W. M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164, USA.
J Mater Chem B. 2020 Mar 11;8(10):2048-2062. doi: 10.1039/c9tb01462d.
Delayed healing and nonhealing of bone defects or resected bone sites remains an important clinical concern in the biomedical field. Osteosarcoma is one of the most common types of primary bone cancers. Among calcium phosphates, hydroxyapatite (HA) and tricalcium phosphate (TCP) are the most widely used in various biomedical applications for bone reconstruction and replacement. In this study, crocin, saffron's natural bioactive and anti-inflammatory molecule, and bicarbonate, a neutralizing agent, were directly loaded onto HA disks to evaluate their in vitro release and effect on human osteoblast and osteosarcoma cell lines. This was assessed through release, initial toxicity, drug optimization, final toxicity studies and in vivo anti-inflammatory assessment through H&E indexing. It is hypothesized that the release of crocin, bicarbonate, and the dual release of both agents will decrease osteosarcoma cellular viability with no effect on osteoblast cells. A plateaued release of crocin and bicarbonate was achieved over seven weeks in physiological and acidic environments, where bicarbonate was shown to modulate the release of crocin. Through morphological characterization and MTT assay analysis, bicarbonate showed no toxicity to human fetal osteoblast (hFOB) cells and crocin significantly enhanced osteoblast proliferation. Through drug concentration optimization, all drug loaded samples decreased human osteosarcoma (MG-63) viability by 50% compared to control samples by Day 11, with clear changes in cell spreading and morphology. Moreover, 3D printed TCP scaffolds loaded with crocin and bicarbonate were tested in vivo in order to assess their preliminary effects on inflammation in a rat distal femur model at 4 days. Lower inflammatory cellular recruitment was achieved in the presence of crocin and bicarbonate, compared to the control. These results suggest a pro-apoptotic mechanism against osteosarcoma as well as anti-inflammatory properties of crocin and bicarbonate, elucidating a potential application for osteosarcoma regulation and wound healing for bone tissue regeneration applications.
骨缺损或切除骨部位的延迟愈合和不愈合仍然是生物医学领域的一个重要临床关注点。骨肉瘤是最常见的原发性骨癌之一。在钙磷酸盐中，羟基磷灰石 (HA) 和磷酸三钙 (TCP) 广泛用于各种骨重建和替代的生物医学应用。在这项研究中，藏红花的天然生物活性和抗炎分子西红花酸和中和剂碳酸氢盐直接负载到 HA 盘上，以评估它们在体外的释放及其对人成骨细胞和骨肉瘤细胞系的影响。这是通过释放、初始毒性、药物优化、最终毒性研究以及通过 H&E 索引进行的体内抗炎评估来评估的。假设西红花酸、碳酸氢盐的释放以及两者的双重释放将降低骨肉瘤细胞的活力，而对成骨细胞没有影响。在生理和酸性环境中，西红花酸和碳酸氢盐实现了 7 周的平台释放，其中碳酸氢盐显示出调节西红花酸释放的作用。通过形态特征和 MTT 分析，碳酸氢盐对人胎成骨细胞（hFOB）细胞没有毒性，西红花酸显著增强了成骨细胞的增殖。通过药物浓度优化，与对照样品相比，所有载药样品在第 11 天使人类骨肉瘤（MG-63）细胞活力降低了 50%，细胞铺展和形态发生明显变化。此外，为了评估在大鼠股骨远端模型中对炎症的初步影响，在 3D 打印的 TCP 支架上负载了西红花酸和碳酸氢盐，并进行了体内测试。与对照相比，在存在西红花酸和碳酸氢盐的情况下，实现了较低的炎症细胞募集。这些结果表明西红花酸和碳酸氢盐对骨肉瘤具有促凋亡作用和抗炎特性，阐明了其在骨肉瘤调节和骨组织再生应用中促进伤口愈合的潜在应用。
