Establishment of a rabbit model of facial skin lifting and application of the absorbable soft tissue plastic belt / 中国比较医学杂志

Objective To establish a rabbit model of facial skin lifting and to evaluate the skin lifting effects of absorbable soft tissue plastic belt, and to provide experimental basis for clinical application of this plastic belt.Methods 36 Japanese white rabbits were randomly divided into model control group (n=6) and plastic belt lifting group (n=30). The model control group received only facial skin resection surgery, while the plastic belt lifting group had facial skin resection and plastic belt implantation.The changes of rabbit general status, skin lifting effects, performance of plastic belt and pathological changes of subcutaneous tissue after implantation were determined during the 4 weeks after surgery. Results The rabbit skin wound was healed within 3-7 days after surgery without infection.Meanwhile, the plastic belts did not show shifting or rupture, and only whitening around the perforations was observed in the two groups.Compared with the model control group, the MA and MB distances in the plastic belt lifting group were significantly lower ( P0.05 ) .Moreover, the molecular weight ( Mw ) , peak molecular weight ( Mp ) , Z molecular weight (Mz) and viscosity were gradually decreased along with the time passing after implantation (P<0.01), and its dispersion Mz/Mw ratio was also gradually decreased from 2 weeks after implantation (P<0.01), and no obvious pathological changes were found after subcutaneous implantation of the plastic belts.Conclusions We have successfully established a facial skin lifting rabbit model, and the plastic belt can obviously lift the facial skin fascia system and keep intact more than 4 weeks in the body.Therefore, this plastic belt can be applied for anti-wrinkle facial soft tissue lifting against the skin damage caused by aging.

Experimental research on the prevention of rabbit postoperative abdominal cavity adhesion with PLGA membrane / 生物医学工程学杂志

The aim of this paper is to explore the prevention of rabbit postoperative abdominal cavity adhesion with poly (lactic-co-glycotic acid) (PLGA) membrane and the mechanism of this prevention function. Sixty-six Japanese white rabbits were randomly divided into normal control group, model control group and PLGA membrane group. The rabbits were treated with multifactor methods to establish the postoperative abdominal cavity adhesion models except for those in the normal control group. PLGA membrane was used to cover the wounds of rabbits in the PLGA membrane group and nothing covered the wounds of rabbits in the model control group. The hematologic parameters, liver and kidney functions and fibrinogen contents were detected at different time. The rabbit were sacrificed 1, 2, 4, 6, 12 weeks after the operations, respectively. The adhesions were graded blindly, and Masson staining and immunohistochemistry methods were used to observe the proliferation of collagen fiber and the expression of transforming growth factor β1 (TGF-β1) on the cecal tissues, respectively. The grade of abdominal cavity adhesion showed that the PLGA membrane-treated group was significant lower than that in the model control group, and it has no influence on liver and kidney function and hematologic parameters. But the fibrinogen content and the number of white blood cell in the PLGA membrane group were significant lower than those of model control group 1 week and 2 weeks after operation, respectively. The density of collagen fiber and optical density of TGF-β1 in the PLGA membrane group were significant lower than those of model control group. The results demonstrated that PLGA membrane could be effective in preventing the abdominal adhesions in rabbits, and it was mostly involved in the reducing of fibrinogen exudation, and inhibited the proliferation of collagen fiber and over-expression of TGF-β1.

Safety study on jiazhu vascular ligating clips in rabbits after laparoscopic cholecystectomy / 中国比较医学杂志

Objective To provide an experimental reference for clinic application of Jiazhu vascular ligating clips on ligation effects and the impact on the body in rabbits after laparoscopoic cholecystectomy.Methods 36 rabbits were randomly divided into 3 groups, normal control group, Jiazhu group and similar product control ( Hem-o-lok) group, 12 rabbits in each group.Except for normal control group, the rabbits were used gallbladder duct and gallbladder artery closed by vascular ligating clips and Hem-o-lok clips in Jiazhu group and similar product control group, respectively.The changes of blood biochemical, electrolytes, hematological parameters, coagulation, ligation effects and organ coefficients were observed at post-operation during 12 months.Results Compared with normal control group, the rabbit weight was reduced in the Jiazhu group at 3 days postoperatively ( P 0.05 ) , and there were all no significant differences with electrolyte, coagulation and organ coefficients between each group (P >0.05).Conclusion Jiazhu vascular ligating clips are safe and reliable to close gallbladder duct and blood vessels, It shows that there are no differences in the validity and security between Jiazhu vascular ligating clips and Hem-o-lok clips.

Effects of PLGA absorbable membrane on preventing postoperative abdominal adhesion in rabbits / 中国医疗器械杂志

<p><b>OBJECTIVE</b>To investigate the effects of PLGA absorbable membrane in prevention of postoperative abdominal adhesion in rabbits.</p><p><b>METHODS</b>66 Japanese white rabbits were randomly divided into three groups: the normal control group n = 6, model control group n = 30 and PLGA group n = 30. Rabbits were received multifactor methods to establish postoperative abdominal adhesion models except for normal control group. The cecum wound was covered PLGA membrane in the PLGA group. At postoperative 1, 2, 4, 6 and 12 weeks, the abdominal cavities were reopened and the adhesive severity was graded blindly, and the hydroxyproline level in cecum tissue was measured and the cecum histopathology was observed.</p><p><b>RESULTS</b>(1) the degree of adhesion and hydroxyproline level in model control group were significantly higher than those of normal control group (P < 0.05, P < 0.01), while the degree of adhesion and hydroxyproline level in PLGA group were significantly lower than those of model control group (P < 0.05). (2) HE staining showed that cecum serosa had obviously inflammatory cell infiltration and fibroblast proliferation, while PLGA could inhibit fibroblast proliferation and reduce the inflammatory cell infiltration and collagen.</p><p><b>CONCLUSION</b>PLGA absorbable membrane can inhibit fibroblast proliferation and collagen to prevent the experimental postoperative peritoneal adhesions.</p>

Applications of polylactide and its copolymers in medical device fields / 中国医疗器械杂志

Polylactide and its copolymers are a kind of biomedical material andhave been approved by U.S. Food and Drug Administration. This paper briefly introduces its applications in surgical suture, orthopedics, plastic surgery, ophthalmology and other medical device fields, and also analyzes its development in our country.