Li Hui, Meng Fengzhen, Hu Chengwei, Wu Zhiyun, Hao Liuzhi, Sun Caijun, Fang Lijing, Pan Fan, Bian Shaoquan, Li Huipeng, Li Mingjun, Liu Bo, Zhao Xiaoli
Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, P. R China.
Institute of clinical translation and regenerative medicine, People's Hospital of Baoan District, The Second Affiliated Hospital of Shenzhen University, Shenzhen, 518101, P. R China.
Adv Sci (Weinh). 2025 Aug;12(30):e2500833. doi: 10.1002/advs.202500833. Epub 2025 May 2.
The microneedle, a minimally invasive transdermal system, provides a convenient and painless method for drug delivery. Among the various types of microneedles, hydrogel-forming microneedles (HFMs) demonstrate distinct advantages in terms of high-dose drug loading and biocompatibility. However, HFMs usually require drying to obtain sufficient puncture strength, which may destroy drug activity and increase storage costs. Herein, a high-strength HFM patch with pH-responsiveness for post-drug loading and long-term release is developed based on acrylonitrile-acrylic acid copolymer. The dipole-dipole and hydrogen bonding interactions formed through gradient solvent replacement are evenly distributed within the cross-linked network, significantly enhancing the mechanical properties of the hydrogel required for epidermal penetration. The prepared hydrogel exhibits a tensile strength of 26 MPa and a Young's modulus of 407 MPa. The microneedles formed from this hydrogel display a single needle mechanical force of 1.18 N. The post-loading mode conferred by pH responsiveness allows the drug to be encapsulated in both the tips and the substrate, acting as a reservoir. Once applied to the skin, the microneedle is activated by body fluids to achieve long-term drug release. Overall, this high-strength HFM improves the mechanical properties in the hydrated state, making it a promising minimally invasive transdermal delivery platform.
微针作为一种微创透皮给药系统，为药物递送提供了一种便捷且无痛的方法。在各类微针中，水凝胶形成微针（HFMs）在高剂量药物负载和生物相容性方面展现出显著优势。然而，HFMs通常需要干燥以获得足够的穿刺强度，这可能会破坏药物活性并增加储存成本。在此，基于丙烯腈-丙烯酸共聚物开发了一种具有pH响应性的高强度HFMs贴片，用于药物后负载和长期释放。通过梯度溶剂置换形成的偶极-偶极相互作用和氢键相互作用均匀分布在交联网络中，显著增强了表皮穿透所需水凝胶的机械性能。制备的水凝胶表现出26MPa的拉伸强度和407MPa的杨氏模量。由这种水凝胶制成的微针单针机械力为1.18N。pH响应赋予的后负载模式使药物能够包封在针尖和基底中，起到储库的作用。一旦应用于皮肤，微针被体液激活以实现药物的长期释放。总体而言，这种高强度HFMs在水合状态下改善了机械性能，使其成为一种有前景的微创透皮给药平台。
