Collagen nanofibers can be employed in hydrogels to create injectable nanocomposite hydrogels, mimicking the fibrous architecture of the natural extracellular matrix (ECM). As long continuous electrospun collagen nanofibers are not applicable, fragmentation is inevitable to obtain injectable hydrogels with a fine viscosity. Here, four methods: hand grinding (HG), homogenizer (HM), mixer milling (MM), and ultrasonication (UH) are used to disintegrate and shorten collagen nanofiber mats before incorporation into an injectable hyaluronic acid hydrogel as a matrix. The Length‐to‐diameter (L/d) ratio and morphology of fragmented collagen are compared by SEM. The injection force, mechanical properties, and cell viability of the selected collagen‐incorporated hydrogels are also evaluated. UH emerges as the most effective method, yielding the highest L/d ratio of 46 and a notable compressive modulus of 8.7 ± 0.92 kPa. Assessment of the in vitro cell viability of the encapsulated chondrocytes in the collagen‐incorporated hydrogels demonstrates good biocompatibility, and hydrogels containing UH short nanofiber, in particular, show an increase in cell proliferation. This work indicates how collagen mats can be effectively broken down and combined with injectable hydrogels to enhance both their mechanical behavior and biocompatibility.

中文翻译：

---

用于注射水凝胶的短胶原纳米纤维的制备：断裂方法、物理力学性能和生物相容性的比较评估

胶原纳米纤维可用于水凝胶中，以制造可注射的纳米复合水凝胶，模仿天然细胞外基质（ECM）的纤维结构。由于不适用长的连续静电纺丝胶原纳米纤维，为了获得具有良好粘度的可注射水凝胶，碎裂是不可避免的。在这里，使用四种方法：手动研磨（HG）、均质器（HM）、混合研磨（MM）和超声处理（UH）来分解和缩短胶原纳米纤维垫，然后将其掺入可注射透明质酸水凝胶作为基质。长度与直径的比（L/d) 通过 SEM 比较碎片胶原蛋白的比例和形态。还评估了所选胶原蛋白水凝胶的注射力、机械性能和细胞活力。UH 成为最有效的方法，产量最高L/d比率为 46，压缩模量为 8.7 ± 0.92 kPa。对掺有胶原蛋白的水凝胶中封装的软骨细胞的体外细胞活力的评估显示出良好的生物相容性，特别是含有 UH 短纳米纤维的水凝胶显示出细胞增殖的增加。这项工作表明如何有效分解胶原蛋白垫并与可注射水凝胶结合，以增强其机械行为和生物相容性。