Alum-tuned hyaluronic acid-based hydrogel with immune checkpoint inhibition for immunophoto therapy of cancer

Smart hydrogel: A new platform for cancer therapy

Cancer is a significant contributor to mortality worldwide, posing a significant threat to human life and health. The unique bioactivity, ability to precisely control drug release, and minimally invasive properties of hydrogels are indispensable attributes that facilitate optimal performance in cancer therapy. However, conventional hydrogels lack the ability to dynamically respond to changes in the surrounding environment, withstand drastic changes in the microenvironment, and trigger drug release on demand. Therefore, this review focuses on smart-responsive hydrogels that are capable of adapting and responding to external stimuli. We comprehensively summarize the raw materials, preparation, and cross-linking mechanisms of smart hydrogels derived from natural and synthetic materials, elucidate the response principles of various smart-responsive hydrogels according to different stimulation sources. Further, we systematically illustrate the important role played by hydrogels in modern cancer therapies within the context of therapeutic principles. Meanwhile, the smart hydrogel that uses machine learning to design precise drug delivery has shown great prospects in cancer therapy. Finally, we present the outlook on future developments and make suggestions for future related work. It is anticipated that this review will promote the practical application of smart hydrogels in cancer therapy and contribute to the advancement of medical treatment.

In Situ Cancer Vaccines: Redefining Immune Activation in the Tumor Microenvironment

Cancer is one of the leading causes of mortality worldwide. Nanomedicines have significantly improved life expectancy and survival rates for cancer patients in current standard care. However, recurrence of cancer due to metastasis remains a significant challenge. Vaccines can provide long-term protection and are ideal for preventing bacterial and viral infections. Cancer vaccines, however, have shown limited therapeutic efficacy and raised safety concerns despite extensive research. Cancer vaccines target and stimulate responses against tumor-specific antigens and have demonstrated great potential for cancer treatment in preclinical studies. However, tumor-associated immunosuppression and immune tolerance driven by immunoediting pose significant challenges for vaccine design. In situ vaccination represents an alternative approach to traditional cancer vaccines. This strategy involves the intratumoral administration of immunostimulants to modulate the growth and differentiation of innate immune cells, such as dendritic cells, macrophages, and neutrophils, and restore T-cell activity. Currently approved in situ vaccines, such as T-VEC, have demonstrated clinical promise, while ongoing clinical trials continue to explore novel strategies for broader efficacy. Despite these advancements, failures in vaccine research highlight the need to address tumor-associated immune suppression and immune escape mechanisms. In situ vaccination strategies combine innate and adaptive immune stimulation, leveraging tumor-associated antigens to activate dendritic cells and cross-prime CD8+ T cells. Various vaccine modalities, such as nucleotide-based vaccines (e.g., RNA and DNA vaccines), peptide-based vaccines, and cell-based vaccines (including dendritic, T-cell, and B-cell approaches), show significant potential. Plant-based viral approaches, including cowpea mosaic virus and Newcastle disease virus, further expand the toolkit for in situ vaccination. Therapeutic modalities such as chemotherapy, radiation, photodynamic therapy, photothermal therapy, and Checkpoint blockade inhibitors contribute to enhanced antigen presentation and immune activation. Adjuvants like CpG-ODN and PRR agonists further enhance immune modulation and vaccine efficacy. The advantages of in situ vaccination include patient specificity, personalization, minimized antigen immune escape, and reduced logistical costs. However, significant barriers such as tumor heterogeneity, immune evasion, and logistical challenges remain. This review explores strategies for developing potent cancer vaccines, examines ongoing clinical trials, evaluates immune stimulation methods, and discusses prospects for advancing in situ cancer vaccination.

Immune checkpoint blocking in cancer therapy using thermosensitive hydrogels: a review

Cancer is a challenging issue requiring new strategies for management and control. Immune checkpoint blockades (ICBs) increase the body's immune response against cancer by targeting specific receptors on T-lymphocytes. The FDA approved different ICBs for cancer treatment: anti-PD-1, PDL-1, and CTLA-4 inhibitors. Many immune checkpoint inhibitors (ICIs) are in clinical trials, highlighting their significance. Challenges like resistance and side effects have led researchers to explore new delivery strategies for ICIs. Thermosensitive hydrogels can change from sol to gel and vice versa due to their structure. They interact with aqueous medium through groups like ethyl, methyl, and propyl, forming hydrogen bonds. These bonds of hydrogen are temperature-sensitive and cause the change of the polymer from sol to gel at a temperature named critical solution temperature (CST). The using temperature-responsive polymers and ICBs showed a promising approach to sustained localized cancer therapy with lowering side effects on normal tissues. In this paper, we first define new investigations on immune therapy in cancer via ICBs. Then, we present recent studies of thermosensitive polymers in cancer therapy and the most used thermosensitive polymers in studies. Eventually, we discuss studies that used thermosensitive polymers in the delivery of ICBs and discuss new investigations in this field.

Synchronously Delivering Melittin and Evoking Ferroptosis via Tumor Microenvironment-Triggered Self-Destructive Metal-Organic Frameworks to Boost Cancer Immunotherapy

The primary goal of treating malignant tumors is to efficiently eliminate the primary tumor and prevent metastasis and recurrence. Unfortunately, the immunosuppressive tumor microenvironment (TME) is a significant obstacle to effective oncotherapy. Herein, a therapeutic strategy based on melittin (MLT) encapsulated in hyaluronic acid-modified metal-organic frameworks (MOFs) is pioneered, focusing on the safe delivery and TME-responsive release of MLT to reshaping the immunosuppressive TME and simultaneously activating the immune system to eradicate cancerous cells. Iron-based MOFs respond to glutathione and pH, degrade within a moderately acidic TME, and achieve tumor-specific release of MLT. Additionally, the iron-mediated Fenton reaction produces reactive oxygen species that augment oxidative stress, ultimately leading to tumor-specific ferroptosis, whereas MLT-induced membrane disruption promotes immunogenic cell death to activate the immune system. In combination with the immune checkpoint inhibitor anti-PD-L1, this nanodrug elicits potent antitumor immune responses, facilitating the infiltration of effector T cells and enhancing systemic antitumor T cell immunity to suppress both primary and distant tumors. This study demonstrates the tremendous potential of nanoscale self-destructive MOFs for the targeted transport and controlled release of MLT and reveals the promoting effect of combined MLT and ferroptosis delivery on cancer immunotherapy.

Anionic polysaccharides as delivery carriers for cancer therapy and theranostics: An overview of significance

Recently, cancer therapy has witnessed remarkable advancements with a growing focus on precision medicine and targeted drug delivery strategies. The application of anionic polysaccharides has gained traction in various drug delivery systems. Anionic polysaccharides have emerged as promising delivery carriers in cancer therapy and theranostics, offering numerous advantages such as biocompatibility, low toxicity, and the ability to encapsulate and deliver therapeutic agents to tumor sites with high specificity. This review underscores the significance of anionic polysaccharides as essential components of the evolving landscape of cancer therapy and theranostics. These polymers can be tailored to carry a wide range of therapeutic cargo, including chemotherapeutic agents, nucleic acids, and imaging agents. Their negative charge enables electrostatic interactions with positively charged drugs and facilitates the formation of stable nanoparticles, liposomes, or hydrogels for controlled drug release. Additionally, their hydrophilic nature aids in prolonging circulation time, reducing drug degradation, and minimizing off-target effects. Besides, some of them could act as targeting agents or therapeutic compounds that lead to improved therapeutic performance. This review offers valuable information for researchers, clinicians, and biomedical engineers. It provides insights into the recent progress in the applications of anionic polysaccharide-based delivery platforms in cancer theranostics to transform patient outcomes.

Chitosan and hyaluronic acid in colorectal cancer therapy: A review on EMT regulation, metastasis, and overcoming drug resistance

Up to 90% of cancer-related fatalities could be attributed to metastasis. Therefore, understanding the mechanisms that facilitate tumor cell metastasis is beneficial for improving patient survival and results. EMT is considered the main process involved in the invasion and spread of CRC. Essential molecular components like Wnt, TGF-β, and PI3K/Akt play a role in controlling EMT in CRC, frequently triggered by various factors such as Snail, Twist, and ZEB1. These factors affect not only the spread of CRC but also determine the reaction to chemotherapy. The influence of non-coding RNAs, especially miRNAs and lncRNAs, on the regulation of EMT is clear in CRC. Exosomes, involved in cell-to-cell communication, can affect the TME and metastasis of CRC. Pharmacological substances and nanoparticles demonstrate promise as efficient modulators of EMT in CRC. Chitosan and HA are two major carbohydrate polymers with considerable potential in inhibiting CRC. Chitosan and HA can be employed to modify nanoparticles to enhance cargo transport for reducing CRC. Additionally, chitosan and HA-modified nanocarriers, which can be utilized as potential approaches in suppressing EMT and reversing drug resistance in CRC, can inhibit EMT and chemoresistance, crucial components in tumorigenesis.

Intravascular Casting Radiopaque Hydrogel Systems for Transarterial Chemo/Cascade Catalytic/Embolization Therapy of Hepatocellular Carcinoma

This paper introduces catheter-directed intravascular casting hydrogels for transarterial chemo/starvation/chemodynamic embolization (TACSCE) therapy of hepatocellular carcinoma (HCC). Comprising Mn ion-crosslinked hyaluronic acid-dopamine (HD) with glucose oxidase (for glucose decomposition to H2O2 in starvation therapy), doxorubicin (for chemotherapy), and iopamidol (for X-ray imaging), these hydrogels are fabricated for transarterial embolization therapy guided by X-ray fluoroscopy. Mn4+ (from MnO2) demonstrates strong coordination with the catechol group of HD, providing hypoxia relief through O2 generation and cellular glutathione (GSH) consumption, compared to the OH radical generation potential of Mn2+. The gelation time-controlled, catheter-injectable, and rheologically tuned multitherapeutic/embolic gel system effectively reaches distal arterioles, ensuring complete intravascular casting with fewer complications related to organic solvents. Glucose deprivation, cascade reactive oxygen species (ROS) generation, GSH depletion, and sustained release profiles of multiple drug cargos from the hydrogel system are also achieved. The combined chemo/starvation/chemodynamic efficacies of these designed hydrogel systems are confirmed in HCC cell cultures and HCC-bearing animal models. The developed radiopaque/injectable/embolic/sol-to-gel transformable systems for TACSCE therapy may offer enhanced therapeutic efficacies compared to typical transarterial embolization and transarterial chemoembolization procedures for HCC.

Innovative theranostic hydrogels for targeted gastrointestinal cancer treatment

Gastrointestinal tumors are the main causes of death among the patients. These tumors are mainly diagnosed in the advanced stages and their response to therapy is unfavorable. In spite of the development of conventional therapeutics including surgery, chemotherapy, radiotherapy and immunotherapy, the treatment of these tumors is still challenging. As a result, the new therapeutics based on (nano)biotechnology have been introduced. Hydrogels are polymeric 3D networks capable of absorbing water to swell with favorable biocompatibility. In spite of application of hydrogels in the treatment of different human diseases, their wide application in cancer therapy has been improved because of their potential in drug and gene delivery, boosting chemotherapy and immunotherapy as well as development of vaccines. The current review focuses on the role of hydrogels in the treatment of gastrointestinal tumors. Hydrogels provide delivery of drugs (both natural or synthetic compounds and their co-delivery) along with gene delivery. Along with delivery, hydrogels stimulate phototherapy (photothermal and photodynamic therapy) in the suppression of these tumors. Besides, the ability of hydrogels for the induction of immune-related cells such as dendritic cells can boost cancer immunotherapy. For more specific cancer therapy, the stimuli-responsive types of hydrogels including thermo- and pH-sensitive hydrogels along with their self-healing ability have improved the site specific drug delivery. Moreover, hydrogels are promising for diagnosis, circulating tumor cell isolation and detection of biomarkers in the gastrointestinal tumors, highlighting their importance in clinic. Hence, hydrogels are diagnostic and therapeutic tools for the gastrointestimal tumors.

"Rigid-Flexible" Dual-Ferrocene Chimeric Nanonetwork for Simultaneous Tumor-Targeted Tracing and Photothermal/Photodynamic Therapy

There is an urgent need to develop phototherapeutic agents with imaging capabilities to assess the treatment process and efficacy in real-time during cancer phototherapy for precision cancer therapy. The safe near-infrared (NIR) fluorescent dyes have garnered significant attention and are desirable for theranostics agents. However, until now, achieving excellent photostability and fluorescence (FL) imaging capability in aggregation-caused quenching (ACQ) dyes remains a big challenge. Here, for the only FDA-approved NIR dye, indocyanine green (ICG), we developed a dual-ferrocene (Fc) chimeric nanonetwork ICG@HFFC based on the rigid-flexible strategy through one-step self-assembly, which uses rigid Fc-modified hyaluronic acid (HA) copolymer (HA-Fc) and flexible octadecylamine (ODA) bonded Fc (Fc-C18) as the delivery system. HA-Fc reserved the ability of HA to target the CD44 receptor of the tumor cell surface, and the dual-Fc region provided a rigid space for securely binding ICG through metal-ligand interaction and π-π conjugation, ensuring excellent photostability. Additionally, the alkyl chain provided flexible confinement for the remaining ICG through hydrophobic forces, preserving its FL. Thereby, a balance is achieved between outstanding photostability and FL imaging capability. In vitro studies showed improved photobleaching resistance, enhanced FL stability, and increased singlet oxygen (1O2) production efficiency in ICG@HFFC. Further in vivo results display that ICG@HFFC had good tumor tracing ability and significant tumor inhibition which also exhibited good biocompatibility.. Therefore, ICG@HFFC provides an encouraging strategy to realize simultaneous enhanced tumor tracing and photothermal/photodynamic therapy (PTT/PDT) and offers a novel approach to address the limitations of ACQ dyes.

Chitosan- and hyaluronic acid-based nanoarchitectures in phototherapy: Combination cancer chemotherapy, immunotherapy and gene therapy

Cancer phototherapy has been introduced as a new potential modality for tumor suppression. However, the efficacy of phototherapy has been limited due to a lack of targeted delivery of photosensitizers. Therefore, the application of biocompatible and multifunctional nanoparticles in phototherapy is appreciated. Chitosan (CS) as a cationic polymer and hyaluronic acid (HA) as a CD44-targeting agent are two widely utilized polymers in nanoparticle synthesis and functionalization. The current review focuses on the application of HA and CS nanostructures in cancer phototherapy. These nanocarriers can be used in phototherapy to induce hyperthermia and singlet oxygen generation for tumor ablation. CS and HA can be used for the synthesis of nanostructures, or they can functionalize other kinds of nanostructures used for phototherapy, such as gold nanorods. The HA and CS nanostructures can combine chemotherapy or immunotherapy with phototherapy to augment tumor suppression. Moreover, the CS nanostructures can be functionalized with HA for specific cancer phototherapy. The CS and HA nanostructures promote the cellular uptake of genes and photosensitizers to facilitate gene therapy and phototherapy. Such nanostructures specifically stimulate phototherapy at the tumor site, with particle toxic impacts on normal cells. Moreover, CS and HA nanostructures demonstrate high biocompatibility for further clinical applications.

Emerging Role of Extracellular Vesicles in Intercellular Communication in the Brain: Implications for Neurodegenerative Diseases and Therapeutics

Extracellular vesicles (EVs) are minute lipid-bilayer sacs discharged by cells, encompassing a diverse array of proteins, nucleic acids, and lipids. The identification of EVs as pivotal agents in intercellular communication has sparked compelling research pathways in the realms of cell biology and neurodegenerative diseases. Utilizing EVs for medicinal reasons has garnered interest due to the adaptability of EV-mediated communication. EVs can be classified based on their physical characteristics, biochemical composition, or cell of origin following purification. This review delves into the primary sub-types of EVs, providing an overview of the biogenesis of each type. Additionally, it explores the diverse environmental conditions triggering EV release and the originating cells, including stem cells and those from the Central Nervous System. Within the brain, EVs play a pivotal role as essential mediators of intercellular communication, significantly impacting synaptic plasticity, brain development, and the etiology of neurological diseases. Their potential diagnostic and therapeutic applications in various brain-related conditions are underscored, given their ability to carry specific cargo. Specially engineered EVs hold promise for treating diverse diseases, including neurodegenerative disorders. This study primarily emphasizes the diagnostic and potential therapeutic uses of EVs in neurological disorders such as Alzheimer's Disease, Huntington's Disease, Parkinson's Disease, Amyotrophic Lateral Sclerosis, and Prions disease. It also summarizes innovative techniques for detecting EVs in the brain, suggesting that EVs could serve as non-invasive biomarkers for early detection, disease monitoring, and prognosis in neurological disorders.