Objective To review the progress and clinical application of malleable bone paste/putty. MethodsRecent literature about malleable bone paste/putty was reviewed and analyzed. ResultsThe preparation and clinical application of malleable bone paste/putty have become increasingly mature. Many kinds of malleable bone paste/putty have been applied extensively and the good clinical results have been achieved in the treatment of the irregular bone defects. The materials and methods for preparing malleable bone paste/putty are different. Then they have different bone repair abilities. ConclusionMalleable bone paste/putty provides effective method to treat irregular bone defects. But the malleable bone paste/putty still has some shortage, so further researches should be carried out.
Objective To review the recent research and clinical progress of artificial osteoconductive materials. Methods Recent and related literatures were extensively and comprehensively reviewed. Results Many achievements about the clinical application of the artificial osteoconductive materials were made. Ithad become one of the hotspots of bone tissue engineering research. Some were clinically applied and good clinical results were achieved. Conclusion As it provides new clinic method for treating bone defect, artificial osteoconductive material is of great potential in its application. To improve its microstructure, macroshape, mechanism of osteoinductive ability, and to accelerate new bone for mation will be the hotspots of the research on artificial osteoconductive material.
Objective To review the recent progress of the small intestinal submucosa (SIS) in application research of tissue repair and reconstruction. Methods The domestic and international articles on the SIS were reviewed and summarized. Results As a natural extracellular matrix, SIS has outstanding biological advantages, such as good mechanical property, tissue compatibility, and lower immunogenicity. SIS has been used to repair and reconstruct various types of tissue defects in animal models and clinical application, especially in the treatment of hernia, urinary system disease, and refractory skin trauma. The development of the tissue engineering technology expands the field of SIS repair and reconstruction and promotes the intensive study of SIS. However, the long-term effect of SIS in tissue repair and reconstruction still remains to be further observation, while the cell/SIS material construction by tissue engineering technology also needs more studies. Conclusion SIS has a widely promising application future in the tissue repair and reconstruction.
Objective To evaluate the effect of tissue engineered skin with isogeneic cells on repairing skin defects in inbred rat model so as to provide relevant evidences for the clinical application. Methods The skins of newborn inbred F344 rats were harvested and treated with Dispase trypsin to isolate the epidermal cells. The skins of adult Sprague Dawley rats were obtained and treated with hypertonic sodium-SDS-trypsin to prepare the acellular dermal matrix. The tissue engineered skin was reconstructed by submerging culturing and air-liquid interface culturing in vitro. The full-thickness skin defects of 1.5 cm × 1.5 cm in size were prepared along the dorsal both sides of 36 adult inbred F344 rats, and 72 defects were repaired with tissue engineered skin in experimental group (n=24), with allogeneic acellular dermal matrix in negative control group (n=24), and with autologous full-thickness skin in positive control group (n=24). Finally the gross observation, the survival rate, wound contraction rate, and histological observation were used to evaluate the effect. Results The wound healed by first intension at 4 weeks postoperatively in the experimental group; the grafts connected with the adjacent tissue tightly and had normal appearance. At 4 weeks after operation, the survival rate of the graft was 0 in the negative control group; the survival rates were 62.5% (15/24) in the experimental group and 91.7% (22/24) in the positive control group, showing significant difference between 2 groups (χ2=5.779, P=0.016). The wound contraction rates of the experimental group and positive control group were significantly lower than that of the negative control group (P lt; 0.05), but no significant difference was found between the experimental group and positive control group (P gt; 0.05). Histological observation showed that slight inflammation reaction appeared at 1 week postoperatively in the experimental group; the regeneration of the blood vessel and the proliferation of the fibroblasts in dermis and the gradual maturation of epidermis were observed at 2 weeks, and new collagen deposition and collagen remodeling in the dermis of the graft were found at 4 weeks postoperatively. Conclusion The tissue engineered skin is able to repair full-thickness skin defect of rats effectively, it has similar effect to the autologous full-thickness skin in preventing the wound contraction and promoting the wound healing, which provides experimental evidences for the clinical application.
Objective To find out the recent progress in research of cl inical appl ication of fascia lata allograft. Methods The domestic and international articles were reviewed to summarize the princi pal properties, processing techniques, and various uses of fascia lata allograft. Results Histologically fascia lata is composed of parallel and compact bundles of collagen fibers with few cells and immunologically it is low-antigenic. After varied tissue processing and storage techniques, fascia lata, as the scaffold only with the extracellular matrix, has been used in cl inical practice and achieved good results, such as ophthalmology, urology, and orthopaedics. Conclusion Because of these unique properites in repairing defects and reconstructing functions, fascia lata allograft, as a natural biomaterial, is promising to be used in more aspects withthe development of the biomedical techniques.
【Abstract】 Objective To explore the interventional effect of platelet lysate (PL) on osteogenic differentiation ofBMSCs by induction in rats in vitro. Methods Twenty-four clean-grade adult Wistar rats, weighing from 250 g to 300 g, maleor female, were included in this study. PL was obtained through three times of centrifugation and repeated freeze-thaw for the blood aspirated from cardiac cavities in 16 Wistar rats. ELISA assay was conducted to detect the concentration of growth factors PDGF, TGF-β1, IGF-1 and VEGF in PL. The BMSCs harvested by flushing femurs of 8 adult Wistar rats were isolated, cultivated and expanded in vitro. The cells at the 4 passage were performed for osteogenic differentiation by induction in three groups of A (5% PL of final concentration in basic induction medium), B (1% PL of final concentration in basic induction medium), and C (no presence of PL in basic induction medium as a control). The morphological changes of the cells were dynamically observed with inverted phase contrast microscope during the whole period. At different time-points, ALP staining (7 days) and ALP/TP (2, 8, 12 days) of the cells were detected to evaluate ALP activity, and the mineral formation in extracellular martrix was examined with Al izarin red staining which provided quantitative analysis of mineral deposits. Results ELISA assay showed that the content of PDGF, TGF-β1, IGF-1 and VEGF in PL reached (300 ± 30), (140 ± 25), (80 ± 35), (70 ± 20) pg/mL, respectively. Morphological observation displayed BMSCs in group A or B gradually turned from spindle-shape to square- or polygon-shape as the morphorlogical type of osteoblast-l ike cells at 7 days. The cells in group A showed slower shape changesbut higher prol iferation than that in group B or C. Moreover, at the 20 days, the cells in group A still displayed dense gro wth and produced obviously decreased amount of mineral deposits in ECM when compared with group B or C. At the 7 days, the cells ofgroup A showed smaller amount of granules positive for ALP staining in cytoplasm when compared with groups B and C, and displayed marked reduction in ALP activity assay at the 2, 8, and 10 days compared with that of groups B and C (P lt; 0.05). At the 20 days, Al izarin red staining showed the number of mineral deposits in groups A, B and C were 7.67 ± 1.10, 12.87 ± 0.81 and 15.59 ± 0.25, respectively, while the area of mineral deposits were (161 778.70 ± 44 550.80), (337 349.70 ± 56 083.24), and (415 921.70 ± 71 725.39) pixels, respectively. The number of mineral deposits and the area of mineral deposits in group A were smaller than those in groups B and C (P lt;0.05). But there was no statistically significant difference between groups B and C (P gt; 0.05). Conclusion PL is a kind of system carrying various growth factors. Exposure of PL inhibits both ALP activity and mineral formation of BMCs in a dose-dependent way under the osteogenic induction environment.
Objective To evaluate the cytotoxicity of microdosis peracetic acid (PAA) so as to provide the evidence for making residual l imit of PAA steril ization. Methods Mouse fibroblasts (L929 cell l ine) cultured in vitro were observed to evaluate the influence of microdosis PAA including 1 × 10-6, 2 × 10-6, 3 × 10-6, 4 × 10-6, 5 × 10-6, and 10 × 10-6 (V/V). Theproliferation of cells was determined by MTT assay at 2, 4, and 7 days of culture. The growth curve and the relative growth rate (RGR) were obtained. The cytotoxicity of PAA at different concentrations was evaluated according to RGR. Results At 2, 4, and 7 days after culture, fibroblasts of 1 × 10-6 group grew with normal morphology analogous to control group, while the cell growth of other groups were poor. With the increase of PAA concentration, the absorbance (A) values decreased, which suggested that there was a significant negative correlation between cell prol iferation and PAA concentration. And the correlation coefficient was — 1.000 at 2 and 4 days, — 0.964 at 7 days. There was no significant difference in A value between 1 × 10-6 group and the control group (P gt; 0.05), while there were significant differences in A value between the control group and other concentration groups (P lt; 0.05). The growth curve of 1 × 10-6 group was similar to that of the control group, both had obvious phase of exponential growth. The growth curves of other groups had no obvious phase of exponential growth. The cytotoxicity of 1 × 10-6 group was classified as level 1, 2 × 10-6 group as level 2, 3 × 10-6 group as level 3, 4 × 10-6 group as level 3-4, 5 × 10-6 group and 10 × 10-6 group as level 4. Conclusion PAA of 1 × 10-6 had no obvious cytotoxicity. The residual l imit of PAA less than 1 × 10-6 was recommended.
Objective To explore the feasibil ity of using PKH26 as a cell tracer to construct tissue engineered bone. Methods BMSCs isolated from the bone marrow of 1-week-old New Zealand white rabbit were cultured. The BMSCs at passage 3 were labeled with PKH26 and were observed under fluorescence microscope. The percentage of the labeled cells wasdetected by Flow cytometer. The labeled cells were induced to differentiate into osteoblasts in vitro and the morphology of the cells after induction was observed under inverted phase contrast microscope. The osteogenic induction was evaluated by ALP staining and Alizarin red staining. The cells labeled with PKH26 were seeded on the bio-derived bone to construct tissue engineered bone in vitro. Then the compound of cells and material were observed under fluorescence microscope. The compound of labeled cells and material were implanted into the rabbit thigh muscle, and the transformation of the labeled cells was observed by fluorescence microscope 14 and 28 days later. Results Fluorescence microscope observation: the BMSCs labeled by PKH26 were spherical and presented with red and uniform-distributed fluorescence, and the contour of the cells were clearly observed when they were adherent 24 hours after culture. Flow cytometric detection revealed that the percentage of labeled cells was 97.2%. After osteogenic induction, the morphology of the cells changed from long-fusiform to polygon-shape or cube-shape, more ECM was secreted, andthe ALP and the Alizarin red staining were positive. At 48 hours after culturing the PKH26 labeled BMSCs with bio-derived bone, the fluorescence microscope observation showed that there was red fluorescence on the surface and inside of the material. At 14 days after implantation, the labeled cells with red and l ight fluorescence were evident in the implantation area; while at 28 days, the cells with red fluorescence were still evident but less in quantity and weaker in fluorescence strength. Conclusion PKH26 can be used as BMSCs label for the construction of tissue engineered bone in vitro and the short-term tracing in vivo.