Study On The Immunity Safety Of Collagen-based Biomimetic Bone Matrix And Fibrin Dressing

Immune mechanism is an important defense mechanism in human body. Any structural change or malfunction will reduce the human immune mechanism's anti-disease capability, resulting in various infectious diseases, inner immunity failure or cancer. In the contemporary years, bio-medicines and bio-products emerge frequently and in a large amount, and their improper ingredients are reported in cases of hurting human health. The safety of bio-medicines and bio-products causes greater and greater concern.The present study chooses two kinds of implanted collagen bio-materials, namely "collagen-based biomimetic bone matrix" and "fibrin dressing". According to the immune reaction types of the potential immune toxic effects, the empirical study of wistar-body-implant is designed to test whether these two materials are effective on wistar's immune mechanism. The outputs are as follows:1. wistar rat is chosen as the study's objects, the collagen-based biomimetic bone matrix and hydroxyapatite are implanted beside wistar's thighbone; fibrinogen and collagen are implanted in the animal's liver. The exposure time span is at least 28d, the amount of the implanting is at the maximum of the certain position. Specifically, collagen-based biomimetic bone matrix is lcm×0.03cm2, hydroxyapatite 1cm×0.01cm2, fibrin dressing 1cm×1cm, and fibrinogen 1cm×1cm.2. An immunosuppressant group is set as positive contrast, three low immunotoxicity material groups are set as parallel contrast, and an sham operated group is set as negative contrast. The result indicates that the immunosuppressant model is established under the condition of 30mg/kg peritoneal injection 10mg/mL Cyclophosphamide 1 time a day, for4 days. Wistars in the immunosuppressant group become obviously mucous membrane hemorrhage of month and nose, the face intumesce, the paraffin section show immune organ have apparente pathological changes, the count of leukocytes,lymphocytes and neutrophilic granulocyte, index of spleena and thymus, the ability of NK cell, T lymphocyte subsets, content of IL-1, IL-6, TNF-α, IgG and IgM in serum have differences compare with negative contrast group significantly (P<0.05).3. Wistars are tested and observed from the perspective of observation, the count of leukocytes,lymphocytes and neutrophilic granulocyte, analyze the index of immune organ, detect the ability of NK cell, analyze the T lymphocyte subsets, detect the content of IL-1, IL-6, TNF-α, IgG and IgM in serum, the result indicates that: (1) Wistars after surgery are have common mental status, increase of body weight and fine wound healing, which compared with negative control group have nonsignificant(P >0.05);(2) The count of leukocytes have no anomaly increase and decrease, and have nonsignificant compared with negative control group(P>0.05); from the 2nd week, the count lymphocytes recovered to common level, have nonsignificant compared with negative control group(P>0.05);(3) Compared with negative control group the index of spleen and thymus have nonsignificant(P>0.05);(4) Wistars after surgery compared with negative group, each immune organ have no pathological changes, structures are normal;(5) The abilities of NK cell have nonsignificat compare with negative control group(P >0.05), but have differences compared with the crude mortality ratio of NK cell(P<0.05);(6) Except the 2nd week, the content CD3+CD4+T lymphocyte, CD3+CD8+T lymphocyte have rise infinitesimally, all results have nonsignificant compared with negative control group(P>0.05);(7) The content of IL-1, IL-6, TNF-αand IgG in serum have nonsignificant compared with negative control group (P>0.05);and no IgM is existence in serum, reveal that no recen infection happened.In summary, collagen-based biomimetic bone matrix and fibrin dressing have no immunotoxicity, the two biomaterials have satisfactory immune safety.