Suitable material for scaffolds that support cell attachment, proliferation, vascularization and contraction has always been a challenge in myocardial tissue engineering. Much research effort has been focused on natural polymers including collagen, gelatin, chitosan, fibrin, alginate, etc. Among them, a collagen/chitosan composite scaffold was widely used for myocardial tissue engineering. Due to the non-proliferative and contractile characteristics of cardiomyocytes, the biocompatibility and mechanical properties of the scaffolds are extremely important for supporting intercellular connection and tissue function for myocardial tissue engineering. To the best of our knowledge, the three crosslinking agents (glutaraldehyde (GTA), genipin (GP), tripolyphosphate (TPP)) have not yet been comparatively studied in myocardial tissue engineering. Thus, the aim of this study is to compare and identify the crosslinking effect of GTA, GP and TPP for myocardial tissue engineering. The collagen/chitosan scaffolds prepared with various crosslinking agents were fabricated and evaluated for physical characteristics, biocompatibility and contractile performance. All the groups of scaffolds exhibited high porosity (>65%) and good swelling ratio suitable for myocardial tissue engineering. TPP crosslinked scaffolds showed excellent mechanical properties, with their elastic modulus (81.0 ± 8.1 kPa) in the physiological range of native myocardium (20∼100 kPa). Moreover, GP and TPP crosslinked scaffolds exhibited better biocompatibility than GTA crosslinked scaffolds, as demonstrated by the live/dead staining and proliferation assay. In addition, cardiomyocytes within TPP crosslinked scaffolds showed the highest expression of cardiac-specific marker protein and the best contractile performance. To conclude, of the three crosslinking agents, TPP was recommended as the most suitable crosslinking agent for collagen/chitosan scaffold in myocardial tissue engineering.

中文翻译：

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用于心肌组织工程的胶原/壳聚糖支架上的各种交联剂的评估。

支持细胞附着、增殖、血管化和收缩的合适支架材料一直是心肌组织工程中的一个挑战。许多研究工作集中在天然聚合物上，包括胶原蛋白、明胶、壳聚糖、纤维蛋白、海藻酸盐等。其中，胶原蛋白/壳聚糖复合支架被广泛用于心肌组织工程。由于心肌细胞的非增殖和收缩特性，支架的生物相容性和力学性能对于支持心肌组织工程的细胞间连接和组织功能极其重要。据我们所知，三种交联剂（戊二醛（GTA）、京尼平（GP）、三聚磷酸盐（TPP））尚未在心肌组织工程中进行比较研究。因此，本研究的目的是比较和鉴定GTA、GP和TPP对心肌组织工程的交联作用。制备了用各种交联剂制备的胶原/壳聚糖支架，并对其物理特性、生物相容性和收缩性能进行了评估。所有组支架均表现出高孔隙率（>65%）和良好的溶胀比，适合心肌组织工程。TPP交联支架表现出优异的力学性能，其弹性模量（81.0±8.1 kPa）处于天然心肌的生理范围（20∼100 kPa）内。此外，活/死染色和增殖测定证明，GP和TPP交联支架比GTA交联支架表现出更好的生物相容性。此外，TPP交联支架内的心肌细胞表现出最高的心脏特异性标记蛋白表达和最好的收缩性能。总之，在三种交联剂中，TPP被推荐作为心肌组织工程中胶原/壳聚糖支架最合适的交联剂。