Bioorthogonal Reaction-Mediated Tumor-Selective Delivery of CRISPR/Cas9 System for Dual-Targeted Cancer Immunotherapy.

CRISPR system-assisted immunotherapy is an attractive option in cancer therapy. However, its efficacy is still less than expected due to the limitations in delivering the CRISPR system to target cancer cells. Here, we report a new CRISPR/Cas9 tumor-targeting delivery strategy based on bioorthogonal reactions for dual-targeted cancer immunotherapy. First, selective in vivo metabolic labeling of cancer and activation of the cGAS-STING pathway was achieved simultaneously through tumor microenvironment (TME)-biodegradable hollow manganese dioxide (H-MnO2 ) nano-platform. Subsequently, CRISPR/Cas9 system-loaded liposome was accumulated within the modified tumor tissue through in vivo click chemistry, resulting in the loss of protein tyrosine phosphatase N2 (PTPN2) and further sensitizing tumors to immunotherapy. Overall, our strategy provides a modular platform for precise gene editing in vivo and exhibits potent antitumor response by boosting innate and adaptive antitumor immunity.

DNAzyme-Assisted Nano-Herb Delivery System for Multiple Tumor Immune Activation.

As a promising therapeutic strategy against cancer, immunotherapy faces critical challenges, especially in solid tumors. Immune checkpoint blockade therapy, particularly blocking the interaction of the programmed cell death 1 (PD1)-PD1 ligand 1 (PD-L1) axis, can reverse the suppression of T cells so as to destroy tumor cells and exert antitumor effects. Here, a strategy of multiple activation of immune pathways is developed, to provide supporting evidence for potential antitumor therapies. Briefly, a pH/glutathione responsive drug-loading hollow-manganese dioxide (H-MnO2 )-based chlorine6 (Ce6)-modified DNAzyme therapeutic nanosystem for the combination of gene therapy and immunotherapy is established. The H-MnO2 nanoparticles could efficiently deliver the DNAzyme and glycyrrhizic acid (GA) to enhance the tumor target effects. In the tumor microenvironments, the biodegradation of H-MnO2 via pH-induced hydrolyzation allows the release of guest DNAzyme payloads and host Mn2+ ions, which serve as PD-L1 mRNA-targeting reagent and require DNAzyme cofactors for activating gene therapy. In addition, Mn2+ is also associated with the immune activation of thcGAS-STING pathway. Auxiliary photosensitizers Ce6 and GA could produce reactive oxygen species, resulting in immunogenic cell death. Overall, this study provides a general strategy for targeted gene inhibition and GA release, which is valuable for the development of potential tumor immunotherapies.

Engineered bacterial membrane vesicle as safe and efficient nano-heaters to reprogram tumor microenvironment for enhanced immunotherapy.

The immunosuppressive tumor microenvironment (TME) in solid tumors often impedes the efficacy of immunotherapy. Bacterial outer membrane vesicles (OMVs), as a promising cancer vaccine that can potently stimulate immune responses, have garnered interest as a potential platform for cancer therapy. However, the low yield of OMVs limits their utilization. To address this limitation, we developed a novel approach to synthesize OMV-like multifunctional synthetic bacterial vesicles (SBVs) by pretreating bacteria with ampicillin and lysing them through sonication. Compared to OMVs, the yield of SBVs increased by 40 times. Additionally, the unique synthesis process of SBVs allows for the encapsulation of bacterial intracellular contents, endowing SBVs with the capability of delivering catalase (CAT) for tumor hypoxia relief and activating the host cyclic GMP-AMP synthase (cGAS)/stimulator of interferon genes (STING) signaling pathway. To overcome the toxicity of lipopolysaccharide (LPS) on the SBVs surface, we decorated SBVs with a biocompatible polydopamine (PDA) shell, which allowed TME reprogramming using SBVs to be conducted without adverse side effects. Additionally, the photosensitizer indocyanine green (ICG) was loaded into the PDA shell to induce immunogenic cell death and further improve the efficacy of immunotherapy. In summary, the SBVs-based therapeutic platform SBV@PDA/ICG (SBV@P/I) can synergistically elicit safe and potent tumor-specific antitumor responses through combined immunotherapy and phototherapy.

Intelligent nanotherapeutic strategies for the delivery of CRISPR system.

CRISPR, as an emerging gene editing technology, has been widely used in multiple fields due to its convenient operation, less cost, high efficiency and precision. This robust and effective device has revolutionized the development of biomedical research at an unexpected speed in recent years. The development of intelligent and precise CRISPR delivery strategies in a controllable and safe manner is the prerequisite for translational clinical medicine in gene therapy field. In this review, the therapeutic application of CRISPR delivery and the translational potential of gene editing was firstly discussed. Critical obstacles for the delivery of CRISPR system in vivo and shortcomings of CRISPR system itself were also analyzed. Given that intelligent nanoparticles have demonstrated great potential on the delivery of CRISPR system, here we mainly focused on stimuli-responsive nanocarriers. We also summarized various strategies for CIRSPR-Cas9 system delivered by intelligent nanocarriers which would respond to different endogenous and exogenous signal stimulus. Moreover, new genome editors mediated by nanotherapeutic vectors for gene therapy were also discussed. Finally, we discussed future prospects of genome editing for existing nanocarriers in clinical settings.

Accurate delivery of pristimerin and paclitaxel by folic acid-linked nano-micelles for enhancing chemosensitivity in cancer therapy.

Chemoresistance remains a huge challenge for effective treatment of non-small cell lung cancer (NSCLC). Previous studies have shown Chinese herbal extracts possess great potential in ameliorating tumor chemoresistance, however, the efficacy is clinically limited mainly because of the poor tumor-targeting and in vivo stability. The construction of nano-delivery systems for herbal extracts has been shown to improve drug targeting, enhance therapeutic efficacy and reduce toxic and side effects. In this study, a folic acid (FA)-modified nano-herb micelle was developed for codelivery of pristimerin (PRI) and paclitaxel (PTX) to enhance chemosensitivity of NSCLC, in which PRI could synergistically enhance PTX-induced growth inhibition of A549 cancer cell. PTX was firstly grafted with the FA-linked polyethylene glycol (PEG) and then encapsulated with PRI to construct the PRI@FA-PEG-PTX (P@FPP) nano-micelles (NMs), which exhibited improved tumor-targeting and in vivo stability. This active-targeting P@FPP NMs displayed excellent tumor-targeting characteristics without obvious toxicity. Moreover, inhibition of tumor growth and metastasis induced by P@FPP NMs were significantly enhanced compared with the combined effects of the two drugs (PRI in combination of PTX), which associated with epithelial mesenchymal transition inhibition to some extent. Overall, this active-targeting NMs provides a versatile nano-herb strategy for improving tumor-targeting of Chinese herbal extracts, which may help in the promotion of enhancing chemosensitivity of NSCLC in clinical applications.