Application of injectable hydrogels in cancer immunotherapy

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.

Remodeling of Effector and Regulatory T Cells by Capture and Utilization of miRNAs Using Nanocomposite Hydrogel for Tumor-Specific Photothermal Immunotherapy

In immunotherapy for malignant tumors, the dysregulation of the balance between effector T cells and regulatory T cells (Tregs) and the uncertain efficacy due to individual differences have been considered as two critical challenges. In this study, we engineered an injectable nanocomposite hydrogel system (SNAs@M-Gel) capable of suppressing Treg proliferation and blocking PD-1/PD-L1-mediated immune evasion effectively, achieved through the stimulus-responsive modulation of multiple tumor-associated microRNAs. Simultaneously, this system enables microRNA-dependent photothermal immunotherapy, facilitating a highly efficient and personalized approach to tumor treatment. Specifically, oxidized sodium alginate (OSA) and cancer cell membrane (CCM)-encapsulated spherical nucleic acid nanoparticles (SNAs@M) were used to construct the SNAs@M-Gel hydrogel in situ at the tumor site through the formation of pH-sensitive Schiff base bonding and cross-linking using endogenous calcium ions (Ca2+). During treatment, SNAs@M-Gel was retained locally for up to 10 days, and SNAs@M nanoparticles were continuously released into the tumor microenvironment. Through the targeting ability of CCM, SNAs@M precisely entered tumor cells and specifically hybridized with the overexpressed miR-214 and miR-130a, leading to a significant downregulation of PD-L1 expression on tumor cells and the restoration of cytotoxic T lymphocyte (CTL) function suppressed by Tregs, thereby remodeling the immune microenvironment. In addition, miRNAs functioned as cross-linking agents, facilitating the aggregation of SNAs and allowing the localized production of photothermal agents directly inside tumor cells, which, under near-infrared (NIR) irradiation, promoted highly selective photothermal therapy. This cascade of events not only led to the destruction of the primary tumor but also resulted in the release of a substantial number of tumor-related antigens, which triggered the maturation of adjacent dendritic cells (DCs) and subsequent priming of tumor-specific CTLs, while simultaneously depleting Tregs, thereby reversing the tumor-promoting immune microenvironment and enhancing the overall therapeutic efficacy of photothermal immunotherapy.

Revolutionizing cancer treatment: the emerging potential and potential challenges of in vivo self-processed CAR cell therapy

Chimeric antigen receptor (CAR) cell immunotherapies, including CAR-T, CAR-Macrophages, CAR-Natural Killer, CAR-γδ T, etc., have demonstrated significant advancements in the treatment of both hematologic malignancies and solid tumors. Despite the notable successes of traditional CAR cell manufacturing, its application remains constrained by the complicated production process and expensive costs. Consequently, efforts are focused on streamlining CAR cell production to enhance efficacy and accessibility. Among numerous proposed strategies, direct in vivo generation of CAR cells represents the most substantial technical challenge, yet holding great promise for achieving clinical efficacy. Herein, we outlined the current state-of-the-art in vivo CAR therapy, including CAR technology development, transfection vectors, and influence factors of construction of CAR in vivo. We also reviewed the types and characteristics of different delivery systems and summarized the advantages of in vivo CAR cell therapy, such as rapid preparation and cost-effectiveness. Finally, we discussed the limitations, including technical issues, challenges in target and signal design, and cell-related constraints. Meanwhile, strategies have correspondingly been proposed to advance the development of CAR cell therapy, in order to open the new horizons on cancer treatment.

Targeting inflammation with hyaluronic acid-based micro- and nanotechnology: A disease-oriented review

Inflammation is a pivotal immune response in numerous diseases and presents therapeutic challenges. Traditional anti-inflammatory drugs and emerging cytokine inhibitors encounter obstacles such as limited bioavailability, poor tissue distribution, and adverse effects. Hyaluronic acid (HA), a versatile biopolymer, is widely employed to deliver therapeutic agents, including anti-inflammatory drugs, genes, and cell therapies owing to its unique properties, such as hydrophilicity, biodegradability, and safety. HA interacts with cell receptors to initiate processes such as angiogenesis, cell proliferation, and immune regulation. HA-based drug delivery systems offer dual strategies for effective inflammation management, capitalizing on passive and active mechanisms. This synergy permits the mitigation of inflammation by lowering the doses of anti-inflammatory drugs and their off-target adverse effects. A diverse array of micro- and nanotechnology techniques enable the fabrication of tailored HA-engineered systems, including hydrogels, microgels, nanogels, microneedles, nanofibers, and 3D-printed scaffolds, for diverse formulations and administration routes. This review explores recent insights into HA pharmacology in inflammatory conditions, material design, and fabrication methods, as well as its applications across a spectrum of inflammatory diseases, such as atherosclerosis, psoriasis, dermatitis, wound healing, rheumatoid arthritis, osteoarthritis, inflammatory bowel disease, and colitis, highlighting its potential for clinical translation.

Current progress in CRISPR-Cas systems for rare diseases

The groundbreaking CRISPR-Cas gene editing method permits exact genetic code alteration. The "CRISPR" DNA protects bacteria from viruses. CRISPR-Cas utilizes a guide RNA to steer the Cas enzyme to the genome's gene editing target. After attaching to a sequence, Cas enzymes cleave DNA to insert, delete, or modify genes. The influence of CRISPR-Cas technology on molecular biology and genetics is profound. It allows for gene function research, animal disease models, and patient genetic therapy. Gene editing has transformed biotechnology, agriculture, and customized medicine. CRISPR-Cas could revolutionize genetics and medicine. CRISPR-Cas may accurately correct genetic flaws that underlie rare diseases, improving their therapy. Gene mutations make CRISPR-Cas gene editing a viable cure for uncommon diseases. We can use CRISPR-Cas to correct genetic abnormalities at the molecular level. This strategy offers hope for remedies and disease understanding. CRISPR-Cas genome editing may enable more targeted and effective treatments for rare medical illnesses with few therapy options. By developing base- and prime-editing CRISPR technology, CRISPR-Cas allows for accurate and efficient genome editing and advanced DNA modification. This advanced method provides precise DNA alterations without double-strand breakage. These advances have improved gene editing safety and precision, reducing unfavorable effects. Lipid nanoparticles, which use viral vectors, improve therapeutic cell and tissue targeting. In rare disorders, gene therapy may be possible with CRISPR-Cas clinical trials. CRISPR-Cas research is improving gene editing, delivery, and rare disease treatment.

DNA hydrogels and their derivatives in biomedical engineering applications

Deoxyribonucleotide (DNA) is uniquely programmable and biocompatible, and exhibits unique appeal as a biomaterial as it can be precisely designed and programmed to construct arbitrary shapes. DNA hydrogels are polymer networks comprising cross-linked DNA strands. As DNA hydrogels present programmability, biocompatibility, and stimulus responsiveness, they are extensively explored in the field of biomedicine. In this study, we provide an overview of recent advancements in DNA hydrogel technology. We outline the different design philosophies and methods of DNA hydrogel preparation, discuss its special physicochemical characteristics, and highlight the various uses of DNA hydrogels in biomedical domains, such as drug delivery, biosensing, tissue engineering, and cell culture. Finally, we discuss the current difficulties facing DNA hydrogels and their potential future development.

Cascade Nanoreactor Employs Mitochondrial-Directed Chemodynamic and δ-ALA-Mediated Photodynamic Synergy for Deep-Seated Oral Cancer Therapy

The management of oral squamous cell carcinoma (OSCC) poses significant challenges, leading to organ impairment and ineffective treatment of deep-seated tumors, adversely affecting patient prognosis. A cascade nanoreactor that integrates photodynamic therapy (PDT) and chemodynamic therapy (CDT) for comprehensive multimodal OSCC treatment is introduced. Utilizing iron oxide and mesoporous silica, the FMMSH drug delivery system, encapsulating the photosensitizer prodrug δ-aminolevulinic acid (δ-ALA), is developed. Triphenylphosphine (TPP) modification facilitates mitochondrial targeting, while tumor cell membrane (TCM) coating provides homotypic targeting. The dual-targeting δ-ALA@FMMSH-TPP-TCM demonstrate efficacy in eradicating both superficial and deep tumors through synergistic PDT/CDT. Esterase overexpression in OSCC cells triggers δ-ALA release, and excessive hydrogen peroxide in tumor mitochondria undergoes Fenton chemistry for CDT. The synergistic interaction of PDT and CDT increases cytotoxic ROS levels, intensifying oxidative stress and enhancing apoptotic mechanisms, ultimately leading to tumor cell death. PDT/CDT-induced apoptosis generates δ-ALA-containing apoptotic bodies, enhancing antitumor efficacy in deep tumor cells. The anatomical accessibility of oral cancer emphasizes the potential of intratumoral injection for precise and localized treatment delivery, ensuring focused therapeutic agent delivery to maximize efficacy while minimizing side effects. Thus, δ-ALA@FMMSH-TPP-TCM, tailored for intratumoral injection, emerges as a transformative modality in OSCC treatment.

Injectable hydrogels as emerging drug-delivery platforms for tumor therapy

Tumor therapy continues to be a prominent field within biomedical research. The development of various drug carriers has been propelled by concerns surrounding the side effects and targeting efficacy of various chemotherapeutic drugs and other therapeutic agents. These carriers strive to enhance drug concentration at tumor sites, minimize systemic side effects, and improve therapeutic outcomes. Among the reported delivery systems, injectable hydrogels have emerged as an emerging candidate for the in vivo delivery of chemotherapeutic drugs due to their minimal invasive drug delivery properties. This review systematically summarizes the composition and preparation methodologies of injectable hydrogels and further highlights the delivery mechanisms of diverse drugs using these hydrogels for tumor therapy, along with an in-depth discussion on the optimized therapeutic efficiency of drugs encapsulated within the hydrogels. The work concludes by providing a dynamic forward-looking perspective on the potential challenges and possible solutions of the in situ injectable hydrogels for non-surgical and real-time diagnostic applications.

Injectable smart stimuli-responsive hydrogels: pioneering advancements in biomedical applications

Hydrogels have established their significance as prominent biomaterials within the realm of biomedical research. However, injectable hydrogels have garnered greater attention compared with their conventional counterparts due to their excellent minimally invasive nature and adaptive behavior post-injection. With the rapid advancement of emerging chemistry and deepened understanding of biological processes, contemporary injectable hydrogels have been endowed with an "intelligent" capacity to respond to various endogenous/exogenous stimuli (such as temperature, pH, light and magnetic field). This innovation has spearheaded revolutionary transformations across fields such as tissue engineering repair, controlled drug delivery, disease-responsive therapies, and beyond. In this review, we comprehensively expound upon the raw materials (including natural and synthetic materials) and injectable principles of these advanced hydrogels, concurrently providing a detailed discussion of the prevalent strategies for conferring stimulus responsiveness. Finally, we elucidate the latest applications of these injectable "smart" stimuli-responsive hydrogels in the biomedical domain, offering insights into their prospects.