Macrophage Membrane-Coated Nano-Gemcitabine Promotes Lymphocyte Infiltration and Synergizes AntiPD-L1 to Restore the Tumoricidal Function

Unlocking the power of nanomedicine: Cell membrane-derived biomimetic cancer nanovaccines for cancer treatment

Over the past decades, nanomedicine researchers have dedicated their efforts to developing nanoscale platforms capable of more precisely delivering drug payloads to attack tumors. Cancer nanovaccines are exhibiting a distinctive capability in inducing tumor-specific antitumor responses. Nevertheless, there remain numerous challenges that must be addressed for cancer nanovaccines to evoke sufficient therapeutic effects. Cell membrane-derived nanovaccines are an emerging class of cancer vaccines that comprise a synthetic nanoscale core camouflaged by naturally derived cell membranes. The specific cell membrane has a biomimetic nanoformulation with several distinctive abilities, such as immune evasion, enhanced biocompatibility, and tumor targeting, typically associated with a source cell. Here, we discuss the advancements of cell membrane-derived nanovaccines and how these vaccines are used for cancer therapeutics. Translational endeavors are currently in progress, and additional research is also necessary to effectively address crucial areas of demand, thereby facilitating the future successful translation of these emerging vaccine platforms.

Hyperbaric oxygen enhances tumor penetration and accumulation of engineered bacteria for synergistic photothermal immunotherapy

Bacteria-mediated cancer therapeutic strategies have attracted increasing interest due to their intrinsic tumor tropism. However, bacteria-based drugs face several challenges including the large size of bacteria and dense extracellular matrix, limiting their intratumoral delivery efficiency. In this study, we find that hyperbaric oxygen (HBO), a noninvasive therapeutic method, can effectively deplete the dense extracellular matrix and thus enhance the bacterial accumulation within tumors. Inspired by this finding, we modify Escherichia coli Nissle 1917 (EcN) with cypate molecules to yield EcN-cypate for photothermal therapy, which can subsequently induce immunogenic cell death (ICD). Importantly, HBO treatment significantly increases the intratumoral accumulation of EcN-cypate and facilitates the intratumoral infiltration of immune cells to realize desirable tumor eradication through photothermal therapy and ICD-induced immunotherapy. Our work provides a facile and noninvasive strategy to enhance the intratumoral delivery efficiency of natural/engineered bacteria, and may promote the clinical translation of bacteria-mediated synergistic cancer therapy.

Engineered biological nanoparticles as nanotherapeutics for tumor immunomodulation

Biological nanoparticles, or bionanoparticles, are small molecules manufactured in living systems with complex production and assembly machinery. The products of the assembly systems can be further engineered to generate functionalities for specific purposes. These bionanoparticles have demonstrated advantages such as immune system evasion, minimal toxicity, biocompatibility, and biological clearance. Hence, bionanoparticles are considered the new paradigm in nanoscience research for fabricating safe and effective nanoformulations for therapeutic purposes. Harnessing the power of the immune system to recognize and eradicate malignancies is a viable strategy to achieve better therapeutic outcomes with long-term protection from disease recurrence. However, cancerous tissues have evolved to become invisible to immune recognition and to transform the tumor microenvironment into an immunosuppressive dwelling, thwarting the immune defense systems and creating a hospitable atmosphere for cancer growth and progression. Thus, it is pertinent that efforts in fabricating nanoformulations for immunomodulation are mindful of the tumor-induced immune aberrations that could render cancer nanotherapy inoperable. This review systematically categorizes the immunosuppression mechanisms, the regulatory immunosuppressive cellular players, and critical suppressive molecules currently targeted as breakthrough therapies in the clinic. Finally, this review will summarize the engineering strategies for affording immune moderating functions to bionanoparticles that tip the tumor microenvironment (TME) balance toward cancer elimination, a field still in the nascent stage.

Efficient Delivery of Lomitapide using Hybrid Membrane-Coated Tetrahedral DNA Nanostructures for Glioblastoma Therapy

Glioblastoma (GBM) is the most aggressive and prevalent primary malignant tumor of the central nervous system. Traditional chemotherapy has poor therapeutic effects and significant side effects due to drug resistance, the natural blood-brain barrier (BBB), and nonspecific distribution, leading to a lack of clinically effective therapeutic drugs. Here, 1430 small molecule compounds are screened based on a high-throughput drug screening platform and a novel anti-GBM drug, lomitapide (LMP) is obtained. Furthermore, a bionic nanodrug delivery system (RFA NPs) actively targeting GBM is constructed, which mainly consists of tetrahedral DNA nanocages (tFNA NPs) loaded with LMP as the core and a folate-modified erythrocyte-cancer cell-macrophage hybrid membrane (FRUR) as the shell. FRUR camouflage conferred unique features on tFNA NPs, including excellent biocompatibility, improved pharmacokinetic profile, efficient BBB permeability, and tumor targeting ability. The results show that the LMP RFA NPs exhibited superior and specific anti-GBM activities, reduced off-target drug delivery, prolonged lifespan, and has negligible side effects in tumor-bearing mice. This study combines high-throughput drug screening with biomimetic nanodrug delivery system technology to provide a theoretical and practical basis for drug development and the optimization of clinical treatment strategies for GBM treatment.

Boosting Checkpoint Immunotherapy with Biomimetic Nanodrug Delivery Systems

Immune checkpoint blockade (ICB) has achieved unprecedented progress in tumor immunotherapy by blocking specific immune checkpoint molecules. However, the high biodistribution of the drug prevents it from specifically targeting tumor tissues, leading to immune-related adverse events. Biomimetic nanodrug delivery systems (BNDSs) readily applicable to ICB therapy have been widely developed at the preclinical stage to avoid immune-related adverse events. By exploiting or mimicking complex biological structures, the constructed BNDS as a novel drug delivery system has good biocompatibility and certain tumor-targeting properties. Herein, the latest findings regarding the aforementioned therapies associated with ICB therapy are highlighted. Simultaneously, prospective bioinspired engineering strategies can be designed to overcome the four-level barriers to drug entry into lesion sites. In future clinical translation, BNDS-based ICB combination therapy represents a promising avenue for cancer treatment.

Cell membrane coated nanoparticles as a biomimetic drug delivery platform for enhancing cancer immunotherapy

Cancer immunotherapy, a burgeoning modality for cancer treatment, operates by activating the autoimmune system to impede the growth of malignant cells. Although numerous immunotherapy strategies have been employed in clinical cancer therapy, the resistance of cancer cells to immunotherapeutic medications and other apprehensions impede the attainment of sustained advantages for most patients. Recent advancements in nanotechnology for drug delivery hold promise in augmenting the efficacy of immunotherapy. However, the efficacy is currently constrained by the inadequate specificity of delivery, low rate of response, and the intricate immunosuppressive tumor microenvironment. In this context, the investigation of cell membrane coated nanoparticles (CMNPs) has revealed their ability to perform targeted delivery, immune evasion, controlled release, and immunomodulation. By combining the advantageous features of natural cell membranes and nanoparticles, CMNPs have demonstrated their unique potential in the realm of cancer immunotherapy. This review aims to emphasize recent research progress and elucidate the underlying mechanisms of CMNPs as an innovative drug delivery platform for enhancing cancer immunotherapy. Additionally, it provides a comprehensive overview of the current immunotherapeutic strategies involving different cell membrane types of CMNPs, with the intention of further exploration and optimization.

Cell Membrane-Coated Biomimetic Nanoparticles in Cancer Treatment

Nanoparticle-based drug delivery systems hold promise for cancer treatment by enhancing the solubility and stability of anti-tumor drugs. Nonetheless, the challenges of inadequate targeting and limited biocompatibility persist. In recent years, cell membrane nano-biomimetic drug delivery systems have emerged as a focal point of research and development, due to their exceptional traits, including precise targeting, low toxicity, and good biocompatibility. This review outlines the categorization and advantages of cell membrane bionic nano-delivery systems, provides an introduction to preparation methods, and assesses their applications in cancer treatment, including chemotherapy, gene therapy, immunotherapy, photodynamic therapy, photothermal therapy, and combination therapy. Notably, the review delves into the challenges in the application of various cell membrane bionic nano-delivery systems and identifies opportunities for future advancement. Embracing cell membrane-coated biomimetic nanoparticles presents a novel and unparalleled avenue for personalized tumor therapy.

Advances in Engineered Macrophages: A New Frontier in Cancer Immunotherapy

Macrophages, as pivotal cells within the tumour microenvironment, significantly influence the impact of and reactions to treatments for solid tumours. The rapid evolution of bioengineering technology has revealed the vast potential of engineered macrophages in immunotherapy, disease diagnosis, and tissue engineering. Given this landscape, the goal of harnessing and innovating macrophages as a novel strategy for solid tumour immunotherapy cannot be overstated. The diverse strategies for engineered macrophages in the realm of cancer immunotherapy, encompassing macrophage drug delivery systems, chimeric antigen receptor macrophage therapy, and synergistic treatment approaches involving bacterial outer membrane vesicles and macrophages, are meticulously examined in this review. These methodologies are designed to enhance the therapeutic efficacy of macrophages against solid tumours, particularly those that are drug-resistant and metastatic. Collectively, these immunotherapies are poised to supplement and refine current solid tumour treatment paradigms, thus heralding a new frontier in the fight against malignant tumours.

Extracellular Matrix-Trapped Bioinspired Lipoprotein Prolongs Tumor Retention to Potentiate Antitumor Immunity

The immunomodulatory effects of many therapeutic agents are significantly challenged by their insufficient delivery efficiency and short retention time in tumors. Regarding the distinctively upregulated fibronectin (FN1) and tenascin C (TNC) in tumor stroma, herein a protease-activated FN1 and/or TNC binding peptide (FTF) is designed and an extracellular matrix (ECM)-trapped bioinspired lipoprotein (BL) (FTF-BL-CP) is proposed that can be preferentially captured by the TNC and/or FN1 for tumor retention, and then be responsively dissociated from the matrix to potentiate the antitumor immunity. The FTF-BL-CP treatment produces a 6.96-, 9.24-, 6.72-, 7.32-, and 6.73-fold increase of CD3+CD8+ T cells and their interferon-γ-, granzyme B-, perforin-, and Ki67-expressing subtypes versus the negative control, thereby profoundly eliciting the antitumor immunity. In orthotopic and lung metastatic breast cancer models, FTF-BL-CP produces notable therapeutic benefits of retarding tumor growth, extending survivals, and inhibiting lung metastasis. Therefore, this ECM-trapping strategy provides an encouraging possibility of prolonging tumor retention to potentiate the antitumor immunity for anticancer immunotherapy.

Macrophage membrane (MMs) camouflaged near-infrared (NIR) responsive bone defect area targeting nanocarrier delivery system (BTNDS) for rapid repair: promoting osteogenesis via phototherapy and modulating immunity

Bone defects remain a significant challenge in clinical orthopedics, but no targeted medication can solve these problems. Inspired by inflammatory targeting properties of macrophages, inflammatory microenvironment of bone defects was exploited to develop a multifunctional nanocarrier capable of targeting bone defects and promoting bone regeneration. The avidin-modified black phosphorus nanosheets (BP-Avidin, BPAvi) were combined with biotin-modified Icaritin (ICT-Biotin, ICTBio) to synthesize Icaritin (ICT)-loaded black phosphorus nanosheets (BPICT). BPICT was then coated with macrophage membranes (MMs) to obtain MMs-camouflaged BPICT (M@BPICT). Herein, MMs allowed BPICT to target bone defects area, and BPICT accelerated the release of phosphate ions (PO43-) and ICT when exposed to NIR irradiation. PO43- recruited calcium ions (Ca2+) from the microenvironment to produce Ca3(PO4)2, and ICT increased the expression of osteogenesis-related proteins. Additionally, M@BPICT can decrease M1 polarization of macrophage and expression of pro-inflammatory factors to promote osteogenesis. According to the results, M@BPICT provided bone growth factor and bone repair material, modulated inflammatory microenvironment, and activated osteogenesis-related signaling pathways to promote bone regeneration. PTT could significantly enhance these effects. This strategy not only offers a solution to the challenging problem of drug-targeted delivery in bone defects but also expands the biomedical applications of MMs-camouflaged nanocarriers.

Enhancing drug penetration in solid tumors via nanomedicine: Evaluation models, strategies and perspectives

Effective tumor treatment depends on optimizing drug penetration and accumulation in tumor tissue while minimizing systemic toxicity. Nanomedicine has emerged as a key solution that addresses the rapid clearance of free drugs, but achieving deep drug penetration into solid tumors remains elusive. This review discusses various strategies to enhance drug penetration, including manipulation of the tumor microenvironment, exploitation of both external and internal stimuli, pioneering nanocarrier surface engineering, and development of innovative tactics for active tumor penetration. One outstanding strategy is organelle-affinitive transfer, which exploits the unique properties of specific tumor cell organelles and heralds a potentially transformative approach to active transcellular transfer for deep tumor penetration. Rigorous models are essential to evaluate the efficacy of these strategies. The patient-derived xenograft (PDX) model is gaining traction as a bridge between laboratory discovery and clinical application. However, the journey from bench to bedside for nanomedicines is fraught with challenges. Future efforts should prioritize deepening our understanding of nanoparticle-tumor interactions, re-evaluating the EPR effect, and exploring novel nanoparticle transport mechanisms.

Gemcitabine-Vitamin E Prodrug-Loaded Micelles for Pancreatic Cancer Therapy

Pancreatic cancer (PC) is an aggressive cancer subtype presenting unmet clinical challenges. Conventional chemotherapy, which includes antimetabolite gemcitabine (GEM), is seriously undermined by a short half-life, its lack of targeting ability, and systemic toxicity. GEM incorporation in self-assembled nanosystems is still underexplored due to GEM's hydrophilicity which hinders efficient encapsulation. We hypothesized that vitamin E succinate-GEM prodrug (VES-GEM conjugate) combines hydrophobicity and multifunctionalities that can facilitate the development of Pluronic® F68 and Pluronic® F127 micelle-based nanocarriers, improving the therapeutic potential of GEM. Pluronic® F68/VES-GEM and Pluronic® F127/VES-GEM micelles covering a wide range of molar ratios were prepared by solvent evaporation applying different purification methods, and characterized regarding size, charge, polydispersity index, morphology, and encapsulation. Moreover, the effect of sonication and ultrasonication and the influence of a co-surfactant were explored together with drug release, stability, blood compatibility, efficacy against tumour cells, and cell uptake. The VES-GEM conjugate-loaded micelles showed acceptable size and high encapsulation efficiency (>95%) following an excipient reduction rationale. Pluronic® F127/VES-GEM micelles evidenced a superior VES-GEM release profile (cumulative release > 50%, pH = 7.4), stability, cell growth inhibition (<50% cell viability for 100 µM VES-GEM), blood compatibility, and extensive cell internalization, and therefore represent a promising approach to leveraging the efficacy and safety of GEM for PC-targeted therapies.

NK cell-based tumor immunotherapy

Natural killer (NK) cells display a unique inherent ability to identify and eliminate virus-infected cells and tumor cells. They are particularly powerful for elimination of hematological cancers, and have attracted considerable interests for therapy of solid tumors. However, the treatment of solid tumors with NK cells are less effective, which can be attributed to the very complicated immunosuppressive microenvironment that may lead to the inactivation, insufficient expansion, short life, and the poor tumor infiltration of NK cells. Fortunately, the development of advanced nanotechnology has provided potential solutions to these issues, and could improve the immunotherapy efficacy of NK cells. In this review, we summarize the activation and inhibition mechanisms of NK cells in solid tumors, and the recent advances in NK cell-based tumor immunotherapy boosted by diverse nanomaterials. We also propose the challenges and opportunities for the clinical application of NK cell-based tumor immunotherapy.

Advanced Generation Therapeutics: Biomimetic Nanodelivery System for Tumor Immunotherapy

Tumor immunotherapy is a safe and effective strategy for precision medicine. However, immunotherapy for most cancer cases still ends in failure, with the root causes of the immunosuppressive and extraordinary heterogeneity of the solid tumors microenvironment. The emerging biomimetic nanodelivery system provides a promising tactic to improve the immunotherapy effect while reducing the adverse reactions on nontarget cells. Herein, we summarize the relationship between tumor occurrence and tumor immune microenvironment, mechanism of tumor immune escape, immunotherapy classification (including adoptive cellular therapy, cytokines, cancer vaccines, and immune checkpoint inhibitors) and recommend target cells for immunotherapy first, and then emphatically introduce the recent advances and applications of the latest biomimetic nanodelivery systems (e.g., immune cells, erythrocytes, tumor cells, platelets, bacteria) in tumor immunotherapy. Meanwhile, we separately summarize the application of tumor vaccines. Finally, the predictable challenges and perspectives in a forward exploration of biomimetic nanodelivery systems for tumor immunotherapy are also discussed.

Biomimetic Macrophage Membrane-Camouflaged Nanoparticles Induce Ferroptosis by Promoting Mitochondrial Damage in Glioblastoma

The increasing understanding of ferroptosis has indicated its role and therapeutic potential in cancer; however, this knowledge has yet to be translated into effective therapies. Glioblastoma (GBM) patients face a bleak prognosis and encounter challenges due to the limited treatment options available. In this study, we conducted a genome-wide CRISPR-Cas9 screening in the presence of a ferroptosis inducer (RSL3) to identify the key driver genes involved in ferroptosis. We identified ALOX15, a key lipoxygenase (LOX), as an essential driver of ferroptosis. Small activating RNA (saRNA) was used to mediate the expression of ALOX15 promoted ferroptosis in GBM cells. We then coated saALOX15-loaded mesoporous polydopamine (MPDA) with Angiopep-2-modified macrophage membranes (MMs) to reduce the clearance by the mononuclear phagocyte system (MPS) and increase the ability of the complex to cross the blood-brain barrier (BBB) during specific targeted therapy of orthotopic GBM. These generated hybrid nanoparticles (NPs) induced ferroptosis by mediating mitochondrial dysfunction and rendering mitochondrial morphology abnormal. In vivo, the modified MM enabled the NPs to target GBM cells, exert a marked inhibitory effect on GBM progression, and promote GBM radiosensitivity. Our results reveal ALOX15 to be a promising therapeutic target in GBM and suggest a biomimetic strategy that depends on the biological properties of MMs to enhance the in vivo performance of NPs for treating GBM.

Mechanism of regulating macrophages/osteoclasts in attenuating wear particle-induced aseptic osteolysis

Joint replacement surgery is the most effective treatment for end-stage arthritis. Aseptic loosening caused by periprosthetic osteolysis is a common complication after joint replacement. Inflammation induced by wear particles derived from prosthetic biomaterials is a major cause of osteolysis. We emphasize that bone marrow-derived macrophages and their fusion-derived osteoclasts play a key role in this pathological process. Researchers have developed multiple intervention approaches to regulate macrophage/osteoclast activation. Aiming at wear particle-induced periprosthetic aseptic osteolysis, this review separately discusses the molecular mechanism of regulation of ROS formation and inflammatory response through intervention of macrophage/osteoclast RANKL-MAPKs-NF-κB pathway. These molecular mechanisms regulate osteoclast activation in different ways, but they are not isolated from each other. There is also a lot of crosstalk among the different mechanisms. In addition, other bone and joint diseases related to osteoclast activation are also briefly introduced. Therefore, we discuss these new findings in the context of existing work with a view to developing new strategies for wear particle-associated osteolysis based on the regulation of macrophages/osteoclasts.

A Dual-Mechanism Based Nutrient Partitioning Nanoregulator for Enhanced Immunotherapy against Anti-PD-1 Resistant Tumors

Competitive consumption of nutrients between rapidly proliferating cancer cells and T cells results in an immunosuppressive tumor microenvironment (TME) and nutrient deprivation of T cells, which can cause low response rate and resistance to immunotherapies. In this study, we proposed a dual-mechanism based nutrient partitioning nanoregulator (designated as DMNPN), which can simultaneously regulate the immunosuppressive TME and enhance T cell nutrient availability. DMNPN consists of a charge-reversal biodegradable mesoporous silica, encapsulating glycolysis inhibitor lonidamine, and small interfering RNA against glutaminase. Through inhibiting glycolysis to decrease the lactic acid production and downregulating glutaminase expression to reduce the uptake of glutamine by tumor cells, DMNPN enables effective remodeling of metabolism and nutrient partitioning, which alleviates the immunosuppressive TME and boosts nutrient availability for T cells with enhanced antitumor immunity. Such a nutrient partitioning nanoregulator can effectively inhibit the growth of anti-programmed death receptor 1 (anti-PD-1) resistant tumors and prevent tumor metastasis and recurrence. Overall, this dual-mechanism based nutrient reallocation strategy provides a promising approach for cancer therapy.