Britton Dustin, Sun Jonathan, Faizi Hammad Ali, Yin Ligeng, Gao Wei, Montclare Jin Kim
Department of Chemical and Biomolecular Engineering, New York University Tandon School of Engineering, Brooklyn, New York 11201, United States.
Department of Chemistry, New York University, New York, New York 10012, United States.
ACS Appl Polym Mater. 2024 Oct 8;6(20):12832-12841. doi: 10.1021/acsapm.4c02468. eCollection 2024 Oct 25.
Rheological modifiers are an important component in the development of skin cream (SC) chassis for personal skin care products (PSCPs). The viscous behavior of a PSCP is critical to its effectiveness where its uniformity and material strength impact its processing, storage, and delivery of active ingredients. Due to the mildly acidic environment of the skin, PSCPs require a SC that will assist in maintaining their material strength at low pHs. We have investigated a coiled-coil protein hydrogel system for the ability to possess pH-responsiveness, where physical cross-linking and material strength is controlled by pH relative to the isoelectric point (pI) of the protein. We recently designed a coiled-coil protein hydrogel variant, Q5, which possesses a relatively low pI that we hypothesized to have improved supramolecular assembly into a hydrogel at acidic conditions. We demonstrate that Q5 can retain a partial solution-to-gel transition at pH 6.0 and acts as a soft hydrogel by rheology. We further tested Q5 to act as a rheological modifier in a standard SC at pH 6.0 and pH 8.0 to test conditions mediated by pH changes in the skin environment. Q5 reveals the ability to uniquely increase material strength at low pH in comparison to a standard rheological modifier like hydroxyethyl cellulose (HEC), suggesting modular protein-based coiled-coil rheological modifiers can be used in PSCPs.
流变改性剂是个人护肤品（PSCPs）护肤霜（SC）底盘开发中的重要组成部分。PSCP的粘性行为对其有效性至关重要，其均匀性和材料强度会影响其活性成分的加工、储存和递送。由于皮肤呈弱酸性环境，PSCP需要一种能在低pH值下帮助维持其材料强度的SC。我们研究了一种卷曲螺旋蛋白水凝胶系统，以了解其具有pH响应性的能力，其中物理交联和材料强度由相对于蛋白质等电点（pI）的pH值控制。我们最近设计了一种卷曲螺旋蛋白水凝胶变体Q5，其pI相对较低，我们假设它在酸性条件下能改善超分子组装成水凝胶的过程。我们证明Q5在pH 6.0时能保留部分溶液到凝胶的转变，并通过流变学表现为一种软凝胶。我们进一步测试了Q5在pH 6.0和pH 8.0的标准SC中作为流变改性剂的作用，以测试由皮肤环境中的pH变化介导的条件。与羟乙基纤维素（HEC）等标准流变改性剂相比，Q5显示出在低pH值下独特增加材料强度的能力，这表明基于模块化蛋白质的卷曲螺旋流变改性剂可用于PSCPs。
