A Tumor-Penetrating Nanomedicine Improves the Chemoimmunotherapy of Pancreatic Cancer

Nanoparticle-Mediated Synergistic Chemoimmunotherapy for Cancer Treatment

Until now, there has been a lack of effective strategies for cancer treatment. Immunotherapy has high potential in treating several cancers but its efficacy is limited as a monotherapy. Chemoimmunotherapy (CIT) holds promise to be widely used in cancer treatment. Therefore, identifying their involvement and potential synergy in CIT approaches is decisive. Nano-based drug delivery systems (NDDSs) are ideal delivery systems because they can simultaneously target immune cells and cancer cells, promoting drug accumulation, and reducing the toxicity of the drug. In this review, we first introduce five current immunotherapies, including immune checkpoint blocking (ICB), adoptive cell transfer therapy (ACT), cancer vaccines, oncolytic virus therapy (OVT) and cytokine therapy. Subsequently, the immunomodulatory effects of chemotherapy by inducing immunogenic cell death (ICD), promoting tumor killer cell infiltration, down-regulating immunosuppressive cells, and inhibiting immune checkpoints have been described. Finally, the NDDSs-mediated collaborative drug delivery systems have been introduced in detail, and the development of NDDSs-mediated CIT nanoparticles has been prospected.

Conquering chemoresistance in pancreatic cancer: Exploring novel drug therapies and delivery approaches amidst desmoplasia and hypoxia

Pancreatic cancer poses a significant challenge within the field of oncology due to its aggressive behaviour, limited treatment choices, and unfavourable outlook. With a mere 10% survival rate at the 5-year mark, finding effective interventions becomes even more pressing. The intricate relationship between desmoplasia and hypoxia in the tumor microenvironment further complicates matters by promoting resistance to chemotherapy and impeding treatment efficacy. The dense extracellular matrix and cancer-associated fibroblasts characteristic of desmoplasia create a physical and biochemical barrier that impedes drug penetration and fosters an immunosuppressive milieu. Concurrently, hypoxia nurtures aggressive tumor behaviour and resistance to conventional therapies. a comprehensive exploration of emerging medications and innovative drug delivery approaches. Notably, advancements in nanoparticle-based delivery systems, local drug delivery implants, and oxygen-carrying strategies are highlighted for their potential to enhance drug accessibility and therapeutic outcomes. The integration of these strategies with traditional chemotherapies and targeted agents reveals the potential for synergistic effects that amplify treatment responses. These emerging interventions can mitigate desmoplasia and hypoxia-induced barriers, leading to improved drug delivery, treatment efficacy, and patient outcomes in pancreatic cancer. This review article delves into the dynamic landscape of emerging anticancer medications and innovative drug delivery strategies poised to overcome the challenges imposed by desmoplasia and hypoxia in the treatment of pancreatic cancer.

Nanodrug Delivery Systems in Antitumor Immunotherapy

Cancer has become one of the most important factors threatening human health, and the global cancer burden has been increasing rapidly. Immunotherapy has become another clinical research hotspot after surgery, chemotherapy, and radiotherapy because of its high efficiency and tumor metastasis prevention. However, problems such as lower immune response rate and immune-related adverse reaction in the clinical application of immunotherapy need to be urgently solved. With the development of nanodrug delivery systems, various nanocarrier materials have been used in the research of antitumor immunotherapy with encouraging therapeutic results. In this review, we mainly summarized the combination of nanodrug delivery systems and immunotherapy from the following 4 aspects: (a) nanodrug delivery systems combined with cytokine therapy to improve cytokines delivery in vivo; (b) nanodrug delivery systems provided a suitable platform for the combination of immune checkpoint blockade therapy with other tumor treatments; (c) nanodrug delivery systems helped deliver antigens and adjuvants for tumor vaccines to enhance immune effects; and (d) nanodrug delivery systems improved tumor treatment efficiency and reduced toxicity for adoptive cell therapy. Nanomaterials chosen by researchers to construct nanodrug delivery systems and their function were also introduced in detail. Finally, we discussed the current challenges and future prospects in combining nanodrug delivery systems with immunotherapy.

Fluorocarbon Modified Chitosan to Enable Transdermal Immunotherapy for Melanoma Treatment

Despite the rapid development of the immune checkpoint blockade (ICB) in melanoma treatment, the immunosuppressive tumor microenvironment (TME) still hinders the efficacy of immunotherapy. Recently, using agonists to modulate the TME have presented promising clinical responses in combination with ICB therapies. However, local intratumoral injection as the commonly used administration route for immune agonists would lead to low patient compliance. Herein, it is demonstrated that fluorocarbon modified chitosan (FCS) can self-assemble with immune adjuvant polyriboinosinic:polyribocytidylic acid (poly(I:C)), forming nanoparticles that can penetrate through cutaneous barriers to enable transdermal delivery. FCS/poly(I:C) can efficiently activate various types of cells presented on the transdermal route (through the skin into the TME), leading to IRF3-mediated IFN-β induction in the activated cells for tumor repression. Furthermore, transdermal FCS/poly(I:C) treatment can significantly magnify the efficacy of the programmed cell death protein 1 (PD-1) blockade in melanoma treatment through activating the immunosuppressive TME. This study approach offered an attractive transdermal approach in combined with ICB therapy for combined immunotherapy, particularly suitable for melanoma treatment.

Advances in Pancreatic Cancer Treatment by Nano-Based Drug Delivery Systems

Pancreatic cancer represents one of the most lethal cancer types worldwide, with a 5-year survival rate of less than 5%. Due to the inability to diagnose it promptly and the lack of efficacy of existing treatments, research and development of innovative therapies and new diagnostics are crucial to increase the survival rate and decrease mortality. Nanomedicine has been gaining importance as an innovative approach for drug delivery and diagnosis, opening new horizons through the implementation of smart nanocarrier systems, which can deliver drugs to the specific tissue or organ at an optimal concentration, enhancing treatment efficacy and reducing systemic toxicity. Varied materials such as lipids, polymers, and inorganic materials have been used to obtain nanoparticles and develop innovative drug delivery systems for pancreatic cancer treatment. In this review, it is discussed the main scientific advances in pancreatic cancer treatment by nano-based drug delivery systems. The advantages and disadvantages of such delivery systems in pancreatic cancer treatment are also addressed. More importantly, the different types of nanocarriers and therapeutic strategies developed so far are scrutinized.

Recent Advances in Well-Designed Therapeutic Nanosystems for the Pancreatic Ductal Adenocarcinoma Treatment Dilemma

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with an extremely poor prognosis and low survival rate. Due to its inconspicuous symptoms, PDAC is difficult to diagnose early. Most patients are diagnosed in the middle and late stages, losing the opportunity for surgery. Chemotherapy is the main treatment in clinical practice and improves the survival of patients to some extent. However, the improved prognosis is associated with higher side effects, and the overall prognosis is far from satisfactory. In addition to resistance to chemotherapy, PDAC is significantly resistant to targeted therapy and immunotherapy. The failure of multiple treatment modalities indicates great dilemmas in treating PDAC, including high molecular heterogeneity, high drug resistance, an immunosuppressive microenvironment, and a dense matrix. Nanomedicine shows great potential to overcome the therapeutic barriers of PDAC. Through the careful design and rational modification of nanomaterials, multifunctional intelligent nanosystems can be obtained. These nanosystems can adapt to the environment's needs and compensate for conventional treatments' shortcomings. This review is focused on recent advances in the use of well-designed nanosystems in different therapeutic modalities to overcome the PDAC treatment dilemma, including a variety of novel therapeutic modalities. Finally, these nanosystems' bottlenecks in treating PDAC and the prospect of future clinical translation are briefly discussed.

Enzyme-Triggered Size-Switchable Nanosystem for Deep Tumor Penetration and Hydrogen Therapy

The poor penetration of nanocarriers within tumor dense extracellular matrices (ECM) greatly restricts the access of anticancer drugs to the deep tumor cells, resulting in low therapeutic efficacy. Moreover, the high toxicity of the traditional chemotherapeutics inevitably causes undesirable side effects. Herein, taking the advantages of biosafe H₂ and small-sized nanoparticles in diffusion within tumor ECM, we develop a matrix metalloprotease 2 (MMP-2) responsive size-switchable nanoparticle (UAMSN@Gel-PEG) that is composed of ultrasmall amino-modified mesoporous silica nanoparticles (UAMSN) wrapped within a PEG-conjugated gelatin to deliver H₂ to the deep part of tumors for effective gas therapy. Ammonia borane (AB) is chosen as the H₂ prodrug that can be effectively loaded into UAMSN by hydrogen-bonding adsorption. Gelatin is used as the substrate of MMP-2 to trigger size change and block AB inside UAMSN during blood circulation. PEG is introduced to further increase the particle size and endow the nanoparticle with long blood circulation to achieve effective tumor accumulation via the EPR effect. After accumulation into the tumor site, MMP-2 promptly digests gelatin to expose UAMSN loading AB for deep tumor penetration. Upon stimulation by the acidic tumor microenvironment, AB decomposes into H₂ for further intratumor diffusion to achieve effective hydrogen therapy. Consequently, such a simultaneous deep tumor penetration of nanocarriers and H₂ results in an evident suppression on tumor growth in a 4T1 tumor-bearing model without any obvious toxicity on normal tissues. Our synthetic nanosystem provides a promising strategy for the development of nanomedicines with enhanced tumor permeability and good biosafety for efficient tumor treatment.

Engineered nanomedicines to overcome resistance of pancreatic cancer to immunotherapy

Pancreatic cancer (PC) is a highly aggressive malignant type of cancer. Although immunotherapy has been successfully used for treatment of many cancer types, many challenges limit its success in PC. Therefore, nanomedicines were engineered to enhance the responsiveness of PC cells to immune checkpoint inhibitors (ICIs). In this review, we highlight recent advances in engineering nanomedicines to overcome PC immune resistance. Nanomedicines were used to increase the immunogenicity of PC cells, inactivate stromal cancer-associated fibroblasts (CAFs), enhance the antigen-presenting capacity of dendritic cells (DCs), reverse the highly immunosuppressive nature of the tumor microenvironment (TME), and, hence, improve the infiltration of cytotoxic T lymphocytes (CTLs), resulting in efficient antitumor immune responses.

Biophysical heterogeneity of myeloid-derived microenvironment to regulate resistance to cancer immunotherapy

Despite the advances in immunotherapy for cancer treatment, patients still obtain limited benefits, mostly owing to unrestrained tumour self-expansion and immune evasion that exploits immunoregulatory mechanisms. Traditionally, myeloid cells have a dominantly immunosuppressive role. However, the complicated populations of the myeloid cells and their multilateral interactions with tumour/stromal/lymphoid cells and physical abnormalities in the tumour microenvironment (TME) determine their heterogeneous functions in tumour development and immune response. Tumour-associated myeloid cells (TAMCs) include monocytes, tumour-associated macrophages (TAMs), myeloid-derived suppressor cells (MDSCs), dendritic cells (DCs), and granulocytes. Single-cell profiling revealed heterogeneous TAMCs composition, sub-types, and transcriptomic signatures across 15 human cancer types. We systematically reviewed the biophysical heterogeneity of TAMC composition and pro/anti-tumoral and immuno-suppressive/stimulating properties of myeloid-derived microenvironments. We also summarised comprehensive clinical strategies to overcome resistance to immunotherapy from three dimensions: targeting TAMCs, reversing physical abnormalities, utilising nanomedicines, and finally, put forward futuristic perspectives for scientific and clinical research.

Kidney-Targeted Nanoparticles Loaded with the Natural Antioxidant Rosmarinic Acid for Acute Kidney Injury Treatment

Acute kidney injury (AKI) is a common clinical disease with high morbidity and mortality, and with a lack of effective drugs for treatment. Oxidative stress is very important in the occurrence and progression of AKI, and antioxidants use is one of the promising treatments. Rosmarinic acid (RA) is a ubiquitous natural polyphenol with powerful antioxidant and anti-inflammatory activities. Due to its inherent characteristic with poor water solubility and inferior bioavailability, its clinical application is impeded. Hence, the authors design a nanoparticle for effectively delivering RA, which is a chemical complex of RA and fourth-generation poly-amidoamine-based amphiphilic polymer (G4-PAMAM). The nanoparticle is modified with l-serine due to the specific interaction between kidney injury molecule-1 (Kim-1) and serine, which eventually generates a promising AKI kidney-targeting nanoparticle (S-G-R). The S-G-R is rapidly cumulated and long-term retained in ischemia-reperfusion-induced AKI kidneys, especially in the damaged renal tubular cells. The S-G-R exhibits more excellent antioxidative and antiapoptotic effects in vitro and has a more outstanding ability to improve the renal function, repair damaged renal tissue, and decrease oxidative stress, inflammatory response and apoptosis of tubular cells in vivo. Overall, this study might develop a safe and effective targeting strategy for the therapy of AKI.

Antitumor Activity of the Zinc Oxide Nanoparticles Coated with Low-Molecular-Weight Heparin and Doxorubicin Complex In Vitro and In Vivo

Various metal oxide nanomaterials have been widely used as carriers to prepare pH-sensitive nanomedicines to respond to the acidic tumor microenvironment promoting antitumor efficiency. Herein, we used zinc oxide nanoparticles (ZnO NPs) as metal oxide nanomaterial coated with low-molecular-weight heparin (LMHP) and doxorubicin (DOX) complex (LMHP-DOX) to prepare ZnO-LD NPs for controllable pH-triggered DOX release on the targeted site. Our results indicated that the released DOX from ZnO-LD NPs was pH-sensitive. The oxygen produced by ZnO-LD NPs in H₂O₂ solution was observed in in vitro experiment. The ZnO-LD NPs entered into both PC-3M and 4T1 tumor cells via clathrin-mediated endocytosis and micropinocytosis pathway. The intracellular reactive oxygen species (ROS) generated by ZnO-LD NPs could significantly increase the caspase 3/7 level, leading to tumor cell apoptosis. The in vitro and in vivo antitumor activity was confirmed in PC-3M and 4T1 cell lines or tumor-bearing mice models. The in vivo and in vitro tumor images via second-order nonlinearity of ZnO-LD NPs indicated that ZnO-LD NPs could penetrate deep into the tumor tissues. Therefore, the ZnO-LD NPs developed in our study could provide an efficient approach for the preparation of pH-sensitive nano delivery systems suitable for tumor therapy and imaging.

Smart hypoxia-responsive transformable and charge-reversible nanoparticles for the deep penetration and tumor microenvironment modulation of pancreatic cancer

The compact extracellular matrix (ECM) of pancreatic ductal adenocarcinoma (PDAC) is the major physical barrier that hinders the delivery of anti-tumor drugs, leading to strong inherent chemotherapy resistance as well as establishing an immunosuppressive tumor microenvironment (TME). However, forcibly destroying the stroma barrier would break the balance of delicate signal transduction and dependence between tumor cells and matrix components. Uncontrollable growth and metastasis would occur, making PDAC more difficult to control. Hence, we design and construct an aptamer-decorated hypoxia-responsive nanoparticle s(DGL)n@Apt co-loading gemcitabine monophosphate and STAT3 inhibitor HJC0152. This nanoparticle can reverse its surficial charge in the TME, and reduce the size triggered by hypoxia. The released ultra-small DGL particles loading gemcitabine monophosphate exhibit excellent deep-tumor penetration, chemotherapy drugs endocytosis promotion, and autophagy induction ability. Meanwhile, HJC0152 inhibits overactivated STAT3 in both tumor cells and tumor stroma, softens the stroma barrier, and reeducates the TME into an immune-activated state. This smart codelivery strategy provides an inspiring opportunity in PDAC treatment.

Microbial hydrogen "manufactory" for enhanced gas therapy and self-activated immunotherapy via reduced immune escape

BACKGROUND

As an antioxidant, hydrogen (H₂) can selectively react with the highly toxic hydroxyl radical (·OH) in tumor cells to break the balance of reactive oxygen species (ROS) and cause oxidative stress. However, due to the high diffusibility and storage difficulty of hydrogen, it is impossible to achieve long-term release at the tumor site, which highly limited their therapeutic effect.

RESULTS

Photosynthetic bacteria (PSB) release a large amount of hydrogen to break the balance of oxidative stress. In addition, as a nontoxic bacterium, PSB could stimulate the immune response and increase the infiltration of CD4+ and CD8+ T cells. More interestingly, we found that hydrogen therapy induced by our live PSB did not lead to the up-regulation of PD-L1 after stimulating the immune response, which could avoid the tumor immune escape.

CONCLUSION

Hydrogen-immunotherapy significantly kills tumor cells. We believe that our live microbial hydrogen production system provides a new strategy for cancer hydrogen treatment combining with enhanced immunotherapy without up-regulating PD-L1.

A Dendritic Polymer-Based Nanosystem Mediates Drug Penetration and Irreversible Endoplasmic Reticulum Stresses in Tumor via Neighboring Effect

Nanoparticles (NPs)-based cancer therapeutics are generally impeded by poor drug penetration into solid tumors due to their dense tumor extracellular matrix (ECM). Herein, pH/redox-responsive dendritic polymer-based NPs are developed to amplify the neighboring effect for improving drug penetration and driving cell apoptosis via combination therapy. Pyropheophorbide a (Ppa) is conjugated with PEGylated dendritic peptides via disulfide bonds and doxorubicin (DOX) encapsulated in the conjugate to construct dual-responsive NPs, PDPP@D. Delayed released DOX and Ppa from PDPP@D exert their combination therapeutic effect to induce cell apoptosis, and then they are liberated out of dying cells to amplify the neighboring effect, resulting in their diffusion through the dense ECM and penetration into solid tumors. Transcriptome studies reveal that PDPP@D leads to irreversible stress on the endoplasmic reticulum and inhibits cell protection through blocking the IRE1-dependent survival pathway and unleashing the DR5-mediated caspase activity to promote cell death. The strategy of amplifying the neighboring effect of NPs through combination therapy may offer great potential in enhancing drug penetration and eradicating solid tumors.

Recent advances in targeted drug delivery for the treatment of pancreatic ductal adenocarcinoma

INTRODUCTION

Pancreatic ductal adenocarcinoma (PDAC) has become a serious health problem with high impact worldwide. The heterogeneity of PDAC makes it difficult to apply drug delivery systems (DDS) used in other cancer models, for example, the poorly developed vascular system makes anti-angiogenic therapy ineffective. Due to its various malignant pathological changes, drug delivery against PDAC is a matter of urgent concern. Based on this situation, various drug delivery strategies specially designed for PDAC have been generated.

AREAS COVERED

This review will briefly describe how delivery systems can be designed through nanotechnology and formulation science. Most research focused on penetrating the stromal barrier, exploiting and alleviating the hypoxic microenvironment, targeting immune cells, or designing vaccines, and combination therapies. This review will summarize the ways to reverse the malignant pathological features of PDAC and hopefully provide ideas for subsequent studies.

EXPERT OPINION

Drug delivery systems designed to achieve penetrating functions or to alleviate hypoxia and activate immunity have achieved good therapeutic results in animal models in several studies. In future studies, there is a need to deliver PDAC therapeutics in a more precise manner, or the use of drug carriers for multiple functions simultaneously, are potential therapeutic strategy.