Dynamic tagging to drive arginine nano-assembly to metabolically potentiate immune checkpoint blockade therapy

Nanomedicine Targeting Myeloid-Derived Suppressor Cells Enhances Anti-Tumor Immunity

Cancer immunotherapy, a field within immunology that aims to enhance the host's anti-cancer immune response, frequently encounters challenges associated with suboptimal response rates. The presence of myeloid-derived suppressor cells (MDSCs), crucial constituents of the tumor microenvironment (TME), exacerbates this issue by fostering immunosuppression and impeding T cell differentiation and maturation. Consequently, targeting MDSCs has emerged as crucial for immunotherapy aimed at enhancing anti-tumor responses. The development of nanomedicines specifically designed to target MDSCs aims to improve the effectiveness of immunotherapy by transforming immunosuppressive tumors into ones more responsive to immune intervention. This review provides a detailed overview of MDSCs in the TME and current strategies targeting these cells. Also the benefits of nanoparticle-assisted drug delivery systems, including design flexibility, efficient drug loading, and protection against enzymatic degradation, are highlighted. It summarizes advances in nanomedicine targeting MDSCs, covering enhanced treatment efficacy, safety, and modulation of the TME, laying the groundwork for more potent cancer immunotherapy.

Arginine-assembly as NO nano-donor prevents the negative feedback of macrophage repolarization by mitochondrial dysfunction for cancer immunotherapy

Repolarizing the tumor-associated macrophages (TAMs) towards the antitumoral M1-like phenotype has been a promising approach for cancer immunotherapy. However, the anti-cancer immune response is severely limited mainly by the repolarized M1-like macrophages belatedly returning to the M2-like phenotype (i.e., negative feedback). Inspired by nitric oxide (NO) effectively preventing repolarization of inflammatory macrophages in inflammatory diseases, herein, we develop an arginine assembly, as NO nano-donor for NO generation to prevent the negative feedback of the macrophage repolarization. The strategy is to first apply reversible tagging of hydrophobic terephthalaldehyde to create an arginine nano-assembly, and then load a toll-like receptor 7/8 agonist resiquimod (R848) (R848@Arg). Through this strategy, a high loading efficiency of 40 % for the arginine and repolarization characteristics for TAMs can be achieved. Upon the macrophage repolarization by R848, NO can be intracellularly generated from the released arginine by the upregulated inducible nitric oxide synthase. Mechanistically, NO effectively prevented the negative feedback of the repolarized macrophage by mitochondrial dysfunction via blocking oxidative phosphorylation. Notably, R848@Arg significantly increased the tumor inhibition ratio by 3.13-fold as compared to the free R848 by maintaining the M1-like phenotype infiltrating into tumor. The Arg-assembly as NO nano-donor provides a promising method for effective repolarization of macrophages.

Intelligent Delivery Systems in Tumor Metabolism Regulation: Exploring the Path Ahead

Cancer metabolism plays multifaceted roles in the initiation and progression of tumors, and interventions in metabolism are considered fundamental approaches for cancer control. Within the vast metabolic networks of tumors, there exist numerous potential therapeutic targets, intricately interconnected with each other and with signaling networks related to immunity, metastasis, drug resistance, and more. Based on the characteristics of the tumor microenvironment, constructing drug delivery systems for multi-level modulation of the tumor microenvironment is proven as an effective strategy for achieving multidimensional control of cancer. Consequently, this article summarizes several features of tumor metabolism to provide insights into recent advancements in intelligent drug delivery systems for achieving multi-level regulation of the metabolic microenvironment in cancer, with the aim of offering a novel paradigm for cancer treatment.

Lung metastasis-Harnessed in-Situ adherent porous organic nanosponge-mediated antigen capture for A self-cascaded detained dendritic cells and T cell infiltration

The infiltration of cytotoxic T lymphocytes promises to suppress the most irresistible metastatic tumor for immunotherapy, yet immune privilege and low immunogenic responses in these aggressive clusters often restrict lymphocyte recruitment. Here, an in situ adherent porous organic nanosponge (APON) doubles as organ selection agent and antigen captor to overcome immune privilege is developed. With selective organ targeting, the geometric effect of APON composed of disc catechol-functionalized covalent organic framework (COF) boosts the drug delivery to lung metastases. Along with a self-cascaded immune therapy, the therapeutic agents promote tumor release of damage-associated molecular patterns (DAMPs), and then, in situ deposition of gels to capture these antigens. Furthermore, APON with catechol analogs functions as a reservoir of antigens and delivers autologous DAMPs to detain dendritic cells, resulting in a sustained enhancement of immunity. This disc sponges (APON) at lung metastasis as antigen reservoirs and immune modulators effectively suppress the tumor in 60 days and enhanced the survival rate.

Arginine-Nanoenzyme with Timely Angiogenesis for Promoting Diabetic Wound Healing

The successful treatment of diabetic wounds requires strategies that promote anti-inflammation, angiogenesis, and re-epithelialization of the wound. Excessive oxidative stress in diabetic ulcers (DUs) inhibits cell proliferation and hinders timely vascular formation and macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2, resulting in a persistent inflammatory environment and a nonhealing wound. We designed arginine-nanoenzyme (FTA) with mimic-catalase and arginine-loading. 2,3,4-trihydroxy benzaldehyde and arginine (Arg) were connected by a Schiff base bond, and the nanoassembly of Arg to FTA was driven by the coordination force between a ferric ion and polyphenol and noncovalent bond force such as a hydrogen bond. FTA could remove excess reactive oxygen species at the wound site in situ and convert it to oxygen to improve hypoxia. Meanwhile, Arg was released and catalytically metabolized by NO synthase in M1 to promote vascular repair in the early phase. In the late phase, the metabolite of Arg catalyzed by arginase in M2 was mainly ornithine, which played a vital role in promoting tissue repair, which implemented angiogenesis timely and prevented hypertrophic scars. Mechanistically, FTA activated the cAMP signaling pathway combined with reducing inflammation and ameliorating angiogenesis, which resulted in excellent therapeutic effects on a DU mice model.

Tumor Metabolism-Rewriting Nanomedicines for Cancer Immunotherapy

Cancer immunotherapy has become an established therapeutic paradigm in oncologic therapy, but its therapeutic efficacy remains unsatisfactory in the majority of cancer patients. Accumulating evidence demonstrates that the metabolically hostile tumor microenvironment (TME), characterized by acidity, deprivation of oxygen and nutrients, and accumulation of immunosuppressive metabolites, promotes the dysfunction of tumor-infiltrating immune cells (TIICs) and thereby compromises the effectiveness of immunotherapy. This indicates the potential role of tumor metabolic intervention in the reinvigoration of antitumor immunity. With the merits of multiple drug codelivery, cell and organelle-specific targeting, controlled drug release, and multimodal therapy, tumor metabolism-rewriting nanomedicines have recently emerged as an attractive strategy to strengthen antitumor immune responses. This review summarizes the current progress in the development of multifunctional tumor metabolism-rewriting nanomedicines for evoking antitumor immunity. A special focus is placed on how these nanomedicines reinvigorate innate or adaptive antitumor immunity by regulating glucose metabolism, amino acid metabolism, lipid metabolism, and nucleotide metabolism at the tumor site. Finally, the prospects and challenges in this emerging field are discussed.

"Reaction"-Like Shaping of Self-Delivery Supramolecular Nanodrugs in the Nanoprecipitation Process

Nanoprecipitation, which is achieved through the diffusion and precipitation of drug molecules in blended solvent and antisolvent phases, is a classic route for constructing nanodrugs (NDs) and previously directed by diffusion-controlled theory. However, the diffusion-controlled mechanism is out of date in the recent preparation of self-delivery supramolecular NDs (SDSNDs), characterized by the construction of drug nanoparticles through supramolecular interactions in the absence of carriers and surfactants. Herein, a "reaction"-like complement, contributed from supramolecular interactions, is proposed for the preparation of naphthoquinone SDSNDs. Different from the diffusion-controlled process, the formation rate of SDSNDs via the "reaction"-like process is almost constant and highly dependent on the supramolecular interaction-determined Gibbs free energy of molecular binding. Thus, the formation rate and drug availability of SDSNDs are greatly improved by engineering the supramolecular interactions, which facilitates the preparation of SDSNDs with expected sizes, components, and therapeutic functions. As a deep understanding of supramolecular-interaction-involved nanoprecipitation, the current "reaction"-like protocol not only provides a theoretical supplement for classic nanoprecipitation but also highlights the potential of nanoprecipitation in shaping self-assembled, coassembled, and metal-ion-associated SDSNDs.

Application of molecular dynamics simulation in self-assembled cancer nanomedicine

Self-assembled nanomedicine holds great potential in cancer theragnostic. The structures and dynamics of nanomedicine can be affected by a variety of non-covalent interactions, so it is essential to ensure the self-assembly process at atomic level. Molecular dynamics (MD) simulation is a key technology to link microcosm and macroscale. Along with the rapid development of computational power and simulation methods, scientists could simulate the specific process of intermolecular interactions. Thus, some experimental observations could be explained at microscopic level and the nanomedicine synthesis process would have traces to follow. This review not only outlines the concept, basic principle, and the parameter setting of MD simulation, but also highlights the recent progress in MD simulation for self-assembled cancer nanomedicine. In addition, the physicochemical parameters of self-assembly structure and interaction between various assembled molecules under MD simulation are also discussed. Therefore, this review will help advanced and novice researchers to quickly zoom in on fundamental information and gather some thought-provoking ideas to advance this subfield of self-assembled cancer nanomedicine.