[Biocompatibility of graded zirconia-hydroxyapatite composite].
摘要
OBJECTIVE: To evaluate the biocompatibility and safety of a novel orthopedics materials-graded zirconia (ZrO2)-hydroxyapatite (HA) composite biomaterials. METHODS: First, ultrafine powers of ZrO2 and HA powder were prepared by chemical precipitation method, then graded ZrO2-HA composite was synthesized by dry-laying and sintering method. After the physiological saline and culture medium extracts of the composite were prepared, four experiments were conducted as follows: (1) The mouse acute toxic test consists of 2 groups (n=10). The extracts were intravenously injected to mice in the first group, and physiological saline to mice in the second group. The dose was 50 g/kg. Their toxicity manifestation, morality and the change of weight were recorded. (2) The standard curve of proliferation and metabolism of L929 cells was established. (3) The cytotoxic test consists of 3 groups: materials group (extracts of the materials), positive control group (culture fluid with 0. 64% phenol), and negative control group (RPMI-1640 culture fluid). Each of three was cultured with cell suspension, and then the morphology of the cells was observed, the relative proliferation rate (RGR) was calculated, and the toxicity was classified. (4) In vitro hemolytic test was divided into 3 groups: extracts, sterile distilled water (positive control) and 0.9% physiological saline. In each of three, 0.2 ml anticoagulant diluted fresh rabbit blood was added. The percentage of hemolysis was tested. (5) The muscle and implantation test were divided into 4 groups (n=3). The composite biomaterials were implanted into pygal muscles on either side and lateral condyles of femurs. After surgery, the rats of four groups were sacrificed at 3, 6, 12 and 24 weeks respectively. Tissue slice and scanning electronic microscopy were performed. RESULTS: (1) General acute toxic test: no mouse died within 3 weeks; no toxicity symptom or adverse effects were shown within 3 days. The weight of materials group increase