Cellular immune response and immune toxicity to BALB/c mice for animal-based collagen / 中国组织工程研究

ABSTRACT

BACKGROUND:Natural colagen is considered to have low immunogenicity and good biocompatibility relatively. OBJECTIVE:To evaluate the immunogenicity of animal-based colagenin vitro. METHODS:Type I colagen was extracted from bovine tendon after immunogenicity removal. The colagen purity was detected by high performance liquid chromatography and residual DNA was measured quantitatively by fluorescence staining. Fifty BALB/c mice were randomly divided into five groups subcutaneous injection of normal saline solution (negative control), bovine colagen (positive control), 33.4, 66.8, 133.4 mg/kg of bovine tendon colagen, respectively, once a day. After 12 days of continuously subcutaneous injection, lymphocyte proliferation, and cel classification and NK cel kiling function of mice were detected; after 3 weeks of continuous injection, the spleen, liver, spleen and lung tissue of mice were taken for histological examination. RESULTS AND CONCLUSION:Compared with the standard type I colagen, the purity of purified type I bovine colagen reached more than 99%, but the residual DNA was below 1 mg/L which was far less than the residue level of conventional cel-free DNA in the matrix (dry weight 50-100 μg/g). After 12 days of continuous injection, there were no changes in lymphocyte proliferation, NK cel kiling function and the proportion of lymphocyte subsets. After 3 weeks of injection, the spleen and lymph sheath of mice around the smal artery became thickened in the 66.8 and 133.6 mg/kg bovine tendon colagen groups, which could cause accidental liver injury and lung injury, but the splenic corpuscle germinal center area had no change. These findings indicate that continuously subcutaneous injection of animal-based colagen can cause the lower lymphocyte immune response to the spleen of BALB/c mice, which may cause accidental liver and lung injuries.