0.05);rate of prophylactic antibiotics was reduced remarkably(P

OBJECTIVE To observe the property,the bacterial retaining effect and the storage time of nonwoven and wrinkle paper.METHODS The weight and shape,and the retaining effect and storage time of 14 kinds of nonwoven and wrinkle paper were observed.RESULTS Bacteria could go through all kinds of nonwoven and wrinkle paper.After sterilization,different quality and different package layer of nonwoven could be kept for 7-30 days.One or two layers of wrinkle paper package could be kept for 3 months.There was no significant difference in keeping place-in sterile room or in ward.CONCLUSIONS The time of preservation validity is related to the quality and the layers of nonwoven.It is suggested that two layers of lower quality nonwoven(28-30 g/m2) be used for lower and middle level dangerous medical material,with 7-10 days of preservation;four layers of high quality nonwoven(above 33 g/m2) could be used for high level dangerous medical material,with a 1 month of preservation.

OBJECTIVE: To investigate the feasibility of a dual-crosslinked injectable hydrogel derived from acellular musclar matrix (AMM) for promoting myoblasts proliferation and myogenic differentiation. METHODS: Firstly, hyaluronic acid was oxidized with NaIO ₄ and methylated to prepare methacrylamidated oxidized hyaluronic acid (MOHA). Then, AMM obtained by washing enzymatically treated muscle tissue was aminolyzed to prepare aminated AMM (AAMM). MOHA hydrogel and AAMM were crosslinked using Schiff based reaction and UV radiation to prepare a dual-crosslinked MOHA/AAMM injectable hydrogel. Fourier transform infrared spectroscopy (FTIR) was used to characterize MOHA, AAMM, and MOHA/AAMM hydrogels. The injectability of MOHA/AAMM hydrogel were evaluated by manual injection, and the gelation performance was assessed by UV crosslinking. The rheological properties and Young's modulus of the hydrogel were examined through mechanical tests. The degradation rate of the hydrogel was assessed by immersing it in PBS. The active components of the hydrogel were verified using immunofluorescence staining and ELISA assay kits. The promotion of cell proliferation by the hydrogel was tested using live/dead staining and cell counting kit 8 (CCK-8) assays after co-culturing with C2C12 myoblasts for 9 days. The effect of the hydrogel on myogenic differentiation was evaluated by immunofluorescence staining and real time quantitative polymerase chain reaction (RT-qPCR). RESULTS: FTIR spectra confirmed the successful preparation of MOHA/AAMM hydrogel. The hydrogel exhibited good injectability and gelation ability. Compared to MOHA hydrogel, MOHA/AAMM hydrogel exhibited higher viscosity and Young's modulus, a reduced degradation rate, and contained a higher amount of collagen (including collagen type Ⅰ and collagen type Ⅲ) as well as bioactive factors (including epidermal growth factor, fibroblast growth factor 2, vascular endothelial growth factor, and insulin-like growth factor 1). The live/dead cell staining and CCK-8 assay indicated that with prolonged incubation time, there was a significant increase in viable cells and a decrease in dead cells in the C2C12 myoblasts within the MOHA/AAMM hydrogel. Compared with MOHA hydrogel, the difference was significant at each time point ( P<0.05). Immunofluorescence staining and RT-qPCR analysis demonstrated that the deposition of IGF-1 and expression levels of myogenic-related genes (including Myogenin, Troponin T, and myosin heavy chain) in the MOHA/AAMM group were significantly higher than those in the MOHA group ( P<0.05). CONCLUSION The MOHA/AAMM hydrogel prepared based on AMM can promote myoblasts proliferation and myogenic differentiation, providing a novel dual-crosslinked injectable hydrogel for muscle tissue engineering.
Hydrogels ; Hyaluronic Acid/pharmacology* ; Vascular Endothelial Growth Factor A/metabolism* ; Tissue Engineering/methods* ; Cell Differentiation ; Myoblasts/metabolism* ; Cell Proliferation