Experimental Study Of Injectable Autologous Fat Particles Transplantation Combined With PRF And SVF

【Background】Injectable autologous fat tissue transplantation of Liposuction is one of the most common methods in soft tissue repair. it often need to repeat injections 2 to 3 times or over-filling for the unpredictable absorption rate (20%～90%).In recent years,with the development of the tissue engineering research at home and abroad, the scholars have promoted the regeneration of adipose tissue with tissue engineering principles. This study would provide a new idea to reduce the absorption of fat tissue transplantation.【Objective】We would construct of an injectable biological graft material of autologous fat particles combined with PRF and SVF, and evaluate the effect of transplanted biological material.【Methods】1.General observation. 2.Histology: HE staining and CD31 immunohistochemistry to observe the histological changes and new blood vessels at different time points after transplantation in the fat tissue for paraffin sections. 3.B ultrasound and caliper measurements: Fat tissue were measured at the prescribed time after surgery, and in accordance with the volume formula: V = a×b×c×0.5 (a for the longitudinal diameter, b for the diameter, c for the thickness.)4. Statistical analysis: The survival and absorption rate of the 4 groups'transplanted fat tissue was analyzed by SPSS16.0 software, using analysis of variance method. The differences between any two groups were compared and were statistically analyzed by using LSD method at different time points.Survival rate (%) = adipose tissue volume at each time point after transplantation / adipose tissue volume at the first postoperative day, absorption rate(%)=1- (adipose tissue volume at each time point after transplantation / fat tissue volume at the first postoperative day).5.Microvessel density analysis: Paraffin sections of the fatty tissue were stained for CD31 immunohistochemistry 1 month after surgery and the improved Weidner method used to count. The differences between any two groups were compared and were statistically analyzed by using LSD method at different time points.【Results】1.An injected autologous fat tissue transplantation on rabbit animal model have been constructed;2. Statistical analysis of the effect of biological material combined autologous fat transplantation:6 months after transplantation,comparison of 4 groups, autologous fat particles transplantation combined with PRF and SVF group (AG + PRF + SVF group) is the lowest absorption rate (17.37±6.22)%, fat particles alone group (AG + NS group) is the highest absorption rate of transplanted fat tissue (49.39±9.47)%, the absorption rate of adipose tissue transplantation of fat particle combined SVF group ( AG + SVF group) and the fat particles composite PRF group (AG + PRF group) were (27.25±4.37)%, (34.61±8.47)%; Compared with control group, AG + PRF + SVF group was of the lowest absorption rate. Compared with pure fat particles, the differences between the AG + PRF + SVF group and the AG + NS group were statistical significant (P <0.0001).3.Histological analysis: At the early stage (1 week ~ 4 weeks), (AG + PRF + SVF) group was of the fastest conversion, minimum fibrosis and inflammatory reaction. AG + NS group was significantly adipose tissue fibrosis, and fat cells surrounded by inflammatory cell infiltration even at the fourth week after surgery. AG + SVF group and the AG + PRF group were of the conversion rate of the middle. No significant difference between the two; after 6 months , the grafted adipose tissue was similar, no significant difference;4.Microvessel density analysis: one month after surgery ,the grafted fat tissue was cut for the paraffin sections and immunohistochemistry . the autologous fat particles combined with PRF and SVF group(AG + PRF + SVF group) is the highest microvessel density (83.80±11.69)%, fat particles alone group (AG + NS group) is the lowest (50.60±6.69)%, microvessel density of the fat particle combined with SVF group (AG + SVF) group and fat particles combined with PRF group (AG + PRF group) were between the former two groups, were (64.20±7.50)%, (64.40±9.61)%. Compared with control group, AG + PRF + SVF group was of the highest microvessel density . Compared with pure fat particles, the differences between the AG + PRF + SVF group and the AG + NS group were statistical significant (P <0.0001).【Conclusion】1.This study has constructed a rabbit models with following advantages: unified standard, precise pointing, easy observation and measurement .2.Injectable autologous fat tissue combined with PRF and SVF is a biological materials which is simple, safe, effective and inexpensive,and provide provide experimental evidence for adipose tissue engineering.