| Objective:to study the effect of VAP/PLGA complex membrane on the healing and adhesion in anastomotic tendon. Methods:48 chickens were divided into four groups randomly, 15 each group. The chickens of A group served as controls, the B group was PLGA, the C group was the low dose VAP, the D group was the high dose VAP. The third and forth toes were chosen and the flexor digitorum superficialis were cut to increase the space of the sheath. Under the FDS the flexor digitorum profundus was sectioned to establish the model. The deep flexor tendon of the third and fourth toes were cut and sutured with a single 6-0 nylon stitch by a modified Kessler technique, encapsulated PLGA membrane,low dose VAP/PLGA membrane and high dose VAP/PLGA membrane. The sheath and skin were sutured and fixed. The material was got after second,third,forth week. The specimens were observed under naked eye,microscope and electricmicroscope. Meanwhile the stress,strain,ridgity and function recovery were quantificationally analyzed to guarantee the objectivity of the results. Results: the gross appearance showed that the tendon in each group had no rupture, after 2 week the membrane smashed and after 4 week the membrane decomposed completely, in which the membrane group had no obvious adhesion, but the no membrane group had wide adhesion, especially the anastomosed tendon. Under light microscope, Tendon endothelium of Low and high dose VAP groups began to proliferate after 2 weeks. Tendon endothelium became apparent thick,split and spindle after 3 weeks. The collagen was parallel with longitude and proliferated through joint. In the joint Tendon cells allay regularly after 4 weeks. In the group without the membrane, the extrathelium became thick and the fiber in the tendon ruptured. The capillary vessel and fiberblast that took on gyrate invaded and past the joint. After 2 weeks of the operation, the proliferous endothelium and extrathelium contain a lot of rough endoplasmic reticulum, meanwhile the surface of cells appear collagen. After 3 weeks the collagen assemble to bundles, in which the structure of fiberblast is same as normal tendon cell. After 2 weeks in the control group thetendon endothelium became denaturalization, a lot of vacuoles appeared. After 3 weeks a lot of dissociative ribosome and rough endoplasmic reticulum and collagen appeared. Rupture strain: after the seventh,fourteenth and twenty eighth day the strain was contrasted and the results showed that the t value of the low dose and high dose VAP group is more apparent that the control group. The biology dynamo showed that the membrane group is better that the no membrane group by the coefficient of the pull from the tendon sheath, the results showed that the membrane group is better the others (P<0.05). there is on difference in membrane groups. The content of hydroxylproline was measured and the results showed that there was no difference early, but later among the low and high dose VAP groups the difference appeared and was apparent (P<0.05). Discussion :the toes between chicken and human have the same anatomy and fuction, the flexor digitorum superficialis include two and have sheaths. So the model is reasonable. Velvet Antler Peptide(VAP)is a peptide from velvet antler which is made of 68 amino acids. Its molecular weight is 7200 and appearance is slightly yellow and white. Its water-solubility is good. VAP can accelerate DNA synthesis and cell proliferation ofrabbit rib cartilaginous cells,human fetal cartilaginous cells and chicken fetal skull osteoblast. VAP has no species specificity. Experiments shows cell proliferation is parallel with the concentration of VAP. VAP stimulates cartilaginous cells and osteoblasts to proliferate, which is the mechanism of fracture healing. Furthermore experiments shows VAP can apparently control the acute and chronic inflammation. VAP can reduce ascorbic acid and cholesterol and improve serum corticoid, all these show VAP possesses better exciting adrenal gland effect. Recent researches found that VAP can effectually treat many skin ,facture and nerve injury. Especially it can improve epidermal cells and fiberblasts proliferation. The objective of this experiment is to observe the effect of tendon healing and adhesion by applying the PLGA compound membrane on the chicken sutured wound. Because of mature process, the PLGA membrane (made in ChangChun institute of applied chemistry, Chinese academy of sciences ) is used. PLGA is made up of PLA and PGA, the proportion is 8:2. After the polymerization the hydrophile and decomposition is accelerated. The membrane is innocuous ,well-compatible and well-infiltrative. In 3 weeks the membrane will decompose. The membrane which is 50 um thickness and is sterilized by the cycloxylethane accords with clinical need, it is applied widely.This experiment chose chickens as the subject of VAP. In 40 healthy chickens 20 were male and 20 were female. The third and fourth toes were studied. The flexor digitorum superficialis (FDS) were removed and the flexor digitorum profundus (FDP) were transected under FDS. Meanwhile the stress,rigidity,function et al were estimated. The content of hydroxylproline and fiberblast et al were analyzed quantificationally. All these can guarantee the objectivity of the experiment. From the experiment, the results show that Velvet Antler Peptide possesses the ability of accelerating the tendon healing. From this experiment, VAP can accelerate the healing of tendon. PLGA wraps the joint of tendon and then the healing speed and time become fast. Meawhile PLGA can prevent the adhesion of tendon. PLGA possesses the ability of well penetration. The time of complete decomposition is about 3 weeks. As a biology barrier PLGA can prevent the adhesion of tendon and the speed of absorb. VAP-PLGA can be used widely with the clinical study.
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