Abstract

Developing smart scaffolds with drug release capability is one of the main approaches to bone tissue engineering. The current study involves the fabrication of novel gelatin (G)–hydroxyapatite (HA)-/vitamin D (VD)-loaded graphene oxide (GO) scaffolds with different concentrations through solvent-casting method. Characterizations confirmed the successful synthesis of HA and GO, and VD was loaded in GO with 36.87 ± 4.87% encapsulation efficiency. Physicochemical characterizations showed that the scaffold containing 1% VD-loaded GO had the best mechanical properties and its porosity percentage and density was in the range of natural spongy bone. All scaffolds were degraded after 1-month, subjecting to phosphate buffer saline. The release profile of VD did not match any mathematical kinetics model, porosities and the degradation rate of the scaffolds were dominant controlling factors of release behavior. Studies on the bioactivity of scaffolds immersed in simulated body fluid indicated that VD and HA could encourage the formation of secondary apatite crystals in vitro. Buccal fat pad-derived stem cells (BFPSCs) were seeded on the scaffolds, MTT assay, alkaline phosphatase activity as an indicator of osteoconductivity, and cell adhesion were conducted in order to evaluate in vitro biological responses. All scaffolds highly supported cell adhesion, MTT assay indicated better cell viability in 0.5% VD-loaded GO containing scaffold, and the scaffold enriched with 2% VD-loaded GO performed the most ALP activity. The results demonstrated the potential of these scaffolds to induce bone regeneration.

中文翻译：

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具有释放维生素 D 能力的骨组织工程明胶-羟基磷灰石/氧化石墨烯支架：制造、表征和体外研究

摘要

开发具有药物释放能力的智能支架是骨组织工程的主要方法之一。目前的研究涉及通过溶剂浇铸法制备不同浓度的新型明胶（G）-羟基磷灰石（HA）-/维生素D（VD）负载的氧化石墨烯（GO）支架。表征证实了 HA 和 GO 的成功合成，并且 VD 以 36.87 ± 4.87% 的封装效率加载到 GO 中。理化表征表明，含有 1% VD 负载的 GO 的支架具有最好的力学性能，其孔隙率和密度在天然海绵骨范围内。所有支架在 1 个月后降解，经受磷酸盐缓冲盐水。VD 的释放曲线与任何数学动力学模型都不匹配，支架的孔隙率和降解速率是释放行为的主要控制因素。对浸泡在模拟体液中的支架的生物活性的研究表明，VD 和 HA 可以促进体外二次磷灰石晶体的形成。将颊脂垫衍生的干细胞 (BFPSCs) 接种在支架上，MTT 测定，碱性磷酸酶活性作为骨传导性的指标，并进行细胞粘附以评估体外生物学反应。所有支架都高度支持细胞粘附，MTT 测定表明在含有 0.5% VD 的 GO 支架中细胞活力更好，富含 2% VD 的 GO 的支架表现出最大的 ALP 活性。结果证明了这些支架诱导骨再生的潜力。