Histocompatibility of poly (lactic-co-glycolic acid)/RNA Ⅲ inhibiting peptide sustained release microspheres / 中国组织工程研究

ABSTRACT

OBJECTIVE: To evaluate the histocompatibility of poly (lactic-co-glycolic acid)/RNA Ⅲ inhibiting peptide (PLGNRIP) sustained release microspheres.METHODS: The crude peptide comprising N to C-terminals was synthesized using Fmoc method. The crude synthetic RNAⅢ peptide was purified by reverse phase high performance liquid chromatography, followed by component harvesting according to ultraviolet absorption peak, and freeze-drying. PLGNRIP sustained release microspheres with a diameter of 50-70 pm were prepared using liquid-phase multiple emulsion method. The histocompatibility of PLGNRIP sustained release microscopes were preliminarily evaluated through the use of acute general toxicity test, MTT cytotoxicity test, intramuscular implantation test, sensitivity test, and pyrogen test.RESULTS: Acute general toxicity test results showed that all included animals survived and presented with no toxicosis reaction and obviously changed body mass. MTT cytotoxicity test results revealed that the average relative growth rate of cells from two eluents was over 85%, with cytotoxicity grade 1, which indicated no cytotoxicity. Intramuscular implantation tests showed that at 4 weeks after implantation of RiP powder or PLGNRIP microscopes, no obviously congested, degenerated, or necrotic tissue was observed. All RIP powder and a part PLGNRIP microscopes were degraded. Fibroblasts accounted for a large proportion in all cells. NO inflammatory cell infiltration, involving neutrophits and multinucleated giant celts, was observed. Sensitivity test rasults displayed that the average primary irritation index was 0.38, 0.33, arid 0.31 in the eluent stock solution, 2% dinitoflruorobenzene, and physiological saline-administerd groups, respectively. Pyrogen test results showed that fervescence of each rabbit in the experiment was under 0.5 ℃ and the sum of fervescence was under 1.3 ℃ .This is in coincidence with evaluation criteria of pyrogen test.CONCLUSION: PLGNRIP sustained release microspheras exhibit good histocompatibility.