Moscow State University of Medicine and Dentistry named after A.I. Evdokimov

Relevance. The effect of a tissue engineering construct based on synthetic octacalcium phosphate activated with plasmid DNA with vascular endothelial growth factor gene on bone morphogenesis at the jaw defect sites of patients was studied. It is shown that the studied osteoplastic material stimulates osteosynthesis pathways already at early stages, and xenogenic hydroxyapatite, triggers osteogenesis processes with considerable delay and does not have time to form a full-fledged bone structure by 6 months.Aim. Evaluate the dynamics of reparative osteogenesis based on the results of histomorphometric diagnostics in patients with defects in the jaw bones of various configurations and lengths with an implanted bone matrix based on synthetic octacalcium phosphate activated with plasmid deoxyribonucleic acid with genes of vascular endothelial growth factor.Materials and methods. Histomorphological examination of bone tissue biopsy of jaws was carried out in 50 patients of both genders, who needed additional volume of bone tissue to install dental implantation. Patients were divided into 2 groups by type of grafted material. 6 months after the surgery, bone biopsies were taken from the bone sites at the stage of implant placement. Histomorphological patterns and histomycrophotograms were studied in bone biopcies.Results. In bone tissue biopsies of patients implanted with a tissue engineering construct based on synthetic octacalcium phosphate activated with plasmid DNA with vascular endothelial growth factor gene, it was revealed that after 6 months there was prevaluation of mature bone tissue (42,71%), with the proportion of differentiated plate bone tissue being < 90%.Conclusions. Histomorphometric analysis showed that in patients implanted with a tissue engineering construct based on synthetic octacalcium phosphate activated with plasmid DNA with vascular endothelial growth factor gene, after 6 months, early rearrangement of bone tissue into a mechanically dense and highly mineralized structure was detected.

ISLET CELL CULTURES AS COMPONENT OF TISSUE-ENGINEERING CONSTRUCT OF PANCREAS

Aim:to develop methods for obtaining islet cell cultures for the purpose of their further use as a suitable component of the pancreatic tissue engineered construct. As a source of islet cell cultures, pancreas of newborn rabbits was used as an accessible and well-studied donor model.Materials and methods.For the obtaining of islet cell cultures, pancreas of 1–3-day-old newborn rabbits were used. Changes occurring during the cultivation of pancreatic tissue were recorded using an inverted microscope and a biostation. Morphological analysis of culture samples was carried out using histological and specifi c immunohistochemical methods. The insulin-producing activity of the cultures was determined by enzyme immunoassay.Results.Three main types of cultures were obtained: isletlike organotypic, suspensionalcytotypic, and monolayered, consisting of progenitor cells. Greater morphological safety and adequate insulin-producing ability was revealed in fl oating islet-like cultures.Conclusion.According to their morphofunctional properties, fl otation islet-like cultures obtained from pancreas of the newborn rabbits can be used as basal cell component of the experimental model of the tissue engineered construct of the pancreas.

Porous Collagen-Hydroxyapatite Scaffolds With Mesenchymal Stem Cells for Bone Regeneration

Current bone grafting materials have significant limitations for repairing maxillofacial and dentoalveolar bone deficiencies. An ideal bone tissue-engineering construct is still lacking. The purpose of the present study was first to synthesize and develop a collagen-hydroxyapatite (Col-HA) composite through controlled in situ mineralization on type I collagen fibrils with nanometer-sized apatite crystals, and then evaluate their biologic properties by culturing with mouse and human mesenchymal stem cells (MSCs). We synthesized Col-HA scaffolds with different Col:HA ratios. Mouse C3H10T1/2 MSCs and human periodontal ligament stem cells (hPDSCs) were cultured with scaffolds for cell proliferation and biocompatibility assays. We found that the porous Col-HA composites have good biocompatibility and biomimetic properties. The Col-HA composites with ratios 80:20 and 50:50 composites supported the attachments and proliferations of mouse MSCs and hPDSCs. These findings indicate that Col-HA composite complexes have strong potentials for bone tissue regeneration.