Recent Advances in Nanoimmunotherapy by Modulating Tumor-Associated Macrophages for Cancer Therapy.

Cancer immunotherapy has yielded remarkable results across a variety of tumor types. Nevertheless, the complex and immunosuppressive microenvironment within solid tumors poses significant challenges to established therapies such as immune checkpoint blockade (ICB) and chimeric antigen receptor T-cell (CAR-T) therapy. Within the milieu, tumor-associated macrophages (TAMs) play a significant role by directly suppressing T-cell functionality and fostering an immunosuppressive environment. Effective regulation of TAMs is, therefore, crucial to enhancing the efficacy of immunotherapies. Various therapeutic strategies targeting TAM modulation have emerged, including blocking TAM recruitment, direct elimination, promoting repolarization toward the M1 phenotype, and enhancing phagocytic capacity against tumor cells. The recently introduced CAR macrophage (CAR-M) therapy opens new possibilities for macrophage-based immunotherapy. Compared with CAR-T, CAR-M may demonstrate superior targeting and infiltration capabilities toward solid tumors. This review predominantly delves into the origin and development process of TAMs, their role in promoting tumor growth, and provides a comprehensive overview of immunotherapies targeting TAMs. It underscores the significance of regulating TAMs in bolstering antitumor therapies while discussing the potential and challenges of developing TAMs as targets for immunotherapy.

A Dual-Stimuli-Responsive Coordination Network Featuring Reversible Wide-Range Luminescence-Tuning Behavior.

We herein report a new coordination network that deforms in a smooth and reversible manner under either thermal or pressure stimulation. Concomitantly, the organic fluorophores coordinatively bound to the channel in a face-to-face arrangement respond to this structural deformation by finely adapting their conformation and arrangement. As a result, the material exhibits a remarkable dual-stimuli-responsive luminescence shift across almost the entire visible region: The emission color of the crystal gradually changes from cyan to green upon heating and then to red upon pressure compression. Furthermore, each stage exhibits a linear dependence of both the emission maximum and intensity on the stimulus and is fully reversible.

GSH/pH dual responsive chitosan nanoparticles for reprogramming M2 macrophages and overcoming cancer chemoresistance.

The combination of two or more drugs with different mechanisms of action is a promising strategy for circumventing multidrug resistance (MDR). However, the antitumor effect of nanosystems is usually limited due to the simultaneous release of different payloads at a single location rather than at their respective sites of action. Herein, we report a GSH and pH dual responsive nanoplatform encapsulated with doxorubicin (DOX) and resiquimod (R848) (GPNP) for combinatorial chemotherapy against cancer cells with drug resistance. GPNP possesses a core-shell structure wherein the polymer shell detaches in the acidic and sialic acid (SA)-rich environment. This leads to the release of R848 into the tumor microenvironment (TME), thereby reprogramming M2 macrophages into M1 macrophages and exposing the core CS(DOX)-PBA to kill MCF-7/ADR cells. Additionally, the nitric oxide (NO) generated by M1 macrophages can suppress the P-glycoprotein (P-gp) expression to reduce the efflux of chemotherapy drugs, thus playing a combined role in overcoming MDR. In vitro studies have demonstrated the effectiveness of GPNP in reprogramming M2 macrophages and inducing apoptosis in MCF-7/ADR cells, resulting in enhanced antitumor efficacy. This work proposed an effective combination strategy to combat chemoresistance, providing new insights into the development of innovative combinatorial therapies against MDR tumors.

An Antibody-like Polymeric Nanoparticle Removes Intratumoral Galectin-1 to Enhance Antitumor T-Cell Responses in Cancer Immunotherapy.

Antibodies have shown potential to deplete immunosuppressive factors in tumor tissues. However, intrinsic drawbacks, including time-consuming processes in preparation, high cost, and short half-life time, greatly restrict their applications. In this work, we report an antibody-like polymeric nanoparticle (APN) that is capable of specifically capturing and removing galectin-1 in tumor tissues, thereby enhancing the antitumor T-cell responses. The APN is composed of an albumin-polymer hybrid nanoparticle (core) and an acid-responsive PEG shell. The core of the APN contains multiple recognition units and Tuftsin peptides to capture target factors and activate macrophage-mediated phagocytosis, respectively. By employing galactose as recognition units, the APN facilitated the phagocytosis of galectin-1 in tumor tissues, thereby improving the antitumor responses of tumor-infiltrating T cells. Since the recognition units in the APN can be further replaced to capture and remove other peptides/proteins, the APN provides a feasible approach for the development of synthetic nanoformulations to regulate biological systems and treat diseases.

A near-infrared light-excitable immunomodulating nano-photosensitizer for effective photoimmunotherapy.

Photodynamic therapy has great potential for tumor ablation and the activation of antitumor immune responses. However, its overall therapeutic efficiency is often limited by the immunosuppressive tumor microenvironment. We developed a near-infrared light-excitable immunomodulating nano-photosensitizer (NeINP) that can improve reactive oxygen species production and regulate the immunosuppressive TME to improve photoimmunotherapy. The NeINP is composed of a photosensitive core and a pH-responsive polymer shell, which allows for NeINP loading and delivery of small-molecular immunomodulators to tumor sites for regulation of the immunosuppressive TME and effective photoimmunotherapy. Through the co-delivery of celecoxib and the NIR-triggered photodynamic core to tumors, the NeINP was shown to regulate the immunosuppressive TME and enhance antitumor immunity, leading to the elimination of residual tumor and reduction of metastasis and recurrence. The NeINP can be optimized to co-deliver other immunomodulators, and thus has potential as a universal platform for efficient, precise photoimmunotherapy.

Multifunctional Nanomodulators Regulate Multiple Pathways To Enhance Antitumor Immunity.

Immunosuppression is a key factor leading to a low therapeutic efficiency of the currently used immunotherapies. Monotherapies are unable to overcome immunosuppression because of the complex interplay of immune cells in tumors. Herein, we report a multifunctional nanomodulator (MFNM) as a carrier to deliver different types of immune modulators for comodulating multiple pathways. An MFNM has a core-shell structure, in which small-molecule drugs are encapsulated in a mesoporous silica nanoparticle (MSN) core with a pH-responsive polymer layer. Further, the polymeric shell provides active sites that are readily modifiable by multiple types of antibodies to regulate the immune-related processes. By codelivering cyclophosphamide (CTX), αPD-L1 (B7-H1), and α4-1BB (CD137L) monoclonal antibodies (mAbs) to tumors, an MFNM has been shown to regulate multiple immune pathways and enhance an antitumor immunity. As antibodies and small-molecule drugs loaded in an MFNM can be modified based on the tumor type, the MFNM provides a feasible platform for the development of advanced immunotherapies that require simultaneous modulation of multiple biological processes.

Virus-like nanoparticle as a co-delivery system to enhance efficacy of CRISPR/Cas9-based cancer immunotherapy.

The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated protein 9 (Cas9) system holds great promise for the cancer gene therapy. However, due to complicated signal networks and various compensatory mechanisms in tumors, adjusting a single molecular pathway has limited effects on cancer treatments. Herein, a virus-like nanoparticle (VLN) was reported as a versatile nanoplatform to co-deliver CRISPR/Cas9 system and small molecule drugs for effective malignant cancer treatment. VLN has a core-shell structure, in which small molecule drugs and CRISPR/Cas9 system are loaded in the mesoporous silica nanoparticle (MSN)-based core, which is further encapsulated with a lipid shell. This structure allows VLN maintaining stable during blood circulation. As reaching tumors, VLN releases the CRISPR/Cas9 system and small molecule drugs in response to the reductive microenvironment, resulting in the synergistic regulation of multiple cancer-associated pathways. By loading a single guide RNA (sgRNA) targeting programmed death-ligand 1 and axitinib, VLN achieved to disrupt multiple immunosuppressive pathways and suppress the growth of melanoma in vivo. More importantly, VLN can co-deliver almost any combination of sgRNAs and small molecule drugs to tumors, suggesting the great potential of VLN as a general platform for the development of advanced combination therapies against malignant tumors.

A promising way to open an energy gap in bilayer graphene.

There has been huge research interest in the energy gap problem of monolayer and bilayer graphene due to their great potential in practical applications. Herein, based on first-principles calculations, we report a promising way to open a large band gap in bilayer graphene (BLG) by sandwiching it between two substrates, although this is not usually expected to occur due to the weak interlayer interactions dominated by van der Waals forces. Taking surface-functionalized boron-nitrides as substrates, we predict from first-principles calculations that BLG can have energy gaps ranging from 0.35 eV to 0.55 eV, depending on the substrates and stacking order. Compared to other methods of band-gap manipulation in BLG, the structural integrity of BLG is well-preserved in our study, and the predicted energy gap is suitable for electric devices. Since the proposed method is easily realized in experiments, our results will hopefully accelerate the application of graphene in semiconductor devices and promote the development of graphene technology.