interact with cells on the molecular level this field is moving closer to growing transplantable bone. The benefits of transplantation of bone would have profound effects on orthopaedic and maxillofacial surgical procedures. In this study, we used the murine MC3T3-EI (subclone 26) osteoblast cell line to seed pre-fabricated scaffolds. We employed scaffolds fabricated using two techniques: the first was Solid Free Form (SFF) fabricated, and the second was paraffin sphere fabricated. Both the SFF and paraffin sphere fabricated scaffolds were made from the same synthetic polymeric material, poly-L-lactic acid (PLLA). Using the SFF technique we fabricated solid/control and nano-fibrous PLLA scaffolds. Using the paraffin sphere technique we fabricated solid/control, nano-fibrous, and surface modified nano-fibrous (SMN) PLLA scaffolds. The SMN fibrous scaffolds had a three-molecular thick layer of gelatin coating the exterior of an otherwise normal nano-fibrous scaffold. This paper is based on results from three experiments. The first was a growth experiment that investigated the difference in cellular growth, migration, penetration, and collagen secretion of solid, nano-fibrous, and SMN paraffin sphere PLLA scaffolds. The second experiment investigated the growth, migration, penetration, and collagen secretion of cells seeded on SFF fabricated solid and nano-fibrous PLLA scaffolds. In both the paraffin sphere and SFF fabrication growth experiments DNA assay did not support the expected differences in growth over two weeks; however, with regard to both scaffold types, histological analysis did support the expected penetration patterns. In the third experiment we used SFF fabricated solid and nano-fibrous scaffolds to provide data that would enable future experimenters to optimize growth conditions for osteoblasts. This was a six-week differentiation experiment that used three media combinations and compared cell growth, migration, and penetration. The histological data from this experiment supported the hypothesis that a combination of the media components would likely best suit the differentiation of osteoblast cells.