Regenerative medicine holds great promise as away to repair or replace portions of whole tissues from defective or damaged organs. Engineered tissue or regenerative medicine consists of three components: (1) various cells such as stem or precursor cel...
Regenerative medicine holds great promise as away to repair or replace portions of whole tissues from defective or damaged organs. Engineered tissue or regenerative medicine consists of three components: (1) various cells such as stem or precursor cells or harvested from donor tissue, (2) artificial structure called scaffold, and (3) biochemical and physiochemical factors to improve cell adhesion, proliferation, migration and differentiation. Of these, the biomaterials that serve as scaffold substrates plays central role. To achieve the goal of tissue reconstruction, scaffold or surface of biomaterials have some specific requirements; high porosity, injectability, synthetic manufacture, biocompatibility, non-immunogenicity, nano size and resorption rates. Because most mammalian cell types are anchorage dependent, the biomaterials have to provide a suitable surface for cell attachment, proliferation, differentiation and migration. Therefore, cell-biomaterial interaction is one of the most important factors in implantable scaffold for regenerative medicine. Thus, the objective of this study was to investigate the correlation behavior of cells and various biomaterials in terms of shape or chemical structure or origins of materials.
First, we used collagen microspheres to assess the ability of human adipose stem cells(hASCs) to proliferate and differentiate into adipocytes on microspheres for repair of depressed or damaged soft tissue. hASCs were seeded onto microspheres and differentiated with adipogenic differentiation condition. The growth of cell, differentiation and function were evaluated by EtBr/Acridine Orange, Oil Red O, Nile Red staining. Through results of this study, hASCs attached and proliferated well on the collagen microspheres and differentiated into adipocyte.
Second, the purified alginate microcapsule and PLGA scaffold modified with hyaluronic acid were evaluated whether modified scaffold are suitable scaffold for tissue engineering or modification method is appropriate. The microcapsuls and disc like HA/PLGA scaffolds were fabricated by tissue engineered method. The porosity and morphology of these scaffolds was examined by SEM and fluorescence microscope. Moreover, MTT assay carried out for the cell viability and proliferation in capsules and scaffolds. Schwann cell and Annulus fibrosus cells attached better to modified scaffold than unpurified or non-modified scaffolds. The alginate microcapsules and HA penentrated PLGA scaffold can be very useful for application in the tissue engineering.
Furthermore, we investigated how human bone marrow stem cells(hMSCs) respond to surface property of scaffolds. We prepared wettable polymer surface by exposing PE sheet to radio frequency plasma discharge, which gradually oxidizes the PE surface. As the surface wettability increased, that is moderate hydrophobic position. The modified PE surfaces were characterized by measuring the water contact angle and viability of hMSCs on PE surface by MTT assay. Moreover, Cells on modified surface were observed by SEM. We found that hMSCs adhered better to highly hydrophilic and rough surfaces than to hydrophobic and smooth surfaces.
Based on these results, the characteristics of biomaterials such as chemical structure, synthetic or natural polymer are the most important factors in cell-biomaterials interaction for regenerative medicine.