Biomedical Engineering, College of Engineering, Texas A&M University, College Station, TX, 77843, USA.
Material Science and Engineering, College of Engineering, Texas A&M University, College Station, TX, 77843, USA.
Adv Mater. 2021 Jun;33(23):e2101238. doi: 10.1002/adma.202101238. Epub 2021 May 3.
Light-responsive biomaterials are an emerging class of materials used for developing noninvasive, noncontact, precise, and controllable biomedical devices. Long-wavelength near-infrared (NIR) radiation is an attractive light source for in situ gelation due to its higher penetration depth and minimum side effects. The conventional approach to obtain crosslinked biomaterials relies heavily on the use of a photoinitiator by generating reactive species when exposed to short-wavelength radiation, which is detrimental to surrounding cells and tissue. Here, a new class of NIR-triggered in situ gelation system based on defect-rich 2D molybdenum disulfide (MoS ) nanoassemblies and thiol-functionalized thermoresponsive polymer in the absence of a photoinitiator is introduced. Exposure to NIR radiation activates the dynamic polymer-nanomaterials interactions by leveraging the photothermal characteristics of MoS and intrinsic phase transition ability of the thermoresponsive polymer. Specifically, upon NIR exposure, MoS acts as a crosslink epicenter by connecting with multiple polymeric chains via defect-driven click chemistry. As a proof-of-concept, the utility of NIR-triggered in situ gelation is demonstrated in vitro and in vivo. Additionally, the crosslinked gel exhibits the potential for NIR light-responsive release of encapsulated therapeutics. These light-responsive biomaterials have strong potential for a range of biomedical applications, including artificial muscle, smart actuators, 3D/4D printing, regenerative medicine, and therapeutic delivery.
光响应生物材料是一类新兴的材料，用于开发非侵入性、非接触式、精确可控的生物医学设备。长波长近红外 (NIR) 辐射是原位凝胶化的理想光源，因为它具有更深的穿透深度和最小的副作用。传统的获得交联生物材料的方法主要依赖于光引发剂的使用，当暴露于短波长辐射时会产生反应性物质，这对周围的细胞和组织有害。在这里，介绍了一种新型的基于富含缺陷的二维二硫化钼 (MoS ) 纳米组装体和巯基功能化的热响应聚合物的 NIR 触发原位凝胶化系统，无需光引发剂。NIR 辐射的照射通过利用 MoS 的光热特性和热响应聚合物的固有相转变能力来激活动态聚合物-纳米材料相互作用。具体来说，在 NIR 照射下，MoS 通过缺陷驱动的点击化学与多个聚合物链连接，充当交联中心点。作为概念验证，在体外和体内证明了 NIR 触发的原位凝胶化的实用性。此外，交联凝胶表现出对包封治疗药物的 NIR 光响应释放的潜力。这些光响应生物材料在包括人工肌肉、智能执行器、3D/4D 打印、再生医学和治疗药物输送在内的一系列生物医学应用中具有很强的潜力。
