京尼平交联对罗非鱼皮胶原纤维水凝胶结构和性能的影响

Effect of Genipin Crosslinking on the Structure and Properties of Tilapia Skin Collagen Fibrillar Hydrogels

摘要: 近年来，罗非鱼皮胶原蛋白在生物材料及组织工程领域的研究日益受到关注，但其较差的机械性能严重限制了其实际应用。为改善胶原纤维水凝胶的结构与力学性能，本研究引入不同浓度的京尼平对其进行交联改性。结果表明，京尼平对水凝胶的交联度呈浓度依赖性，当京尼平浓度达到8 mM时，交联反应趋于平衡。通过衰减全反射傅里叶变换红外光谱以及扫描电镜等分析技术分析表明，京尼平与胶原纤维间通过共价键相互作用，促使水凝胶网络致密化，纤维直径减小。进一步研究发现，京尼平交联降低了水凝胶的孔隙率，提高了其表面亲水性、机械强度及溶胀性能。未交联水凝胶的最大压缩强度为23.32 kPa，当京尼平浓度为6 mM时，强度提高至28.14 kPa (相对增幅20.58%)，之后趋于稳定；未交联水凝胶的保水率为281.97%，当京尼平浓度为10 mM时，提高至1740.31% (绝对提高1458.34个百分点，相对增幅517.20%)。本研究为改善水产胶原基生物材料的性能提供了有效的实验依据。

Abstract: In recent years, collagen derived from tilapia skin has attracted increasing attention in the fields of biomaterials and tissue engineering; however, its poor mechanical properties severely limit its practical application. To improve the structural and mechanical performance of the collagen fibrillar hydrogel, different concentrations of genipin were introduced for crosslinking modification. The results showed that the crosslinking degree of the hydrogel was dependent on the genipin concentration, and the crosslinking reaction reached equilibrium when the genipin concentration reached 8 mM. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) analyses revealed that genipin interacted with collagen fibers through covalent bonds, leading to densification of the hydrogel network and a reduction in fiber diameter. Further investigations demonstrated that genipin crosslinking decreased the porosity of the hydrogel while improving its surface hydrophilicity, mechanical strength, and swelling properties. The maximum compressive strength of the uncross-linked hydrogel was 23.32 kPa; upon treatment with 6 mM genipin, the strength increased to 28.14 kPa (a relative increase of 20.58%) and subsequently plateaued. The water retention rate of the uncross-linked hydrogel was 281.97%, whereas after cross-linking with 10 mM genipin, it rose to 1740.31% (an absolute increase of 1458.34 percentage points, corresponding to a relative increase of 517.20%). This study provides a solid experimental basis for improving the properties of aquatic collagen-based biomaterials.