Dental and Periodontal Research Center, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran.
Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran.
J Biomater Appl. 2021 May;35(10):1253-1263. doi: 10.1177/0885328221998525. Epub 2021 Feb 25.
Biocompatible, biodegradable, and injectable hydrogels are a novel and promising approach for bone regeneration. In this study, poly(caprolactone)-poly(ethylene glycol)-poly(caprolactone) (PCL-PEG-PCL), PCL-PEG-PCL-gelatin (Gel), PCL-PEG-PCL-Gel/nano-hydroxyapatite (nHA) injectable hydrogels were synthesized and evaluated in a mouse model of subcutaneous transplantation after 14 days. PCL-PEG-PCL-Gel and PCL-PEG-PCL-Gel/nHA hydrogels were fabricated with precipitation method. Structure, intermolecular interaction, and the reaction between the PCL-PEG-PCL, Gel, and nHA were evaluated using a scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (H-NMR), and carbon nuclear magnetic resonance (C-NMR). Fourteen days after subcutaneous injection, the existence of an immune system reaction was investigated using Hematoxylin and Eosin (H&E) staining. Using immunofluorescence imaging, the number of CD68 cells was determined in the periphery of the hydrogel. The CD8/CD4 lymphocyte ratio was also calculated in blood samples. We monitored the expression of , , , and using real-time PCR assay. The chemical evaluation revealed the successful integration of Gel and nHA to the PCL-PEG-PCL backbone. Histological examination showed the lack of inflammation at the site of injection. No toxicological effects were determined in hepatic and renal tissues. The addition of nHA to the PCL-PEG-PCL-Gel decreased biodegradation time. None of the hydrogels caused statistically significant differences in the number of CD68 cells (p > 0.05). The CD8/CD4 lymphocyte ratio remained unchanged in all groups (p > 0.05). Compared to the PCL-PEG-PCL group, the addition of nHA and Gel increased the expression of , , , and (p < 0.05). In conclusion, the current study showed that PCL-PEG-PCL-Gel/nHA hydrogels could be used in conditions without prominent toxic effects and inflammatory responses.
生物相容、可生物降解和可注射水凝胶是一种用于骨再生的新型、有前途的方法。在这项研究中，聚己内酯-聚乙二醇-聚己内酯（PCL-PEG-PCL）、PCL-PEG-PCL-明胶（Gel）、PCL-PEG-PCL-Gel/纳米羟基磷灰石（nHA）可注射水凝胶在小鼠皮下移植模型中于 14 天后进行了评价。PCL-PEG-PCL-Gel 和 PCL-PEG-PCL-Gel/nHA 水凝胶是通过沉淀法制备的。使用扫描电子显微镜（SEM）、傅里叶变换红外光谱（FT-IR）、质子核磁共振（H-NMR）和碳核磁共振（C-NMR）评估了 PCL-PEG-PCL、Gel 和 nHA 之间的结构、分子间相互作用和反应。皮下注射 14 天后，使用苏木精和伊红（H&E）染色法研究了免疫系统反应的存在。通过免疫荧光成像，测定了水凝胶周围 CD68 细胞的数量。还计算了血液样本中 CD8/CD4 淋巴细胞比值。使用实时 PCR 检测，监测了 、 、 、 基因的表达。化学评价表明 Gel 和 nHA 成功地整合到 PCL-PEG-PCL 主链中。组织学检查显示注射部位无炎症。在肝和肾组织中未发现毒性作用。将 nHA 添加到 PCL-PEG-PCL-Gel 中会降低水凝胶的降解时间。在所有组中，CD68 细胞的数量均无统计学差异（p>0.05）。所有组的 CD8/CD4 淋巴细胞比值均保持不变（p>0.05）。与 PCL-PEG-PCL 组相比，添加 nHA 和 Gel 会增加 、 、 、 基因的表达（p<0.05）。总之，本研究表明 PCL-PEG-PCL-Gel/nHA 水凝胶可在无明显毒性作用和炎症反应的条件下使用。
