To date the low mechanical strength and high swelling rate of gelatin‐based products have limited their use toward many tissue engineering targets. Here a new approach to tuning methacrylated gelatin (GelMA) properties involving the carbodiimide coupling of polyethylene glycol (PEG) to the GelMA molecule is investigated. PEGylation improves the capacity of the solution to flow and reduces hydrogel swelling, while in composite form with nano‐hydroxyapatite (nHA) particles there is no impact on swelling. Differential scanning calorimetry (DSC) reveals that PEGylation likely restores some of the triple helical nature of gelatin to the GelMA and increases steric hindrance. Furthermore, triethyleneglycol dimethacrylate inclusion in GelMA‐PEG composites is able to address the loss in dynamic stiffness reported as a result of PEGylation. Altogether PEGylated GelMA shows evidence of reduced interaction with water compared to control GelMA, whether alone or in composite form. By tuning this interaction and reducing the volume of water necessary to solvate GelMA, the potential to use GelMA composites for a variety of tissue engineering applications is greatly improved.

中文翻译：

---

碳二亚胺偶联方法使GelMA聚乙二醇化并进一步调节GelMA复合材料的性能

迄今为止，基于明胶的产品的低机械强度和高溶胀率已将其限制用于许多组织工程目标。在这里，研究了一种新的方法来调节甲基丙烯酸明胶（GelMA）的性能，其中涉及到聚乙二醇（PEG）与GelMA分子的碳二亚胺偶联。聚乙二醇化可提高溶液的流动能力并减少水凝胶溶胀，而与纳米羟基磷灰石（nHA）颗粒形成复合形式时，对溶胀没有影响。差示扫描量热法（DSC）显示，聚乙二醇化可能会恢复明胶对GelMA的某些三重螺旋性质，并增加空间位阻。此外，GelMA-PEG复合材料中包含的三乙二醇二甲基丙烯酸酯能够解决因PEG化而导致的动态刚度损失。总的来说，与对照GelMA相比，无论是单独还是复合形式，PEG化GelMA均显示出与水相互作用减少的证据。通过调节这种相互作用并减少溶剂化GelMA所需的水量，大大提高了将GelMA复合材料用于各种组织工程应用的潜力。