Tetrahedral Framework Nucleic Acids Inhibit Skin Fibrosis via the Pyroptosis Pathway

Tetrahedral DNA-Based Functional MicroRNA-21 Delivery System: Application to Corneal Epithelial Wound Healing

Corneal injury occurs frequently which may lead to serious visual impairment. Rapid and efficient re-epithelialization after corneal epithelial injury is the key issue for maintaining corneal homeostasis. Among various treatment strategies, microRNA (miR)-based therapy shows great potential. However, structural limitations of miRNAs hinder its biomedical functionality. Nucleic acid nanotechnology is an appealing candidate for gene delivery because of its flexible modification and excellent biocompatibility. Herein, modified 3D tetrahedral framework nucleic acids (tFNAs) utilized as gene carriers for miR-21 delivery are constructed. TFNAs-miR-21 (T-21) shows great enzymatic resistance in extracellular environment and payload delivery into human corneal epithelial cells (HCECs) via clathrin-mediated endocytosis. T-21 facilitates proliferation and migration in HCECs via activating PI3K/AKT and ERK1/2 signaling pathways in vitro. In vivo studies, T-21 can be internalized by corneal epithelium in mice. In the mice corneal scratch model, T-21 ophthalmic solutions used as eye drops show no apparent side effects on the ocular surface histologically and exert great potential in accelerating corneal wound healing. These findings demonstrate that modified tFNAs are promising candidates for miRNA delivery for corneal wound healing. The convenient administration and great biocompatibility of tetrahedral DNA nanoparticles highlight its potential as gene transporter in solving ocular problems.

Recent advances in molecular mechanisms of skin wound healing and its treatments

The skin, being a multifaceted organ, performs a pivotal function in the complicated wound-healing procedure, which encompasses the triggering of several cellular entities and signaling cascades. Aberrations in the typical healing process of wounds may result in atypical scar development and the establishment of a persistent condition, rendering patients more vulnerable to infections. Chronic burns and wounds have a detrimental effect on the overall quality of life of patients, resulting in higher levels of physical discomfort and socio-economic complexities. The occurrence and frequency of prolonged wounds are on the rise as a result of aging people, hence contributing to escalated expenditures within the healthcare system. The clinical evaluation and treatment of chronic wounds continue to pose challenges despite the advancement of different therapeutic approaches. This is mainly owing to the prolonged treatment duration and intricate processes involved in wound healing. Many conventional methods, such as the administration of growth factors, the use of wound dressings, and the application of skin grafts, are used to ease the process of wound healing across diverse wound types. Nevertheless, these therapeutic approaches may only be practical for some wounds, highlighting the need to advance alternative treatment modalities. Novel wound care technologies, such as nanotherapeutics, stem cell treatment, and 3D bioprinting, aim to improve therapeutic efficacy, prioritize skin regeneration, and minimize adverse effects. This review provides an updated overview of recent advancements in chronic wound healing and therapeutic management using innovative approaches.

Macrophage-Targeting DNA Nanomaterials: A Future Direction of Biological Therapy

DNA can be used for precise construction of complex and flexible micro-nanostructures, including DNA origami, frame nucleic acids, and DNA hydrogels. DNA nanomaterials have good biocompatibility and can enter macrophages via scavenger receptor-mediated endocytosis. DNA nanomaterials can be uniquely and flexibly designed to ensure efficient uptake by macrophages, which represents a novel strategy to regulate macrophage function. With the development of nanotechnology, major advances have been made in the design and manufacturing of DNA nanomaterials for clinical therapy. In diseases accompanied by macrophage disturbances including tumor, infectious diseases, arthritis, fibrosis, acute lung injury, and atherosclerosis, DNA nanomaterials received considerable attention as potential treatments. However, we lack sufficient information to guarantee precise targeting of macrophages by DNA nanomaterials, which precludes their therapeutic applications. In this review, we summarize recent studies of macrophage-targeting DNA nanomaterials and discuss the limitations and challenges of this approach with regard to its potential use as a biological therapy.

Framework nucleic acids as promising reactive oxygen species scavengers for anti-inflammatory therapy

Reactive oxygen species (ROS) are an array of derivatives of molecular oxygen that participate in multiple physiological processes under the control of redox homeostasis. However, under pathological conditions, the over-production of ROS often leads to oxidative stress and inflammatory reactions, indicating a potential therapeutic target. With the rapid development of nucleic acid nanotechnology, scientists have exploited various DNA nanostructures with remarkable biocompatibility, programmability, and structural stability. Among these novel organic nanomaterials, a group of skeleton-like framework nucleic acid (FNA) nanostructures attracts the most interest due to their outstanding self-assembly, cellular endocytosis, addressability, and functionality. Surprisingly, different FNAs manifest similarly satisfactory antioxidative and anti-inflammatory effects during their biomedical application process. First, they are intrinsically endowed with the ability to neutralize ROS due to their DNA nature. Therefore, they are extensively involved in the complicated inflammatory signaling network. Moreover, the outstanding editability of FNAs also allows for flexible modifications with nucleic acids, aptamers, peptides, antibodies, low-molecular-weight drugs, and so on, thus further strengthening the targeting and therapeutic ability. This review focuses on the ROS-scavenging potential of three representative FNAs, including tetrahedral framework nucleic acids (tFNAs), DNA origami, and DNA hydrogels, to summarize the recent advances in their anti-inflammatory therapy applications. Although FNAs exhibit great potential in treating inflammatory diseases as promising ROS scavengers, massive efforts still need to be made to overcome the emerging challenges in their clinical translation.

Tetrahedral framework nucleic acids for improving wound healing

Wounds are one of the most common health issues, and the cost of wound care and healing has continued to increase over the past decade. In recent years, there has been growing interest in developing innovative strategies to enhance the efficacy of wound healing. Tetrahedral framework nucleic acids (tFNAs) have emerged as a promising tool for wound healing applications due to their unique structural and functional properties. Therefore, it is of great significance to summarize the applications of tFNAs for wound healing. This review article provides a comprehensive overview of the potential of tFNAs as a novel therapeutic approach for wound healing. In this review, we discuss the possible mechanisms of tFNAs in wound healing and highlight the role of tFNAs in modulating key processes involved in wound healing, such as cell proliferation and migration, angiogenesis, and tissue regeneration. The targeted delivery and controlled release capabilities of tFNAs offer advantages in terms of localized and sustained delivery of therapeutic agents to the wound site. In addition, the latest research progress on tFNAs in wound healing is systematically introduced. We also discuss the biocompatibility and biosafety of tFNAs, along with their potential applications and future directions for research. Finally, the current challenges and prospects of tFNAs are briefly discussed to promote wider applications.

Targeting Lysosome for Enhanced Cancer Photodynamic/Photothermal Therapy in a "One Stone Two Birds" Pattern

Highly immunogenic programmed death of tumor cells, such as immunogenic cell death (ICD) and pyroptosis, strengthens antitumor responses and thus represents a promising target for cancer immunotherapy. However, the development of ICD and pyroptosis inducers remains challenging, and their efficiency is typically compromised by self-protective autophagy. Here, we report a potent ICD and pyroptosis-inducing strategy by coupling combined photodynamic/photothermal therapy (PTT/PDT) to biological processes in cancer cells. For this purpose, we rationally synthesize a lysosomal-targeting boron-dipyrromethene dimer (BDPd) with intense NIR absorption/emission, high reactive oxygen species (ROS) yield, and photothermal abilities, which can be self-assembled with Pluronic F127, producing lysosomal-acting nanomicelles (BDPd NPs) to facilitate cancer cell internalization of BDPd and generation of intracellular ROS. Owing to the favorable lysosomal-targeting ability of the morpholine group on BDPd, the intracellular BDPd NPs can accumulate in the lysosome and induce robust lysosomal damage in cancer cells upon 660 nm laser irradiation, which results in the synergetic induction of pyroptosis and ICD via activating NLRP3/GSDMD and caspase-3/GSDME pathways simultaneously. More importantly, PTT/PDT-induced self-protective autophagic degradation was blocked due to the dysfunction of lysosomes. Either intratumorally or intravenously, the injected BDPd NPs could markedly inhibit the growth of established tumor tissues upon laser activation, provoke local and systemic antitumor immune responses, and prolong the survival time in the mouse triple-negative breast cancer model. Collectively, this work represents a promising strategy to boost the therapeutic potential of PTT/PDT by coupling phototherapeutic reagents with the subcellular organelles, creating a "one stone two birds" pattern.

A Novel Bioswitchable miRNA Mimic Delivery System: Therapeutic Strategies Upgraded from Tetrahedral Framework Nucleic Acid System for Fibrotic Disease Treatment and Pyroptosis Pathway Inhibition

There has been considerable interest in gene vectors and their role in regulating cellular activities and treating diseases since the advent of nucleic acid drugs. MicroRNA (miR) therapeutic strategies are research hotspots as they regulate gene expression post-transcriptionally and treat a range of diseases. An original tetrahedral framework nucleic acid (tFNA) analog, a bioswitchable miR inhibitor delivery system (BiRDS) carrying miR inhibitors, is previously established; however, it remains unknown whether BiRDS can be equipped with miR mimics. Taking advantage of the transport capacity of tetrahedral framework nucleic acid (tFNA) and upgrading it further, the treatment outcomes of a traditional tFNA and BiRDS at different concentrations on TGF-β- and bleomycin-induced fibrosis simultaneously in vitro and in vivo are compared. An upgraded traditional tFNA is designed by successfully synthesizing a novel BiRDS, carrying a miR mimic, miR-27a, for treating skin fibrosis and inhibiting the pyroptosis pathway, which exhibits stability and biocompatibility. BiRDS has three times higher efficiency in delivering miRNAs than the conventional tFNA with sticky ends. Moreover, BiRDS is more potent against fibrosis and pyroptosis-related diseases than tFNAs. These findings indicate that the BiRDS can be applied as a drug delivery system for disease treatment.

Tetrahedral framework nucleic acid loaded with glabridin: A transdermal delivery system applicated to anti-hyperpigmentation

Topical application of tyrosinase inhibitors, such as hydroquinone and arbutin, is the most common clinical treatment for hyperpigmentation. Glabridin (Gla) is a natural isoflavone that inhibits tyrosinase activity, free radical scavenging, and antioxidation. However, its water solubility is poor, and it cannot pass through the human skin barrier alone. Tetrahedral framework nucleic acid (tFNA), a new type of DNA biomaterial, can penetrate cells and tissues and can be used as carriers to deliver small-molecule drugs, polypeptides, and oligonucleotides. This study aimed to develop a compound drug system using tFNA as the carrier to transport Gla and deliver it through the skin to treat pigmentation. Furthermore, we aimed to explore whether tFNA-Gla can effectively alleviate the hyperpigmentation caused by increased melanin production and determine whether tFNA-Gla exerts substantial synergistic effects during treatment. Our results showed that the developed system successfully treated pigmentation by inhibiting regulatory proteins related to melanin production. Furthermore, our findings showed that the system was effective in treating epidermal and superficial dermal diseases. The tFNA-based transdermal drug delivery system can thus develop into novel, effective options for non-invasive drug delivery through the skin barrier.

A Mitochondrial Nanoguard Modulates Redox Homeostasis and Bioenergy Metabolism in Diabetic Peripheral Neuropathy

As a major late complication of diabetes, diabetic peripheral neuropathy (DPN) is the primary reason for amputation. Nevertheless, there are no wonder drugs available. Regulating dysfunctional mitochondria is a key therapeutic target for DPN. Resveratrol (RSV) is widely proven to guard mitochondria, yet the unsatisfactory bioavailability restricts its clinical application. Tetrahedral framework nucleic acids (tFNAs) are promising carriers due to their excellent cell entrance efficiency, biological safety, and structure editability. Here, RSV was intercalated into tFNAs to form the tFNAs-RSV complexes. tFNAs-RSV achieved enhanced stability, bioavailability, and biocompatibility compared with tFNAs and RSV alone. With its treatment, reactive oxygen species (ROS) production was minimized and reductases were activated in an in vitro model of DPN. Besides, respiratory function and adenosine triphosphate (ATP) production were enhanced. tFNAs-RSV also exhibited favorable therapeutic effects on sensory dysfunction, neurovascular deterioration, demyelination, and neuroapoptosis in DPN mice. Metabolomics analysis revealed that redox regulation and energy metabolism were two principal mechanisms that were impacted during the process. Comprehensive inspections indicated that tFNAs-RSV inhibited nitrosation and oxidation and activated reductase and respiratory chain. In sum, tFNAs-RSV served as a mitochondrial nanoguard (mito-guard), representing a viable drilling target for clinical drug development of DPN.

Expression and correlation of the Pi3k/Akt pathway and VEGF in oral submucous fibrosis

Oral submucous fibrosis (OSF) has a high incidence in Asia countries, but its underlying molecular mechanism was not exploited completely. In this research, we investigated the expression of the phosphatidyl inositol 3-kinase (Pi3k)/protein kinase B (Akt) pathway and vascular endothelial growth factor (VEGF) in oral submucosal fibrosis, explore the correlation between the Pi3k/Akt pathway and VEGF, and identify the mechanisms involved in OSF. The pathological changes and fibrosis stages of OSF tissues (n = 30, 10 each of early, moderate and advanced OSF) were determined using Haematoxylin-eosin staining (HE) and Masson staining, respectively. Collagen type I (Col-I), Pi3k, Akt, VEGF, TGF-β and p-Akt expression was detected using immunohistochemistry, qPCR and WB. The correlation between Pi3k, Akt and VEGF was analysed. Col-I expression increased as OSF progressed. However, their expression was downregulated in normal and moderate to advanced OSF tissues. VEGF expression positively correlated with Pi3k and Akt expression. VEGF expression correlated positively and negatively with the Pi3k inhibitor, LY294002 below and above a concentration of 10 μM, respectively. VEGF expression correlated positively with the Pi3k/Ak activator, IGF-1. Due to the synergistic effect between Pi3k/Akt pathway and VEGF on OSF lesions and fibrosis process, targeted Pi3k/Akt pathway regulation can induce VEGF expression and improve ischemia, ultimately treating OSF.

Functional micro-RNA drugs acting as a fate manipulator in the regulation of osteoblastic death

Bone loss is prevalent in clinical pathological phenomena such as osteoporosis, which is characterized by decreased osteoblast function and number, increased osteoclast activity, and imbalanced bone homeostasis. However, current treatment strategies for bone diseases are limited. Regulated cell death (RCD) is a programmed cell death pattern activated by the expression of specific genes in response to environmental changes. Various studies have shown that RCD is closely associated with bone diseases, and manipulating the death fate of osteoblasts could contribute to effective bone treatment. Recently, microRNA-targeting therapy drugs have emerged as a potential solution because of their precise targeting, powerful curative effect, and limited side effects. Nevertheless, their clinical application is limited by their inherent instability, easy enzymatic degradation, and poor membrane penetrability. To address this challenge, a self-assembling tetrahedral DNA nanostructure (TDN)-based microRNA (Tmi) delivery system has been proposed. TDN features excellent biocompatibility, cell membrane penetrability, serum stability, and modification versatility, making it an ideal nucleic acid carrier for miRNA protection and intracellular transport. Once inside cells, Tmi can dissociate and release miRNAs to manipulate key molecules in the RCD signaling pathway, thereby regulating bone homeostasis and curing diseases caused by abnormal RCD activation. In this paper, we discuss the impact of the miRNA network on the initiation and termination of four critical RCD programs in bone tissues: apoptosis, autophagy, pyroptosis, and ferroptosis. Furthermore, we present the Tmi delivery system as a miRNA drug vector. This provides insight into the clinical translation of miRNA nucleic acid drugs and the application of miRNA drugs in bone diseases.

Recent progress and application of the tetrahedral framework nucleic acid materials on drug delivery

INTRODUCTION

The application of DNA framework nucleic acid materials in the biomedical field has witnessed continual expansion. Among them, tetrahedral framework nucleic acids (tFNAs) have gained significant traction as the foremost biological vectors due to their superior attributes of editability, low immunogenicity, biocompatibility, and biodegradability. tFNAs have demonstrated promising results in numerous in vitro and in vivo applications.

AREAS COVERED

This review summarizes the latest research on tFNAs in drug delivery, including a discussion of the advantages of tFNAs in regulating biological behaviors, and highlights the updated development and advantageous applications of tFNAs-based nanostructures from static design to dynamically responsive design.

EXPERT OPINION

tFNAs possess distinct biological regulatory attributes and can be taken up by cells without the requirement of transfection, differentiating them from other biological vectors. tFNAs can be easily physically/chemically modified and seamlessly incorporated with other functional systems. The static design of the tFNAs-based drug delivery system makes it versatile, reproducible, and predictable. Further use of the dynamic response mechanism of DNA to external stimuli makes tFNAs-based drug delivery more effective and specific, improving the uptake and utilization of the payload by the intended target. Dynamic targeting is poised to become the future primary approach for drug delivery.

DNA Tetrahedra-Based Delivery of MicroRNA-22 to Reduce Depressive Symptoms in Mice

Major depressive disorder (MDD) is a common illness with an increasing lifetime prevalence. Thus, an increasing number of studies have investigated the association between MDD and microRNAs (miRNAs), which are a novel approach for treating depression. However, the therapeutic potential of miRNA-based strategies has several limitations. To overcome these limitations, DNA tetrahedra (TDNs) have been used as piggyback materials. In this study, we successfully used TDNs as carriers of miRNA-22-3p (miR-22-3p) and synthesized a novel DNA nanocomplex (TDN-miR-22-3p), which was used in a lipopolysaccharide (LPS)-induced depression cell model. The results suggest that miR-22-3p may regulate inflammation by regulating phosphatase and tensin homologue (PTEN), an important regulatory molecule in the PI3K/AKT pathway, and downregulating the expression of NLRP3. We further validated the role of TDN-miR-22-3p in vivo using an LPS-induced animal model of depression. The results indicate that it ameliorated depression-like behavior and attenuated the expression of inflammation-related factors in mice. This study demonstrates the establishment of a straightforward and efficacious miRNA delivery system and the potential of TDNs as therapeutic vectors and tools for mechanistic studies. To the best of our knowledge, this is the first study to use TDNs in combination with miRNAs to treat depression.

Albumin-based formononetin nanomedicines for lung injury and fibrosis therapy via blocking macrophage pyroptosis

Pulmonary fibrosis that occurs following lung injury is a progressive and fatal disease since continual damage to lung tissue triggers the dysregulated inflammation response and accompanying abnormal healing process. Pyroptosis of alveolar macrophages has been found to play an essential role in the deterioration of lung injury and fibrosis. However, the lack of inhibitors against this inflammatory cell death in macrophages and the dense stroma pose major barriers to lung injury and fibrosis treatment. Herein, we developed an albumin-based nanoformulation to realize active delivery of formononetin (FMN) to improve the treatment of lung injury and fibrosis. The obtained nanoparticle, FMN@BSA NPs, could efficiently accumulate at the impaired lesion benefiting from the leaky vasculatures and the affinity between albumin and the overexpressed SPARC protein. Through blocking the NLRP3 inflammasome-involved pyroptosis process of macrophages, FMN@BSA NPs remarkably improved lung function and prolonged animal survival in the bleomycin (BLM)-induced lung injury and fibrosis model without noticeable side effects. Meanwhile, we proved FMN as a pyroptosis inhibitor and the corresponding lipid metabolism-related mechanisms through multi-omics analysis. This study first employed an albumin-based nanoparticle to deliver the pyroptosis inhibitor to the impaired lung tissue actively, providing a promising strategy for lung injury and fibrosis treatment.

Multifunctional DNA Tetrahedron for Alzheimer's Disease Mitochondria-Targeted Therapy by MicroRNA Regulation

The principal hallmark of Alzheimer's disease (AD) is neuron mitochondrial dysfunction, whereas mitochondrial miRNAs potentially play important roles. Nevertheless, efficacious mitochondria organelle therapeutic agents for treatment and management of AD are highly advisable. Herein, we report a multifunctional DNA tetrahedron-based mitochondria-targeted therapeutic platform, termed tetrahedral DNA framework-based nanoparticles (TDFNs), which was modified with triphenylphosphine (TPP) for mitochondria-targeting, cholesterol (Chol) for crossing the central nervous system, and functional antisense oligonucleotide (ASO) for both AD diagnosis and gene silencing therapy. After injecting intravenously through the tail vein of 3 × Tg-AD model mice, TDFNs can both easily cross the blood brain barrier and accurately arrive at the mitochondria. The functional ASO could not only be detected via the fluorescence signal for diagnosis but also mediate the apoptosis pathway through knocking miRNA-34a down, leading to recovery of the neuron cells. The superior performance of TDFNs suggests the great potential in mitochondria organelle therapeutics.

Antifibrotic Effects of Tetrahedral Framework Nucleic Acids by Inhibiting Macrophage Polarization and Macrophage-Myofibroblast Transition in Bladder Remodeling

Bladder outlet obstruction (BOO) is a prevalent condition arising from urethral stricture, posterior urethral valves, and benign prostatic hyperplasia. Long-term obstruction can lead to bladder remodeling, which is characterized by inflammatory cell infiltration, detrusor hypertrophy, and fibrosis. Until now, there are no efficacious therapeutic options for BOO-induced remodeling. Tetrahedral framework nucleic acids (tFNAs) are a type of novel 3D DNA nanomaterials that possess excellent antifibrotic effects. Here, to determine the treatment effects of tFNAs on BOO-induced remodeling is aimed. Four single-strand DNAs are self-assembled to form tetrahedral framework DNA nanostructures, and the antifibrotic effects of tFNAs are investigated in an in vivo BOO animal model and an in vitro transforming growth factor beta1 (TGF-β1)-induced fibrosis model. The results demonstrated that tFNAs could ameliorate BOO-induced bladder fibrosis and dysfunction by inhibiting M2 macrophage polarization and the macrophage-myofibroblast transition (MMT) process. Furthermore, tFNAs regulate M2 polarization and the MMT process by deactivating the signal transducer and activator of transcription (Stat) and TGF-β1/small mothers against decapentaplegic (Smad) pathways, respectively. This is the first study to reveal that tFNAs might be a promising nanomaterial for the treatment of BOO-induced remodeling.

Advances in energy metabolism in renal fibrosis

Renal fibrosis is a common pathway toward chronic kidney disease (CKD) and is the main pathological predecessor for end-stage renal disease; thus, preventing progressive CKD and renal fibrosis is essential to reducing their consequential morbidity and mortality. Emerging evidence has connected renal fibrosis to metabolic reprogramming; abnormalities in energy metabolism pathways, such as glycolysis, the tricarboxylic acid cycle, and lipid metabolism, are known to cause diseases of diverse etiologies. Cytokine interventions in affected metabolic pathways may significantly reduce the degree of fibrosis, highlighting therapeutic targets for drug development for renal fibrosis. Here, we discuss the relationship between glycolysis, lipid metabolism, mitochondrial and peroxisome dysfunction, and renal fibrosis in detail and propose that targeted therapies for specific metabolic pathways are expected to represent the next generation of treatments for renal fibrosis.

Albumin-Coated Framework Nucleic Acids as Bionic Delivery System for Triple-Negative Breast Cancer Therapy

Triple-negative breast cancer (TNBC) is a subtype of breast cancer, and it has aggressive and more frequent tissue metastases than other breast cancer subtypes. Because the proliferation of TNBC tumor cells does not depend on estrogen receptor (ER), progesterone receptor (PR), and Erb-B2 receptor tyrosine kinase 2 (HER2) and lacks accurate drug targets, conventional chemotherapy is challenging to be effective, and adverse reactions are severe. At present, the treatment strategy for TNBC generally depends on a combination of surgery, radiotherapy, and chemotherapy. Conventional administration methods have minimal effects on TNBC and cause severe damage to normal tissues. Therefore, it is an urgent task to develop an efficient and practical way of drug delivery and open up a new horizon of targeted therapy for TNBC. In our work, bovine serum albumin (BSA) acted as the protective film to prolong the circulation time of the tetrahedral framework nucleic acid (tFNA) delivery system and resist immune clearance in vivo. tFNA was used as a carrier loaded with DOX and AS1411 aptamers for the targeted treatment of triple-negative breast cancer. Compared with existing approaches, this optimized system exhibits stronger tumor-targeting so that tFNAs can be more concentrated around the tumor tissue, reducing DOX toxicity to other organs. This bionic delivery system exhibited effective tumor growth inhibition in the TNBC mice model, offering the clinical potential to promote the treatment of TNBC with great potential for clinical translation.

Self-Assembled Immunostimulatory Tetrahedral Framework Nucleic Acid Vehicles for Tumor Chemo-immunotherapy

Some chemotherapeutic agents, such as anthracyclines and oxaliplatin, can induce immunogenic cell death (ICD) with additional immune responses against cancer. However, ICD-based immunotherapy is limited by the nonspecific distribution of drugs and various side effects. Here, an immunostimulatory self-assembled tetrahedral framework nucleic acid (tFNA) vehicle was constructed to potentiate the chemo-immunotherapy, in which doxorubicin (DOX) acted as a chemotherapeutic agent and an ICD-inducer. Meanwhile, the immunostimulatory CpG-tFNA was employed as a nanocarrier to deliver DOX and an adjuvant to enhance the immunotherapy. Damage-associated molecular patterns (DAMPs) generated by DOX from dying tumor cells, such as calreticulin (CRT), high mobility group protein 1(HMGB1), and adenosine triphosphate (ATP), can activate dendritic cells (DCs) and trigger an immunological response. Afterward, CpG-tFNA with immunostimulatory properties works to boost the DOX-induced immunotherapy. Consequently, CpG-tFNA/DOX showed excellent antitumor effects and immunological activation, including CD8⁺ T cell proliferation and antitumor cytokine TNF-α and IFN-γ secretion. Moreover, chemo-immunotherapy can also be enhanced synergistically when coadministered with PD-L1. In conclusion, CpG-tFNA/DOX promotes the ICD-associated chemo-immunotherapy and strengthens the connection between traditional chemotherapy and immunotherapy, representing a novel strategy for clinical application. Moreover, the concept of ICD-related immunotherapy can also be extended to other treatments such as radiotherapy which can induce immunogenic cell death as well.

Pyroptosis and inflammasomes in diabetic wound healing

Diabetic wound is one of the complications of diabetes and is not easy to heal. It often evolves into chronic ulcers, and severe patients will face amputation. Compared with normal wounds, diabetic wounds have an increased proportion of pro-inflammatory cytokines that are detrimental to the normal healing response. The burden of this disease on patients and healthcare providers is overwhelming, and practical solutions for managing and treating diabetic wounds are urgently needed. Pyroptosis, an inflammatory type of programmed cell death, is usually triggered by the inflammasome. The pyroptosis-driven cell death process is primarily mediated by the traditional signaling pathway caused by caspase -1 and the non-classical signaling pathways induced by caspase -4/5/11. Growing evidence that pyroptosis promotes diabetic complications, including diabetic wounds. In addition, inflammation is thought to be detrimental to wound healing. It is worth noting that the activation of the NLRP3 inflammasome plays a crucial role in the recovery of diabetic wounds. This review has described the mechanisms of pyroptosis-related signaling pathways and their impact on diabetic wounds. It has discussed new theories and approaches to promote diabetic wound healing, as well as some potential compounds targeting pyroptosis and inflammasome signaling pathways that could be new approaches to treating diabetic wounds.