İzmir Institute of Technology, Department of Bioengineering, İzmir 35433, Turkey.
Institute of Biomaterials, Department of Material Science and Engineering, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen 91058, Germany.
Biofabrication. 2024 Mar 13;16(2). doi: 10.1088/1758-5090/ad2c98.
One of the key challenges in biofabrication applications is to obtain bioinks that provide a balance between printability, shape fidelity, cell viability, and tissue maturation. Decellularization methods allow the extraction of natural extracellular matrix, preserving tissue-specific matrix proteins. However, the critical challenge in bone decellularization is to preserve both organic (collagen, proteoglycans) and inorganic components (hydroxyapatite) to maintain the natural composition and functionality of bone. Besides, there is a need to investigate the effects of decellularized bone (DB) particles as a tissue-based additive in bioink formulation to develop functional bioinks. Here we evaluated the effect of incorporating DB particles of different sizes (≤45 and ≤100m) and concentrations (1%, 5%, 10% (wt %)) into bioink formulations containing gelatin (GEL) and pre-osteoblasts (MC3T3-E1) or human mesenchymal stem cells (hTERT-MSCs). In addition, we propose a minimalistic bioink formulation using GEL, DB particles and cells with an easy preparation process resulting in a high cell viability. The printability properties of the inks were evaluated. Additionally, rheological properties were determined with shear thinning and thixotropy tests. The bioprinted constructs were cultured for 28 days. The viability, proliferation, and osteogenic differentiation capacity of cells were evaluated using biochemical assays and fluorescence microscopy. The incorporation of DB particles enhanced cell proliferation and osteogenic differentiation capacity which might be due to the natural collagen and hydroxyapatite content of DB particles. Alkaline phosphatase activity is increased significantly by using DB particles, notably, without an osteogenic induction of the cells. Moreover, fluorescence images display pronounced cell-material interaction and cell attachment inside the constructs. With these promising results, the present minimalistic bioink formulation is envisioned as a potential candidate for bone tissue engineering as a clinically translatable material with straightforward preparation and high cell activity.
生物制造应用中的一个关键挑战是获得在可印刷性、形状保真度、细胞活力和组织成熟度之间取得平衡的生物墨水。脱细胞方法允许提取天然细胞外基质，保留组织特异性基质蛋白。然而，骨脱细胞化的关键挑战是保留有机（胶原、蛋白聚糖）和无机成分（羟磷灰石），以维持骨的天然组成和功能。此外，需要研究脱细胞骨（DB）颗粒作为组织添加剂在生物墨水配方中的作用，以开发功能性生物墨水。在这里，我们评估了不同大小（≤45 和≤100m）和浓度（1%、5%、10%（wt%））的 DB 颗粒掺入包含明胶（GEL）和前成骨细胞（MC3T3-E1）或人间充质干细胞（hTERT-MSCs）的生物墨水配方中的效果。此外，我们提出了一种使用 GEL、DB 颗粒和细胞的最小化生物墨水配方，具有简单的制备过程，可实现高细胞活力。评估了墨水的可印刷性特性。此外，通过剪切变稀和触变测试确定了流变特性。将生物打印构建体培养 28 天。使用生化测定和荧光显微镜评估细胞的活力、增殖和成骨分化能力。DB 颗粒的掺入增强了细胞增殖和成骨分化能力，这可能是由于 DB 颗粒中天然胶原和羟磷灰石的含量。碱性磷酸酶活性显著增加，特别是在没有细胞成骨诱导的情况下。此外，荧光图像显示出明显的细胞-材料相互作用和细胞在构建体内的附着。鉴于这些有希望的结果，目前的最小化生物墨水配方有望成为骨组织工程的潜在候选物，作为一种具有临床转化潜力的材料，具有简单的制备和高细胞活性。
