Leng Yokly, Britten Collin N, Tarannum Fatema, Foley Kayla, Billings Christopher, Liu Yingtao, Walters Keisha B
School of Chemical, Materials, and Biological Engineering, University of Oklahoma, Norman, Oklahoma 73019, United States.
Ralph E. Martin Department of Chemical Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States.
ACS Omega. 2024 Aug 28;9(36):37687-37701. doi: 10.1021/acsomega.4c02475. eCollection 2024 Sep 10.
Phosphorus-based stimuli-responsive hydrogels have potential in a wide range of applications due to their ionizable phosphorus groups, biocompatibility, and tunable swelling capacity utilizing hydrogel design parameters and external stimuli. In this study, poly(2-methacryloyloxyethyl phosphate) (PMOEP) hydrogels were synthesized via aqueous activators regenerated by electron transfer atomic transfer radical polymerization using ascorbic acid as the reducing agent. Swelling and deswelling behaviors of PMOEP hydrogels were examined in different salt solutions, pH conditions, and temperatures. The degree of swelling in salt solutions followed CaCl < MgCl < KCl < NaCl with a decrease in swelling rate at higher concentrations until reaching a saturation point. In water, the degree of swelling increased significantly around neutral pH and remained constant at basic pH values. The effects of polymerization conditions, including pH, temperature (30, 40, 50 °C), and MOEP concentration (40, 50, 60% v/v MOEP/HO), on the hydrogel swelling behavior in various salt solutions were also investigated. PMOEP hydrogels showed a decrease in the degree of swelling as the pH was increased above the native pH of the monomer solution. Scanning electron microscopy and energy-dispersive spectroscopy were utilized to examine the microstructure and chemical composition of the dried hydrogel after salt solution swelling. Cytotoxicity testing using rat bone marrow stem cells confirmed the biocompatibility of the PMOEP hydrogels. A unique feature of this effort was evaluation of these phosphate hydrogels for use in expansion microscopy where a significant twofold enhancement in cellular expansion capacity was showcased utilizing 4T1 mouse breast cancer cells. This comprehensive study provides valuable insights into the stimuli-responsive behavior and expansion characteristics of phosphate hydrogels, highlighting their potential in diverse biomedical applications.
基于磷的刺激响应水凝胶由于其可电离的磷基团、生物相容性以及利用水凝胶设计参数和外部刺激的可调溶胀能力，在广泛的应用中具有潜力。在本研究中，以抗坏血酸为还原剂，通过电子转移原子转移自由基聚合再生的水性活化剂合成了聚（2-甲基丙烯酰氧基乙基磷酸酯）（PMOEP）水凝胶。研究了PMOEP水凝胶在不同盐溶液、pH条件和温度下的溶胀和去溶胀行为。盐溶液中的溶胀度遵循CaCl＜MgCl＜KCl＜NaCl，在较高浓度下溶胀率降低，直至达到饱和点。在水中，溶胀度在中性pH附近显著增加，在碱性pH值下保持恒定。还研究了聚合条件，包括pH、温度（30、40、50℃）和MOEP浓度（40、50、60% v/v MOEP/HO）对各种盐溶液中水凝胶溶胀行为的影响。当pH值高于单体溶液的天然pH值时,PMOEP水凝胶的溶胀度降低。利用扫描电子显微镜和能量色散光谱研究了盐溶液溶胀后干燥水凝胶的微观结构和化学成分。使用大鼠骨髓干细胞进行的细胞毒性测试证实了PMOEP水凝胶的生物相容性。这项工作的一个独特之处是评估了这些磷酸盐水凝胶在膨胀显微镜中的应用，其中利用4T1小鼠乳腺癌细胞展示了细胞膨胀能力显著提高两倍。这项全面的研究为磷酸盐水凝胶的刺激响应行为和膨胀特性提供了有价值的见解，突出了它们在各种生物医学应用中的潜力。
