The aim of this study was to evaluate biocompatibility of hydroxyapatite (HAP) from fish waste using in vitro and in vivo assays. Fish samples (whitemouth croaker - Micropogonias furnieri) from the biowaste was used as HAP source. Pre-osteoblastic MC3T3-E1 cells were used in vitro study. In addition, bone defects were artificially created in rat calvaria and filled with HAP in vivo. The results demonstrated that HAP reduced cytotoxicity in pre-osteoblast cells after 3 and 6 days following HAP exposure. DNA concentration was lower in the HAP group after 6 days. Quantitative RT-PCR did not show any significant differences (p > 0.05) between groups. In vivo study revealed that bone defects filled with HAP pointed out moderate chronic inflammatory cells with slight proliferation of blood vessels after 7 and 15 days. Chronic inflammatory infiltrate was absent after 30 days of HAP exposure. There was also a decrease in the amount of biomaterial, being followed by newly formed bone tissue. All experimental groups also demonstrated strong RUNX-2 immoexpression in the granulation tissue as well as in cells in close contact with biomaterial. The number of osteoblasts inside the defect area was lower in the HAP group when compared to control group after 7 days post-implantation. Similarly, the osteoblast surface as well as the percentage of bone surface was higher in control group when compared with HAP group after 7 days post-implantation. Taken together, HAP from fish waste is a promising possibility that should be explored more carefully by tissue-engineering or biotechnology.

本研究的目的是使用体外和体内测定法评估鱼粪中羟基磷灰石 (HAP) 的生物相容性。来自生物废物的鱼样品（白口黄花鱼 - Micropogonias furnieri）被用作 HAP 来源。成骨前MC3T3-E1细胞用于体外研究。此外，在大鼠颅盖骨中人工制造骨缺损并在体内填充 HAP。结果表明，在 HAP 暴露后 3 天和 6 天后，HAP 降低了前成骨细胞的细胞毒性。6天后HAP组的DNA浓度较低。定量 RT-PCR 未显示任何显着差异 ( p > 0.05) 组之间。体内研究表明，填充 HAP 的骨缺损在 7 天和 15 天后指出中度慢性炎症细胞，血管轻度增殖。暴露于 HAP 30 天后，慢性炎症浸润消失。生物材料的数量也有所减少，其次是新形成的骨组织。所有实验组还在肉芽组织以及与生物材料密切接触的细胞中表现出强烈的 RUNX-2 免疫表达。植入后 7 天，与对照组相比，HAP 组缺损区域内的成骨细胞数量较低。同样，植入后7天，对照组的成骨细胞表面和骨表面百分比高于HAP组。综合起来，