Epigenetic Remodeling Hydrogel Patches for Multidrug-Resistant Triple-Negative Breast Cancer

Multiplex Methionine Modulating Hydrogel for Cancer Metabolic Therapy

The reliance on high levels of methionine by tumor cells provides an attractive target for cancer treatment. However, systemic methionine blockade may raise concerns about potential side effects given the broad and essential functions of methionine in cellular metabolism. Here, a combined drug delivery platform for multilayered constraint of methionine within tumor lesions is developed. Small molecule inhibitors PF9366 and adenosine dialdehyde are encapsulated by tumor cell-targeting nanoparticles (NPs) to achieve a cascaded blockage of intracellular methionine metabolism. These NPs are further co-loaded with the extracellular methionine uptake inhibitor JPH203 into a type of reactive oxygen species-sensitive hydrogel, assembling the multiplex methionine modulating hydrogel (3 M Gel). In murine models of triple-negative breast cancer (TNBC), hepatocellular carcinoma, and colorectal cancer, the in situ formed 3 M Gel exhibits superior efficacy in restricting S-adenosyl methionine generation and histone methylation, stimulating immunogenic cell death in tumor cells, thereby eliciting potent innate and adaptive immune responses to restrain tumor progression. Moreover, remodeling of the tumor microenvironment by 3 M Gel overcomes immune checkpoint blockade resistance in TNBC. This study presents a localized triple regulation strategy and paves a new path for amino acid starvation-based cancer therapy.

Emerging roles of hyaluronic acid hydrogels in cancer treatment and wound healing: A review

Hyaluronic acid (HA)-derived hydrogels demonstrate a significant development in the biomedical uses, especially in cancer treatment and wound repair. Cancer continues to be one of the leading causes of death worldwide, with current therapies frequently impeded by lack of specificity, side effects, and the emergence of resistance. HA hydrogels, characterized by their distinctive three-dimensional structure, hydrophilic nature, and biocompatibility, develop an advanced platform for precise drug delivery, improving therapeutic results while minimizing systemic toxicity. These hydrogels facilitate the controlled release of drugs, genes, and various therapeutic substances, enhancing the effectiveness of chemotherapy, radiotherapy, and immunotherapy. Additionally, they can be designed to react to stimuli such as pH, light, and magnetic fields, enhancing their therapeutic capabilities. In the process of wound healing, the hydrophilic and porous characteristics of HA hydrogels establish a moist environment encouraging cell growth and contributes to the tissue recovery. By imitating the extracellular matrix, they promote tissue regeneration, improve angiogenesis, and influence immune reactions. This review examines the various functions of HA-based hydrogels in cancer treatment and wound healing, highlighting their advancement, applications, and ability to change existing therapeutic methods in these important health sectors.

Biofabrication of Tunable 3D Hydrogel for Investigating the Matrix Stiffness Impact on Breast Cancer Chemotherapy Resistance

Matrix stiffness is a key factor in breast cancer progression, but its impact on cell function and response to treatment is not fully understood. Here, we developed a stiffness-tunable hydrogel-based three-dimensional system that recapitulates the extracellular matrix and physiological properties of human breast cancer in vitro. Adjusting the ratio of GelMA to PEGDA in the hydrogel formulation enabled the fine-tuning of matrix stiffness across a range of 7 to 52 kPa. Utilizing this three-dimensional (3D) hydrogel platform for a breast cancer cell culture has enabled precise functional evaluations. Variations in matrix stiffness resulted in significant changes in the morphology of breast cancer cells after 2 weeks of incubation. The analysis of transcriptomic sequencing revealed that the 3D microenvironment significantly changed the expression of a wide panel of transcriptomic profiles of breast cancer cells in various matrix stiffness. Gene Ontology analysis further suggested that specific biological functions could potentially be linked to the magnitude of the matrix stiffness. According to our findings, extracellular matrix rigidity modulates the sensitivity of breast cancer cells to paclitaxel and adriamycin. Notably, the expression of ABCB1 and YAP1 genes may be upregulated in the 3D culture environment, potentially contributing to the increased drug resistance observed in breast cancer cells. This work aims to establish facile adjustable hydrogels to deepen insights into matrix rigidity effects on breast cancer cells within 3D microenvironments, highlighting the critical role of extracellular matrix stiffness in modulating cell-matrix interactions.

Injectable and Degradable Zwitterionic Cryogels as Cancer Vaccine Platforms to Prevent Cancer Recurrence after Surgery

Cancer has become a highly prevalent disease and poses serious threats to human health. Conventional cancer treatments still face high risks of recurrence. Training the immune system to recognize and eliminate tumors via external stimulation, such as vaccines, emerges as a promising approach for cancer prevention and treatment. However, injectable vaccines may have limited immune activation, causing difficulties in maintaining long-term immune surveillance of tumorigenesis by tumor-specific cytotoxic T cells. Here, degradable zwitterionic cryogels were prepared using the cryogelation technique. The cryogenic preparation maintained the biological activities of tumor antigens and immune adjuvants loaded in the cryogels. The macroporous structure endowed the injectability of cryogels into the body via conventional syringes. In the presence of proteases, the cryogels degraded, allowing sustained release of antigens and adjuvants, ensuring continued dendritic cell (DC) recruitment and antigen presentation to maturing tumor-specific cytotoxic T cells. In vivo experiments demonstrated that the cryogel cancer vaccines elicited robust immune activation and effectively modulated tumor microenvironments. The combination with photothermal therapy significantly inhibited tumor growth, showing great potential for preventing postoperative recurrence. Additionally, the zwitterionic cryogels were biocompatible without obvious toxicities during degradation. The cryogels could serve as effective vaccine platforms to prevent cancer recurrence after surgery.

3D-Printed Breast Prosthesis that Smartly Senses and Targets Breast Cancer Relapse

Breast reconstruction is essential for improving the appearance of patients after cancer surgery. Traditional breast prostheses are not appropriate for those undergoing partial resections and cannot detect and treat locoregional recurrence. Personalized shape prostheses that can smartly sense tumor relapse and deliver therapeutics are needed. A 3D-printed prosthesis that contains a therapeutic hydrogel is developed. The hydrogel, which is fabricated by crosslinking the polyvinyl alcohol with N1-(4-boronobenzyl)-N3-(4-boronophenyl)-N1, N1, N3, N3-tetramethylpropane-1,3-diaminium, is responsive to reactive oxygen species (ROS) in the tumor microenvironment. Specifically, RSL3, a ferroptosis inducer that is loaded in hydrogels, can trigger tumor ferroptosis. Intriguingly, RSL3 encapsulated in the ROS-responsive hydrogel exerts antitumor effects by increasing the numbers of tumor-infiltrated CD4+ T cells, CD8+ T cells, and M1 macrophages while reducing the number of M2 macrophages. Therefore, this new prosthesis not only allows personalized shape reconstruction, but also detects and inhibits tumor recurrence. This combination of aesthetic appearance and therapeutic function can be very beneficial for breast cancer patients undergoing surgery.

Stimuli-Responsive Covalent Organic Frameworks for Cancer Therapy

Chemotherapy as a common anticancer therapeutic modality is often challenged by various obstacles such as poor stability, low solubility, and severe side effects of chemotherapeutic agents as well as multidrug resistance of cancerous cells. Nanoparticles in the role of carriers for chemotherapeutic drugs and platforms for combining different therapeutic approaches have effectively participated in overcoming such drawbacks. In particular, nanoparticles able to induce their therapeutic effect in response to specific stimuli like tumor microenvironment characteristics (e.g., hypoxia, acidic pH, high levels of glutathione, and overexpressed hydrogen peroxide) or extrinsic stimulus of laser light bring about more precise and selective treatments. Among them, nanostructures of covalent organic frameworks (COFs) have drawn great interest in biomedical fields during recent years. Possessing large surface area, high porosity, structural stability, and customizable architecture, these biocompatible porous crystalline polymers properly translate to promising platforms for drug delivery and induction of combination therapies. With the focus on stimuli-responsive characteristics of nanoscale COFs, this study aims to propose an overview of their potentiality in cancer treatment on the basis of chemotherapy alone or in combination with sonodynamic, chemodynamic, photodynamic, and photothermal therapies.

Regulation of tumor antigens-Dependent immunotherapy via the hybrid M1 macrophage/tumor lysates Hydrogel

Tumor treatment poses a significant obstacle in contemporary healthcare. Using components derived from a patient's own cellular and tissue materials to prepare hydrogels and other therapeutic systems has become a novel therapeutic approach, drawing considerable interest for their applicability in basic research on cancer immunotherapy. These hydrogels can engage with cellular components directly and offer a supportive scaffold, aiding in the normalization of tumor tissues. Additionally, their superior capability for encapsulating targeted anti-tumor medications amplifies treatment effectiveness. Given their origin from a patient's own cells, these hydrogels circumvent the risks of immune rejection by the body and severe side effects typically associated with foreign substance. In this study, we developed a composite hydrogel constructed by the cellular lysates of autologous tumor cells and M1 macrophages. This combination promoted the M2 macrophages polarization to the M1 phenotype. Subsequently, the polarized M1 macrophages infiltrated into the hydrogel and can directly capture tumor antigens. As antigen-presenting cells, M1 macrophages can stimulate the production of antigen-specific T cells to kill tumor cells. This work proposes a dual-benefit research strategy that not only polarizes M2 macrophages but also enhances immune activation, boosting T cell-mediated tumor-killing effects. This approach offers a new therapeutic option for clinical cancer immunotherapy.

Unzippable Siamese Nanoparticles for Programmed Two-Stage Cancer Immunotherapy

Epigenetic drugs (epi-drugs) can destruct cancer cells and initiate both innate and adaptive immunity, yet they have achieved very limited success in solid tumors so far, partly attributing to their concurrent induction of the myeloid-derived suppressor cell (MDSC) population. Here, dissociable Siamese nanoparticles (SIANPs) are developed for tumor cell-targeted delivery of epi-drug CM-272 and MDSC-targeted delivery of small molecule inhibitor Ibrutinib. The SIANPs are assembled via interparticle DNA annealing and detached via tumor microenvironment-triggered strand separation. Such binary regulation induces endogenous retrovirus expression and immunogenic cell death in tumor cells while restraining the immunosuppressive effects of MDSCs, and synergistically promotes dendritic cell maturation and CD8+ T cell activation for tumor inhibition. Significantly, immune microenvironment remodeling via SIANPs further overcomes tumor resistance to immune checkpoint blockade therapy. This study represents a two-pronged approach for orchestrating immune responses, and paves a new way for employing epi-drugs in cancer immunotherapy.

The role of mesenchymal stem cells in cancer and prospects for their use in cancer therapeutics

Mesenchymal stem cells (MSCs) are recruited by malignant tumor cells to the tumor microenvironment (TME) and play a crucial role in the initiation and progression of malignant tumors. This role encompasses immune evasion, promotion of angiogenesis, stimulation of cancer cell proliferation, correlation with cancer stem cells, multilineage differentiation within the TME, and development of treatment resistance. Simultaneously, extensive research is exploring the homing effect of MSCs and MSC-derived extracellular vesicles (MSCs-EVs) in tumors, aiming to design them as carriers for antitumor substances. These substances are targeted to deliver antitumor drugs to enhance drug efficacy while reducing drug toxicity. This paper provides a review of the supportive role of MSCs in tumor progression and the associated molecular mechanisms. Additionally, we summarize the latest therapeutic strategies involving engineered MSCs and MSCs-EVs in cancer treatment, including their utilization as carriers for gene therapeutic agents, chemotherapeutics, and oncolytic viruses. We also discuss the distribution and clearance of MSCs and MSCs-EVs upon entry into the body to elucidate the potential of targeted therapies based on MSCs and MSCs-EVs in cancer treatment, along with the challenges they face.

Recent advancements of hydrogels in immunotherapy: Breast cancer treatment

Breast cancer is the most prevalent cancer among women and the leading cause of cancer-related deaths in this population. Recent advances in Immunotherapy, or combined immunotherapy, offering a more targeted and less toxic approach, expand the survival rate of patients more than conventional treatment. Notably, hydrogels, a versatile platform provided promising avenues to combat breast cancer in preclinical studies and extended to clinical practices. With advantages such as the alternation of tumor microenvironment, immunomodulation, targeted delivery of therapeutic agents, and their sustained release at specific sites of interest, hydrogels can potentially be used for the treatment of breast cancer. This review highlights the advantages, mechanisms of action, stimuli-responsiveness properties, and recent advancements of hydrogels for treating breast cancer immunotherapy. Moreover, post-treatment and its clinical translations are discussed in this review. The integration of hydrogels in immunotherapy strategies may pave the way for more effective, personalized, and patient-friendly approaches to combat breast cancer, ultimately contributing to a brighter future for breast cancer patients.

A Hydrogen-Bonded Organic Framework-Based Mitochondrion-Targeting Bioorthogonal Platform for the Modulation of Mitochondrial Epigenetics

Bioorthogonal chemistry represents a powerful tool in chemical biology, which shows great potential in epigenetic modulation. As a proof of concept, the epigenetic modulation model of mitochondrial DNA (mtDNA) is selected because mtDNA establishes a relative hypermethylation stage under oxidative stress, which impairs the mitochondrion-based therapeutic effect during cancer therapy. Herein, we design a new biocompatible hydrogen-bonded organic framework (HOF) for a HOF-based mitochondrion-targeting bioorthogonal platform TPP@P@PHOF-2. PHOF-2 can activate a prodrug (pro-procainamide) in situ, which can specifically inhibit DNA methyltransferase 1 (DNMT1) activity and remodel the epigenetic modification of mtDNA, making it more susceptible to ROS damage. In addition, PHOF-2 can also catalyze artemisinin to produce large amounts of ROS, effectively damaging mtDNA and achieving better chemodynamic therapy demonstrated by both in vitro and in vivo studies. This work provides new insights into developing advanced bioorthogonal therapy and expands the applications of HOF and bioorthogonal catalysis.

Using nanotechnology to progress the utilization of marine natural products in combating multidrug resistance in cancer: A prospective strategy

Achieving targeted, customized, and combination therapies with clarity of the involved molecular pathways is crucial in the treatment as well as overcoming multidrug resistance (MDR) in cancer. Nanotechnology has emerged as an innovative and promising approach to address the problem of drug resistance. Developing nano-formulation-based therapies using therapeutic agents poses a synergistic effect to overcome MDR in cancer. In this review, we aimed to highlight the important pathways involved in the progression of MDR in cancer mediated through nanotechnology-based approaches that have been employed to circumvent them in recent years. Here, we also discussed the potential use of marine metabolites to treat MDR in cancer, utilizing active drug-targeting nanomedicine-based techniques to enhance selective drug accumulation in cancer cells. The discussion also provides future insights for developing complex targeted, multistage responsive nanomedical drug delivery systems for effective cancer treatments. We propose more combinational studies and their validation for the possible marine-based nanoformulations for future development.

Postoperative tumor treatment strategies: From basic research to clinical therapy

Despite progression in advanced treatments for malignant tumors, surgery remains the primary treatment intervention, which removes a large portion of firm tumor tissues; however, the postoperative phase poses a possible risk for provincial tumor recurrence and metastasis. Consequently, the prevention of tumor recurrence and metastasis has attracted research attention. In this review, we summarized the postoperative treatment strategies for various tumors from both basic research and clinical perspectives. We delineated the underlying factors contributing to the recurrence of malignant tumors with a substantial prevalence rate, related molecular mechanisms of tumor recurrence post‐surgery, and related means of monitoring recurrence and metastasis after surgery. Furthermore, we described relevant therapeutic approaches for postoperative tumor recurrence, including chemotherapy, radiation therapy, immunotherapy, targeted therapy, and photodynamic therapy. This review focused on the emerging technologies used for postoperative tumor treatment in recent years in terms of functional classification, including the prevention of postoperative tumor recurrence, functional reconstruction, and monitoring of recurrence. Finally, we discussed the future development and deficiencies of postoperative tumor therapy. To understand postoperative treatment strategies for tumors from clinical treatment and basic research and further guide the research directions for postoperative tumors.

Triune Nanomodulator Enables Exhausted Cytotoxic T Lymphocyte Rejuvenation for Cancer Epigenetic Immunotherapy

Oncogene activation and epigenome dysregulation drive tumor initiation and progression, contributing to tumor immune evasion and compromising the clinical response to immunotherapy. Epigenetic immunotherapy represents a promising paradigm in conquering cancer immunosuppression, whereas few relevant drug combination and delivery strategies emerge in the clinic. This study presents a well-designed triune nanomodulator, termed ROCA, which demonstrates robust capabilities in tumor epigenetic modulation and immune microenvironment reprogramming for cancer epigenetic immunotherapy. The nanomodulator is engineered from a nanoscale framework with epigenetic modulation and cascaded catalytic activity, which self-assembles into a nanoaggregate with tumor targeting polypeptide decoration that enables loading of the immunogenic cell death (ICD)-inducing agent. The nanomodulator releases active factors specifically triggered in the tumor microenvironment, represses oncogene expression, and initiates the type 1 T helper (TH1) cell chemokine axis by reversing DNA hypermethylation. This process, together with ICD induction, fundamentally reprograms the tumor microenvironment and significantly enhances the rejuvenation of exhausted cytotoxic T lymphocytes (CTLs, CD8+ T cells), which synergizes with the anti-PD-L1 immune checkpoint blockade and results in a boosted antitumor immune response. Furthermore, this strategy establishes long-term immune memory and effectively prevents orthotopic colon cancer relapse. Therefore, the nanomodulator holds promise as a standalone epigenetic immunotherapy agent or as part of a combination therapy with immune checkpoint inhibitors in preclinical cancer models, broadening the array of combinatorial strategies in cancer immunotherapy.

A MgAl-LDH-CuS nanosheet-based thermo-responsive composite hydrogel with nir-responsive angiogenesis inhibitor releasing capability for multimode starvation therapy

The rapid proliferation of tumors is highly dependent on the nutrition supply of blood vessels. Cutting off the nutrient supply to tumors is an effective strategy for cancer treatment, known as starvation therapy. Although various hydrogel-based biomaterials have been developed for starvation therapy through glucose consumption or intravascular embolization, the limitations of single-mode starvation therapy hinder their therapeutic effects. Herein, we propose a dual-function nutrition deprivation strategy that can block the nutrients delivery through extravascular gelation shrinkage and inhibit neovascularization through angiogenesis inhibitors based on a novel NIR-responsive nanocomposite hydrogel. CuS nanodots-modified MgAl-LDH nanosheets loaded with angiogenesis inhibitor (sorafenib, SOR) are incorporated into the poly(n-isopropylacrylamide) (PNIPAAm) hydrogel by radical polymerization to obtain the composite hydrogel (SOR@LDH-CuS/P). The SOR@LDH-CuS/P hydrogel can deliver hydrophobic SOR with a NIR-responsive release behavior, which could decrease the tumor vascular density and accelerate cancer cells apoptosis. Moreover, the SOR@LDH-CuS/P hydrogel exhibits higher (3.5 times) compressive strength than that of the PNIPAAm, which could squeeze blood vessels through extravascular gelation shrinkage. In vitro and in vivo assays demonstrate that the interruption of nutrient supply by gelation shrinkage and the prevention of angiogenesis by SOR is a promising strategy to inhibit tumor growth for multimode starvation therapy.

Robust and sensitive conductive nanocomposite hydrogel with bridge cross-linking-dominated hierarchical structural design

Conductive hydrogels have a remarkable potential for applications in soft electronics and robotics, owing to their noteworthy attributes, including electrical conductivity, stretchability, biocompatibility, etc. However, the limited strength and toughness of these hydrogels have traditionally impeded their practical implementation. Inspired by the hierarchical architecture of high-performance biological composites found in nature, we successfully fabricate a robust and sensitive conductive nanocomposite hydrogel through self-assembly-induced bridge cross-linking of MgB2 nanosheets and polyvinyl alcohol hydrogels. By combining the hierarchical lamellar microstructure with robust molecular B─O─C covalent bonds, the resulting conductive hydrogel exhibits an exceptional strength and toughness. Moreover, the hydrogel demonstrates exceptional sensitivity (response/relaxation time, 20 milliseconds; detection lower limit, ~1 Pascal) under external deformation. Such characteristics enable the conductive hydrogel to exhibit superior performance in soft sensing applications. This study introduces a high-performance conductive hydrogel and opens up exciting possibilities for the development of soft electronics.

Multifunctional hydrogel for synergistic reoxygenation and chemo/photothermal therapy in metastatic breast cancer recurrence and wound infection

Metastatic recurrence and postoperative wound infection are two major challenges for breast cancer patients. In this study, a multifunctional responsive hydrogel system was developed for synergistic reoxygenation and chemo/photothermal therapy in metastatic breast cancer and wound infection. The hydrogel system was obtained by cross-linking Prussian blue-modified N-carboxyethyl chitosan (PBCEC) and oxidized sodium alginate using the amino and aldehyde groups on the polysaccharides, resulting in the formation of responsive dynamic imine bonds. Conditioned stimulation (e.g., acid microenvironment) enabled the controlled swelling of hydrogels as well as subsequent slow release of loaded doxorubicin (DOX). Additionally, this hydrogel system decomposed endogenous reactive oxygen species into oxygen to relieve the hypoxic tumor microenvironment and promote the healing of infected-wounds. Both in vitro and in vivo experiments demonstrated the synergistic reoxygenation and chemo/photothermal effects of the PB/DOX hydrogel system against metastatic breast cancer and its recurrence, as well as postoperative wound infection. Thus, the combination of reoxygenation and chemo/photothermal therapy represents a novel strategy for treating and preventing tumor recurrence and associated wound infection.

Preventing acute liver injury via hepatocyte-targeting nano-antioxidants

Acute liver injury (ALI) is a severe liver disease that is characterized by sudden and massive hepatocyte necrosis and deterioration of liver functions. Oxidative stress is increasingly recognized as a key factor in the induction and progression of ALI. Scavenging excessive reactive oxygen species (ROS) with antioxidants has become a promising therapeutic option, but intrinsically hepatocyte-targeting antioxidants with excellent bioavailability and biocompatibility are yet to be developed. Herein, self-assembling nanoparticles (NPs) composed of amphiphilic polymers are introduced to encapsulate organic Selenium compound L-Se-methylselenocysteine (SeMC) and form SeMC NPs, which protect the viabilities and functions of cultured hepatocytes in drug- or chemical-induced acute hepatotoxicity models via efficient ROS removal. After further functionalization with the hepatocyte-targeting ligand glycyrrhetinic acid (GA), the resultant GA-SeMC NPs exhibit enhanced hepatocyte uptake and liver accumulation. In mouse models of ALI induced by acetaminophen (APAP) or carbon tetrachloride (CCl4 ), treatment with GA-SeMC NPs significantly decrease the levels of hepatic lipid peroxidation, tissue vacuolization and serum liver transaminases, while prominently increase that of endogenous antioxidant enzymes. Our study therefore presents a liver-targeting drug delivery strategy for the prevention and treatment of hepatic diseases.

Smartphone-based iontophoresis transdermal drug delivery system for cancer treatment

Cancer is a leading cause of the death worldwide. However, the conventional cancer therapy still suffers from several limitations, such as systemic side effects, poor efficacy, and patient compliance due to limited accessibility to the tumor site. To address these issues, the localized drug delivery system has emerged as a promising approach. In this study, we developed an iontophoresis-based transdermal drug delivery system (TDDS) controlled by a smartphone application for cancer treatment. Iontophoresis, a low-intensity electric current-based TDDS, enhances drug permeation across the skin to provide potential for localized drug delivery and minimize systemic side effects. The fundamental mechanism of our system was modeled using finite element analysis and its performance was corroborated through the flow-through skin permeation tests using a plastic-based microfluidic chip. The results of in vitro cell experiments and skin deposition tests successfully demonstrated that our smartphone-controlled iontophoresis system significantly enhanced the drug permeation for cancer treatment. Therefore, this hand-held smartphone-based iontophoresis TDDS could be a powerful tool for self-administrated anticancer drug delivery applications.

"Ice and Fire" Supramolecular Cell-Conjugation Drug Delivery Platform for Deep Tumor Ablation and Boosted Antitumor Immunity

Cancer recurrence and metastasis are two major challenges in the current clinical therapy. In this work, a novel diketopyrrolopyrrole-based photothermal reagent (DCN) with unique J-aggregation-induced redshift is synthesized to achieve efficient tumor thermal ablation under safe power (0.33 W cm-2 ). Meanwhile, S-nitroso-N-acetylpenicillamine (SNAP) is co-loaded with near-infrared-absorbing DCN in amphiphilic polymers to realize heat-induced massive release of nitric oxide (NO), which can form oxidant peroxynitrite (ONOO- ) to active matrix metalloproteinases (MMPs), thereby degrading the compact tumor extracellular matrix to improve the ablation depth and infiltration of immune cells. Through a facile supramolecular assembly method, the DCN/SNAP nanoparticles are anchored to liquid-nitrogen-frozen cancer cells, achieving enhanced antitumor immune responses and effective inhibition of distant tumors and pulmonary metastases after only one treatment. The safety and effectiveness of this supramolecular cell-conjugation platform are verified by 2D/3D cellular experiments and bilateral tumor model, confirming the thermal-ablation-gas-permeation-antigen-presentation therapeutic mode has promising anticancer prospects.

Engineered Hierarchical Microdevices Enable Pre-Programmed Controlled Release for Postsurgical and Unresectable Cancer Treatment

Drug treatment is required for both resectable and unresectable cancers to strive for any meaningful improvement in patient outcomes. However, the clinical benefit of receiving conventional systemic administrations is often less than satisfactory. Drug delivery systems are preferable substitutes but still fail to meet diverse clinical demands due to the difficulty in programming drug release profiles. Herein, a microfabrication concept, termed "Hierarchical Multiple Polymers Immobilization" (HMPI), is introduced and biodegradable-polymer-based hierarchical microdevices (HMDs) that can pre-program any desired controlled release profiles are engineered. Based on the first-line medication of pancreatic and breast cancer, controlled release of single gemcitabine and the doxorubicin/paclitaxel combination in situ for multiple courses is implemented, respectively. Preclinical models of postsurgical pancreatic, postsurgical breast, and unresectable breast cancer are established, and the designed HMDs are demonstrated as well-tolerable and effective treatments for inhibiting tumor growth, recurrence, and metastasis. The proposed HMPI strategy allows the creation of tailorable and high-resolution hierarchical microstructures for pre-programming controlled release according to clinical medication schedules, which may provide promising alternative treatments for postsurgical and unresectable tumor control.

Reshaping Intratumoral Mononuclear Phagocytes with Antibody-Opsonized Immunometabolic Nanoparticles

Mononuclear phagocytes (MPs) are vital components of host immune defenses against cancer. However, tumor-infiltrating MPs often present tolerogenic and pro-tumorigenic phenotypes via metabolic switching triggered by excessive lipid accumulation in solid tumors. Inspired by viral infection-mediated MP modulation, here enveloped immunometabolic nanoparticles (immeNPs) are designed to co-deliver a viral RNA analog and a fatty acid oxidation regulator for synergistic reshaping of intratumoral MPs. These immeNPs are camouflaged with cancer cell membranes for tumor homing and opsonized with anti-CD163 antibodies for specific MP recognition and uptake. It is found that internalized immeNPs coordinate lipid metabolic reprogramming with innate immune stimulation, inducing M2-to-M1 macrophage repolarization and tolerogenic-to-immunogenic dendritic cell differentiation for cytotoxic T cell infiltration. The authors further demonstrate that the use of immeNPs confers susceptibility to anti-PD-1 therapy in immune checkpoint blockade-resistant breast and ovarian tumors, and thereby provide a promising strategy to expand the potential of conventional immunotherapy.

Gel/hydrogel-based in situ biomaterial platforms for cancer postoperative treatment and recovery

Tumor surgical resection is the major strategy for cancer treatment. Meanwhile, perioperative treatment especially the postoperative adjuvant anticancer strategies play essential roles in satisfying therapeutic results and rapid recovery. Postoperative tumor recurrence, metastasis, bleeding, inter-tissue adhesion, infection, and delayed wound healing are vital risks that could lead to poor prognosis or even treatment failure. Therefore, methods targeting these postoperative complications are in desperate need. In situ biomaterial-based drug delivery platforms are promising candidates for postoperative treatment and recovery, resulting from their excellent properties including good biocompatibility, adaptive shape, limited systemic effect, designable function, and easy drug loading. In this review, we focus on introducing the gel/hydrogel-based in situ biomaterial platforms involving their properties, advantages, and synthesis procedures. Based on the loaded contents in the gel/hydrogel such as anticancer drugs, immunologic agents, cell components, and multifunctional nanoparticles, we further discuss the applications of the in situ platforms for postoperative tumor recurrence and metastasis inhibition. Finally, other functions aiming at fast postoperative recovery were introduced, including hemostasis, antibacterial infection, adhesion prevention, tissue repair, and wound healing. In conclusion, gel/hydrogel is a developing and promising platform for postoperative treatment, exhibiting gratifying therapeutic effects and inconspicuous toxicity to normal tissues, which deserves further research and exploration.

Implantable, Biodegradable, and Wireless Triboelectric Devices for Cancer Therapy through Disrupting Microtubule and Actins Dynamics

Electric-field-based stimulation is emerging as a new cancer therapeutic modality through interfering with cell mitosis. To address its limitations of complicated wire connections, bulky devices, and coarse spatial resolution, an improved and alternative method is proposed for wirelessly delivering electrical stimulation into tumor tissues through designing an implantable, biodegradable, and wirelessly controlled therapeutic triboelectric nanogenerator (ET-TENG). With the excitation of ultrasound (US) to the ET-TENG, the implanted ET-TENG can generate an alternating current voltage and concurrently release the loaded anti-mitotic drugs into tumor tissues, which synergistically disrupts the assembly of microtubules and filament actins, induces cell cycle arrest, and finally enhances cell death. With the assistance of US, the device can be completely degraded after the therapy, getting free of a secondary surgical extraction. The device can not only work around those unresectable tumors, but also provides a new application of wireless electric field in cancer therapy.

Targeted Reprogramming of Vitamin B3 Metabolism as a Nanotherapeutic Strategy towards Chemoresistant Cancers

Cancer-associated fibroblasts (CAFs) promote cancer stem cell (CSC)-mediated chemoresistance and immunosuppressive tumor microenvironment. However, direct depletion of CAFs may increase cancer invasiveness and metastasis. As a generalized strategy against chemoresistant cancers, Gemini-like homotypic targeting nanoparticles (NPs) are designed for two-pronged CAF transformation and cancer cell elimination. The CAF-targeted NPs couple vitamin B3 metabolic reprogramming to epigenetic modulation of secreted pro-stemness and immunosuppressive factors, thereby diminishing CSC and suppressive immune cell populations to enhance cancer cell drug susceptibility and cytotoxic T cell infiltration. In mouse models of breast, liver, pancreatic and colorectal cancers that are resistant to their respective first-line chemotherapeutics, a single dose of hydrogel co-delivering the Gemini-like NPs can rehabilitate chemosensitivity, induce immune activation, and achieve tumor regression. Moreover, it stimulates robust T cell memory for long-term protection against tumor rechallenge. This study thus represents an innovative approach with broad applicability for overcoming cancer chemoresistance.

Programmable DNA Hydrogel Provides Suitable Microenvironment for Enhancing TSPCS Therapy in Healing of Tendinopathy

Tendon stem/progenitor cells (TSPCs) therapy is a promising strategy for enhancing cell matrix and collagen synthesis, and regulating the metabolism of the tendon microenvironment during tendon injury repair. Nevertheless, the barren microenvironment and gliding shear of tendon cause insufficient nutrition supply, damage, and aggregation of injected TSPCs around tendon tissues, which severely hinders their clinical application in tendinopathy. In this study, a TSPCs delivery system is developed by encapsulating TSPCs within a DNA hydrogel (TSPCs-Gel) as the DNA hydrogel offers an excellent artificial extracellular matrix (ECM) microenvironment by providing nutrition for proliferation and protection against shear forces. This delivery method restricts TSPCs to the tendons, significantly extending their retention time. It is also found that TSPCs-Gel injections can promote the healing of rat tendinopathy in vivo, where cross-sectional area and load to failure of injured tendons in rats are significantly improved compared to the free TSPCs treatment group at 8 weeks. Furthermore, the potential healing mechanism of TSPCs-Gel is investigated by RNA-sequencing to identify a series of potential gene and signaling pathway targets for further clinical treatment strategies. These findings suggest the potential pathways of using DNA hydrogels as artificial ECMs to promote cell proliferation and protect TSPCs in TSPC therapy.

In Situ Tumor Vaccine for Lymph Nodes Delivery and Cancer Therapy Based on Small Size Nanoadjuvant

Tumor vaccine is a promising cancer treatment modality, however, the convenient antigens loading in vivo and efficient delivery of vaccines to lymph nodes (LNs) still remain a formidable challenge. Herein, an in situ nanovaccine strategy targeting LNs to induce powerful antitumor immune responses by converting the primary tumor into whole-cell antigens and then delivering these antigens and nanoadjuvants simultaneously to LNs is proposed. The in situ nanovaccine is based on a hydrogel system, which loaded with doxorubicin (DOX) and nanoadjuvant CpG-P-ss-M. The gel system exhibits ROS-responsive release of DOX and CpG-P-ss-M, generating abundant in situ storage of whole-cell tumor antigens. CpG-P-ss-M adsorbs tumor antigens through the positive surface charge and achieves charge reversal, forming small-sized and negatively charged tumor vaccines in situ, which are then primed to LNs. Eventually, the tumor vaccine promotes antigens uptake by dendritic cells (DCs), maturation of DCs, and proliferation of T cells. Moreover, the vaccine combined with anti-CTLA4 antibody and losartan inhibits tumor growth by 50%, significantly increasing the percentage of splenic cytotoxic T cells (CTLs), and generating tumor-specific immune responses. Overall, the treatment effectively inhibits primary tumor growth and induces tumor-specific immune response. This study provides a scalable strategy for in situ tumor vaccination.

Targeting LSD1 in tumor immunotherapy: rationale, challenges and potential

Lysine-specific demethylase 1 (LSD1) is an enzyme that removes lysine methylation marks from nucleosome histone tails and plays an important role in cancer initiation, progression, metastasis, and recurrence. Recent research shows that LSD1 regulates tumor cells and immune cells through multiple upstream and downstream pathways, enabling tumor cells to adapt to the tumor microenvironment (TME). As a potential anti-tumor treatment strategy, immunotherapy has developed rapidly in the past few years. However, most patients have a low response rate to available immune checkpoint inhibitors (ICIs), including anti-PD-(L)1 therapy and CAR-T cell therapy, due to a broad array of immunosuppressive mechanisms. Notably, inhibition of LSD1 turns "cold tumors" into "hot tumors" and subsequently enhances tumor cell sensitivity to ICIs. This review focuses on recent advances in LSD1 and tumor immunity and discusses a potential therapeutic strategy for combining LSD1 inhibition with immunotherapy.

Lysine-specific demethylase 1 as a therapeutic cancer target: observations from preclinical study

INTRODUCTION

Lysine-specific histone demethylase 1A (KDM1A/LSD1) has emerged as an important therapeutic target in various cancer types. LSD1 regulates a wide range of biological processes that influence cancer development, progression, metastasis, and therapy resistance. However, recent studies have revealed novel aspects of LSD1 biology, shedding light on its involvement in immunogenicity, antitumor immunity, and DNA damage response. These emerging findings have the potential to be leveraged in the design of effective LSD1-targeted therapies.

AREAS COVERED

This paper discusses the latest developments in the field of LSD1 biology, focusing on its role in regulating immunogenicity, antitumor immunity, and DNA damage response mechanisms. The newfound understanding of these mechanisms has opened possibilities for the development of novel LSD1-targeted therapies for cancer treatment. Additionally, the paper provides an overview of LSD1 inhibitor-based combination therapies for the treatment of cancer.

EXPERT OPINION

Exploiting LSD1 role in antitumor immunity and DNA damage response provides cues to not only understand the LSD1-resistant mechanisms but also rationally design new combination therapies that are more efficient and less toxic than monotherapy. The exploration of LSD1 biology and the development of LSD1-targeted therapies hold great promise for the future of cancer treatment.

Engineering Female Germline Stem Cells with Exocytotic Polymer Dots

Germline stem cells (GSCs) are the only cell population capable of passing genetic information to offspring, making them attractive targets in reproductive biology and fertility research. However, it is generally more difficult to introduce exogenous biomolecules into GSCs than other cell types, impeding the exploration and manipulation of these cells for biomedical purposes. Herein, semiconductor polymer dots (Pdots)-based nanocomplex Pdot-siRNA is developed and achieves effective knockdown of target genes in female germline stem cells (FGSCs). Advantage of high fluorescence brightness of Pdots is taken for comprehensive investigation of their cellular uptake, intracellular trafficking, and exocytosis in FGSCs. Importantly, Pdots show excellent biocompatibility and minimally disturb the differentiation of FGSCs. Intracellular Pdots escape from the lysosomes and undergo active exocytosis, which makes them ideal nanocarriers for bioactive cargos. Moreover, Pdot-siRNA can penetrate into 3D ovarian organoids derived from FGSCs and down-regulate the expression levels of target genes. This study investigates the interface between a type of theranostic nanoparticles and FGSCs for the first time and sheds light on the manipulation and medical application of FGSCs.

Overcoming Cancer Multi-drug Resistance (MDR): Reasons, mechanisms, nanotherapeutic solutions, and challenges

Multi-drug resistance (MDR) in cancer cells, either intrinsic or acquired through various mechanisms, significantly hinders the therapeutic efficacy of drugs. Typically, the reduced therapeutic performance of various drugs is predominantly due to the inherent over expression of ATP-binding cassette (ABC) transporter proteins on the cell membrane, resulting in the deprived uptake of drugs, augmenting drug detoxification, and DNA repair. In addition to various physiological abnormalities and extensive blood flow, MDR cancer phenotypes exhibit improved apoptotic threshold and drug efflux efficiency. These severe consequences have substantially directed researchers in the fabrication of various advanced therapeutic strategies, such as co-delivery of drugs along with various generations of MDR inhibitors, augmented dosage regimens and frequency of administration, as well as combinatorial treatment options, among others. In this review, we emphasize different reasons and mechanisms responsible for MDR in cancer, including but not limited to the known drug efflux mechanisms mediated by permeability glycoprotein (P-gp) and other pumps, reduced drug uptake, altered DNA repair, and drug targets, among others. Further, an emphasis on specific cancers that share pathogenesis in executing MDR and effluxed drugs in common is provided. Then, the aspects related to various nanomaterials-based supramolecular programmable designs (organic- and inorganic-based materials), as well as physical approaches (light- and ultrasound-based therapies), are discussed, highlighting the unsolved issues and future advancements. Finally, we summarize the review with interesting perspectives and future trends, exploring further opportunities to overcome MDR.

Lysine-Specific Demethylase 1 Promises to Be a Novel Target in Cancer Drug Resistance: Therapeutic Implications

Chemotherapy, targeted therapy, and immunotherapy are effective against most tumors, but drug resistance remains a barrier to successful treatment. Lysine-specific demethylase 1 (LSD1), a member of histone demethylation modifications, can regulate invasion, metastasis, apoptosis, and immune escape of tumor cells, which are associated with tumorigenesis and tumor progression. Recent studies suggest that LSD1 ablation regulates resensitivity of tumor cells to anticarcinogens containing immune checkpoint inhibitors (ICIs) via multiple upstream and downstream pathways. In this review, we describe the recent findings about LSD1 biology and its role in the development and progression of cancer drug resistance. Further, we summarize LSD1 inhibitors that have a reversal or resensitive effect on drug resistance and discuss the possibility of targeting LSD1 in combination with other agents to surmount resistance.

Recent progress of antibacterial hydrogels in wound dressings

Hydrogels are essential biomaterials due to their favorable biocompatibility, mechanical properties similar to human soft tissue extracellular matrix, and tissue repair properties. In skin wound repair, hydrogels with antibacterial functions are especially suitable for dressing applications, so novel antibacterial hydrogel wound dressings have attracted widespread attention, including the design of components, optimization of preparation methods, strategies to reduce bacterial resistance, etc. In this review, we discuss the fabrication of antibacterial hydrogel wound dressings and the challenges associated with the crosslinking methods and chemistry of the materials. We have investigated the advantages and limitations (antibacterial effects and antibacterial mechanisms) of different antibacterial components in the hydrogels to achieve good antibacterial properties, and the response of hydrogels to stimuli such as light, sound, and electricity to reduce bacterial resistance. Conclusively, we provide a systematic summary of antibacterial hydrogel wound dressings findings (crosslinking methods, antibacterial components, antibacterial methods) and an outlook on long-lasting antibacterial effects, a broader antibacterial spectrum, diversified hydrogel forms, and the future development prospects of the field.

Composite Hydrogel for Spatiotemporal Lipid Intervention of Tumor Milieu

Induction of immunogenic cell death (ICD) plays crucial roles in cancer immunotherapy, whereas its efficacy is severely compromised by redundant antioxidant defenses in cancer cells and aberrant lipid metabolism in immunosuppressive cell populations. In this work, it is found that hollow mesoporous CuS nanoparticles (NPs) possess an intrinsic capacity of inhibiting glutathione peroxidase 4 (GPX4). When loaded with an inhibitor of the ferroptosis suppressor protein 1 (FSP1), these NPs block two parallel redox systems and cooperate with near-infrared irradiation to reinforce ICD. A hydrogel co-delivering cancer-cell-targeting CuS NPs and immunosuppressive-cell-targeting sulfo-N-succinimidyl oleate (SSO) for spatiotemporal lipid intervention i further fabricated. While the CuS NPs augment ICD via synergistic lipid peroxidation, SSO reinstates immune perception via lipid metabolic reprogramming, thereby coordinately triggering robust innate and adaptive immunity to restrain tumor growth, relapse, and metastasis. This study provides an immunometabolic therapy via orchestrated lipid modulation in the tumor milieu.

Covalent organic framework nanomedicines: Biocompatibility for advanced nanocarriers and cancer theranostics applications

Nanomedicines for drug delivery and imaging-guided cancer therapy is a rapidly growing research area. The unique properties of nanomedicines have a massive potential in solving longstanding challenges of existing cancer drugs, such as poor localization at the tumor site, high drug doses and toxicity, recurrence, and poor immune response. However, inadequate biocompatibility restricts their potential in clinical translation. Therefore, advanced nanomaterials with high biocompatibility and enhanced therapeutic efficiency are highly desired to fast-track the clinical translation of nanomedicines. Intrinsic properties of nanoscale covalent organic frameworks (nCOFs), such as suitable size, modular pore geometry and porosity, and straightforward post-synthetic modification via simple organic transformations, make them incredibly attractive for future nanomedicines. The ability of COFs to disintegrate in a slightly acidic tumor microenvironment also gives them a competitive advantage in targeted delivery. This review summarizes recently published applications of COFs in drug delivery, photo-immuno therapy, sonodynamic therapy, photothermal therapy, chemotherapy, pyroptosis, and combination therapy. Herein we mainly focused on modifications of COFs to enhance their biocompatibility, efficacy and potential clinical translation. This review will provide the fundamental knowledge in designing biocompatible nCOFs-based nanomedicines and will help in the rapid development of cancer drug carriers and theranostics.

Lysine-Specific Demethylase 1 (LSD1)-Mediated Epigenetic Modification of Immunogenicity and Immunomodulatory Effects in Breast Cancers

Tumor evolution to evade immune surveillance is a hallmark of carcinogenesis, and the modulation of tumor immunogenicity has been a challenge to present therapeutic responses in immunotherapies alone for numerous cancers. By altering the cell phenotype and reshaping the tumor microenvironment, epigenetic modifications enable tumor cells to overcome immune surveillance as a mechanism of cancer progression and immunotherapy resistance. Demethylase enzymatic activity of lysine-specific demethylase 1 (LSD1), a histone demethylase first identified in 2004, plays a pivotal role in the vast cellular processes of cancer. While FDA-approved indications for epigenetic therapies are limited to hematological malignancies, it is imperative to understand how epigenetic machinery can be targeted to prime immunotherapy responses in breast cancers. In this review, we discuss the potential roles of epigenetics and demethylating agent LSD1 as a potent new cancer management strategy to combat the current challenges of breast cancers, which have presented modest efficacy to immune checkpoint inhibitors till date. Additionally, we describe the combined use of LSD1-specific inhibitors and immune checkpoint inhibitors in existing breast cancer preclinical and clinical trials that elicits a robust immune response and benefit. Overall, the promising results observed in LSD1-targeting therapies signify the central role of epigenetics as a potential novel strategy to overcome resistance commonly seen in immunotherapies.

Novel strategies to reverse chemoresistance in colorectal cancer

Colorectal cancer (CRC) is a common gastrointestinal malignancy with high morbidity and fatality. Chemotherapy, as traditional therapy for CRC, has exerted well antitumor effect and greatly improved the survival of CRC patients. Nevertheless, chemoresistance is one of the major problems during chemotherapy for CRC and significantly limits the efficacy of the treatment and influences the prognosis of patients. To overcome chemoresistance in CRC, many strategies are being investigated. Here, we review the common and novel measures to combat the resistance, including drug repurposing (nonsteroidal anti-inflammatory drugs, metformin, dichloroacetate, enalapril, ivermectin, bazedoxifene, melatonin, and S-adenosylmethionine), gene therapy (ribozymes, RNAi, CRISPR/Cas9, epigenetic therapy, antisense oligonucleotides, and noncoding RNAs), protein inhibitor (EFGR inhibitor, S1PR2 inhibitor, and DNA methyltransferase inhibitor), natural herbal compounds (polyphenols, terpenoids, quinones, alkaloids, and sterols), new drug delivery system (nanocarriers, liposomes, exosomes, and hydrogels), and combination therapy. These common or novel strategies for the reversal of chemoresistance promise to improve the treatment of CRC.

Fluoroalkane modified cationic polymers for personalized mRNA cancer vaccines

Messenger RNA (mRNA) vaccines, while demonstrating great successes in the fight against COVID-19, have been extensively studied in other areas such as personalized cancer immunotherapy based on tumor neoantigens. In addition to the design of mRNA sequences and modifications, the delivery carriers are also critical in the development of mRNA vaccines. In this work, we synthesized fluoroalkane-grafted polyethylenimine (F-PEI) for mRNA delivery. Such F-PEI could promote intracellular delivery of mRNA and activate the Toll-like receptor 4 (TLR4)-mediated signaling pathway. The nanovaccine formed by self-assembly of F-PEI and the tumor antigen-encoding mRNA, without additional adjuvants, could induce the maturation of dendritic cells (DCs) and trigger efficient antigen presentation, thereby eliciting anti-tumor immune responses. Using the mRNA encoding the model antigen ovalbumin (mRNA^OVA), our F-PEI-based mRNA^OVA cancer vaccine could delay the growth of established B16-OVA melanoma. When combined with immune checkpoint blockade therapy, the F-PEI-based MC38 neoantigen mRNA cancer vaccine was able to suppress established MC38 colon cancer and prevent tumor reoccurrence. Our work presents a new tool for mRNA delivery, promising not only for personalized cancer vaccines but also for other mRNA-based immunotherapies.

Prodrug nanoparticles potentiate tumor chemo-immunometabolic therapy by disturbing oxidative stress

Constant oxidative stress and lactate accumulation are two main causes of tumor immunosuppression, their concurrent reduction plays a dominant role in effective antitumor immunity, but remains challenging. Herein, reactive oxygen species (ROS) responsive prodrug nanoparticles (designed as DHCRJ) are constructed for metabolic amplified chemo-immunotherapy against triple-negative breast cancer (TNBC) by modulating oxidative state and hyperglycolysis. Specifically, DHCRJ is prepared by the self-assembly of DOX prodrug-tethered ROS consuming bond-bridged copolymers with the loading of bromodomain-containing protein 4 inhibitor (BRD4i) JQ1. Interestingly, the nanoparticle polymer network could reduce ROS to relieve tumor hypoxia and realize the dense-to-loose structure inversion arising from ROS-triggered network collapse, which favors JQ1 release and hyaluronidase (Hyal)-activatable DOX prodrugs generation. More importantly, disruption of oxidative stress decreases glucose uptake and assists JQ1 to down-regulate oncogene c-Myc driven tumor glycolysis for blocking the source of lactate and reshaping immunosuppressive tumor microenvironment (ITME). Meanwhile, benefiting from the synergistic effect of DOX prodrugs and JQ1, DHCRJ is able to facilitate tumor immunogenicity and potentiate systemic immune responses through antigen processing and presentation pathway. In this manner, DHCRJ significantly suppresses tumor growth and metastasis with prolonged survival. Collectively, this study represents a proof of concept antioxidant-enhanced chemo-immunometabolic therapy strategy using ROS-reducing nanoparticles for efficient synergistic therapeutic modality of TNBC.

Multidimensional Quantitative Measurement of Cancer Chemoresistance through Differential ZIF-8 Nanoparticle Cellular Retention

Chemoresistance of cancer cells is conventionally quantified by half-maximal inhibitory concentration (IC₅₀) or multidrug resistance gene 1 (MDR1) values, but these metrics can only reflect the overall drug resistance level of a cancer cell line. Meanwhile, the multidimensional evaluation of both the heterogeneity in a cell line and the drug resistance degree of each cell still presents a daunting challenge. We report here that the cellular heterogeneity, cellular cross contamination, and the proportion of chemoresistant cancer cells can be visualized via flow cytometry through the differential cellular retention of fluorescent ZIF-8 nanoparticles. In addition, we show that the degree of drug resistance exhibited by each cell subpopulation can be quantified by differing fluorescence of the drug-resistant and drug-sensitive cells in the corresponding flow cytometry profile, and the quantified metric S is highly consistent with the MDR1 expression results. Importantly, this novel strategy is applicable to various cancer cell lines, thus demonstrating a universal diagnosis platform for multidimensional, quantitative, and highly efficient diagnosis of cancer chemoresistance.

A state-of-the-art review on LSD1 and its inhibitors in breast cancer: Molecular mechanisms and therapeutic significance

Breast cancer (BC) is a kind of malignant cancer in women, and it has become the most diagnosed cancer worldwide since 2020. Histone methylation is a common biological epigenetic modification mediating varieties of physiological and pathological processes. Lysine-specific demethylase 1 (LSD1), a first identified histone demethylase, mediates the removal of methyl groups from histones H3K4me1/2 and H3K9me1/2 and plays a crucial role in varieties of cancer progression. It is also specifically amplified in breast cancer and contributes to BC tumorigenesis and drug resistance via both demethylase and non-demethylase manners. This review will provide insight into the overview structure of LSD1, summarize its action mechanisms in BC, describe the therapeutic potential of LSD1 inhibitors in BC, and prospect the current opportunities and challenges of targeting LSD1 for BC therapy.

Responsive Hydrogels Based on Triggered Click Reactions for Liver Cancer

Globally, liver cancer, which is one of the major cancers worldwide, has attracted the growing attention of technological researchers for its high mortality and limited treatment options. Hydrogels are soft 3D network materials containing a large number of hydrophilic monomers. By adding moieties such as nitrobenzyl groups to the network structure of a cross-linked nanocomposite hydrogel, the click reaction improves drug-release efficiency in vivo, which improves the survival rate and prolongs the survival time of liver cancer patients. The application of a nanocomposite hydrogel drug delivery system can not only enrich the drug concentration at the tumor site for a long time but also effectively prevents the distant metastasis of residual tumor cells. At present, a large number of researches have been working toward the construction of responsive nanocomposite hydrogel drug delivery systems, but there are few comprehensive articles to systematically summarize these discoveries. Here, this systematic review summarizes the synthesis methods and related applications of nanocomposite responsive hydrogels with actions to external or internal physiological stimuli. With different physical or chemical stimuli, the structural unit rearrangement and the controlled release of drugs can be used for responsive drug delivery in different states.

DLGAP1-AS2-Mediated Phosphatidic Acid Synthesis Activates YAP Signaling and Confers Chemoresistance in Squamous Cell Carcinoma

Squamous cell carcinomas (SCC) constitute a group of human malignancies that originate from the squamous epithelium. Most SCC patients experience treatment failure and relapse and have a poor prognosis due to de novo and acquired resistance to first-line chemotherapeutic agents. To identify chemoresistance mechanisms and explore novel targets for chemosensitization, we performed whole-transcriptome sequencing of paired resistant and parental SCC cells. We identified DLGAP1 antisense RNA 2 (D-AS2) as a crucial noncoding RNA that contributes to chemoresistance in SCC. Mechanistically, D-AS2 affected chromatin accessibility around the histone mark H3K27ac of FAM3 metabolism regulating signaling molecule D (FAM3D), reducing FAM3D mRNA transcription and extracellular protein secretion. FAM3D interacted with the Gαi-coupled G protein-coupled receptors (GPCRs) formyl peptide receptor 1 (FPR1) and FPR2 to suppress phospholipase D (PLD) activity, and reduced FAM3D increased PLD signaling. Moreover, activated PLD promoted phosphatidic acid (PA) production and subsequent nuclear translocation of yes-associated protein (YAP). Accordingly, in vivo administration of a D-AS2-targeting antisense oligonucleotide sensitized SCC to cisplatin treatment. In summary, this study shows that D-AS2/FAM3D-mediated PLD/PA lipid signaling is essential for SCC chemoresistance, suggesting D-AS2 can be targeted to sensitize SCC to cytotoxic chemotherapeutic agents.

Discovery of protein-based natural hydrogel from the girdle of the 'sea cockroach' Chiton articulatus (Chitonida: Chitonidae)

Hydrogels are widely used materials in biomedical, pharmaceutical, cosmetic, and agricultural fields. However, these hydrogels are usually formed synthetically via a long and complicated process involving crosslinking natural polymers. Herein, we describe a natural hydrogel isolated using a 'gentle' acid treatment from the girdle of a chiton species (Chiton articulatus). This novel hydrogel is shown to have a proliferative effect on mouse fibroblast cells (cell line, L929). The swelling capacity of this natural hydrogel was recorded as approximately 1,200% in distilled water, which is within desired levels for hydrogels. Detailed characterizations reveal that the hydrogel consists predominantly (83.93%) of protein. Considering its non-toxicity, proliferative effect and swelling properties, this natural hydrogel is an important discovery for material sciences, with potential for further applications in industry. Whether the girdle has some hydrogel activity in the living animal is unknown, but we speculate that it may enable the animal to better survive extreme environmental conditions by preventing desiccation.

Self-Rectifiable and Hypoxia-Assisted Chemo-Photodynamic Nanoinhibitor for Synergistic Cancer Therapy

Photodynamic therapy (PDT) can eradicate cancer cells under light irradiation, mainly because of reactive singlet oxygen (¹O₂) being transformed from intratumoral oxygen. Nonetheless, the consumption of oxygen during PDT results in serious hypoxic conditions and an elevated hypoxia-inducing factor-1α (HIF-1α) level that hamper further photodynamic efficacy and induce tumor metastasis. To address this problem, we developed hypoxia-assisted NP-co-encapsulating Ce6 (photosensitizer) and YC-1 (HIF-1α inhibitor) as a self-rectifiable nanoinhibitor for synergistic antitumor treatment. PDT-aggravated intracellular hypoxic stress facilitated NP dissociation to release the drug (YC-1), which achieved tumor killing and HIF-1α inhibition to further enhance the therapeutic effect of PDT and prevent tumor metastasis. Besides, in vivo studies revealed that the HC/PI@YC-1 NPs afforded synergistic anticancer efficacy with minimal toxicity. Therefore, this study provides a prospective approach against PDT drawbacks and combination cancer therapy.

The Role of Long Non-Coding RNAs in the Tumor Immune Microenvironment

Tumorigenesis is a complicated process caused by successive genetic and epigenetic alterations. The past decades demonstrated that the immune system affects tumorigenesis, tumor progression, and metastasis. Although increasing immunotherapies are revealed, only a tiny proportion of them are effective. Long non-coding RNAs (lncRNAs) are a class of single-stranded RNA molecules larger than 200 nucleotides and are essential in the molecular network of oncology and immunology. Increasing researches have focused on the connection between lncRNAs and cancer immunotherapy. However, the in-depth mechanisms are still elusive. In this review, we outline the latest studies on the functions of lncRNAs in the tumor immune microenvironment. Via participating in various biological processes such as neutrophil recruitment, macrophage polarization, NK cells cytotoxicity, and T cells functions, lncRNAs regulate tumorigenesis, tumor invasion, epithelial-mesenchymal transition (EMT), and angiogenesis. In addition, we reviewed the current understanding of the relevant strategies for targeting lncRNAs. LncRNAs-based therapeutics may represent promising approaches in serving as prognostic biomarkers or potential therapeutic targets in cancer, providing ideas for future research and clinical application on cancer diagnosis and therapies.

An Insight into Skeletal Networks Analysis for Smart Hydrogels

Hydrogels are 3D cross‐linked polymer networks. Benefiting from the flexible designs and reasonable constructions of these networks, a large number of smart hydrogels with response characteristics to specific stimuli have received widespread attention and developed rapidly. The skeletal networks composed of the skeletal polymer chains and effectual cross‐links are the soul of such soft materials, and the response behaviors fundamentally depend on the dynamic characteristics of skeletal networks. Herein, the novel concepts of skeletal networks analysis to describe, understand, and guide the advanced designs and applications of smart hydrogels are proposed. Representative glucose‐sensitive hydrogels and DNA‐based smart hydrogels are reviewed to demonstrate the principle of skeletal networks analysis and clarify its practical guidance. Summarizing and classifying the characterizations and conversions of skeletal networks dynamics based on different response mechanisms provides a realistic solution. On this basis, advanced applications of smart hydrogels guided by skeletal networks dynamics including biochemical detection, cell mechanics sensing, drug delivery systems, and dynamic complex soft materials are typically reviewed. The skeletal networks analysis for smart hydrogels is of great significance for understanding the microstructures of hydrogels and guiding the designs of soft materials and their smart applications in the fields of analytical science and advanced materials.

Homotypic targeting of immunomodulatory nanoparticles for enhanced peripheral and central immunity

OBJECTIVES

Synthetic oligodeoxynucleotides (ODNs) that contain unmethylated cytosine-phosphate-guanine (CpG) motifs serve as immune adjuvants in disease treatment. However, the poor cell permeability and safety concerns limit their medical applications, and biocompatible strategies for efficient delivery of functional CpG ODNs are highly desirable.

MATERIALS AND METHODS

Self-assembled, cell membrane-coated CpG nanoparticles (NP) are prepared, and their physicochemical properties are characterized. The uncoated and membrane-coated CpG NP are compared for their biocompatibility, cellular uptake kinetics, endocytic pathways, subcellular localization, and immunostimulatory activities in macrophages and microglia.

RESULTS

Macrophage- or microglia-derived cell membrane camouflaging alters the endocytic pathways of CpG NP, promotes their targeted delivery to the cells with homologous membrane, ensures their endosomal localization, and enhances their immunomodulatory effects.

CONCLUSIONS

We design a type of biomimetic NP consisting of self-assembled CpG NP core and cell membrane shell, and demonstrate its advantages in the modulation of peripheral and central immune cells. Our study provides a new strategy for the application of CpG ODNs.

RNA Hydrogel Combined with MnO2 Nanoparticles as a Nano-Vaccine to Treat Triple Negative Breast Cancer

Hypoxia is not only the reason of tumor metastasis but also enhances the spread of cancer cells from the original tumor site, which results in cancer recurrence. Herein, we developed a self-assembled RNA hydrogel that efficiently delivered synergistic DNA CpG and short hairpin RNA (shRNA) adjuvants, as well as MnO₂ loaded-photodynamic agent chlorine e6 (MnO₂@Ce6), and a chemotherapy drug doxorubicin (DOX) into MDA-MB-231cells. The RNA hydrogel consists of one tumour suppressor miRNA (miRNA-205) and one anti-metastatic miRNA (miRNA-182), both of which showed an outstanding effect in synergistically abrogating tumours. The hydrogel would be dissociated by endogenous Dicer enzyme to release loaded therapeutic molecules, and in the meantime induce decomposition of tumor endogenous H₂O₂ to relieve tumor hypoxia. As a result, a remarkable synergistic therapeutic effect is achieved through the combined chemo-photodynamic therapy, which simultaneously triggers a series of anti-tumor immune responses. Besides, the hydrogel as the carrier which modified aptamer to targeted MDA-MB-231 has the advantages of good biocompatibility and low cytotoxicity. This strategy could be implemented to design any other microRNA (miRNA) as the carrier, combined with other treatment methods to treat human cancer, thereby overcoming the limitations of current cancer therapies.