Meniscus is mainly composed of three different cell types; chondrocytes(Ch) situate in the superficial zone, whereas fibroblast-like cells locate in the peripheral region having long cell extensions in contact with different parts of the matrix, fibrochondrocytes(FC), is from the inner part of the meniscus and show a clear cell associated matrix. The aim of this study is to develop meniscus cell population using with mesenchymal stem cells (MSCs). For this purpose, MSCs were isolated from rabbit bone marrow and verified by flow cytometry analyses using cell surface markers (CD73APC, CD90FITC, CD34PE, CD45PE/Cy5.5). The results indicate that CD73 and CD90-positive cells were 92.8%, and CD 45 and CD 34-negative cells were 52.4%. Differentiation potential of MSCs were also evaluated by differentiating into Ch, osteoblasts (Ob), adipocytes (Ad), fibroblasts (Fb). Histology stainings showed that differentiated Ch can produce proteoglycans, Ob have mineralization property, Fb have spindle shape and Ad have oil drops morphology. Afterwards Fb, Ch and undifferentiated MSCs (for formation of the FC) were seeded in same plate in cocktail medium and Fb, Ch, seeded individually, were used as control group. Proliferation activity of the cells was analyzed by XTT assay at 3^th,7^thand14^thdays. In addition, cells were analyzed by flow cytometry with identical surface markers at 3^th,7^thand14^thdays. Results show that cell cocktail have the greatest proliferation ability with a greater speed than the individual Ch or Fb cultures. In addition, FC formation was identified by histological staining. In conclusion, meniscus specific cell population has been successfully generated from the cell cocktail containing rabbit MSCs.

Dura mater is a thick membrane that is the outermost of the three layers of the meninges that surround the brain and spinal cord. Appropriate dural healing is crucial to prevent cerebrospinal fluid leaks but the entire process has been barely understood so far. Understanding of dural healing and tissue neoformation over the dural grafts, which are usually used for duraplasty, is still partial. Therefore, implantation of decellular dura mater (DM) to recipient from different donor and vitalization with recipient”s mesenchymal stem cells for the treatment of tissue on transplantation process is significant approach. This approach prevents immunological reactions and provides long-term stabilization. According to this study, it is believed that this approach will provide DM healing and become crucial in DM transplantation.

The aim of this study was to develop a new construct by tissue engineering of the human DM based on a decellular allograft. Thus human DM collected from forensic medicine and decellularized using the detergent sodium dodecyl sulfate (SDS) in the multiple process of physical, enzimatic and chemical steps. Decellularization were exposing the tissue to freeze-thaw cycles, incubation in hypotonic tris-HCl buffer, 0.1% (w/v) SDS in hypotonic buffer and hypertonic buffer followed by disinfection using 0.1% (v/v) peracetic acid and final washing in phosphate-buffered saline. As a result of all these processes, cellular components of DM were removed by preserving the extracellular matrix without any significant loss in mechanical properties. Based on the histological analysis of the decellularized DM revealed the absence of visible whole cells. Collagen and glycosaminoglycan (GAG) contents of decellular DM evaluated histological staining by Masson Trichrome and Alcian blue respectively. Also biochemical tests were carried out by spectrophotometry (Quickzym Biosciences, The Netherlands) and total GAG content were analyzed by 1.9 dimethylmethylene blue assay. The histoarchitecture was unchanged, and there were no significant changes of total collagen and GAG content. Biomechanical properties were determined by tensile tests, which has confirmed the retention of biomechanical properties following decellularization. The mean tensile strengths were 7,424±4,20 MPa for control group, 5,254±2,068 MPa for decellularization group. There was no statistically significant difference between tensile strength (p=0,277) and tissue thickness (p=0, 520) for both group.

In conclusion, this study has developed biomechanically functional decellularized DM scaffold for use in DM repair. In addition, this study is a part of the progressing study and additional studies investigating the biocompatibility performance of the decellularized DM scaffold and there is need for in vivo studies.