Immunostimulant Hydrogel-Guided Tumor Microenvironment Reprogramming to Efficiently Potentiate Macrophage-Mediated Cellular Phagocytosis for Systemic Cancer Immunotherapy

Photodynamic Therapy Synergizes CD47 Blockade Strategy for Enhanced Antitumor Therapy

The antitumor strategies based on innate immunity activation have become favored by researchers in recent years. In particular, strategies targeting antiphagocytic signaling blockade to enhance phagocytosis have been widely reported. For example, the addition of prophagocytic signals such as calreticulin could make the strategy significantly more effective. In this study, an antitumor strategy that combines photodynamic therapy (PDT) with CD47 blockade has been reported. This approach promotes the maturation of dendritic cells and the presentation of tumor antigens by PDT-mediated tumor immunogenic cell death, as well as the enhancement of cytotoxic T lymphocyte infiltration in tumor areas and the phagocytic activity of phagocytes. Furthermore, the downregulation and blockage of CD47 protein could further promote phagocytic activity, strengthen the innate immune system, and ultimately elevate the antitumor efficacy and inhibit tumor metastasis.

Petaloid Metal-Organic Frameworks for Resiquimod Delivery To Potentiate Antitumor Immunity

The morphological features of materials significantly influence their interactions with cells, consequently affecting the cellular uptake of these materials. In this study, we examine the cellular uptake behavior of spherical metal-organic frameworks (MOFs) and petaloid MOFs, both possessing similar sizes and compositions. In comparison to spherical MOFs, dendritic cells (DCs) and macrophages exhibit superior phagocytic uptake of petaloid MOFs. Next, the results demonstrate that R848@petaloid MOFs more effectively promote the repolarization of tumor-associated macrophages (TAMs) from the M2 to M1 phenotype and the maturation of DCs. More importantly, the R848-loaded petaloid MOFs are found to significantly enhance the therapeutic effects of radiotherapy (RT) by eliciting antitumor responses. Furthermore, R848@petaloid MOFs combined with RT and αPD-L1 elicit a potent abscopal effect, effectively suppressing tumor metastasis. Therefore, this work proposes a new strategy to enhance the uptake of immunomodulators by immune cells through modulating the morphology of drug delivery carriers.

Dismantlable Coronated Nanoparticles for Coupling the Induction and Perception of Immunogenic Cell Death

Therapy-induced immunogenic cell death (ICD) can initiate both innate and adaptive immune responses for amplified anti-tumor efficacy. However, dying cell-released ICD signals are prone to being sequestered by the TIM-3 receptors on dendritic cell (DC) surfaces, preventing immune surveillance. Herein, dismantlable coronated nanoparticles (NPs) are fabricated as a type of spatiotemporally controlled nanocarriers for coupling tumor cell-mediated ICD induction to DC-mediated immune sensing. These NPs are loaded with an ICD inducer, mitoxantrone (MTO), and wrapped by a redox-labile anti-TIM-3 (αTIM-3) antibody corona, forming a separable core-shell structure. The antibody corona disintegrates under high levels of extracellular reactive oxygen species in the tumor microenvironment, exposing the MTO-loaded NP core for ICD induction and releasing functional αTIM-3 molecules for DC sensitization. Systemic administration of the coronated NPs augments DC maturation, promotes cytotoxic T cell recruitment, enhances tumor susceptibility to immune checkpoint blockade, and prevents the side effects of MTO. This study develops a promising nanoplatform to unleash the potential of host immunity in cancer therapy.

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.

Oral biomimetic virus vaccine hydrogel for robust abscopal antitumour efficacy

Remarkable progress has been made in tumour immunotherapy in recent decades. However, the clinical outcomes of therapeutic interventions remain unpredictable, largely because of inefficient immune responses. To address this challenge and optimise immune stimulation, we present a novel administration route for enhancing the bioavailability of immunotherapeutic drugs. Our approach involves the development of an oral tumour vaccine utilising virus-like particles derived from the Hepatitis B virus core (HBc) antigen. The external surfaces of these particles are engineered to display the model tumour antigen OVA, whereas the interiors are loaded with cytosine phosphoguanosine oligodeoxynucleotide (CpG ODN), resulting in a construct called CpG@OVAHBc with enhanced antigenicity and immune response. For oral delivery, CpG@OVAHBc is encapsulated in a crosslinked dextran hydrogel called CpG@OVAHBc@Dex. The external hydrogel shield safeguards the biomimetic virus particles from degradation by gastric acid and proteases. Upon exposure to intestinal flora, the hydrogel disintegrates, releasing CpG@OVAHBc at the intestinal mucosal site. Owing to its virus-like structure, CpG@OVAHBc exhibits enhanced adhesion to the mucosal surface, facilitating uptake by microfold cells (M cells) and subsequent transmission to antigen-presenting cells. The enzyme-triggered release of this oral hydrogel ensures the integrity of the tumour vaccine within the digestive tract, allowing targeted release and significantly improving bioavailability. Beyond its efficacy, this oral hydrogel vaccine streamlines drug administration, alleviates patient discomfort, and enhances treatment compliance without the need for specialised injection methods. Consequently, our approach expands the horizons of vaccine development in the field of oral drug administration.

Recent advancements of hydrogels in immunotherapy: Breast cancer treatment

Breast cancer is the most prevalent cancer among women and the leading cause of cancer-related deaths in this population. Recent advances in Immunotherapy, or combined immunotherapy, offering a more targeted and less toxic approach, expand the survival rate of patients more than conventional treatment. Notably, hydrogels, a versatile platform provided promising avenues to combat breast cancer in preclinical studies and extended to clinical practices. With advantages such as the alternation of tumor microenvironment, immunomodulation, targeted delivery of therapeutic agents, and their sustained release at specific sites of interest, hydrogels can potentially be used for the treatment of breast cancer. This review highlights the advantages, mechanisms of action, stimuli-responsiveness properties, and recent advancements of hydrogels for treating breast cancer immunotherapy. Moreover, post-treatment and its clinical translations are discussed in this review. The integration of hydrogels in immunotherapy strategies may pave the way for more effective, personalized, and patient-friendly approaches to combat breast cancer, ultimately contributing to a brighter future for breast cancer patients.

Macrophage membrane-coated nanoparticles for the treatment of infectious diseases

Infectious diseases severely threaten human health, and traditional treatment techniques face multiple limitations. As an important component of immune cells, macrophages display unique biological properties, such as biocompatibility, immunocompatibility, targeting specificity, and immunoregulatory activity, and play a critical role in protecting the body against infections. The macrophage membrane-coated nanoparticles not only maintain the functions of the inner nanoparticles but also inherit the characteristics of macrophages, making them excellent tools for improving drug delivery and therapeutic implications in infectious diseases (IDs). In this review, we describe the characteristics and functions of macrophage membrane-coated nanoparticles and their advantages and challenges in ID therapy. We first summarize the pathological features of IDs, providing insight into how to fight them. Next, we focus on the classification, characteristics, and preparation of macrophage membrane-coated nanoparticles. Finally, we comprehensively describe the progress of macrophage membrane-coated nanoparticles in combating IDs, including drug delivery, inhibition and killing of pathogens, and immune modulation. At the end of this review, a look forward to the challenges of this aspect is presented.

Microfluidics-derived hierarchical microparticles for the delivery of dienogest for localized endometriosis therapy

Drug therapy is one of the most important strategies for treating gynecological diseases. Local drug delivery is promising for achieving optimal regional drug exposure, considering the complex anatomy and dynamic environment of the upper genital tract. Here, we present microparticle-based microcarriers with a hierarchical structure for localized dienogest (DNG) delivery and endometriosis treatment. The microparticles were fabricated by microfluidics and consisted of photo-crosslinked bovine serum albumin hydrogel particles (D@P-B MPs) encapsulating DNG-loaded PLGA (poly lactic-co-glycolic acid) microspheres. Such design enables the microparticles to have sustained release capacity and cell adhesion ability. Based on this, the microparticles were applied for the treatment of peritoneal endometriosis through intraperitoneal injection. The performance of the microparticles in inhibiting the growth of ectopic lesions as well as their anti-inflammatory, anti-angiogenesis, and pelvic pain-relieving effects are well demonstrated in vivo. These findings indicate that the present hierarchical microparticles are good candidates for localized treatment of endometriosis and are promising for the management of gynecological diseases. STATEMENT OF SIGNIFICANCE: We prepared photo-crosslinked bovine serum albumin hydrogel particles (D@P-B MPs) encapsulating DNG-loaded PLGA microspheres using microfluidic electrospray. Such hierarchical structure provided multiple functions of the particles as drug carriers. The hierarchical microparticles not only supported the sustained release of drugs but also provided adhesion to human ectopic endometrial stromal cells. The hierarchical microparticles represented a localized treatment method for endometriosis and is promising for the management of gynecological diseases.

Chemoimmunotherapeutic Nanogel for Pre- and Postsurgical Treatment of Malignant Melanoma by Reprogramming Tumor-Associated Macrophages

Surgery is the primary method to treat malignant melanoma; however, the residual microtumors that cannot be resected completely often trigger tumor recurrence, causing tumor-related mortality following melanoma resection. Herein, we developed a feasible strategy based on the combinational chemoimmunotherapy by cross-linking carboxymethyl chitosan (CMCS)-originated polymetformin (PolyMetCMCS) with cystamine to prepare stimuli-responsive nanogel (PMNG) owing to the disulfide bond in cystamine that can be cleaved by the massive glutathione (GSH) in tumor sites. Then, chemotherapeutic agent doxorubicin (DOX) was loaded in PMNG, which was followed by a hyaluronic acid coating to improve the overall biocompatibility and targeting ability of the prepared nanogel (D@HPMNG). Notably, PMNG effectively reshaped the tumor immune microenvironment by reprogramming tumor-associated macrophage phenotypes and recruiting intratumoral CD8+ T cells owing to the inherited immunomodulatory capability of metformin. Consequently, D@HPMNG treatment remarkably suppressed melanoma growth and inhibited its recurrence after surgical resection, proposing a promising solution for overcoming lethal melanoma recurrence.

A Gene-Editable Palladium-Based Bioorthogonal Nanoplatform Facilitates Macrophage Phagocytosis for Tumor Therapy

Macrophage phagocytosis of tumor cells has emerged as an attractive strategy for tumor therapy. Nevertheless, immunosuppressive M2 macrophages in the tumor microenvironment and the high expression of anti-phagocytic signals from tumor cells impede therapeutic efficacy. To address these issues and improve the management of malignant tumors, in this study we developed a gene-editable palladium-based bioorthogonal nanoplatform, consisting of CRISPR/Cas9 gene editing system-linked Pd nanoclusters, and a hyaluronic acid surface layer (HBPdC). This HBPdC nanoplatform exhibited satisfactory tumor-targeting efficiency and triggered Fenton-like reactions in the tumor microenvironment to generate reactive oxygen species for chemodynamic therapy and macrophage M1 polarization, which directly eliminated tumor cells, and stimulated the antitumor response of macrophages. HBPdC could reprogram tumor cells through gene editing to reduce the expression of CD47 and adipocyte plasma membrane-associated protein, thereby promoting their recognition and phagocytosis by macrophages. Moreover, HBPdC induced the activation of sequestered prodrugs via bioorthogonal catalysis, enabling chemotherapy and thereby enhancing tumor cell death. Importantly, the Pd nanoclusters of HBPdC were sufficiently cleared through basic metabolic pathways, confirming their biocompatibility and biosafety. Therefore, by promoting macrophage phagocytosis, the HBPdC system developed herein represents a highly promising antitumor toolset for cancer therapy applications.

Cellular crosstalk of macrophages and therapeutic implications in non-small cell lung cancer revealed by integrative inference of single-cell transcriptomics

Introduction: Non-small cell lung cancer (NSCLC) exhibits heterogeneity with diverse immune cell infiltration patterns that can influence tumor cell behavior and immunotherapy. A comprehensive characterization of the tumor microenvironment can guide precision medicine. Methods: Here, we generated a single-cell atlas of 398170 cells from 52 NSCLC patients, and investigated the imprinted genes and cellular crosstalk for macrophages. Subsequently, we evaluated the effect of tumor cells on macrophages and verified the expression of marker genes using co-culture experiments, flow cytometry and RT-qPCR assays. Results: Remarkable macrophage adaptability to NSCLC environment was observed, which contributed to generating tumor-associated macrophages (TAMs). We identified 5 distinct functional TAM subtypes, of which the majority were SELENOP-positive macrophages, with high levels of SLC40A1 and CCL13. The TAMs were also involved in mediating CD8+ T cell activity and form intercellular interaction with cancer cells, as indicated by receptor-ligand binding. Indirect coculture of tumor cells SPC-A1 and THP-1 monocytes, produced M2-like TAMs that highly expressed several markers of SELENOP-positive macrophages. The abundance of this type TAMs seemed to be associated with poorer overall survival rates [hazard ratio (HR) = 1.34, 95% confidence interval (CI) = 0.98-1.83, p = 0.068] based on deconvolution of TCGA-LUAD dataset. Discussion: In summary, we provided a high-resolution molecular resource of TAMs, and displayed the acquired properties in the tumor microenvironment. Dynamic crosstalk between TAMs and tumor cells via multiple ligand-receptor pairs were revealed, emphasizing its role in sustaining the pro-tumoral microenvironment and its implications for cancer therapy.