Scaffold design for artificial tissue with bone marrow stem cells
Objectives: The aim of this study was to test polymeric origin materials (collagen, fibrin, polyimide film and polylactic acid) for scaffolds formation and their iocompatibility with heart tissue.
Materials and Methods: In our study we used bone marrow stem cells (rBMCs) derived from rabbit’s bone sacrum and polymeric origin materials for scaffold formation as commercially available bovine collagen scaffolds, fibrin scaffolds produced from clotted rabbit plasma, different combinations of commercially available 12.7 μm (0.5 mil) thickness Kapton® 50HN polyimide film (PI) and electrospun Poly(lactic acid) (PLA) mats. Histological evaluation of differentiated cell phenotype in the scaffold has been performed using primary antibodies against desmin, myogenin. Cell imaging has been made after 3 days of rBMCs growing in the scaffolds (PLA, PI film, PLA-PI film). Cells mobility was evaluated after 14 days.
Results: Cells were grown in vitro and survive in solid collagen and clotted fibrin scaffolds for two weeks. Histological analysis revealed that cells penetrate only upper but not deeper layers of the scaffold and 90% of the cells are residing in the zone of outer layer of 400±45 μm. Opposite results were obtained using fibrin scaffold where cells are visible through all the thickness. Analyses of rBMCs potential differentiation in the fibrin scaffold showed desmin expression and rBMCs turn to the myogenic lineage.
Cell mobility on smooth PI and laser micro-machined did not differ, and was 20 ± 2 μm/h (n=50) and 18 ± 4 μm/h (n=50), respectively. Our results shows that hMSCs are capable to spread through the whole 100 ± 10 μm thickness of PLA scaffold after 3-day cultivation and demonstrates that multilayer scaffold composed of PI and PLA materials ensures sufficient environment for cell growth.
Conclusions: The obtained results suggest that electrospinning technology and femtosecond laser micro-structuring could be employed for development of multilayer scaffold. Different biopolymers as PLA, fibrin and collagen could be used as appropriate environment for cells inhabitation. PI could be suitable as a barrier to implement cell migration from scaffold. However additional studies are needed to determine optimal parameters of inner and outer scaffold layers.