A DNA Nanoraft-Based Cytokine Delivery Platform for Alleviation of Acute Kidney Injury

DNA Origami Enhanced Cytokine Immunotherapy for Alleviating Renal Ischemia-Reperfusion Injury

Renal ischemia-reperfusion injury (IRI) is a major contributing factor to the development of acute kidney injury (AKI) and has resulted in considerable morbidity and mortality. Persistent inflammatory responses and excessive reactive oxygen species (ROS) in the kidney following IRI can severely delay tissue repair, making it challenging to effectively promote IRI regeneration. Herein, we report an approach to enhance immunotherapy using interleukin-10 (IL-10) to promote IRI regeneration by loading IL-10 onto rectangular DNA origami nanostructures (rDON). rDON can significantly enhance the renal accumulation and retention time of IL-10, enabling it to effectively polarize type 1 macrophages into type 2 macrophages, thereby significantly reducing proinflammatory factors and increasing anti-inflammatory factors. In addition, DNA origami helps mitigate the harmful effects of ROS during renal IRI. The administration of IL-10-loaded DNA origami effectively improves kidney function, resulting in a notable reduction in blood urea nitrogen, serum uric acid, and serum creatinine levels. Our study demonstrates that the integration of anti-inflammatory cytokines within DNA origami holds promise as a strategic approach for cytokine immunotherapy in patients with AKI and other renal disorders.

Differentiated management of ROS level in tumor and kidney to alleviate Cis-platinum induced acute kidney injury with improved efficacy

Cisplatin (DDP) is a prevalent chemotherapeutic agent used in tumor therapy, yet DDP-induced acute kidney injury (AKI) severely limits its clinical application. Antioxidants as reactive oxygen species (ROS) scavengers can circumvent this adverse effect while leading to the decrease of efficacy to tumor. Herein, we report ultrasmall ruthenium nanoparticles (URNPs) as switchable ROS scavengers/generators to alleviate DDP-induced AKI and improve its therapeutic efficacy. In the physiological environment of the kidney, URNPs mimic multi-enzyme activities, such as superoxide dismutase and catalase, effectively protecting the renal cell and tissue by down-regulating the increased ROS level caused by DDP and alleviating AKI. Specifically, URNPs are oxidized by high levels of H2O2 in the tumor microenvironment (TME), resulting in the generation of oxygen vacancies and Ru3+/Ru4+ ions. This unique structure transformation endows URNPs to generate singlet oxygen (1O2) under laser irradiation and hydroxyl radicals (∙OH) through a Fenton-like reaction in tumor cell and tissue. The simultaneous generation of multifarious ROS effectively improves the efficacy of DDP in vitro and in vivo. This TME-responsive ROS scavenger/generator acts as an adjuvant therapeutic agent to minimize side effects and improve the efficacy of chemotherapy drugs, providing a new avenue to chemotherapy and facilitating clinical tumor therapy.

Programmable DNA Scaffolds Enable Orthogonal Engineering of Cell Membrane-Based Nanovesicles for Therapeutic Development

Cell membrane-based nanovesicles (CMNVs) play pivotal roles in biomolecular transportation in living organisms and appear as attractive bioinformed nanomaterials for theranostic applications. However, the current surface-engineering technologies are limited in flexibility and orthogonality, making it challenging to simultaneously display multiple different ligands on the CMNV surface in a precisely controlled manner. Here, we developed a DNA scaffold-programmed approach to orthogonally engineer CMNVs with versatile ligands. The designed DNA scaffolds can rapidly anchor onto the CMNV surface, and their unique sequences and hybridized properties enable independent control of the loading of multiple different types of biomolecules on the CMNVs. As a result, the orthogonal engineering of CMNVs with a renal targeted peptide and a therapeutic protein at controlled ratios demonstrated an enhanced renal targeting and repair potential in vivo. This study highlights that a DNA scaffold-programmed platform can provide a potent means for orthogonal and flexible surface engineering of CMNVs for diverse therapeutic purposes.

Ultrasmall Nanoparticles Regulate Immune Microenvironment by Activating IL-33/ST2 to Alleviate Renal Ischemia-Reperfusion Injury

Renal ischemia-reperfusion injury (IRI) is a common disease with high morbidity and mortality. Renal IRI can cause the disorder of immune microenvironment and reprograming the immune microenvironment to alleviate excessive inflammatory response is crucial for its treatment. Cytokine IL-33 can improve the immune inflammatory microenvironment by modulating both innate and adaptive immune cells, and serve as an important target for modulating immune microenvironment of renal IRI. Herein, we report that bilobetin-functionalized ultrasmall Cu2- xSe nanoparticles (i.e., CSPB NPs) can activate the PKA/p-CREB/IL-33/ST2 signaling pathway to regulate innate and adaptive immune cells for reprograming the immune microenvironment of IRI-induced acute kidney injury. The biocompatible CSPB NPs can promote the polarization of M1-like macrophages into M2-like macrophages, and the expansion of ILC2 and Treg cells by activating IL-33/ST2 to modulate the excessive immune inflammatory response of renal IRI. More importantly, they can rapidly accumulate at the injured kidney to significantly alleviate IRI. This work demonstrates that modulating the expression of cytokines to reprogram immune microenvironment has great potential in the treatment of renal IRI and other ischemic diseases.

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.

CD44-targeted melanin-based nanoplatform for alleviation of ischemia/reperfusion-induced acute kidney injury

Ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) is a serious kidney disease with high morbidity and mortality. However, there is no effective clinical treatment strategy. Herein, we developed a CD44 targeting nanoplatform based on HA-assembled melanin NPs covalently coupled with dexamethasone for I/R-induced AKI therapy by alleviating oxidative/inflammatory- induced damage. The constructed HA-MNP-DXM NPs had good dispersion, stability, and broad-spectrum scavenging capabilities against multiple reactive free radicals. Moreover, the NPs could be efficiently internalized and exhibited antioxidative, anti-inflammatory, and antiapoptotic effects in CoCl2-stimulated renal tubular epithelial NRK-52E cells. Furthermore, the I/R-induced AKI murine model was established to evaluate the in vivo performance of NPs. The results suggested the NPs could specifically target impaired kidneys upon intravenous administration according to NIR-II fluorescence imaging and showed high biosafety. Importantly, the NPs could improve renal function, alleviate oxidative stress and inflammatory reactions, inhibit apoptosis of tubular cells, and restore mitochondrial structure and function, exhibiting excellent therapeutic effects. Further therapeutic mechanism indicated the NPs maintained the cellular/mitochondrial redox balance by modulating the Nrf2 and HO-1 expression. Therefore, the NPs can be a promising therapeutic candidate for the treatment of I/R-induced AKI.

A DNA-based and bifunctional nanomedicine for alleviating multi-organ injury in sepsis under diabetic conditions

Sepsis, defined as a life-threatening organ dysfunction, is associated with increased mortality in individuals with diabetes mellitus. In sepsis under diabetic conditions (SUDC), the superimposed inflammatory response and excessive production of reactive oxygen species (ROS) can cause severe damage to the kidney and liver, making it challenging to effectively repair multi-organ injury. In this study, we report the development of a DNA-based bifunctional nanomedicine, termed IL10-rDON, generated by assembling interleukin 10 (IL10) with rectangular DNA origami nanostructures (rDON) to address multi-organ dysfunction in SUDC. IL10-rDON was shown to predominantly accumulate in the kidney and liver of diabetic mice in vivo and effectively alleviate inflammatory responses through its anti-inflammatory IL10 component. In addition, the consumption of rDON itself significantly reduced excessive ROS in the liver and kidney. Serum and histological examinations further confirmed that IL10-rDON treatment could effectively improve liver and kidney function, as well as the survival of mice with SUDC. This study demonstrates an attractive antioxidant and anti-inflammatory nanomedicine for addressing acute liver and renal failure. The integration of rDON with therapeutic agents using DNA nanotechnology is a promising strategy for generating multifunctional nanomedicine to treat multi-organ dysfunction and other complicated diseases. STATEMENT OF SIGNIFICANCE: Sepsis under diabetic conditions (SUDC) leads to high mortality due to multiple organ failure such as acute liver and kidney injury. The anti-inflammatory cytokine interleukin 10 (IL10) holds great potential to treat SUDC, while disadvantages of IL-10 such as short half-life, non-specific distribution and lack of antioxidant activities limit its wide clinical applications. In this study, we developed a DNA-based, bifunctional nanomedicine (IL10-rDON) by assembling IL10 with rectangular DNA origami nanostructures (rDON). We found that IL10-rDON preferentially accumulated and sufficiently attenuated the increased levels of ROS and inflammation in the kidney and liver injury sites, and eventually improved the survival rate of mice with SUDC. Our finding provides new insights into the application of DNA-based nanomedicine in treating multi-organ failure.

Recent Advances in Nanomaterials for the Treatment of Acute Kidney Injury

Acute kidney injury (AKI) is a serious clinical syndrome with high morbidity, elevated mortality, and poor prognosis, commonly considered a "sword of Damocles" for hospitalized patients, especially those in intensive care units. Oxidative stress, inflammation, and apoptosis, caused by the excessive production of reactive oxygen species (ROS), play a key role in AKI progression. Hence, the investigation of effective and safe antioxidants and inflammatory regulators to scavenge overexpressed ROS and regulate excessive inflammation has become a promising therapeutic option. However, the unique physiological structure and complex pathological alterations in the kidneys render traditional therapies ineffective, impeding the residence and efficacy of most antioxidant and anti-inflammatory small molecule drugs within the renal milieu. Recently, nanotherapeutic interventions have emerged as a promising and prospective strategy for AKI, overcoming traditional treatment dilemmas through alterations in size, shape, charge, and surface modifications. This Review succinctly summarizes the latest advancements in nanotherapeutic approaches for AKI, encompassing nanozymes, ROS scavenger nanomaterials, MSC-EVs, and nanomaterials loaded with antioxidants and inflammatory regulator. Following this, strategies aimed at enhancing biocompatibility and kidney targeting are introduced. Furthermore, a brief discussion on the current challenges and future prospects in this research field is presented, providing a comprehensive overview of the evolving landscape of nanotherapeutic interventions for AKI.

A quantitative review of nanotechnology-based therapeutics for kidney diseases

Kidney-specific nanocarriers offer a targeted approach to enhance therapeutic efficacy and reduce off-target effects in renal treatments. The nanocarriers can achieve organ or cell specificity via passive targeting and active targeting mechanisms. Passive targeting capitalizes on the unique physiological traits of the kidney, with factors like particle size, charge, shape, and material properties enhancing organ specificity. Active targeting, on the other hand, achieves renal specificity through ligand-receptor interactions, modifying nanocarriers with molecules, peptides, or antibodies for receptor-mediated delivery. Nanotechnology-enabled therapy targets diseased kidney tissue by modulating podocytes and immune cells to reduce inflammation and enhance tissue repair, or by inhibiting myofibroblast differentiation to mitigate renal fibrosis. This review summarizes the current reports of the drug delivery systems that have been tested in vivo, identifies the nanocarriers that may preferentially accumulate in the kidney, and quantitatively compares the efficacy of various cargo-carrier combinations to outline optimal strategies and future research directions. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Multipathway Regulation for Targeted Atherosclerosis Therapy Using Anti-miR-33-Loaded DNA Origami

Given the multifactorial pathogenesis of atherosclerosis (AS), a chronic inflammatory disease, combination therapy arises as a compelling approach to effectively address the complex interplay of pathogenic mechanisms for a more desired treatment outcome. Here, we present cRGD/ASOtDON, a nanoformulation based on a self-assembled DNA origami nanostructure for the targeted combination therapy of AS. cRGD/ASOtDON targets αvβ3 integrin receptors overexpressed on pro-inflammatory macrophages and activated endothelial cells in atherosclerotic lesions, alleviates the oxidative stress induced by extracellular and endogenous reactive oxygen species, facilitates the polarization of pro-inflammatory macrophages toward the anti-inflammatory M2 phenotype, and inhibits foam cell formation by promoting cholesterol efflux from macrophages by downregulating miR-33. The antiatherosclerotic efficacy and safety profile of cRGD/ASOtDON, as well as its mechanism of action, were validated in an AS mouse model. cRGD/ASOtDON treatment reversed AS progression and restored normal morphology and tissue homeostasis of the diseased artery. Compared to probucol, a clinical antiatherosclerotic drug with a similar mechanism of action, cRGD/ASOtDON enabled the desired therapeutic outcome at a notably lower dosage. This study demonstrates the benefits of targeted combination therapy in AS management and the potential of self-assembled DNA nanoformulations in addressing multifactorial inflammatory conditions.

Platelet membrane-coated bio-nanoparticles of indocyanine green/elamipretide for NIR diagnosis and antioxidant therapy in acute kidney injury

Acute kidney injury (AKI) is a prevalent condition in critically ill patients that is often associated with significant morbidity and mortality. As the lack of effective early diagnosis methods often delays AKI treatment, there is currently no definitive clinical intervention available. In this study, we aimed to address these challenges by developing a nano-system called Platelet membranes-ICG-SS31-PLGA (PISP), which was designed to selectively target to the kidney site, taking advantage of the natural tendency of platelets to accumulate at sites of vascular injury. This approach allowed for the accumulation of PISP within the kidney as the disease progresses. By incorporating ICG, the in vivo distribution of PISP can be observed for NIR diagnosis of AKI. This non-invasive imaging technique holds great promise for early detection and monitoring of AKI. Furthermore, Elamipretide (SS31) acts as a mitochondria-targeted antioxidant that protects against mitochondrial damage and reduces oxidative stress, inflammation, and apoptosis. The combination of diagnostic and therapeutic capabilities within a single nano-system makes the PISP approach a valuable tool for addressing AKI. This intervention helps to prevent the deterioration of AKI and promotes the recovery. STATEMENT OF SIGNIFICANCE.

Advanced applications of DNA nanostructures dominated by DNA origami in antitumor drug delivery

DNA origami is a cutting-edge DNA self-assembly technique that neatly folds DNA strands and creates specific structures based on the complementary base pairing principle. These innovative DNA origami nanostructures provide numerous benefits, including lower biotoxicity, increased stability, and superior adaptability, making them an excellent choice for transporting anti-tumor agents. Furthermore, they can considerably reduce side effects and improve therapy success by offering precise, targeted, and multifunctional drug delivery system. This comprehensive review looks into the principles and design strategies of DNA origami, providing valuable insights into this technology's latest research achievements and development trends in the field of anti-tumor drug delivery. Additionally, we review the key function and major benefits of DNA origami in cancer treatment, some of these approaches also involve aspects related to DNA tetrahedra, aiming to provide novel ideas and effective solutions to address drug delivery challenges in cancer therapy.

Addressing the in vivo delivery of nucleic-acid nanostructure therapeutics

DNA and RNA nanostructures are being investigated as therapeutics, vaccines, and drug delivery systems. These nanostructures can be functionalized with guests ranging from small molecules to proteins with precise spatial and stoichiometric control. This has enabled new strategies to manipulate drug activity and to engineer devices with novel therapeutic functionalities. Although existing studies have offered encouraging in vitro or pre-clinical proof-of-concepts, establishing mechanisms of in vivo delivery is the new frontier for nucleic-acid nanotechnologies. In this review, we first provide a summary of existing literature on the in vivo uses of DNA and RNA nanostructures. Based on their application areas, we discuss current models of nanoparticle delivery, and thereby highlight knowledge gaps on the in vivo interactions of nucleic-acid nanostructures. Finally, we describe techniques and strategies for investigating and engineering these interactions. Together, we propose a framework to establish in vivo design principles and advance the in vivo translation of nucleic-acid nanotechnologies.

Nanomedicine in kidney disease

PURPOSE OF REVIEW

The pathophysiological understanding of kidney-related disorders has profoundly increased; however, tissue-specific and cell-specific treatments in this field remain scarce. Advances in nanomedicine enable alteration of pharmacokinetics and targeted treatments improving efficiency and reducing toxicity. This review addresses recent developments of nanocarriers used for various purposes in the broad field of kidney disease, which may pave a path to new therapeutic and diagnostic solutions employing nanomedicine.

RECENT FINDINGS

Controlled delivery of antiproliferative medications enables improved treatment of polycystic kidney disease and fibrosis. Directed anti-inflammatory treatment mitigated glomerulonephritis and tubulointerstitial nephritis. Multiple injury pathways in AKI have been targeted, with therapeutic solutions for oxidative stress, mitochondrial dysfunction, local inflammation and improving self-repair mechanisms. In addition to such treatment development, noninvasive early detection methods (minutes after ischemic insult) have been demonstrated as well. Sustained release of therapies that reduce ischemia-reperfusion injury as well as new aspects for immunosuppression bring hope to improving kidney transplant outcomes. The latest breakthroughs in gene therapy are made achievable by engineering the targeted delivery of nucleic acids for new treatments of kidney disease.

SUMMARY

Recent advances in nanotechnology and pathophysiological understanding of kidney diseases show potential for translatable therapeutic and diagnostic interventions in multiple etiologies of kidney disease.

Simultaneous Elimination of Reactive Oxygen Species and Activation of Nrf2 by Ultrasmall Nanoparticles to Relieve Acute Kidney Injury

Excess reactive oxygen species (ROS) can induce serious acute kidney injury (AKI) to result in numerous deaths annually in clinical practice. Elimination of excess ROS by advanced nanotechnology is a very promising AKI therapy. In this Article, we report that PVP-stabilized and quercetin-functionalized ultrasmall Cu_2-xSe nanoparticles (abbreviated as CSPQ NPs) can efficiently scavenge ROS and increase the expression of intracellular antioxidative enzymes by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) protein, which drastically alleviates the cellular oxidative stress. Our ultrasmall nanoparticles exhibit excellent biocompatibility. They can be rapidly accumulated into the injured kidney to simultaneously eliminate ROS and activate Nrf2 to improve the renal function. This work demonstrates the great potential of simultaneous elimination of ROS and activation of intracellular Nrf2 in treatment of AKI. It also highlights the potential of CSPQ NPs in protection and prevention of AKI.

Nanodrugs alleviate acute kidney injury: Manipulate RONS at kidney

Currently, there are no clinical drugs available to treat acute kidney injury (AKI). Given the high prevalence and high mortality rate of AKI, the development of drugs to effectively treat AKI is a huge unmet medical need and a research hotspot. Although existing evidence fully demonstrates that reactive oxygen and nitrogen species (RONS) burst at the AKI site is a major contributor to AKI progression, the heterogeneity, complexity, and unique physiological structure of the kidney make most antioxidant and anti-inflammatory small molecule drugs ineffective because of the lack of kidney targeting and side effects. Recently, nanodrugs with intrinsic kidney targeting through the control of size, shape, and surface properties have opened exciting prospects for the treatment of AKI. Many antioxidant nanodrugs have emerged to address the limitations of current AKI treatments. In this review, we systematically summarized for the first time about the emerging nanodrugs that exploit the pathological and physiological features of the kidney to overcome the limitations of traditional small-molecule drugs to achieve high AKI efficacy. First, we analyzed the pathological structural characteristics of AKI and the main pathological mechanism of AKI: hypoxia, harmful substance accumulation-induced RONS burst at the renal site despite the multifactorial initiation and heterogeneity of AKI. Subsequently, we introduced the strategies used to improve renal targeting and reviewed advances of nanodrugs for AKI: nano-RONS-sacrificial agents, antioxidant nanozymes, and nanocarriers for antioxidants and anti-inflammatory drugs. These nanodrugs have demonstrated excellent therapeutic effects, such as greatly reducing oxidative stress damage, restoring renal function, and low side effects. Finally, we discussed the challenges and future directions for translating nanodrugs into clinical AKI treatment.

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AKI is a common clinical acute syndrome with high morbidity and mortality but without effective clinical drug available.

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Hypoxia and accumulation of toxic substances are key pathological features of various heterogeneous AKI.

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Excessive RONS is the core of the pathological mechanism of AKI.

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The development of nanodrugs is expected to achieve successful treatment in AKI.

2D-nanomaterials for AKI treatment

Acute kidney injury has always been considered a sword of Damocles over hospitalized patients and has received increasing attention due to its high morbidity, elevated mortality, and poor prognosis. Hence, AKI has a serious detrimental impact not only on the patients, but also on the whole society and the associated health insurance systems. Redox imbalance caused by bursts of reactive oxygen species at the renal tubules is the key cause of the structural and functional impairment of the kidney during AKI. Unfortunately, the failure of conventional antioxidant drugs complicates the clinical management of AKI, which is limited to mild supportive therapies. Nanotechnology-mediated antioxidant therapies represent a promising strategy for AKI management. In recent years, two-dimensional (2D) nanomaterials, a new subtype of nanomaterials with ultrathin layer structure, have shown significant advantages in AKI therapy owing to their ultrathin structure, large specific surface area, and unique kidney targeting. Herein, we review recent progress in the development of various 2D nanomaterials for AKI therapy, including DNA origami, germanene, and MXene; moreover, we discuss current opportunities and future challenges in the field, aiming to provide new insights and theoretical support for the development of novel 2D nanomaterials for AKI treatment.

A fluorescent nano vector for early diagnosis and enhanced Interleukin-33 therapy of thoracic aortic dissection

Thoracic aortic dissection (TAD) is the most devastating complication of vascular disease. The accuracy of the clinical diagnosis and treatment of TAD at the early stage is still limited. Herein, we report a nano-delivery strategy for early diagnosis and the first case of interleukin-33 (IL-33) based therapy for the effective intervention of TAD. A targeted fluorescent nano vector (FNV) is designed to co-assemble with IL-33, which protects IL-33 and prolongs its half-life. With specific targeting ability to the thoracic aorta, FNV can diagnose TAD at its early stage through fluorescent imaging. FNV@IL-33 nanocomplex presents better therapeutic effects on mice TAD progression compared with that of IL-33 alone by reducing smooth muscle apoptosis. Administration of FNV@IL-33 two weeks before onset, the development of TAD is greatly intervened. Our study provides a novel approach for early diagnosis and effective IL-33 therapy of TAD, which opens attractive opportunities for clinical prevention of cardiovascular diseases.

NIR-II Photoacoustic-Active DNA Origami Nanoantenna for Early Diagnosis and Smart Therapy of Acute Kidney Injury

Herein, we designed and synthesized a novel microRNA (miR)-responsive nanoantenna capable of early diagnosis and smart treatment of acute kidney injury (AKI). The nanoantenna was made of two miniature gold nanorods (AuNRs) (e.g., length: ∼48 nm; width: ∼9 nm) linked together by a rectangular DNA origami nanostructure (rDONs) scaffold (e.g., length: ∼90 nm; width: ∼60 nm) (rDONs@AuNR dimer). The surface plasmon resonance peak of the constructed nanoantenna is located within the NIR-II window (e.g., ∼1060 nm), thus guaranteeing photoacoustic (PA) imaging of the nanoantenna in deep tissues. Intriguingly, the nanoantenna displayed exclusive kidney retention in both healthy mice and ischemia reperfusion-induced AKI mice by leveraging the kidney-targeting ability of rDONs. Distinguished from the stable signals in the healthy mice, the PA signals of the nanoantenna would turn down in the AKI mice due to the AuNR detached from rDONs upon interaction with miR-21, which were up-expressed in AKI mice. The limit of detection toward miR-21 was down to 2.8 nM, enabling diagnosis of AKI as early as 10 min post-treatment with ischemia reperfusion, around 2 orders of magnitude earlier than most established probes. Moreover, the naked rDON scaffold generated by AKI could capture more reactive oxygen species (e.g., 1.5-fold more than rDONs@AuNR dimer), alleviating ischemic AKI. This strategy provided a new avenue for early diagnosis and smart treatment of AKI.

Biodegradable and Antioxidant DNA Hydrogel as a Cytokine Delivery System for Diabetic Wound Healing

Impaired diabetic wound healing is associated with the persistence of chronic inflammation and excessive oxidative stress, which has become one of the most serious clinical challenges. Wound dressings with anti-inflammatory and reactive oxygen species (ROS)-scavenging properties are desirable for diabetic wound treatment. In this study, a shape-adaptable, biodegradable, biocompatible, antioxidant, and immunomodulatory interleukin-33 (IL-33)-cytogel is developed by encapsulating IL-33 into physically cross-linked DNA hydrogels and used as wound dressings to promote diabetic wound healing. The porous microstructures and biodegradable properties of the IL-33-cytogel ensure the local sustained-release of IL-33 in the wound area, where the sustained-release of IL-33 is maintained for at least 7 days. IL-33-cytogel can induce local accumulation of group 2 innate lymphoid cells (ILC2s) and regulatory T cells (Tregs), as well as M1-to-M2 transition at the wound sites. Additionally, the antioxidant and biocompatible characteristics of DNA hydrogels promote the scavenging of intracellular ROS without affecting cell viability. As a result, local inflammation in the diabetic wound area is resolved upon IL-33-cytogel treatment, which is accompanied by improved granulation tissue regeneration and accelerated wound closure. This study demonstrates a promising strategy in tissue engineering and regenerative medicine by incorporating DNA hydrogels and cytokine immunotherapy for promoting diabetic wound healing.

Applications of Functional DNA Materials in Immunomodulatory Therapy

In recent years, nanoscale or microscale functional materials derived from DNA have shown great potential for immunotherapy as superior delivery carriers. DNA nanostructures with excellent programmability and addressability enable the precise assembly of molecules or nanoparticles. DNA hydrogels have predictable structures and adjustable mechanical strength, thus being advantageous in controllable release of cargos. In addition, utilizing systematic evolution of ligands by exponential enrichment technology, a variety of DNA aptamers have been screened for specific recognition of ions, molecules, and even cells. Moreover, a wide variety of chemical modifications can further enrich the function of DNA. The unique advantages of functional DNA materials make them extremely attractive in immunomodulation. Recently, functional DNA materials-based immunotherapy has shown great potential in fighting against many diseases like cancer, viral infection, and inflammation. Therefore, in this review, we focus on discussing the progress of the applications of functional DNA materials in immunotherapy; before that, we also summarize the characteristics of the functional DNA materials descried above. Finally, we discuss the challenges and future opportunities of functional DNA materials in immunomodulatory therapy.

Nucleic acid nanoassembly-enhanced RNA therapeutics and diagnosis

RNAs are involved in the crucial processes of disease progression and have emerged as powerful therapeutic targets and diagnostic biomarkers. However, efficient delivery of therapeutic RNA to the targeted location and precise detection of RNA markers remains challenging. Recently, more and more attention has been paid to applying nucleic acid nanoassemblies in diagnosing and treating. Due to the flexibility and deformability of nucleic acids, the nanoassemblies could be fabricated with different shapes and structures. With hybridization, nucleic acid nanoassemblies, including DNA and RNA nanostructures, can be applied to enhance RNA therapeutics and diagnosis. This review briefly introduces the construction and properties of different nucleic acid nanoassemblies and their applications for RNA therapy and diagnosis and makes further prospects for their development.

DNA Origami as a Nanomedicine for Targeted Rheumatoid Arthritis Therapy through Reactive Oxygen Species and Nitric Oxide Scavenging

Rheumatoid arthritis (RA) severely threatens human health by causing inflammation, swelling, and pain in the joints and resulting in persistent synovitis and irreversible joint disability. In the development of RA, pro-inflammatory M1 macrophages, which express high levels of reactive oxygen species (ROS) and nitric oxide (NO), induce synovial inflammation and bone erosion. Eliminating ROS and NO in the inflamed joints is a potential RA therapeutic approach, which can drive the transition of pro-inflammatory M1 macrophages to the anti-inflammatory M2 phenotype. Taking advantage of the intrinsic ROS- and NO-scavenging capability of DNA molecules, herein, we report the development of folic acid-modified triangular DNA origami nanostructures (FA-tDONs) for targeted RA treatment. FA-tDONs could efficiently scavenge ROS and NO and actively target M1 macrophages, facilitating the M1-to-M2 transition and the recovery of associated cytokines and biomarkers to the normal level. The therapeutic efficacy of FA-tDONs was examined in the RA mouse model. As validated by appearance, histological, and serum examinations, FA-tDONs treatment effectively alleviated synovial infiltration and cartilage damage, attenuating disease progression. This study demonstrated the usage of DNA origami for RA treatment and suggested its potential in other antioxidant therapies.

Multifunctional Magnetic CuS/Gd2O3 Nanoparticles for Fluorescence/Magnetic Resonance Bimodal Imaging-Guided Photothermal-Intensified Chemodynamic Synergetic Therapy of Targeted Tumors

Chemodynamic therapy (CDT), which consumes endogenous hydrogen peroxide (H₂O₂) to generate reactive oxygen species (ROS) and causes oxidative damage to tumor cells, shows tremendous promise for advanced cancer treatment. However, the rate of ROS generation based on the Fenton reaction is prone to being restricted by inadequate H₂O₂ and unattainable acidity in the hypoxic tumor microenvironment. We herein report a multifunctional nanoprobe (BCGCR) integrating bimodal imaging and photothermal-enhanced CDT of the targeted tumor, which is produced by covalent conjugation of bovine serum albumin-stabilized CuS/Gd₂O₃ nanoparticles (NPs) with the Cy5.5 fluorophore and the tumor-targeting ligand RGD. BCGCR exhibits intense near-infrared (NIR) fluorescence and acceptable r₁ relaxivity (∼15.3 mM^-1 s^-1) for both sensitive fluorescence imaging and high-spatial-resolution magnetic resonance imaging of tumors in living mice. Moreover, owing to the strong NIR absorbance from the internal CuS NPs, BCGCR can generate localized heat and displays a high photothermal conversion efficiency (30.3%) under 980 nm laser irradiation, which enables photothermal therapy and further intensifies ROS generation arising from the Cu-induced Fenton-like reaction for enhanced CDT. This synergetic effect shows such an excellent therapeutic efficacy that it can ablate xenografted tumors in vivo. We believe that this strategy will be beneficial to exploring other advanced nanomaterials for the clinical application of multimodal imaging-guided synergetic cancer therapies.

Physically Cross-Linked DNA Hydrogel-Based Sustained Cytokine Delivery for In Situ Diabetic Alveolar Bone Rebuilding

The development of a biodegradable and shape-adaptable bioscaffold that can enhance local cytokine retention and bioactivity is essential for the application of immunotherapy in periodontal diseases. Here, we report a biodegradable, anti-inflammatory, and osteogenic ILGel that uses a physically cross-linked DNA hydrogel as a soft bioscaffold for the long-term sustained release of cytokine interleukin-10 (IL-10) to accelerate diabetic alveolar bone rebuilding. Porous microstructures of ILGel favored the encapsulation of IL-10 and maintained IL-10 bioactivity for at least 7 days. ILGel can be gradually degraded or hydrolyzed under physiological conditions, avoiding the potential undesired side effects on dental tissues. Long-term sustained release of bioactive IL-10 from ILGel not only promoted M2 macrophage polarization and attenuated periodontal inflammation but also triggered osteogenesis of mesenchymal stem cells (MSCs), leading to accelerated alveolar bone formation and healing of alveolar bone defects under diabetic conditions in vivo. ILGel treatment significantly accelerated the defect healing rate of diabetic alveolar injury up to 93.42 ± 4.6% on day 21 post treatment compared to that of free IL-10 treatment (63.30 ± 7.39%), with improved trabecular architectures. Our findings imply the potential application of the DNA hydrogel as the bioscaffold for cytokine-based immunotherapy in diabetic alveolar bone injury and other periodontal diseases.

An auto-photoacoustic melanin-based drug delivery nano-platform for self-monitoring of acute kidney injury therapy via a triple-collaborative strategy

Rhabdomyolysis-induced acute kidney injury (AKI) is closely related to toxic reactive oxygen species (ROS), apoptosis, and inflammation. Excessive activation of poly (ADP-ribose) polymerase-l (PARP-1) by ROS can cause mitochondrial dysfunction and release of the proapoptotic protein AIF, which triggers an intrinsic PARP-1-dependent cell death program. Considering these characteristics of rhabdomyolysis-induced AKI, we developed a targeting nanodrug delivery platform by loading PJ34 and coupling anti-GPR97 with melanin nanoparticles (GMP nanoparticles) that could realize photoacoustic self-monitoring and triple-collaborative treatment (antioxidant, antiapoptotic, and anti-inflammatory). The nanoparticles exhibited good dispersibility, solubility, and broad-spectrum ROS scavenging ability. In vitro experiments revealed high biocompatibility of the GMP nanoparticles and strong ability of scavenging multiple toxic ROS, antiapoptotic activity, and anti-inflammatory activity. Because melanin nanoparticles possess inherent photoacoustic (PA) imaging capability, they can not only serve as a drug carrier but also perform self-monitoring for real-time tracking of GMP biodistribution and renal uptake in a murine AKI model through PA imaging. In vivo experiments showed that the GMP nanoparticles could effectively reduce oxidative stress, apoptosis, and inflammatory response in mice with rhabdomyolysis-induced AKI, and the mechanism of alleviation was verified through western blot experiments. These results indicated that the nanoplatform could realize the targeted delivery and curative effect monitoring under the guidance of PA imaging, which is of great significance for the prevention and treatment of AKI. STATEMENT OF SIGNIFICANCE: : A targeting nanodrug delivery platform was developed by loading PJ34 and coupling anti-GPR97 with melanin nanoparticles (GMP nanoparticles) for photoacoustic self-monitoring and triple-collaborative treatment (antioxidant, antiapoptotic, and anti-inflammatory) of acute kidney injury (AKI). Further studies indicated that the Keap-1/Nrf2/HO-1 and PARP-1/AIF signaling pathways are involved in the therapeutic mechanisms to alleviate AKI. Immunohistochemical staining and routine blood test confirmed the anti-inflammatory performance of GMP nanoparticles. Compared to exogenous nanomaterials, we used endogenous melanin with broad ROS scavenging capacity as the nanocarrier and antioxidant, which not only overcomes the defects of high specificity, potential toxicity, low loading capacity, and high cost but also shows good biosafety and photoacoustic imaging performance in vivo.

Nucleic Acid Nanotechnology for Diagnostics and Therapeutics in Acute Kidney Injury

Acute kidney injury (AKI) has impacted a heavy burden on global healthcare system with a high morbidity and mortality in both hospitalized and critically ill patients. However, there are still some shortcomings in clinical approaches for the disease to date, appealing for an earlier recognition and specific intervention to improve long-term outcomes. In the past decades, owing to the predictable base-pairing rule and highly modifiable characteristics, nucleic acids have already become significant biomaterials for nanostructure and nanodevice fabrication, which is known as nucleic acid nanotechnology. In particular, its excellent programmability and biocompatibility have further promoted its intersection with medical challenges. Lately, there have been an influx of research connecting nucleic acid nanotechnology with the clinical needs for renal diseases, especially AKI. In this review, we begin with the diagnostics of AKI based on nucleic acid nanotechnology with a highlight on aptamer- and probe-functionalized detection. Then, recently developed nanoscale nucleic acid therapeutics towards AKI will be fully elucidated. Furthermore, the strengths and limitations will be summarized, envisioning a wiser and wider application of nucleic acid nanotechnology in the future of AKI.

Salting-Out of DNA Origami Nanostructures by Ammonium Sulfate

DNA origami technology enables the folding of DNA strands into complex nanoscale shapes whose properties and interactions with molecular species often deviate significantly from that of genomic DNA. Here, we investigate the salting-out of different DNA origami shapes by the kosmotropic salt ammonium sulfate that is routinely employed in protein precipitation. We find that centrifugation in the presence of 3 M ammonium sulfate results in notable precipitation of DNA origami nanostructures but not of double-stranded genomic DNA. The precipitated DNA origami nanostructures can be resuspended in ammonium sulfate-free buffer without apparent formation of aggregates or loss of structural integrity. Even though quasi-1D six-helix bundle DNA origami are slightly less susceptible toward salting-out than more compact DNA origami triangles and 24-helix bundles, precipitation and recovery yields appear to be mostly independent of DNA origami shape and superstructure. Exploiting the specificity of ammonium sulfate salting-out for DNA origami nanostructures, we further apply this method to separate DNA origami triangles from genomic DNA fragments in a complex mixture. Our results thus demonstrate the possibility of concentrating and purifying DNA origami nanostructures by ammonium sulfate-induced salting-out.