Inhibiting Effects Of Vitamin E And Tetrandrine On Periprosthetic Capsular Formation In Rabbits

Objective: To study the effects of tetrandrine and high dose of vitamin E on inhibition of periprosthetic capsular formation.To investigate the lasting time of effective concenstration after topical application of tetrandrine .To provide potential clinical way to prevent capsular contracture. Methods: 12 female New Zealand white rabbits were randomly divided into 4 groups of 3 animals each .4 smooth silicone implants(15ml each) were implanted beneath the panniculus carnosus muscle of each rabbit. The experimental animals were given either 20 mg tetrandrine in implant cavity intraoperatively or/and vitamin E enriched rabbit forage(containing 10 g vitamin E per kg forage ) for 3 months.all animals were sacrificed 3 months post operation .defections related to capsular contracture were physically and biochemically performed.In addition ,capsular histological examinations were also carried out. 4 female New Zealand white rabbits were not divided into groups . silicone sheet (1.5×1.5cm) and 20 mg tetrandrine were implanted in one cavity beneath the panniculus carnosus muscle of rabbit. 8 cavities were formed in each animal.The experimental animals were sacrificed 3,6,9,12 weeks post operation. The examinition of concenstration were performed. Results: 1 capsular physical examination 1.1 capsular tensility: Capsular tensility of the control group was abviously higher than those of the three experimental groups(vitamin E group,tetrandrine group, double-drug group) (p<0.01).Capsular tensility of the double-drug group was lower than those of vitamin E group and tetrandrine group(p<0.01).The difference between vitamin E group and tetrandrine group was not statistically significant(p>0.05). 1.2 capsular thickness:Capsular thickness of double-drug group was abviously thinner than those of the other three groups(control group,vitamin E group,tetrandrine group,)(p<0.05). The differences among the other three groups were not statistically significant. (p>0.05) 1.3 capsular wet weight:Capsular wet weight of the control group was abviously higher than those of the three experimental groups( vitamin E group,tetrandrine group, double-drug group) (p<0.01). Capsular wet weight of the double-drug group was lower than those of vitamin E group and tetrandrine group(p<0.01).The difference between vitaminE group and tetrandrine group was not statistically significant. (p>0.05) 2 capsular histology examination 2.1 HE staining: The capsular microstructure of control group was similar to those of the three experimental groups( vitaminEgroup,tetrandrine group, double-drug group),The inner layer of capsule was smooth,most of cells were fibroblasts, macrophages and lymphocytes were occasionally found.The middle layer was thicker collagen stroma with scattered fibroblasts.The outer layer was loose connective tissue with scattered fibroblasts and blood vessels. 2.2 Van Gieson staining: Collagen fibres of control group was dense,the middle layer was thicker than those of three experimental groups. Among 4 groups, the middle layer of double-drug group was the thinnest. 2.3 capsular ultrastructrue :Typical myofibroblasts were found in all of 4 types of capsules,with an indented nucleus,abundant microfilaments in the cytoplasm. Myofibroblasts with swelled mitochondrions and dilated rough endoplasmic reticulum were found in three experimental groups.part of cells began to necrosis in double-drug group. 2.4 α-smooth muscle actin immunohistochemical staining and cell counting The expreression of α-smooth muscle actin(α-SMA) was found in all of 4 types of capsules.There were brown-staining granules in cytoplasm.The myofibroblast number of control group was abviously higher than those of the three experimental groups(vitamin E group,tetrandrine group, double-drug group) (p<0.01). The myofibroblast number of double-drug group and tetrandrine group was lower than that of vitamin E group (p<0.01). The difference between double-drug group and tetrandrine groupwas not statistically significant(p>0.05). 3 collagen content Capsular coll...