Nanotechnology-enabled immunogenic cell death for improved cancer immunotherapy

Tumor immunotherapy has revolutionized the field of oncology treatments in recent years. As one of the promising strategies of cancer immunotherapy, tumor immunogenic cell death (ICD) has shown significant potential for tumor therapy. Nanoparticles are widely used for drug delivery due to their versatile characteristics, such as stability, slow blood elimination, and tumor-targeting ability. To increase the specificity of ICD inducers and improve the efficiency of ICD induction, functionally specific nanoparticles, such as liposomes, nanostructured lipid carriers, micelles, nanodiscs, biomembrane-coated nanoparticles and inorganic nanoparticles have been widely reported as the vehicles to deliver ICD inducers in vivo. In this review, we summarized the strategies of different nanoparticles for ICD-induced cancer immunotherapy, and systematically discussed their advantages and disadvantages as well as provided feasible strategies for solving these problems. We believe that this review will offer some insights into the design of effective nanoparticulate systems for the therapeutic delivery of ICD inducers, thus, promoting the development of ICD-mediated cancer immunotherapy.

Reduction-responsive dextran-based Pt(IV) nano-prodrug showed a synergistic effect with doxorubicin for effective melanoma treatment

Melanoma, the deadliest skin cancer with high metastasis potential, has posed a great threat to human health. Accordingly, early efficient blocking of melanoma progression is vital in antitumor treatment. Herein, a reduction-responsive dextran-based Pt(IV) nano-prodrug (PDPN) was synthesized and used for doxorubicin (DOX) delivery to combat melanoma synergistically. First, PDPN was prepared by one-pot chemical coupling of carboxylated methoxy poly(ethylene glycol) (mPEG), dextran (Dex), and the crosslinking agent cisPt (IV)-COOH. PDPN had a spherical structure (R_h = 34 ± 11.3 nm). Then, DOX was encapsulated into the PDPN core to form DOX-loaded PDPN (PDPN-DOX). The obtained PDPN-DOX displayed reduction-responsive release of DOX and Pt, thus showing a synergistic anticancer effect in B16F10 cells (combination index, 0.46). Furthermore, in vivo experiments demonstrated that PDPN-DOX was effective for the synergistic treatment of subcutaneous melanoma. Collectively, the as-prepared PDPN could serve as a promising and versatile nano-prodrug carrier for the co-delivery of chemotherapeutics in tumor combination therapy.

Mechanoresponsive Drug Delivery Systems for Vascular Diseases

Mechanoresponsive drug delivery systems (DDS) have emerged as promising candidates to improve the current effectiveness and lower the side effects typically associated with direct drug administration in the context of vascular diseases. Despite tremendous research efforts to date, designing drug delivery systems able to respond to mechanical stimuli to potentially treat these diseases is still in its infancy. By understanding relevant biological forces emerging in healthy and pathological vascular endothelium, it is believed that better-informed design strategies can be deduced for the fabrication of simple-to-complex macromolecular assemblies capable of sensing mechanical forces. These responsive systems are discussed through insights into essential parameter design (composition, size, shape, and aggregation state) , as well as their functionalization with (macro)molecules that are intrinsically mechanoresponsive (e.g., mechanosensitive ion channels and mechanophores). Mechanical forces, including the pathological shear stress and exogenous stimuli (e.g., ultrasound, magnetic fields), used for the activation of mechanoresponsive DDS are also introduced, followed by in vitro and in vivo experimental models used to investigate and validate such novel therapies. Overall, this review aims to propose a fresh perspective through identified challenges and proposed solutions that could be of benefit for the further development of this exciting field.

Artificial intelligence aids in development of nanomedicines for cancer management

Over the last decade, the nanomedicine has experienced unprecedented development in diagnosis and management of diseases. A number of nanomedicines have been approved in clinical use, which has demonstrated the potential value of clinical transition of nanotechnology-modified medicines from bench to bedside. The application of artificial intelligence (AI) in development of nanotechnology-based products could transform the healthcare sector by realizing acquisition and analysis of large datasets, and tailoring precision nanomedicines for cancer management. AI-enabled nanotechnology could improve the accuracy of molecular profiling and early diagnosis of patients, and optimize the design pipeline of nanomedicines by tuning the properties of nanomedicines, achieving effective drug synergy, and decreasing the nanotoxicity, thereby, enhancing the targetability, personalized dosing and treatment potency of nanomedicines. Herein, the advances in AI-enabled nanomedicines in cancer management are elaborated and their application in diagnosis, monitoring and therapy as well in precision medicine development is discussed.

Reactive oxygen species-upregulating nanomedicines towards enhanced cancer therapy

Reactive oxygen species (ROS) play a crucial role in physiological and pathological processes, emerging as a therapeutic target in cancer. Owing to the high concentration of ROS in solid tumor tissues, ROS-based treatments, such as photodynamic therapy and chemodynamic therapy, and ROS-responsive drug delivery systems have been widely explored to powerfully and specifically suppress tumors. However, their anticancer efficacy is still hampered by the heterogeneous ROS levels, and thus comprehensively upregulating the ROS levels in tumor tissues can ensure an enhanced therapeutic effect, which can further sensitize and/or synergize with other therapies to inhibit tumor growth and metastasis. Herein, we review the recently emerging drug delivery strategies and technologies for increasing the H₂O₂, ˙OH, ¹O₂, and ˙O₂^- concentrations in cancer cells, including the efficient delivery of natural enzymes, nanozymes, small molecular biological molecules, and nanoscale Fenton-reagents and semiconductors and neutralization of intracellular antioxidant substances and localized input of mechanical and electromagnetic waves (such as ultrasound, near infrared light, microwaves, and X-rays). The applications of these ROS-upregulating nanosystems in enhancing and synergizing cancer therapies including chemotherapy, chemodynamic therapy, phototherapy, and immunotherapy are surveyed. In addition, we discuss the challenges of ROS-upregulating systems and the prospects for future studies.

Lactose-modified enzyme-sensitive branched polymers as a nanoscale liver cancer-targeting MRI contrast agent

Signal enhancement of magnetic resonance imaging (MRI) in the diseased region is dependent on the molecular structure of the MRI contrast agent. In this study, a macromolecular contrast agent, Branched-LAMA-DOTA-Cy5.5-Gd (BLDCGd), was prepared to target liver cancer. Due to the affinity of lactose to the Asialoglycoprotein receptor (ASGPR) over-expressed on the surface of liver cancer cells, lactose was selected as the targeting moiety in the contrast agent. A cathepsin B-sensitive tetrapeptide, GFLG, was used as a linkage moiety to construct a cross-linked macromolecular structure of the contrast agent, and the contrast agent could be degraded into fragments for clearance. A small-molecular-weight molecule, DOTA-Gd, and a fluorescent dye, Cy5.5, were conjugated to the macromolecular structure via a thiol-ene click reaction. The contrast agent, BLDCGd, had a high molecular weight (81 kDa) and a small particle size (59 ± 12 nm). Its longitudinal relaxivity (12.62 mM^-1 s^-1) was 4-fold that of the clinical agent DTPA-Gd (3.42 mM^-1 s^-1). Signal enhancement of up to 184% was observed at the tumor site in an H22 cell-based mouse model. A high accumulation level of BLDCGd in the liver tumor observed from MRI was confirmed from the fluorescence images obtained from the same contrast agent. BLDCGd showed no toxicity to HUVECs and H22 cells in vitro, and low blood chemistry indexes and no distinct histopathological abnormalities were also observed in vivo after injection of BLDCGd since it could be metabolized through the kidneys according to the in vivo MRI results of major organs. Therefore, the branched macromolecule BLDCGd could have great potential as an efficacious and bio-safe nanoscale MRI contrast agent for clinical diagnosis of liver cancer.

Effect of regulatory cell death on the occurrence and development of head and neck squamous cell carcinoma

Head and neck cancer is a malignant tumour with a high mortality rate characterized by late diagnosis, high recurrence and metastasis rates, and poor prognosis. Head and neck squamous cell carcinoma (HNSCC) is the most common type of head and neck cancer. Various factors are involved in the occurrence and development of HNSCC, including external inflammatory stimuli and oncogenic viral infections. In recent years, studies on the regulation of cell death have provided new insights into the biology and therapeutic response of HNSCC, such as apoptosis, necroptosis, pyroptosis, autophagy, ferroptosis, and recently the newly discovered cuproptosis. We explored how various cell deaths act as a unique defence mechanism against cancer emergence and how they can be exploited to inhibit tumorigenesis and progression, thus introducing regulatory cell death (RCD) as a novel strategy for tumour therapy. In contrast to accidental cell death, RCD is controlled by specific signal transduction pathways, including TP53 signalling, KRAS signalling, NOTCH signalling, hypoxia signalling, and metabolic reprogramming. In this review, we describe the molecular mechanisms of nonapoptotic RCD and its relationship to HNSCC and discuss the crosstalk between relevant signalling pathways in HNSCC cells. We also highlight novel approaches to tumour elimination through RCD.

An antioxidant and antibacterial polydopamine-modified thermo-sensitive hydrogel dressing for Staphylococcus aureus-infected wound healing

Bacteria-infected wound healing is a complex and chronic process that poses a great threat to human health. A thermo-sensitive hydrogel that undergoes a sol-gel transition at body temperature is an attractive wound dressing for healing acceleration and infection prevention. In this paper, we present a thermo-sensitive and reactive oxygen species (ROS)-scavenging hydrogel based on polydopamine modified poly(ε-caprolactone-co-glycolide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-glycolide) (PDA/P2) triblock copolymer. The PDA/P2 solution at a concentration of 30 wt% could form a gel at 34-38 °C. The ROS-scavenging ability of PDA/P2 was demonstrated by DPPH and ABTS assays and intracellular ROS downregulation in RAW264.7 cells. Furthermore, silver nanoparticles were encapsulated in the hydrogel (PDA/P2-4@Ag gel) to provide antibacterial activity against E. coli and S. aureus. An in vivo S. aureus-infected rat model demonstrated that the PDA/P2-4@Ag hydrogel dressing could promote wound healing via inhibiting bacterial growth, alleviating the inflammatory response, and inducing angiogenesis and collagen deposition. This study provides a new strategy to prepare temperature-sensitive hydrogel-based multifunctional wound dressings.

Enzyme and Reactive Oxygen Species-Responsive Dual-Drug Delivery Nanocomplex for Tumor Chemo-Photodynamic Therapy

Introduction

Combination therapy is a promising approach to promote the efficacy and reduce the systemic toxicity of cancer therapy. Herein, we examined the potency of a combined chemo-phototherapy approach by constructing a hyaluronidase- and reactive oxygen species-responsive hyaluronic acid nanoparticle carrying a chemotherapy drug and a photosensitizer in a tumor-bearing mouse model. We hypothesized that following decomposition, the drugs inside the nanocomplex will be released in the tumors to provide effective tumor treatment. We aimed to design a smart drug delivery system that can improve traditional chemotherapy drug delivery and enhance the therapeutic efficacy in combination with photodynamic therapy.

Methods

Hydrophilic hyaluronic acid (HA) was covalently modified with a hydrophobic 5β-cholanic acid (CA) via an ROS-cleavable thioketal (tk) linker for a targeted co-deliver of 10-Hydroxy camptothecin (HCPT) and Chlorin e6 (Ce6) into tumors to improve the efficiency of combined chemo-photodynamic therapy.

Results

The obtained HA-tk-CA nanoparticle carrying HCPT and Ce6, named HTCC, accumulated in the tumor through the enhanced permeable response (EPR) effect and HA-mediated CD44 targeting after intravenous administration. Upon laser irradiation and hyaluronidase degradation, HTCC was disrupted to release HCPT and Ce6 into the tumors. Compared to the monotherapy approach, HTCC demonstrated enhanced tumor growth inhibition and minimized systemic toxicity in a tumor-bearing mouse model.

Conclusion

Our results suggested that controlled dual-drug release not only improved tumor drug delivery efficacy, but also reduced systemic side effects. In addition to HCPT and Ce6 delivery, the HA-tk-CA nanocomplex can be used to deliver other drugs in synergistic cancer therapy. Since most current combined therapy uses free drugs with distinct spatiotemporal distributions, the simultaneous co-delivery of dual drugs with a remote on-demand drug delivery nanosystem provides an alternative strategy for drug delivery design.

Nanomedicine embraces cancer radio-immunotherapy: mechanism, design, recent advances, and clinical translation

Cancer radio-immunotherapy, integrating external/internal radiation therapy with immuno-oncology treatments, emerges in the current management of cancer. A growing number of pre-clinical studies and clinical trials have recently validated the synergistic antitumor effect of radio-immunotherapy, far beyond the "abscopal effect", but it suffers from a low response rate and toxicity issues. To this end, nanomedicines with an optimized design have been introduced to improve cancer radio-immunotherapy. Specifically, these nanomedicines are elegantly prepared by incorporating tumor antigens, immuno- or radio-regulators, or biomarker-specific imaging agents into the corresponding optimized nanoformulations. Moreover, they contribute to inducing various biological effects, such as generating in situ vaccination, promoting immunogenic cell death, overcoming radiation resistance, reversing immunosuppression, as well as pre-stratifying patients and assessing therapeutic response or therapy-induced toxicity. Overall, this review aims to provide a comprehensive landscape of nanomedicine-assisted radio-immunotherapy. The underlying working principles and the corresponding design strategies for these nanomedicines are elaborated by following the concept of "from bench to clinic". Their state-of-the-art applications, concerns over their clinical translation, along with perspectives are covered.

Banoxantrone Coordinated Metal-Organic Framework for Photoacoustic Imaging-Guided High Intensity Focused Ultrasound Therapy

Photoacoustic (PA) imaging with high spatial resolution has great potential as desired monitoring means in the high-intensity focused ultrasound (HIFU) surgery of tumor. However, its penetration depth in the tissue is insufficient for achieving accurate intraoperative navigation, leading to residual tumor tissue. Nanomedicine provides a new opportunity for PA imaging to guide HIFU surgery. Studies have found that the hypoxic heterogeneity of tumor is effectively reversed by HIFU. Herein, a specific metal-organic framework nanosystem, constructed by coordination of banoxantrone (AQ4N) and Mn²⁺ , is designed based on HIFU to reverse the hypoxic heterogeneity of tumors. It can provide exogenous light-absorbing substances, thus improving the penetrability of PA imaging signal through the deep tissue and achieving clearer PA imaging for guiding HIFU surgery. In turn, AQ4N, in the hypoxic homogenous environment of the tumor provided by HIFU, is activated sequentially to specifically treat the residual hypoxic tumor cells. This combination treatment manifests higher tumor suppressors activation and lower expression of genes related to tumor progression. This strategy addresses the dissatisfaction with PA imaging-guided HIFU therapy and is promising for translation into a clinical combination regimen.

Improved cancer immunotherapy strategies by nanomedicine

Cancer immunotherapy agents fight cancer via immune system stimulation and have made significant advances in minimizing side effects and prolonging the survival of patients with solid tumors. However, major limitations still exist in cancer immunotherapy, including the inefficiency of immune response stimulation in specific cancer types, therapy resistance caused by the tumor microenvironment (TME), toxicities by the immune imbalance, and short lifetime of stimulator of interferon genes (STING) agonist. Recent advances in nanomedicine have shown significant potential in overcoming the obstacles of cancer immunotherapy. Several nanoscale agents have been reported for cancer immunotherapy, including nanoscale cancer vaccines impacting the STING pathway, nanomaterials reprogramming TME, nano-agents triggering immune response with immune checkpoint inhibitor synergy, ferroptosis-mediated and indoleamine-2,3-dioxygenase immunosuppression-mediated cancer immunotherapy, and nanomedicine-meditated chimeric antigen receptor-T-cell therapy. Herein, we summarize the major advances and innovations in nanomedicine-based cancer immunotherapy, and outline the opportunities and challenges to integrate more advanced nanomaterials into cancer immunotherapy. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Attenuating Metabolic Competition of Tumor Cells for Favoring the Nutritional Demand of Immune Cells by a Branched Polymeric Drug Delivery System

Tumor cells are dominant in the nutritional competition in the tumor microenvironment, and their metabolic abnormalities often lead to microenvironmental acidosis and nutrient deprivation, thereby impairing the function of immune cells and diminishing the antitumor therapeutic effect. Herein, a branched polymeric conjugate and its efficacy in attenuating the metabolic competition of tumor cells are reported. Compared with the control nanoparticles prepared from its linear counterpart, the branched-conjugate-based nanoparticles can more efficiently accumulate in the tumor tissue and interfere with the metabolic processes of tumor cells to increase the concentration of essential nutrients and reduce the level of immunosuppressive metabolites in the TME, thus creating a favorable environment for infiltrated immune cells. Its combined treatment with an immune checkpoint inhibitor (ICI) achieves an enhanced antitumor effect. The work presents a promising approach for targeting metabolic competition in the TME to enhance the chemo-immunotherapeutic effect against cancers.

Mechanisms and challenges of nanocarriers as non-viral vectors of therapeutic genes for enhanced pulmonary delivery

With the rapid development of biopharmaceuticals and the outbreak of COVID-19, the world has ushered in a frenzy to develop gene therapy. Therefore, therapeutic genes have received enormous attention. However, due to the extreme instability and low intracellular gene expression of naked genes, specific vectors are required. Viral vectors are widely used attributed to their high transfection efficiency. However, due to the safety concerns of viral vectors, nanotechnology-based non-viral vectors have attracted extensive investigation. Still, issues of low transfection efficiency and poor tissue targeting of non-viral vectors need to be addressed. Especially, pulmonary gene delivery has obvious advantages for the treatment of inherited lung diseases, lung cancer, and viral pneumonia, which can not only enhance lung targeting and but also reduce enzymatic degradation. For systemic diseases therapy, pulmonary gene delivery can enhance vaccine efficacy via inducing not only cellular, humoral immunity but also mucosal immunity. This review provides a comprehensive overview of nanocarriers as non-viral vectors of therapeutic genes for enhanced pulmonary delivery. First of all, the characteristics and therapeutic mechanism of DNA, mRNA, and siRNA are provided. Thereafter, the advantages and challenges of pulmonary gene delivery in exerting local and systemic effects are discussed. Then, the inhalation dosage forms for nanoparticle-based drug delivery systems are introduced. Moreover, a series of materials used as nanocarriers for pulmonary gene delivery are presented, and the endosomal escape mechanisms of nanocarriers based on different materials are explored. The application of various non-viral vectors for pulmonary gene delivery are summarized in detail, with the perspectives of nano-vectors for pulmonary gene delivery.

Epsilon-caprolactone-modified polyethylenimine as a genetic vehicle for stem cell-based bispecific antibody and exosome synergistic therapy

Bispecific antibodies (BsAb) have gained significant momentum in clinical application. However, the rapid enzymolysis and metabolism of protein drugs usually induce short circulation in vivo, and developing an efficient protein delivery system still is a bottleneck. Mesenchymal stem cells (MSCs) have become an attractive therapeutic carrier for cancers. Genetic modification enables MSCs to express and secrete specific proteins, which is essential for therapeutic efficacy. However, efficient gene transfer into MSCs is still a challenge. In this study, we applied epsilon-caprolactone-modified polyethylenimine (PEI-CL) as an efficacy carrier for plasmid transfection into MSC that served as in situ 'cell factory' for anti-CD3/CD20 BsAb preparation. Herein, the PEI-CL encapsulates the minicircle plasmid and mediates cell transfection efficiently. Thus, the anti-CD3/CD20 BsAb is secreted from MSC and recruited T cell, resulting in highly sensitive cytotoxicity in the human B-cell lymphoma. Furthermore, these stem cells produce exosomes bearing MiR-15a/MiR-16, which could negatively regulate cancer's oncogenes BCL-2 for adjuvant therapy. Meanwhile, high immunologic factors like tumor necrosis factor-α and interferon-γ are generated and enhance immunotherapy efficacy. The engineered MSCs are demonstrated as an efficient route for BsAb production, and these bioactive components contribute to synergistic therapy, which would be an innovative treatment.