Drug-eluting immune checkpoint blockade antibody-nanoparticle conjugate enhances locoregional and systemic combination cancer immunotherapy through T lymphocyte targeting

Biodegradable pyroptosis inducer with multienzyme-mimic activity kicks up reactive oxygen species storm for sensitizing immunotherapy

Triggering pyroptosis is a major new weathervane for activating tumor immune response. However, biodegradable pyroptosis inducers for the safe and efficient treatment of tumors are still scarce. Herein, a novel tumor microenvironment (TME)-responsive activation nanoneedle for pyroptosis induction, copper-tannic acid (CuTA), was synthesized and combined with the sonosensitizer Chlorin e6 (Ce6) to form a pyroptosis amplifier (CuTA-Ce6) for dual activation and amplification of pyroptosis by exogenous ultrasound (US) and TME. It was demonstrated that Ce6-triggered sonodynamic therapy (SDT) further enhanced the cellular pyroptosis caused by CuTA, activating the body to develop a powerful anti-tumor immune response. Concretely, CuTA nanoneedles with quadruple mimetic enzyme activity could be activated to an "active" state in the TME, destroying the antioxidant defense system of the tumor cells through self-destructive degradation, breaking the "immunosilent" TME, and thus realizing the pyroptosis-mediated immunotherapy with fewer systemic side effects. Considering the outstanding oxygen-producing capacity of CuTA and the distinctive advantages of US, the sonosensitizer Ce6 was attached to CuTA via an amide reaction, which further amplified the pyroptosis and sensitized pyroptosis-induced immunotherapy with the two-pronged strategy of CuTA enzyme-catalyzed cascade and US-driven SDT pathway to generate a "reactive oxygen species (ROS) storm". Conclusively, this work provided a representative paradigm for achieving safe, reliable and efficient pyroptosis, which was further enhanced by SDT for more robust immunotherapy.

Research progress on novel antibody drug conjugates in cancer therapy

Traditional antibody drug conjugates (ADC) combine monoclonal antibodies with cytotoxic drugs to accurately strike cancer cells, but there are still many shortcomings in stability, targeting, efficacy, and safety. Novel ADC, such as bi-specific, site-specific, dual-payload, and pro-drug type ADC, can be optimized by simultaneously binding 2 different antigens or epitopes, selecting more stable linkers, coupling with specific amino acid sites of antibodies, carrying different drug payloads, and adopting prodrug strategies, while retaining the characteristics of traditional ADC. Significantly improving the stability, targeting, efficacy and safety of drugs can better meet the needs of clinical treatment. Novel ADC will play a more important role in cancer treatment in the future. Discussing the progress of novel ADC in cancer treatment and analyzing their advantages and challenges can provide theoretical support for the development of anti-cancer strategies and provide directions for drug research and development.

Nanotechnologies for Physiology-Informed Drug Delivery to the Lymphatic System

Accompanying the increasing translational impact of immunotherapeutic strategies to treat and prevent disease has been a broadening interest across both bioscience and bioengineering in the lymphatic system. Herein, the lymphatic system physiology, ranging from its tissue structures to immune functions and effects, is described. Design principles and engineering approaches to analyze and manipulate this tissue system in nanoparticle-based drug delivery applications are also elaborated.

Recent advances in targeted antibacterial therapy basing on nanomaterials

Bacterial infection has become one of the leading causes of death worldwide, particularly in low-income countries. Despite the fact that antibiotics have provided successful management in bacterial infections, the long-term overconsumption and abuse of antibiotics has contributed to the emergence of multidrug resistant bacteria. To address this challenge, nanomaterials with intrinsic antibacterial properties or that serve as drug carriers have been substantially developed as an alternative to fight against bacterial infection. Systematically and deeply understanding the antibacterial mechanisms of nanomaterials is extremely important for designing new therapeutics. Recently, nanomaterials-mediated targeted bacteria depletion in either a passive or active manner is one of the most promising approaches for antibacterial treatment by increasing local concentration around bacterial cells to enhance inhibitory activity and reduce side effects. Passive targeting approach is widely explored by searching nanomaterial-based alternatives to antibiotics, while active targeting strategy relies on biomimetic or biomolecular surface feature that can selectively recognize targeted bacteria. In this review article, we summarize the recent developments in the field of targeted antibacterial therapy based on nanomaterials, which will promote more innovative thinking focusing on the treatment of multidrug-resistant bacteria.

Immunosuppressive adenosine-targeted biomaterials for emerging cancer immunotherapy

Immunotherapy has paved the way for the future of cancer therapy, but there are still significant challenges to be overcome, such as the occurrence of immune escape or suppression. Adenosine is essential in modulating the immune responses of immune cells and maintaining immune tolerance. Emerging adenosine pathway inhibitors are considered a breakthrough in cancer immunotherapy, with emphasis first being placed on the top-down blockade of adenosine signaling axis, followed by combination therapy. However, these therapeutic strategies rely on adenosine inhibitors, mainly small molecules or antibody proteins, which are limited by a single route of administration and off-target toxicity. Therefore, synergistic nanomedicine with accurate delivery targeting deeper tumors is focused on in preclinical studies. This review discusses how adenosine reshapes immunosuppressive microenvironments through its effects on immune cells, including lymphocytes and myeloid cells. Additionally, it will be the first discussion of a comprehensive strategy of biomaterials in modulating the adenosine signaling pathway, including inhibition of adenosine production, inhibition of adenosine binding to immune cells, and depletion of adenosine in the microenvironments. Furthermore, biomaterials integrating multiple therapeutic modalities with adenosine blocking are also discussed as a promising strategy for promoting cancer immunotherapy.

Nanobiotherapeutic strategies to target immune microenvironment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the subtype with the least favourable outcomes in breast cancer. Besides chemotherapy, there is a chronic lack of other effective treatments. Advances in omic technologies have liberated us from the ambiguity of TNBC heterogeneity in terms of cancer cell and immune microenvironment in recent years. This new understanding of TNBC pathology has already led to the exploitation of novel nanoparticulate systems, including tumor vaccines, oncolytic viruses, and antibody derivatives. The revolutionary ideas in the therapeutic landscape provide new opportunities for TNBC patients. Translating these experimental medicines into clinical benefit is both appreciated and challenging. In this review, we describe the prospective nanobiotherapy of TNBC that has been developed to overcome clinical obstacles, and provide our vision for this booming field at the overlap of cancer biotherapy and nanomaterial design.

Elicitation of stem-like CD8+ T cell responses via lymph node-targeted chemoimmunotherapy evokes systemic tumor control

Background

Tumor-draining lymph nodes (TdLNs) are critical in the regulation of local and systemic antitumor T cell immunity and are implicated in coordinating responses to immunomodulatory therapies.

Methods

Biomaterial nanoparticles that deliver chemotherapeutic drug paclitaxel to TdLNs were leveraged to explore its effects in combination and immune checkpoint blockade (ICB) antibody immunotherapy to determine the benefit of TdLN-directed chemoimmunotherapy on tumor control.

Results

Accumulation of immunotherapeutic drugs in combination within TdLNs synergistically enhanced systemic T cell responses that led to improved control of local and disseminated disease and enhanced survival in multiple murine breast tumor models.

Conclusions

These findings suggest a previously underappreciated role of secondary lymphoid tissues in mediating effects of chemoimmunotherapy and demonstrate the potential for nanotechnology to unleashing drug synergies via lymph node targeted delivery to elicit improved response of breast and other cancers.

A Self-amplifying ROS-sensitive prodrug-based nanodecoy for circumventing immune resistance in chemotherapy-sensitized immunotherapy

Circumventing immune resistance and boosting immune response is the ultimate goal of cancer immunotherapy. Herein, we reported a tumor-associated macrophage (TAM) membrane-camouflaged nanodecoy containing a self-amplifying reactive oxygen species (ROS)-sensitive prodrug nanoparticle for specifically inducing immunogenic cell death (ICD) in combination with TAM depletion. A versatile ROS-cleavable camptothecin (CPT) prodrug (DCC) was synthesized through a thioacetal linker between CPT and the ROS generator cinnamaldehyde (CA), which could self-assemble into a uniform prodrug nanoparticle to realize a positive feedback loop of "ROS-triggered CA/CPT release and CA/CPT-mediated ROS generation." This DCC was further modified with the TAM membrane (abbreviated as DCC@M2), which could not only target both primary tumors and lung metastasis nodules through VCAM-1/α₄β₁ integrin interaction but also absorb CSF-1 secreted by tumor cells to disturb the interaction between TAMs and cancer cells. Our nanodecoy could effectively induce ICD cascade and deplete TAMs for priming tumor-specific effector T cell infiltration for antitumor immune response activation, which represents a versatile approach for cancer immunotherapy. STATEMENT OF SIGNIFICANCE: A tumor-associated macrophage (TAM) membrane-camouflaged nanodecoy containing a self-amplifying reactive oxygen species (ROS)-sensitive prodrug nanoparticle was fabricated for the first time. This ROS-cleavable camptothecin (CPT)/cinnamaldehyde (CA) prodrug (DCC) could self-assemble into a uniform nanoparticle to realize the positive feedback loop of "ROS-triggered CA/CPT release and CA/CPT-mediated ROS generation." After TAM membrane coating, this system (DCC@M2) could not only target both primary tumors and lung metastatic nodules but also scavenge CSF-1 secreted by tumor cells for TAM depletion for sufficient chemotherapy-sensitized immunotherapy.

Nanomedicines for Overcoming Cancer Drug Resistance

Clinically, cancer drug resistance to chemotherapy, targeted therapy or immunotherapy remains the main impediment towards curative cancer therapy, which leads directly to treatment failure along with extended hospital stays, increased medical costs and high mortality. Therefore, increasing attention has been paid to nanotechnology-based delivery systems for overcoming drug resistance in cancer. In this respect, novel tumor-targeting nanomedicines offer fairly effective therapeutic strategies for surmounting the various limitations of chemotherapy, targeted therapy and immunotherapy, enabling more precise cancer treatment, more convenient monitoring of treatment agents, as well as surmounting cancer drug resistance, including multidrug resistance (MDR). Nanotechnology-based delivery systems, including liposomes, polymer micelles, nanoparticles (NPs), and DNA nanostructures, enable a large number of properly designed therapeutic nanomedicines. In this paper, we review the different mechanisms of cancer drug resistance to chemotherapy, targeted therapy and immunotherapy, and discuss the latest developments in nanomedicines for overcoming cancer drug resistance.

Nanodrugs Targeting T Cells in Tumor Therapy

In contrast to conventional anti-tumor agents, nano-carriers allow co-delivery of distinct drugs in a cell type-specific manner. So far, many nanodrug-based immunotherapeutic approaches aim to target and kill tumor cells directly or to address antigen presenting cells (APC) like dendritic cells (DC) in order to elicit tumor antigen-specific T cell responses. Regulatory T cells (Treg) constitute a major obstacle in tumor therapy by inducing a pro-tolerogenic state in APC and inhibiting T cell activation and T effector cell activity. This review aims to summarize nanodrug-based strategies that aim to address and reprogram Treg to overcome their immunomodulatory activity and to revert the exhaustive state of T effector cells. Further, we will also discuss nano-carrier-based approaches to introduce tumor antigen-specific chimeric antigen receptors (CAR) into T cells for CAR-T cell therapy which constitutes a complementary approach to DC-focused vaccination.

Tolerance Induced by Antigen-Loaded PLG Nanoparticles Affects the Phenotype and Trafficking of Transgenic CD4+ and CD8+ T Cells

We have shown that PLG nanoparticles loaded with peptide antigen can reduce disease in animal models of autoimmunity and in a phase 1/2a clinical trial in celiac patients. Clarifying the mechanisms by which antigen-loaded nanoparticles establish tolerance is key to further adapting them to clinical use. The mechanisms underlying tolerance induction include the expansion of antigen-specific CD4⁺ regulatory T cells and sequestration of autoreactive cells in the spleen. In this study, we employed nanoparticles loaded with two model peptides, GP_33–41 (a CD8 T cell epitope derived from lymphocytic choriomeningitis virus) and OVA_323–339 (a CD4 T cell epitope derived from ovalbumin), to modulate the CD8⁺ and CD4⁺ T cells from two transgenic mouse strains, P14 and DO11.10, respectively. Firstly, it was found that the injection of P14 mice with particles bearing the MHC I-restricted GP_33–41 peptide resulted in the expansion of CD8⁺ T cells with a regulatory cell phenotype. This correlated with reduced CD4⁺ T cell viability in ex vivo co-cultures. Secondly, both nanoparticle types were able to sequester transgenic T cells in secondary lymphoid tissue. Flow cytometric analyses showed a reduction in the surface expression of chemokine receptors. Such an effect was more prominently observed in the CD4⁺ cells rather than the CD8⁺ cells.

Innovations in lymph node targeting nanocarriers

Lymph nodes are secondary lymphoid tissues in the body that facilitate the co-mingling of immune cells to enable and regulate the adaptive immune response. They are also tissues implicated in a variety of diseases, including but not limited to malignancy. The ability to access lymph nodes is thus attractive for a variety of therapeutic and diagnostic applications. As nanotechnologies are now well established for their potential in translational biomedical applications, their high relevance to applications that involve lymph nodes is highlighted. Herein, established paradigms of nanocarrier design to enable delivery to lymph nodes are discussed, considering the unique lymph node tissue structure as well as lymphatic system physiology. The influence of delivery mechanism on how nanocarrier systems distribute to different compartments and cells that reside within lymph nodes is also elaborated. Finally, current advanced nanoparticle technologies that have been developed to enable lymph node delivery are discussed.