| Hydroxyapatite(HA) is the major inorganic reconstituent of bone. Due to its properties of biocompatibility and osteo-conduction, it is generally used to repair the bone defect as a medical biomaterial. Nevertheless the pure hydroxyapatite is granular or brittle massae and hardly to be shaped. Aim to the clinic exercise, it is one of the focuses of biomaterial research to compose hydroxyapatite with other material to improve its character. Silicon rubber (SR) which is a well-known typical medical high polymer material be used in medical apparatus and instrument, man-made organ and medicine slow-release system. Does the new material composed of hydroxyapatite and silicone rubber possess suitable mechanical function like silicone rubber and good biocompatibility that can compare with hydroxyapatite ? We have done some experimental study on the biocompatibility of this HA-SR composite.ObjectiveAccording to the requirement and standard of International Organization for Standardization (ISO), the purpose of our study is to evaluate the biocompatibility and biological security of the composite of hydroxyapatite and silicone rubber in vivo and to provide the basis for its clinical application in the future.Methods1 To investigate the acute systemic toxic reaction induced by the HA-SR composite, the diffusion solution of the HA-SR composite at different concentration gradient were injected in the abdominal cavity of mice, then the researcher observing the acute toxic reaction that possibly occur.2 To investigate the acute and subchronic toxic reaction on the whole bodies induced by the HA-SR composite after implanting in vivo and its effects on partial constitution of animal organs after implanting in vivo. According to the evaluate criteria of medical implanted materials, biology and animal trial recommended in GB/T16 886.5-1997-ISO10 993-5:1992, The HA-SR composite were implanted into the muscle and on the mandible surface of rabbit, blood was drawn at different point. General and histochemical examinations of blood were performed at different points. The inflammation index, the biochemical index of blood and functional indexes of liver and kidney were tested by use of Beckman automatic biochemical analysis device, to evaluate the acute toxicity on the whole body. On the other hand, the specimens were harvested at different point respectively and examined by histology ,to evaluate the tissue response to the composite, after implantation 3 months, the rabbit's liver and kidney were harvested to evaluate the chronic toxicity by histology examination.3 And to evaluate the potential and degree of subcuticular stimulation reaction, the primary irritation index (PII) was worked out by observing at the rate point of animals back after the subcutaneous injection of the diffusion solution of the HA-SR composite.Results1 The acute systemic toxicity test showed that there was no obvious significance between the treatment group and the control group at different period (P>0.05). The leaching liquor of the HA-SR composite did not induce the acute toxic reaction on the mice.2 The acute and subchronic toxicity test results showed that the HA-SR composite had no apparent inflammatory reaction in vivo. There was no obvious significance between the treatment group and control at different period (P>0.05). There were no obvious changes in general blood, the indexes of inflammation and biochemical blood as well as the function of liver and kidney. Pathologic tissue section showed that the peripheral packed tissue of materials and the inflammation change accorded with the general regularity of inflammatory outcome. Subperiosteum implantation results demonstrated that the HA-SR composite have good biocompatibility to the soft tissue and bone of rabbits.3 The primary irritation index (PII) was measured 0~4 after the diffusion solution was injected into the back of animals, and the stimulation reaction was very slight according to the criteria.ConclusionIn brief, the HA-SR composite have good biocompatibility to the rabbit muscle and bone tissue and high biological security in vivo. The results indicated the HA-SR composite have good capability and it can be used as a good tissue substitute for the soft tissue and bone. |
PDF Full Text Request