A dual-crosslinked injectable hydrogel derived from muscular decellularized matrix promoting myoblasts proliferation and myogenic differentiation / 中国修复重建外科杂志

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.

Effects of low concentration 5-fluorouracil and triamcinolone acetonide on ear hypertrophic scar in a rat model / 中华医学美学美容杂志

Objective To explore the effect of low concentration 5-fluorouracil combined with triamcinolone acetonide on rabbit ear hypertrophic scar model.Methods White rabbits post-traumatic scars were randomly divided into A,B,C and D groups,each group contained 18 cases.Group A was given triamcinolone acetonide and low concentration 5-fluorouracil,Group B was given low concentration 5-fluorouracil,Group C was given triamcinolone acetonide and Group D was used as the control group.The dynamic changes of the scar were observed by naked eyes,hematoxylin-eosin (HE) staining and van Gieson (VG) staining through microscope.Vascular endothelial growth factor (VEGF) and CD34 were detected and compared within 4 groups by immunohistochemical staining.Results We successfully established a rabbit ear scar model.It was observed that the scars of Groups A,B and C had been shorter and flatter than Group D,close to the normal tissue.In HE and VG staining,the number of fibroblasts,inflammatory cells,blood vessels in groups A,B and C had been decreased,compared with Group D.Immunohistochemical results showed that the positive rates of VEGF and CD34 from the most to the lest were Groups D,B,C and A.The scar proliferation index from the most to the lest were Groups D,B,C and A.Conclusions The effect of low concentration 5-fluorouracil in treatment of the rabbit ear hypertrophic scar is better than that of triamcinolone acetonide.Low concentration 5-fluorouracil combined with triamcinolone acetonide has a synergistic effect in treatment of hypertrophic scar,which has better effect than that of low concentration 5-fluorouracil or triamcinolone acetonide alone.

Effects of electron beam and triamcinolone acetonide on the rabbit ear scar / 中华医学美学美容杂志

Objective To observe the morphological changes by different electron beam radiation methods and different triamcinolone acetonide treatments on the role of hypertrophic scar of rabbit ear,and to explore the optimal treatment for the rabbit ear scar.Methods The ventral rabbit ear hypertrophic scar model was established,and intervention began at 28 days after surgery.The animals were randomly divided into control group (group A),saline group (group B),surgery plus saline group (group C),triamcinolone acetonide group (group D),surgery plus triamcinolone group (group E),and electron beam group (group F),2 days after surgical electron beam group (group G),and 7 days after surgical electron beam group (group H).HE stain,VG stain,toluidine blue stain,CD34 and Alpha-SMA immunohistochemical staining were performed,and comparied on histomorphology of each group.Results Collagen fibers observed showed that there was no statistically significance between groups A and B,groups D and G and groups F and H (P＞0.05),and the difference was statistically significant between other groups (P＜0.05).Mast cells were not typical by toluidine blue staining.The microvascular observation showed there was no statistically significance between groups A and B,groups F and H,and groups G and H (P＞0.05),and the difference was statistically significant between other groups (P＜0.05).Myofibroblasts showed no statistically significance between the groups A and B (P＞0.05),but the difference was statistically significant between other groups (P＜0.05).Conclusions Compared with electron beam radiation methods,triamcinolone acetonide injection is a better treatment.Early postoperative radiotherapy is better than late.Triamcinolone acetonide or electron beam radiation combined with surgery is better than simple treatment.