Erol Kadir, Alkan Mehmet Hüseyin, Alacabey İhsan
Department of Medical Services and Techniques, Vocational School of Health Services, Hitit University, 19030 Çorum, Turkey.
Department of Basic Pharmaceutical Sciences, Faculty of Pharmacy, Dicle University, 21280 Diyarbakır, Turkey.
Gels. 2025 Aug 12;11(8):634. doi: 10.3390/gels11080634.
Catalase is a pivotal antioxidant enzyme that decomposes hydrogen peroxide and reduces oxidative stress. However, its low thermal and operational stability limits applications in challenging environments, particularly those contaminated with emerging pollutants such as polystyrene-based microplastics (PS-MPs). In this study, cryogels composed of Poly(2-hydroxyethyl methacrylate-co-allyl glycidyl ether) [Poly(HEMA-co-AGE)] were synthesized and evaluated as immobilization matrices to enhance catalase stability. Cryogels containing varying AGE concentrations were characterized using FT-IR, SEM, TEM, TGA, and BET analyses. The formulation with 250 µL AGE exhibited optimal physicochemical properties, including improved water retention, increased surface area, and high immobilization capacity (356.3 mg·g). Immobilized catalase maintained superior activity under PS-MP-induced stress across a range of concentrations (0-1.0 mg·mL), temperatures (4-60 °C), and exposure times (up to 5 h). Kinetic modeling revealed a significant improvement in substrate affinity, with Km decreasing from 54.9 to 17.1 mM, while Vmax decreased moderately. Long-term stability tests showed that immobilized catalase retained ~80% activity after 70 days at 4 °C and 55% after 15 reuse cycles. Desorption studies confirmed the reusability of the cryogel system. These findings suggest that Poly(HEMA-co-AGE) cryogels provide a robust and reusable platform for catalase stabilization, offering potential for applications such as wastewater treatment and biosensing in microplastic-contaminated systems.
过氧化氢酶是一种关键的抗氧化酶，可分解过氧化氢并减轻氧化应激。然而，其较低的热稳定性和操作稳定性限制了它在具有挑战性的环境中的应用，特别是那些被新兴污染物如聚苯乙烯基微塑料（PS-MPs）污染的环境。在本研究中，合成了由聚（甲基丙烯酸2-羟乙酯-co-烯丙基缩水甘油醚）[聚（HEMA-co-AGE）]组成的冷冻凝胶，并将其作为固定化基质进行评估，以提高过氧化氢酶的稳定性。使用傅里叶变换红外光谱（FT-IR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、热重分析（TGA）和比表面积分析（BET）对含有不同AGE浓度的冷冻凝胶进行了表征。含有250 μL AGE的配方表现出最佳的物理化学性质，包括改善的保水性、增加的表面积和高固定化容量（356.3 mg·g）。固定化过氧化氢酶在一系列浓度（0-1.0 mg·mL）、温度（4-60 °C）和暴露时间（长达5小时）的PS-MP诱导应激下保持了优异的活性。动力学建模显示底物亲和力有显著提高，Km从54.9 mM降至17.1 mM，而Vmax适度下降。长期稳定性测试表明，固定化过氧化氢酶在4 °C下70天后保留了约80%的活性，在15次重复使用循环后保留了55%的活性。解吸研究证实了冷冻凝胶系统的可重复使用性。这些发现表明，聚（HEMA-co-AGE）冷冻凝胶为过氧化氢酶的稳定化提供了一个强大且可重复使用的平台，在微塑料污染系统中的废水处理和生物传感等应用方面具有潜力。
