Li Feiyang, Liu Yuan, Xu Yingqi, Li Yanqun, Liu Juan, Lv Minmin, Ruan Changshun, Pan Haobo, Zhao Xiaoli
Research Center for Human Tissues and Organs Degeneration, Institute of Biomedicine and Biotechnology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, 518055 Shenzhen, PR China.
Nano Science and Technology Institute, University of Science and Technology of China, 215123 Suzhou, PR China.
ACS Omega. 2020 Jul 31;5(31):19796-19804. doi: 10.1021/acsomega.0c02621. eCollection 2020 Aug 11.
Bone regeneration has attracted extensive attention in the field of regenerative medicine. The influence of biomaterial on the extracellular environment is important for regulating the biological functions of cells for tissue regeneration. Among the various influencing factors, we had previously demonstrated that the extracellular pH value in the local microenvironment during biomaterial degradation affected the balance of bone formation and resorption. However, there is a lack of techniques for conveniently detecting the pH of the extracellular environment. In light of the development of fluorescent pH-sensing probes, herein, we fabricated a novel ratiometric fluorescent microgel (F-MG) for real-time and spatiotemporal monitoring of microenvironment pH. F-MGs were prepared from polyurethane with a size of around 75 μm by loading with pH-sensitive bovine serum albumin nanoparticles (BNPs) and pH-insensitive Nile red as a reference. The pH probes exhibited reversible fluorescence response to pH change and worked in a linear range of 6-10. F-MGs were biocompatible and could be used for long-term pH detection. It could be used to map interfacial pH on biomaterials during their degradation through pseudocolored images formed by the fluorescence intensity ratio between the green fluorescence of BNPs and the red fluorescence of Nile red. This study provided a useful tool for studying the influence of biomaterial microenvironment on biological functions of surrounding cells.
骨再生在再生医学领域备受关注。生物材料对细胞外环境的影响对于调节组织再生中细胞的生物学功能至关重要。在各种影响因素中，我们之前已经证明生物材料降解过程中局部微环境的细胞外pH值会影响骨形成与吸收的平衡。然而，目前缺乏方便检测细胞外环境pH值的技术。鉴于荧光pH传感探针的发展，在此我们制备了一种新型比率荧光微凝胶（F-MG），用于实时和时空监测微环境pH值。F-MG由聚氨酯制成，尺寸约为75μm，通过负载pH敏感的牛血清白蛋白纳米颗粒（BNP）和pH不敏感的尼罗红作为参考物。该pH探针对pH变化表现出可逆的荧光响应，在6-10的线性范围内起作用。F-MG具有生物相容性，可用于长期pH检测。它可通过BNP的绿色荧光与尼罗红的红色荧光强度比形成的伪彩色图像，用于绘制生物材料降解过程中的界面pH值。本研究为研究生物材料微环境对周围细胞生物学功能的影响提供了一个有用的工具。
