Speaker
Description
Introduction
Bone loss due to various infections, aging, tumors or genetic disorders is worldwide problem; moreover, not all defects can be regenerated by using today’s technologies. For this reason scientists construct artificial bone scaffolds which could provide new bone treatment strategy. Scaffolds surface biodecoration highly enhances their integration and allows to control damaged tissue regeneration. Hard tissue scaffold coating with cell derived extracellular matrix (ECM) is a rapidly growing field of research. Usually bone scaffolds are decorated by ECMs synthesized by primary bone marrow-derived mesenchymal stem cells (BMSC), adipose stromal cells (ASC), dermal fibroblasts, osteoblast/fibroblast coculture, and osteoblast cell line. It was shown that ECMs formed by cells of osteogenic origin contains additional proteins which even more enhances new bone formation compared to non-bone related MSCs. However, the extraction procedure of BMSCs or osteoblasts is painful and requires additional surgical interventions to the patient’s body. One of the possible candidates to overcome this issue could be dental pulp stem cells (DPSCs). So far, there are no studies in which the ECM formed by DPSCs would be detailed analyzed. Therefore, DPSCs-ECM compositions as well as its adaptability for artificial bone construction were studied.
Methodology
Primary rat DPSCs and pulmonary trunk blood vessels endothelial stem cells (PTEC) were used for in vitro studies. DPSCs were seeded on porous polylactic acid (PLA) scaffolds printed by FDM 3D printing technology and grown for 7 days to produce cell secreted ECM. Later, samples were decellularized (PLA+ECM scaffolds) and used for cell-scaffold interaction (adhesion, migration, proliferation) studies, proteomic analysis of ECM composition, and osteo- and angiogenesis induction assessment. Finally, PLA-ECM ability promote new bone formation was evaluated by implanting PLA+ECM scaffolds into the critical-size rat calvaria defects. In all experiments pure PLA scaffolds were used as a control.
Results
Cell-scaffold interaction studies demonstrated that DPSC derived ECM initiates enhanced mesenchymal stem cells (MSC) adhesion, migration, and proliferation. Furthermore, its detail proteomic analysis revealed that proteins retained on PLA scaffolds after decellularization, according to Enrichr database, contributes to biological processes associated with bone/cartilage formation, angiogenesis, ECM formation, immune response, protein processing, and membrane transport. PLA-ECM induced increased ALP activity, osteogenic- and angiogenic-related genes and proteins expression up-regulation in DPSCs, likewise positive stimulation of PTEC migration confirmed its osteogenic and angiogenic properties in vitro. Finally, in the case of rat calvaria defects DPSCs synthesized ECM recruited endogenous stem cells, thus promoting new bone formation process.
Conclusions
Results showed that PLA-ECM improves surface properties required for initiation of bone self-healing process. Therefore, DPSC secreted ECM can be a promising tool for various scaffolds decoration in the field of bone tissue engineering. Nevertheless, additional studies are necessary were synergistic effects of ECM with different biomaterials formulations would be evaluated.
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