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The purpose of this study was to compare the use of autologous fibrin to human amniotic membrane (HAM) as a scaffold in cultivating autologous conjunctiva for transplantation in treatment of conjunctival defect. An experimental study was performed using 18 adult New Zealand white strain rabbits which were divided into 3 groups. Each group consists of 6 rabbits. The conjunctiva on the temporal site was excised to create a conjunctival epithelial defect. The excised area in the Group 1 was transplanted with autologous conjunctiva cultivated on autologous fibrin; Group 2 was transplanted with autologous conjunctiva cultivated on HAM and Group 3 was left bare. The rabbits were followed up at regular intervals until 6 weeks. The mean period of complete conjunctival epithelization was 11.50 ± 8.22 days for the autologous fibrin group, 15.33 ± 11.80 days for the HAM group and 25.33 ± 5.32 days in the bare sclera group. The epithelization rate for the autologous fibrin group was faster compared to the other two groups. However all the results were not statistically significant (p value >0.05). There were no postoperative complications noted during the follow up. Autologous fibrin is comparable to HAM as a scaffold for cultivation of conjunctiva in the treatment of conjunctival defect.

(1) Background: Stem cells in combination with scaffolds and bioactive molecules have made significant contributions to the regeneration of damaged bone tissues. A co-culture system can be effective in enhancing the proliferation rate and osteogenic differentiation of the stem cells. Hence, the aim of this study was to investigate the osteogenic differentiation of human adipose derived stem cells when co-cultured with human osteoblasts and seeded on polycaprolactone (PCL):hydroxyapatite (HA) scaffold; (2) Methods: Human adipose-derived stem cells (ASC) and human osteoblasts (HOB) were seeded in three different ratios of 1:2, 1:2 and 2:1 in the PCL-HA scaffolds. The osteogenic differentiation ability was evaluated based on cell morphology, proliferation rate, alkaline phosphatase (ALP) activity, calcium deposition and osteogenic genes expression levels using quantitative RT-PCR; (3) Results: The co-cultured of ASC/HOB in ratio 2:1 seeded on the PCL-HA scaffolds showed the most positive osteogenic differentiation as compared to other groups, which resulted in higher ALP activity, calcium deposition and osteogenic genes expression, particularly Runx, ALP and BSP. These genes indicate that the co-cultured ASC/HOB seeded on PCL-HA was at the early stage of osteogenic development; (4) Conclusions: The combination of co-culture system (ASC/HOB) and PCL-HA scaffolds promote osteogenic differentiation and early bone formation.

Osteoarthritis (OA) is one of the leading joint diseases induced by abnormalities or inflammation in the synovial membrane and articular cartilage, causing severe pain and disability. Along with the cartilage malfunction, imbalanced oxygen uptake occurs, changing chondrocytes into type I collagen- and type X collagen-producing dedifferentiated cells, contributing to OA progression. However, mounting evidence suggests treating OA by inducing a hypoxic environment in the articular cartilage, targeting the inhibition of several OA-related pathways to bring chondrocytes into a normal state. This review discusses the implications of OA-diseased articular cartilage on chondrocyte phenotypes and turnover and debates the hypoxic mechanism of action. Furthermore, this review highlights the new understanding of OA, provided by tissue engineering and a regenerative medicine experimental design, modeling the disease into diverse 2D and 3D structures and investigating hypoxia and hypoxia-inducing biomolecules and potential cell therapies. This review also reports the mechanism of hypoxic regulation and highlights the importance of activating and stabilizing the hypoxia-inducible factor and related molecules to protect chondrocytes from mitochondrial dysfunction and apoptosis occurring under the influence of OA.