State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Shanghai Engineering Research Center of Nano-Biomaterials and Regenerative Medicine, College of Biological Science and Medical Engineering, Donghua University, Shanghai 201620, China.
College of Chemistry and Chemical Engineering, Donghua University, Shanghai 201620, China.
ACS Appl Mater Interfaces. 2023 Mar 15;15(10):12809-12821. doi: 10.1021/acsami.2c22584. Epub 2023 Feb 28.
Immune checkpoint blockade (ICB) therapy has become a promising strategy in treating multiple tumor types, but the therapeutic efficacy is still unsatisfactory due to the temporary and inefficient blocking and the poor immune responsiveness. Herein, we report the development of dual reactive oxygen species (ROS)- and pH-responsive core-shell tecto dendrimers loaded with gold nanoparticles (for short, Au CSTDs) to deliver a plasmid-clustered regularly interspersed short palindromic repeats (CRISPR)/Cas9 system for the permanent disruption of the programmed death ligand 1 (PD-L1) gene in cancer cells to boost cancer immunotherapy. In our work, Au CSTDs were constructed using lactobionic acid (LA)-modified generation 5 poly(amidoamine) dendrimers entrapped with gold nanoparticles as cores and phenylboronic acid (PBA)-conjugated generation 3 dendrimers as shells the formation of responsive phenylborate ester bonds between PBA and LA. The plasmid-CRISPR/Cas9 system can be efficiently compacted and specifically taken up by cancer cells overexpressing sialic acids due to the PBA-mediated targeting and be responsively released in cancer cells by the responsive dissociation of the Au CSTDs, leading to the successful endosomal escape and the efficient knockout of the PD-L1 gene. Further delivery in a mouse melanoma model reveals that the developed Au CSTDs/plasmid-CRISPR/Cas9 complexes can be specifically accumulated at the tumor site for enhanced computed tomography (CT) imaging of tumors, owing to the X-ray attenuation effect of Au, and disrupt the PD-L1 expression in tumor cells, thus promoting the ICB-based antitumor immunity. The designed dual-responsive Au CSTDs may be developed as a versatile tool for genetic engineering of other cell types to achieve different therapeutic effects for expanded space of biomedical applications.
免疫检查点阻断（ICB）疗法已成为治疗多种肿瘤类型的有前途的策略，但由于阻断的暂时性和低效性以及免疫反应性差，治疗效果仍不尽人意。在此，我们报告了双重活性氧（ROS）和 pH 响应核壳 tecto 树枝状聚合物负载金纳米粒子（简称 Au CSTDs）的开发，用于递送质粒聚集的规则间隔短回文重复（CRISPR）/Cas9 系统，以永久性破坏癌细胞中的程序性死亡配体 1（PD-L1）基因，从而增强癌症免疫治疗。在我们的工作中，Au CSTDs 是使用乳酰酸（LA）修饰的第五代聚（酰胺胺）树枝状聚合物作为核心，负载金纳米粒子，并在其表面包裹苯硼酸（PBA）修饰的第三代树枝状聚合物形成的，其中 PBA 与 LA 之间形成了响应性的苯硼酸酯键。由于 PBA 介导的靶向作用，过表达唾液酸的癌细胞可以有效地浓缩和特异性摄取质粒-CRISPR/Cas9 系统，并且由于 Au CSTDs 的响应性解离，该系统可以在癌细胞中响应性释放，从而导致成功的内涵体逃逸和 PD-L1 基因的有效敲除。进一步在小鼠黑色素瘤模型中的递送表明，所开发的 Au CSTDs/质粒-CRISPR/Cas9 复合物可以特异性地积聚在肿瘤部位，用于增强肿瘤的计算机断层扫描（CT）成像，这是由于 Au 的 X 射线衰减效应，并且可以破坏肿瘤细胞中 PD-L1 的表达，从而促进基于 ICB 的抗肿瘤免疫。设计的双重响应性 Au CSTDs 可作为用于其他细胞类型的基因工程的通用工具，以实现扩展的生物医学应用空间中的不同治疗效果。
