丹酚酸B缓释羟基磷灰石颗粒与成骨细胞的活性

Effect of salvianolic acid B-loaded hydroxyapatite sustained release spherules on the activity of osteoblasts

背景:前期实验制备了羟基磷灰石颗粒堆积型多孔支架,可通过调节羟基磷灰石颗粒的尺寸及微观空隙结构更好地构建修复超临界尺寸的生物陶瓷支架。如果再将一些可促骨愈合的药物负载其上,既可控制药物的局部浓度以提高利用率,增加专一性、又可降低不良反应,加快骨愈合。目的:观察载丹酚酸B缓释羟基磷灰石颗粒对体外培养成骨细胞活性的影响。方法:分离培养SD大鼠成骨细胞,将羟基磷灰石颗粒、无壳聚糖包裹的丹酚酸B缓释羟基磷灰石颗粒、壳聚糖包裹的丹酚酸B缓释羟基磷灰石颗粒分别与成骨细胞共培养,采用AlamarBlue法检测各组成骨细胞增殖活性;碱性磷酸酶活性检测各组成骨细胞分化情况;免疫细胞化学染色观察各组成骨细胞中Ⅰ型胶原和骨钙素表达。结果与结论:壳聚糖包裹的丹酚酸B缓释羟基磷灰石颗粒能显著促进SD大鼠成骨细胞的增殖,同时加强碱性磷酸酶表达,其效应持续时间高于羟基磷灰石组、无壳聚糖包裹的丹酚酸B缓释羟基磷灰石组;Ⅰ型胶原和骨钙素表达与羟基磷灰石组无差异。而无壳聚糖包裹的丹酚酸B缓释羟基磷灰石组由于药物的突释对细胞造成毒性,从第2天细胞开始皱缩以致死亡。说明壳聚糖包裹的丹酚酸B缓释羟基磷灰石颗粒在较长时间内具有促进成骨细胞增殖和分化,对成骨细胞的生物学活性无影响,并保持成骨细胞的生物学活性。

BACKGROUND： Hydroxyapatite （HA） spherules, a new type of bone repair material, have been prepared in preliminary experiment. Bio-ceramic scaffold in a super-critical size can be constructed by adjusting HA spherules size and micro-structure. Loading some drugs that can promote bone healing on the scaffold, can control the local concentration of drugs and then improve efficiency, increase specificity, reduce side effects, and accelerate bone healing. OBJECTIVE： To investigate the influence of salvianolic acid B （Sal B）-loaded HA sustained-release spherules on the activity of osteoblasts cultured in vitro. METHODS： Osteoblasts were isolated from SD rats and co-cultured with HA spherules, Sal B-loaded HA sustained release spherules, chitosan-coated Sal B-loaded HA sustained release spherules respectively. The proliferation of rat osteoblasts was evaluated with Alamar Blue assay; The alkaline phosphatase activities were measured to detect the differentiation of osteoblasts. Expression of collagen Ⅰ and osteocalcin were examined with immunocytochemistry. RESULTS AND CONCLUSION： Sal B-loaded HA sustained release spherules coated with chitosan could enhance significantly the proliferation of rat osteoblasts and alkaline phosphatase expression, the effect duration was longer than that of HA group and Sal B-loaded HA spherules without chitosan. There was no significant difference in collagen Ⅰ and osteocalcin compared with HA group. Sal B-loaded HA spherules without chitosan made cells shrinkage and death because of the toxicity to the cells induced by drug sudden release from the second day. Sal B-loaded HA sustained release spherules coated with chitosan can enhance the proliferation and differentiation of rat osteoblasts for a long term, have no influence on the bioactivity of osteoblasts and also can maintain the bioactivity of osteoblasts.