Differential proteomic analysis on osteoblasts stimulated by mechanical strain / 医用生物力学

Objective To identify the differentially expressed proteins and clarify the major proteins involved in the molecular mechanism of osteoblasts under mechanical strain loading. Method Saos 2 osteoblastic cells were subjected to 12% elongation for 24 hours by using Flexcell strain loading system. Proteins extracted from Saos 2 cells were separated by two dimensional electrophoresis (2 DE). Differential expressed protein spots among groups were submitted to matrix assisted laser desorption/ionization time of flight mass spectrometer (MALDI TOF MS) assay and peptide mass fingerprinting (PMF) identification. The Swiss Prot and NCBI databases were used to obtain further information about proteins identified. Results Saos 2 stimulated by mechanical strain showed a significant difference in 2 DE system compared with the control group. A total of (1031±41) or (928±25) protein spots were resolved by 2 DE of controls or experimental groups extractions respectively. 17 significant up regulated proteins were identified. These associated proteins fell into 6 groups, including stress reaction, energy metabolism, cell proliferation, reconstruction of cytoskeleton, signaling and osteogenesis. Conclusions The Saos 2 can express differential proteins stimulated by mechanical strains and these proteins may play an important role in molecular mechanism of osteoblasts under mechanical strain loading.

Constructing tissue engineered trachea-like cartilage graft in vitro by using bone marrow stromal cells sheet and PLGA internal support: experimental study in bioreactor / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the feasibility of constructing tissue engineered trachea-like cartilage graft in vitro by using bone marrow stromal cells (BMSCs) sheet and PLGA internal support.</p><p><b>METHODS</b>Rabbit BMSCs were expanded and induced by transforming growth factor-1 to improve chondrocyte phenotype of BMSCs. BMSCs sheets were obtained by continuous culture and wrapped the PGLA scaffold in the shape of cylinder. The constructs were incubated in spinner flask for 8 weeks and cartilage formation was investigated by gross inspection, histology, glycosaminoglycan and mechanical strength content.</p><p><b>RESULTS</b>After in vitro culture, cartilage like tissue in cylindrical shape had been regenerated successfully. Stiff, shiny, pearly opalescence tissues were observed. Histological analysis showed engineered trachea cartilage consisted of evenly spaced lacunae embedded in matrix, cells stationed in the lacunae could be noticed clearly. Safranin-O staining on the sections showed homogenous and positive red staining, which demonstrated that the engineered tissue was rich in proteoglycans.</p><p><b>CONCLUSIONS</b>Based on the cell sheet and internal support strategy, trachea-like cartilage in cylindrical shape could be successfully fabricated which provided a highly effective cartilage graft substitute and could be useful in many situations of trachea-cartilage loss encountered in clinical practice.</p>

The preparation of series of the controllable degradation coral-hydroxyapatite (SCHA-200R) and the on its application as the scaffold in bone tissue-engineering / 中华整形外科杂志

<p><b>OBJECTIVE</b>Fabricate series of the controllable degradation coral-hydroxyapatite.</p><p><b>METHODS</b>The natural coral undergo a chemical reaction with (NH4)2 HPO4 at high temperature and pressure for different time-lengths. After getting the products, the components and the special structures were analyzed. Observe the biologic degradation of the reaction products and analyze the metal elements and their contents. Haemolysis tests, cytotoxity tests and bone compatibility tests were performed to assess the biocompatibility of the products.</p><p><b>RESULTS</b>When hydrothermal reactions happened under different conditions, the different gradients of CaCO3/hydroxyapatite materials were produced. These types of materials kept the characteristic of interconnected micro-porous network structures. A thin layer of compact material can be seen on the surface of its trabecula ultra-micro structure. The SCHA-200R has a good biocompatibility.</p><p><b>CONCLUSIONS</b>Gradient HA (SCHA-200R) materials can be formed by adjusting the same temperature, same pressure and different time-length of the reaction. This kind of gradient material keeps the quality of micro-porous network structures. The SCHA-200R is a potential candidate scaffold for bone tissue engineering.</p>

Experimental study of tissue engineered bone loaded with osteointergrated dental implants / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate osteogenesis and integration of osteointergrated dental implants with marrow stromal osteoblast and cancellous bone matrix compound artificial bone (MCCAB) when embedded subcutaneously.</p><p><b>METHODS</b>Osteointergrated dental implants (3 mm in diameter) were inserted into cancellous bone matrix (CBM) columns (5 mm in diameter). Marrow stromal osteoblast (MSO) were cultured and expanded in the column and on the surface. The osteointergrated dental implants loaded MSO-Alginate-CBM compound was formatted. This compound was then implanted subcutaneously in nude mice, and the osteointergrated dental implants loaded Alginate-CBM compounds were implanted as control. The compound was in the mice for 4 to 8 weeks and then harvested and assessed by means of gross observation, X-ray examination, histologic observation and computerized histomorphometry for evaluation of bone formation.</p><p><b>RESULTS</b>The osteogenesis of the osteointergrated dental implants loaded MSO-Alginate-CBM compound was better than that of the the osteointergrated dental implants loaded Alginate-CBM compound. Both intramembranous and cartilaginous osteogenesis was seen but the former was predominant. A large amount of new bone formed around the implant and integrated well with the implant. In the control, only slight cartilage osteogenesis was seen and no integration was found.</p><p><b>CONCLUSIONS</b>The results suggest that the new bone forms in the scaffolds and on the surface of the implant, and integration between the implant and artificial bone also occurs when they are implanted in the nude mice.</p>