Roy Chowdhury Sulob, Dey Krittika, Basu Bikramjit
Materials Research Centre, Indian Institute of Science, Bangalore 560012, India.
ACS Omega. 2025 May 2;10(18):18428-18443. doi: 10.1021/acsomega.4c10743. eCollection 2025 May 13.
In developing hydrogel scaffolds for the soft tissue regeneration, a number of inorganic or carbonaceous fillers are embedded in alginate/gelatin-based hydrogel while manufacturing shape fidelity compliant constructs using three-dimensional (3D) extrusion printing. Among the spectrum of nanofillers, nanohydroxyapatite (nHAP), due to its intrinsic bioactivity, could promote mineralization and interaction with host tissues while conferring superior mechanical properties (strength and elastic modulus). Against this backdrop, this study demonstrates the effectiveness of nHAP reinforcement in tuning several clinically relevant properties such as rheological properties, mechanical properties, swelling, degradation, and antimicrobial properties. At higher concentrations of nHAP (0.75%) in the hydrogel matrix (3A5G0.75H), a 3.13-fold increment in the compressive strength was observed, with the gel stability window and the thermal stability of the cross-linked graft being extended to greater than 40 and 143 °C, respectively. This study demonstrated the printability of the nHAP-reinforced hydrogel ink by fabricating the matrix-shaped graft of dimension 20 mm in diameter and 10 mm in thickness, and the buildability was established by making the bulk-sized construct up to 62 layers (20 mm in height) with a well-maintained pore interconnectivity, as demonstrated using micro-CT analysis. Interestingly, the CFU study revealed a 2.9- and 1.5-fold improvement in the reduction of bacterial adhesion for 3A5G0.75H with respect to and bacteria. Cell culture studies on the 3D printed scaffolds w.r.to NIH 3T3 fibroblast cell line demonstrated a consistent increase in cell viability and pronounced filopodial extensions, confirming the cytocompatibility of 3A5G0.75H scaffolds and their ability to support cellular growth during an culture. Taken together, the present study uncovers a process science-based understanding of the 3D buildability and biophysical properties of different concentrations of nHAP-reinforced hydrogel inks with clinically relevant properties.
在开发用于软组织再生的水凝胶支架时，在使用三维（3D）挤压打印制造形状保真的顺应性构建体的过程中，多种无机或碳质填料被嵌入藻酸盐/明胶基水凝胶中。在一系列纳米填料中，纳米羟基磷灰石（nHAP）因其固有的生物活性，可促进矿化以及与宿主组织的相互作用，同时赋予优异的机械性能（强度和弹性模量）。在此背景下，本研究证明了nHAP增强在调节多种临床相关特性（如流变学特性、机械性能、肿胀、降解和抗菌性能）方面的有效性。在水凝胶基质（3A5G0.75H）中nHAP浓度较高（0.75%）时，观察到抗压强度增加了3.13倍，交联接枝的凝胶稳定性窗口和热稳定性分别扩展到大于40℃和143℃。本研究通过制造直径20毫米、厚度10毫米的基质形状接枝，证明了nHAP增强水凝胶墨水的可打印性，并通过使用微型计算机断层扫描（micro-CT）分析表明，通过制造高达62层（高度20毫米）且孔隙互连性良好的块状构建体，确立了其可构建性。有趣的是，菌落形成单位（CFU）研究表明，相对于 和 细菌，3A5G0.75H在减少细菌粘附方面有2.9倍和1.5倍的改善。对3D打印支架针对NIH 3T3成纤维细胞系的细胞培养研究表明，细胞活力持续增加且丝状伪足明显延伸，证实了3A5G0.75H支架的细胞相容性及其在 培养期间支持细胞生长的能力。综上所述，本研究揭示了基于过程科学对不同浓度nHAP增强水凝胶墨水的3D可构建性和生物物理特性以及临床相关特性的理解。
