BODIPY Photocage-Enabled Visualization and Optical Control of saRNA Delivery and Immunogenicity

在持续的SARS-CoV-2大流行期间，基于rna的疫苗由于其增强的免疫反应和无细胞制造，已成为传统疫苗接种方法的一种有效且经济的替代方法。然而，RNA固有的单链特性常常导致化学不稳定性，从而降低了效率。规避这个问题的一种方法是使用先进的递送策略，这种策略可以稳定RNA结构，并允许有效的体内递送和释放。本提案的目的是通过将近红外光激活的BODIPY光笼（Bpc）集成到负载RNA的阳离子聚合物中，开发一种光响应和荧光自我报告的RNA递送系统。在目前的设计中，Bpc既可以作为发光的自我报告装置，也可以作为光敏装置。Bpc发射将允许对纳米载体分布进行实时监测，光笼过程将允许使用光按需释放负载的RNA。为了进一步探索这个递送平台，我还将研究硝基功能化Bpc （BpcNO2）的递送和控释特性，其光依赖性荧光变化可以作为量化RNA释放量的内部指标。这项工作的成功将提供1)一种新颖、直接和生物相容性的策略来构建近红外光响应和荧光可追踪的RNA递送系统，该系统能够保持RNA的结构完整性并确保RNA的翻译效率；2)一种化学生物学工具来探测免疫原性RNA的体内分布和调节剂量。

RNA-based vaccines because of their enhanced immune response and cell-free manufacturing have become a potent and economical alternative to conventional vaccination approaches during the ongoing SARS-CoV-2 pandemic. The intrinsic single-stranded nature of RNA, however, oftentimes results in chemical instability and thus attenuated efficiency. One way to circumvent this issue is to use advanced delivery strategies which can stabilize RNA structures as well as allow efficient in vivo delivery and release. The objective of this proposal is to develop a light-responsive and fluorescent self-reporting RNA delivery system through integrating NIR light activated BODIPY photocages (Bpc) into RNA-loaded cationic polymers. In the current design, Bpc function both as the emissive self-reporters and photosensitive units. The Bpc emission will allow for real-time monitoring of the nanocarrier distribution and the photocaging process will enable on-demand release of the loaded RNA using light. To further explore this delivery platform, I will also investigate the delivery and controlled release properties of the nitro-functionalized Bpc (BpcNO2), the light-dependent fluorescence change of which can serve as an internal indicator to quantify the amount of released RNA. The success of the proposed work will offer 1) a novel, straightforward and biocompatible strategy to construct NIR light responsive and fluorescence traceable RNA delivery systems which are capable of maintaining the structural integrity and ensuring the translational efficiency of RNAs and 2) a chemical biology tool to probe the in vivo distribution and modulate the dose of immunogenic RNAs.