Jahangir Shahrbanoo, Vecstaudza Jana, Augurio Adriana, Canciani Elena, Stipniece Liga, Locs Janis, Alini Mauro, Serra Tiziano
AO Research Institute Davos, 7270 Davos, Switzerland.
Rudolfs Cimdins Riga Biomaterials Innovations and Development Centre of RTU, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Riga Technical University, Pulka 3, LV-1007 Riga, Latvia.
Materials (Basel). 2023 Nov 17;16(22):7214. doi: 10.3390/ma16227214.
Osteochondral (OC) disorders such as osteoarthritis (OA) damage joint cartilage and subchondral bone tissue. To understand the disease, facilitate drug screening, and advance therapeutic development, in vitro models of OC tissue are essential. This study aims to create a bioprinted OC miniature construct that replicates the cartilage and bone compartments. For this purpose, two hydrogels were selected: one composed of gelatin methacrylate (GelMA) blended with nanosized hydroxyapatite (nHAp) and the other consisting of tyramine-modified hyaluronic acid (THA) to mimic bone and cartilage tissue, respectively. We characterized these hydrogels using rheological testing and assessed their cytotoxicity with live-dead assays. Subsequently, human osteoblasts (hOBs) were encapsulated in GelMA-nHAp, while micropellet chondrocytes were incorporated into THA hydrogels for bioprinting the osteochondral construct. After one week of culture, successful OC tissue generation was confirmed through RT-PCR and histology. Notably, GelMA/nHAp hydrogels exhibited a significantly higher storage modulus (G') compared to GelMA alone. Rheological temperature sweeps and printing tests determined an optimal printing temperature of 20 °C, which remained unaffected by the addition of nHAp. Cell encapsulation did not alter the storage modulus, as demonstrated by amplitude sweep tests, in either GelMA/nHAp or THA hydrogels. Cell viability assays using Ca-AM and EthD-1 staining revealed high cell viability in both GelMA/nHAp and THA hydrogels. Furthermore, RT-PCR and histological analysis confirmed the maintenance of osteogenic and chondrogenic properties in GelMA/nHAp and THA hydrogels, respectively. In conclusion, we have developed GelMA-nHAp and THA hydrogels to simulate bone and cartilage components, optimized 3D printing parameters, and ensured cell viability for bioprinting OC constructs.
骨软骨（OC）疾病，如骨关节炎（OA），会损害关节软骨和软骨下骨组织。为了了解这种疾病、促进药物筛选并推动治疗方法的发展，OC组织的体外模型至关重要。本研究旨在创建一种生物打印的OC微型构建体，以复制软骨和骨部分。为此，选择了两种水凝胶：一种由甲基丙烯酸明胶（GelMA）与纳米级羟基磷灰石（nHAp）混合而成，另一种由酪胺修饰的透明质酸（THA）组成，分别模拟骨组织和软骨组织。我们使用流变学测试对这些水凝胶进行了表征，并通过活死检测评估了它们的细胞毒性。随后，将人成骨细胞（hOBs）封装在GelMA-nHAp中，同时将微丸软骨细胞掺入THA水凝胶中，用于生物打印骨软骨构建体。培养一周后，通过逆转录聚合酶链反应（RT-PCR）和组织学证实成功生成了OC组织。值得注意的是，与单独的GelMA相比，GelMA/nHAp水凝胶表现出显著更高的储能模量（G'）。流变温度扫描和打印测试确定最佳打印温度为20°C，该温度不受nHAp添加的影响。如振幅扫描测试所示，细胞封装在GelMA/nHAp或THA水凝胶中均未改变储能模量。使用钙黄绿素乙酰甲酯（Ca-AM）和碘化丙啶（EthD-1）染色的细胞活力检测显示，GelMA/nHAp和THA水凝胶中的细胞活力都很高。此外，RT-PCR和组织学分析分别证实了GelMA/nHAp和THA水凝胶中骨生成和软骨生成特性的维持。总之，我们开发了GelMA-nHAp和THA水凝胶来模拟骨和软骨成分，优化了3D打印参数，并确保了用于生物打印OC构建体的细胞活力。
