Improvement in the repair of defects in maxillofacial soft tissue in irradiated minipigs by a mixture of adipose-derived stem cells and platelet-rich fibrin.

To find out if adipose-derived stem cells (ASC) and platelet-rich fibrin (PRF), alone or combined, had any effect on the repair of maxillofacial soft tissue defects in irradiated minipigs, ASC were isolated, characterised, and expanded. Twenty female minipigs, the right parotid glands of which had been irradiated, were randomly divided into 4 groups of 5 each: those in the first group were injected with both ASC and PRF (combined group), the second group was injected with ASC alone (ASC group), the third group with PRF alone (PRF group), and the fourth group with phosphate buffer saline (PBS) (control group). Six months after the last injection, the size and depth of each defect were assessed, and subcutaneous tissues were harvested, stained with haematoxylin and eosin, and examined immunohistologically and for apoptosis. Expanded cells were successfully isolated and identified. Six months after injection the defects in the 3 treated groups were significantly smaller (p<0.001) and shallower (p<0.001) than those in the control group. Those in the combined group were the smallest and shallowest. Haematoxylin and eosin showed that the 3 treated groups contained more subcutaneous adipose tissue than the control group, and also had significantly greater vascular density (p<0.001) and fewer apoptotic cells (p<0.001). Both ASC and PRF facilitate the repair of defects in maxillofacial soft tissue in irradiated minipigs, and their combined use is more effective than their use as single agents.

[Experimental study on effect of hirudin in inhibiting hyperplastic scar fibroblasts].

OBJECTIVE: To study the effect of hirudin on the function of human hyperplastic scar fibroblasts (HSFBs). METHODS: HSFBs were cultured in vitro. Hirudin solution in the concentration of 1, 10, and 50 kU/L was respectively added into DMEM culture medium to form 1, 10, and 50 kU/L hirudin groups, with 9 wells in each group. HSFBs cultured without hirudin were set up as control group. Cell inhibition rate, secretion level of TGF-beta1 from cells, and expression levels of mRNA of type I and III precollagen were determined at 24, 48, and 72 h after culture. RESULTS: Inhibition rates of HSFBs growth was respectively (29.3 +/- 0.9)%, (30.1 +/- 0.3)%, and (45.2 +/- 1.9)% when cultured with 10 kU/L hirudin for 24, 48, and 72 hs, which were higher than those in control group [(0.0 +/- 0.0)%, P < 0.05]. There was statistically significant difference between control group and 1 and 50 kU/L hirudin groups in the inhibition rates of HSFBs at some time points (P < 0.05). Secretion level of TGF-beta1 of HSFBs in 1, 10, 50 kU/L hirudin groups was respectively (228.5 +/- 1.8), (210.5 +/- 11.1), and (168.5 +/- 14.1) pg/mL when cultured for 48 hs, of which the last 2 figures were significantly lower than that of control group [(265.0 +/- 1.5) pg/mL, P < 0.05]. Hirudin in the concentration of 10 and 50 kU/L could inhibit the expression of mRNA of type I and III precollagen in HSFBs. CONCLUSIONS: Hirudin solution in the concentration of 10 and 50 kU/L can inhibit the proliferation of HSFBs and secretion of TGF-beta1 and collagen in certain degree.

Inhibition of vascular endothelial growth factor expression in keloid fibroblasts by vector-mediated vascular endothelial growth factor shRNA: a therapeutic potential strategy for keloid.

Vascular endothelial growth factor (VEGF) plays important roles in the regulation of angiogenesis and inflammation in both pathological and physiological wound repair. Several strategies have been developed for keloid therapy; however, a universally effective treatment has not been explored to date. In this study, three potential short interfering RNA (siRNA) sequences for the VEGF gene were cloned into expression plasmids and transfected into keloid fibroblasts. PGC-VEGF shRNA 2 (short hairpin RNA 2) plasmid significantly inhibited VEGF expression determined by real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and fibroblasts growth was also significantly by (methyl thiazolyl tetrazolium) MTT assay and apoptosis detection, whereas the control transfection showed no obviously effects. Plasminogen activator inhibitor-1 (PAI-1) expression in pGC-VEGF shRNA2 group was also obviously downregulated when compared to the pGC-VEGF shRNA negative control and mock group. These results suggest that modulation of VEGF production by vector-based RNAi in keloid fibroblasts may be a therapeutic potential strategy for keloid.