Nanodrugs alleviate acute kidney injury: Manipulate RONS at kidney

Physiological principles underlying the kidney targeting of renal nanomedicines

Kidney disease affects more than 10% of the global population and is associated with considerable morbidity and mortality, highlighting a need for new therapeutic options. Engineered nanoparticles for the treatment of kidney diseases (renal nanomedicines) represent one such option, enabling the delivery of targeted therapeutics to specific regions of the kidney. Although they are underdeveloped compared with nanomedicines for diseases such as cancer, findings from preclinical studies suggest that renal nanomedicines may hold promise. However, the physiological principles that govern the in vivo transport and interactions of renal nanomedicines differ from those of cancer nanomedicines, and thus a comprehensive understanding of these principles is needed to design nanomedicines that effectively and specifically target the kidney while ensuring biosafety in their future clinical translation. Herein, we summarize the current understanding of factors that influence the glomerular filtration, tubular uptake, tubular secretion and extrusion of nanoparticles, including size and charge dependency, and the role of specific transporters and processes such as endocytosis. We also describe how the transport and uptake of nanoparticles is altered by kidney disease and discuss strategic approaches by which nanoparticles may be harnessed for the detection and treatment of a variety of kidney diseases.

Recent Development and Applications of Polydopamine in Tissue Repair and Regeneration Biomaterials

The various tissue damages are a severe problem to human health. The limited human tissue regenerate ability requires suitable biomaterials to help damage tissue repair and regeneration. Therefore, many researchers devoted themselves to exploring biomaterials suitable for tissue repair and regeneration. Polydopamine (PDA) as a natural and multifunctional material which is inspired by mussel has been widely applied in different biomaterials. The excellent properties of PDA, such as strong adhesion, photothermal and high drug-loaded capacity, seem to be born for tissue repair and regeneration. Furthermore, PDA combined with different materials can exert unexpected effects. Thus, to inspire researchers, this review summarizes the recent and representative development of PDA biomaterials in tissue repair and regeneration. This article focuses on why apply PDA in these biomaterials and what PDA can do in different tissue injuries.

Ultrasmall Cu2O@His Nanozymes with RONS Scavenging Capability for Anti-inflammatory Therapy

High concentrations of reactive oxygen and nitrogen species (RONS) are key characteristics of inflammatory sites. Scavenging RONS at the site of inflammation is an effective therapeutic strategy. This study introduces ultrasmall Cu2O@His nanoparticles with RONS-scavenging ability for the treatment of inflammatory bowel disease (IBD) in mice. The strong coordination between the nitrogen atom in histidine (His) and copper enhances the dispersion and stability of Cu2O@His. Due to their small size and large surface area, Cu2O@His exhibits outstanding RONS-clearing ability. Importantly, Cu2O@His can target mitochondrial sites and repair damaged mitochondria. With excellent dispersion and scavenging RONS ability, Cu2O@His demonstrates good efficacy in treating mouse IBD. This work provides a new paradigm for developing nanozymes with an ultrasmall size and multiple scavenging RONS abilities.

Natural ursolic acid based self-therapeutic polymer as nanocarrier to deliver natural resveratrol for natural therapy of acute kidney injury

Acute kidney injury (AKI) is a common kidney disease associated with excessive reactive oxygen species (ROS). Unfortunately, due to the low kidney targeting and undesired side effects, the existing antioxidant and anti-inflammatory drugs are unavailable for AKI management in clinic. Therefore, it's essential to develop effective nanodrugs with high renal targeting and biocompatibility for AKI treatment. Herein, we reported a novel nanodrug for AKI treatment, utilizing poly(ursolic acid) (PUA) as a bioactive nanocarrier and resveratrol (RES) as a model drug. The PUA polymer was synthesized form ursolic acid with intrinsic antioxidant and anti-inflammatory activities, and successfully encapsulated RES through a nanoprecipitation method. Subsequently, we systemically investigated the therapeutic potential of RES-loaded PUA nanoparticles (PUA NPs@RES) against AKI. In vitro results demonstrated that PUA NPs@RES effectively scavenged ROS and provided substantial protection against H2O2-induced cellular damage. In vivo studies revealed that PUA NPs significantly improved drug accumulation in the kidneys and exhibited favorable biocompatibility. Furthermore, PUA NPs alone exhibited additional anti-inflammatory and antioxidant effect, synergistically enhancing therapeutic efficacy in AKI mouse models when combined with RES. Overall, our study successfully developed an effective nanodrug using self-therapeutic nanocarriers, presenting a promising option for the treatment of AKI.

Injectable hydrogel with selenium nanoparticles delivery for sustained glutathione peroxidase activation and enhanced osteoarthritis therapeutics

Reactive oxygen burst in articular chondrocytes is a major contributor to osteoarthritis progression. Although selenium is indispensable role in the antioxidant process, the narrow therapeutic window, delicate toxicity margins, and lack of an efficient delivery system have hindered its translation to clinical applications. Herein, transcriptomic and biochemical analyses revealed that osteoarthritis was associated with selenium metabolic abnormality. A novel injectable hydrogel to deliver selenium nanoparticles (SeNPs) was proposed to intervene selenoprotein expression for osteoarthritis treatment. The hydrogels based on oxidized hyaluronic acid (OHA) cross-linked with hyaluronic acid-adipic acid dihydrazide (HA-ADH) was formulated to load SeNPs through a Schiff base reaction. The hydrogels were further incorporated with SeNPs, which exhibited minimal toxicity, mechanical properties, self-healing capability, and sustained drug release. Encapsulated with SeNPs, the hydrogels facilitated cartilage repair through synergetic effects of scavenging reactive oxygen species (ROS) and depressing apoptosis. Mechanistically, the hydrogel restored redox homeostasis by targeting glutathione peroxidase-1 (GPX1). Therapeutic outcomes of the SeNPs-laden hydrogel were demonstrated in an osteoarthritis rat model created by destabilization of the medial meniscus, including cartilage protection, subchondral bone sclerosis improvement, inflammation attenuation, and pain relief were demonstrated. These results highlight therapeutic potential of OHA/HA-ADH@SeNPs hydrogels, providing fundamental insights into remedying selenium imbalance for osteoarthritis biomaterial development.

Endogenous stimuli-responsive drug delivery nanoplatforms for kidney disease therapy

Kidney disease is one of the most life-threatening health problems, affecting millions of people in the world. Commonly used steroids and immunosuppressants often fall exceptionally short of outcomes with inescapable systemic toxicity. With the booming research in nanobiotechnology, stimuli-responsive nanoplatform has come an appealing therapeutic strategy for kidney disease. Endogenous stimuli-responsive materials have shown profuse promise owing to their enhanced spatiotemporal control and precise to the location of the lesion. This review focuses on recent advances stimuli-responsive drug delivery nano-architectonics for kidney disease. First, a brief introduction of pathogenesis of kidney disease and pathological microenvironment were provided. Then, various endogenous stimulus involved in drug delivery nanoplatforms including pH, ROS, enzymes, and glucose were categorized based on the pathological mechanisms of kidney disease. Next, we separately summarized literature examples of endogenous stimuli-responsive nanomaterials, and outlined the design strategies and response mechanisms. Finally, the paper was concluded by discussing remaining challenges and future perspectives of endogenous stimuli-responsive drug delivery nanoplatform for expediting the speed of development and clinical applications.

Supramolecular Nano-Assembly of Caffeate-Strengthened Phenylboronic Ester with Multistep ROS Scavenging Ability for Targeted Therapy of Acute Kidney Injury

Acute kidney injury (AKI) is a life-threatening complication with a considerable occurrence among patients. AKI is typically accompanied by an elevation in reactive oxidative species (ROS) in renal tissues, which is the main contributor to kidney damage. Herein, a supramolecular nano-assembly (Ser-HPEC) containing an ethyl caffeate-strengthened phenylboronic ester with ROS-triggered antioxidative ability is proposed for AKI-targeted therapy. Nano-assemblies can rapidly accumulate in the ischemia-reperfusion-injured kidney via kidney injury molecule-1 (Kim-1)-mediated homing ability of l-serine. By consuming pathological levels of ROS, two different antioxidants, ethyl caffeate and 4-hydroxybenzyl alcohol, are spontaneously released from a single module to relieve oxidative stress and diminish acute inflammation in injured renal tissue. The multistep ROS scavenging strategy combined with a precise targeting capability endows the aforementioned nano-assembly with effectiveness in preserving the integrity and functions of the injured kidney, providing new inspiration for the treatment of inflammatory diseases, including AKI.

Nanomedicines for the management of diabetic nephropathy: present progress and prospects

Diabetic nephropathy (DN) is a serious microvascular consequence of diabetes mellitus (DM), posing an encumbrance to public health worldwide. Control over the onset and progress of DN depend heavily on early detection and effective treatment. DN is a major contributor to end-stage renal disease, and a complete cure is yet to be achieved with currently available options. Though some therapeutic molecules have exhibited promise in treating DN complications, their poor solubility profile, low bioavailability, poor permeation, high therapeutic dose and associated toxicity, and low patient compliance apprehend their clinical usefulness. Recent research has indicated nano-systems as potential theranostic platforms displaying futuristic promise in the diagnosis and treatment of DN. Early and accurate diagnosis, site-specific delivery and retention by virtue of ligand conjugation, and improved pharmacokinetic profile are amongst the major advantages of nano-platforms, defining their superiority. Thus, the emergence of nanoparticles has offered fresh approaches to the possible diagnostic and therapeutic strategies regarding DN. The present review corroborates an updated overview of different types of nanocarriers regarding potential approaches for the diagnosis and therapy of DN.

Therapeutic application of traditional Chinese medicine in kidney disease: Sirtuins as potential targets

Sirtuins are a family of NAD+ III-dependent histone deacetylases that consists of seven family members, Sirt1-Sirt7, which regulate various signalling pathways and are involved in many critical biological processes of kidney diseases. Traditional Chinese medicine (TCM), as an essential part of the global healthcare system, has multi-component and multi-pathway therapeutic characteristics and plays a role in preventing and controlling various diseases. Through ongoing collaboration with modern medicine, TCM has recently achieved many remarkable advancements in theoretical investigation, mechanistic research, and clinical applications related to kidney diseases. Therefore, a comprehensive and systematic summary of TCM that focuses on sirtuins as the intervention target for kidney diseases is necessary. This review introduces the relationship between abnormal sirtuins levels and common kidney diseases, such as diabetic kidney disease and acute kidney injury. Based on the standard biological processes, such as inflammation, oxidative stress, autophagy, mitochondrial homeostasis, and fibrosis, which are underlying kidney diseases, comprehensively describes the roles and regulatory effects of TCM targeting the sirtuins family in various kidney diseases.

Self-assembled hemin-conjugated heparin with dual-enzymatic cascade reaction activities for acute kidney injury

Nanozymes have prominent catalytic activities with high stability as a substitute for unstable and expensive natural enzymes. However, most nanozymes are metal/inorganic nanomaterials, facing difficulty in clinical translation due to their unproven biosafety and limited biodegradability issues. Hemin, an organometallic porphyrin, was newly found to possess superoxide dismutase (SOD) mimetic activity along with previously known catalase (CAT) mimetic activity. However, hemin has poor bioavailability due to its low water solubility. Therefore, a highly biocompatible and biodegradable organic-based nanozyme system with SOD/CAT mimetic cascade reaction activity was developed by conjugating hemin to heparin (HepH) or chitosan (CS-H). Between them, Hep-H formed a smaller (<50 nm) and more stable self-assembled nanostructure and even possessed much higher and more stable SOD and CAT activities as well as the cascade reaction activity compared to CS-H and free hemin. Hep-H also showed a better cell protection effect against reactive oxygen species (ROS) compared to CS-H and hemin in vitro. Furthermore, Hep-H was selectively delivered to the injured kidney upon intravenous administration at the analysis time point (24 h) and exhibited excellent therapeutic effects on an acute kidney injury model by efficiently removing ROS, reducing inflammation, and minimizing structural and functional damage to the kidney.

Antioxidative 0-dimensional nanodrugs overcome obstacles in AKI antioxidant therapy

Acute kidney injury (AKI) is a commonly encountered syndrome associated with various aetiologies and pathophysiological processes leading to enormous health risks and economic losses. In the absence of specific drugs to treat AKI, hemodialysis remains the primary clinical treatment for AKI patients. The revelation of the pathology opens new horizons for antioxidant therapy in the treatment of AKI. However, small molecule antioxidant drugs and common nanozymes have failed to challenge AKI due to their unsatisfactory drug properties and renal physiological barriers. 0-Dimensional (0D) antioxidant nanodrugs stand out at this time thanks to their small size and high performance. Recently, a number of research studies have been carried out around 0D nanodrugs for alleviating AKI, and their multi-antioxidant enzyme mimetic activities, smooth glomerular filtration barrier permeability and excellent biocompatibility have been investigated. Here, we comprehensively summarize recent advances in 0D nanodrugs for AKI antioxidant therapy. We classify these representative studies into three categories according to the characteristics of 0D nanomaterials, namely ultra-small metal nanodots, inorganic non-metallic quantum dots and polymer nanodots. We focus on the antioxidant mechanisms and their distribution in vivo in each inspiring work, and the purpose and ingenuity of each design are rigorously captured and described. Finally, we provide our reflections and prospects for 0D antioxidant nanodrugs in AKI treatment. This mini review provides unique insights and valuable clues in the design of 0D nanodrugs and other kidney absorbable drugs.

Antioxidant nanozymes in kidney injury: mechanism and application

Excessive production of reactive oxygen species (ROS) in the kidneys is involved in the pathogenesis of kidney diseases, such as acute kidney injury (AKI) and diabetic kidney disease (DKD), and is the main reason for the progression of kidney injury. ROS can easily lead to lipid peroxidation and damage the tubular epithelial cell membrane, proteins and DNA, and other molecules, which can trigger cellular oxidative stress. Effective scavenging of ROS can delay or halt the progression of kidney injury by reducing inflammation and oxidative stress. With the development of nanotechnology and an improved understanding of nanomaterials, more researchers are applying nanomaterials with antioxidant activity to treat kidney injury. This article reviews the detailed mechanism between ROS and kidney injury, as well as the applications of nanozymes with antioxidant effects based on different materials for various kidney injuries. To better guide the applications of antioxidant nanozymes in kidney injury and other inflammatory diseases, at the end of this review we also summarize the aspects of nanozymes that need to be improved. An in-depth understanding of the role played by ROS in the occurrence and progression of kidney injury and the mechanism by which antioxidant nanozymes reduce oxidative stress is conducive to improving the therapeutic effect in kidney injury and inflammation-related diseases.

3D hypoxia-mimicking and anti-synechia hydrogel enabling promoted neovascularization for renal injury repair and regeneration

In-situ renal tissue engineering is promising yet challenging for renal injury repair and regeneration due to the highly vascularized structure of renal tissue and complex high-oxidative stress and ischemic microenvironment. Herein, a novel biocompatible 3D porous hydrogel (DFO-gel) with sustained release capacity of hypoxia mimicking micromolecule drug deferoxamine (DFO) was developed for in-situ renal injury repair. In vitro and in vivo experimental results demonstrated that the developed DFO-gels can exert the synchronous benefit of scavenging excess reactive oxygen species (ROS) regulating inflammatory microenvironment and promoting angiogenesis for effective renal injury repair by up-regulating hypoxia-inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF). The in-situ neogenesis of neonatal glomerular- and tubular-like structures in the implanted areas in the partially nephrectomized rats also suggested the potential for promoting renal injury repair and regeneration. This multifunctional hydrogel can not only exhibit the sustained release and promoted bio-uptake capacity for DFO, but also improve the renal injured microenvironment by alleviating oxidative and inflammatory stress, accelerating neovascularization, and promoting efficient anti-synechia. We believe this work offers a promising strategy for renal injury repair and regeneration.

Beyond antioxidation: Harnessing the CeO2 nanoparticles as a renoprotective contrast agent for in vivo spectral CT angiography

It is a challenging task to develop a contrast agent that not only provides excellent image contrast but also protects impaired kidneys from oxidative-related stress during angiography. Clinically approved iodinated CT contrast media are associated with potential renal toxicity, making it necessary to develop a renoprotective contrast agent. Here, we develop a CeO2 nanoparticles (NPs)-mediated three-in-one renoprotective imaging strategy, namely, i) renal clearable CeO2 NPs serve as a one-stone-two-birds antioxidative contrast agent, ii) low contrast media dose, and iii) spectral CT, for in vivo CT angiography (CTA). Benefiting from the merits of advanced sensitivity of spectral CT and K-edge energy of Cerium (Ce, 40.4 keV), an improved image quality of in vivo CTA is successfully achieved with a 10 times reduction of contrast agent dosage. In parallel, the sizes of CeO2 NPs and broad catalytic activities are suitable to be filtered via glomerulus thus directly alleviating the oxidative stress and the accompanying inflammatory injury of the kidney tubules. In addition, the low dosage of CeO2 NPs reduces the hypoperfusion stress of renal tubules induced by concentrated contrast agents used in angiography. This three-in-one renoprotective imaging strategy helps prevent kidney injury from being worsened during the CTA examination.

Selenium Nanodots (SENDs) as Antioxidants and Antioxidant-Prodrugs to Rescue Islet β Cells in Type 2 Diabetes Mellitus by Restoring Mitophagy and Alleviating Endoplasmic Reticulum Stress

Preventing islet β-cells death is crucial for treating type 2 diabetes mellitus (T2DM). Currently, clinical drugs are being developed to improve the quality of T2DM care and self-care, but drugs focused on reducing islets β-cell death are lacking. Given that β-cell death in T2DM is dominated ultimately by excessive reactive oxygen species (ROS), eliminating excessive ROS in β-cells is a highly promising therapeutic strategy. Nevertheless, no antioxidants have been approved for T2DM therapy because most of them cannot meet the long-term and stable elimination of ROS in β-cells without eliciting toxic side-effects. Here, it is proposed to restore the endogenous antioxidant capacity of β-cells to efficiently prevent β-cell death using selenium nanodots (SENDs), a prodrug of the antioxidant enzyme glutathione peroxidase 1 (GPX1). SENDs not only scavenge ROS effectively, but also "send" selenium precisely to β-cells with ROS response to greatly enhance the antioxidant capacity of β-cells by increasing GPX1 expression. Therefore, SENDs greatly rescue β-cells by restoring mitophagy and alleviating endoplasmic reticulum stress (ERS), and demonstrate much stronger efficacy than the first-line drug metformin for T2DM treatment. Overall, this strategy highlights the great clinical application prospects of SENDs, offering a paradigm for an antioxidant enzyme prodrug for T2DM treatment.

Effects of melatonin against acute kidney injury: A systematic review and meta-analysis

INTRODUCTION

Melatonin is a hormone synthesized by the pineal gland, and has antioxidative effects in reducing acute kidney injury (AKI). In the past three years, an increasing number of studies have evaluated whether melatonin has a protective effect on AKI. The study systematically reviewed and assessed the efficacy and safety of melatonin in preventing AKI.

MATERIAL AND METHODS

A systematic literature search was conducted in the PubMed, Embase, and Web of Science databases on February 15, 2023. Eligible records were screened according to the inclusion and exclusion criteria. The odds ratio and Hedges' gwith the corresponding 95% confidence intervals were selected to evaluate the effects of melatonin on AKI. We pooled extracted data using a fixed- or random-effects model based on a heterogeneity test.

RESULTS

There were five studies (one cohort study and four randomized controlled trials) included in the meta-analysis. Although the glomerular filtration rate (GFR) may be significantly improved by melatonin, the incidence of AKI was not significantly decreased in the melatonin group compared with the control group in randomized controlled trials (RCTs).

CONCLUSIONS

In our study, the present results do not support a direct effect of melatonin use on the reduction of AKI. More well-designed clinical studies with larger sample size are required in the future.

Oral Metal-Free Melanin Nanozymes for Natural and Durable Targeted Treatment of Inflammatory Bowel Disease (IBD)

Oral antioxidant nanozymes bring great promise for inflammatory bowel disease (IBD) treatment. To efficiently eliminate reactive oxygen species (ROS), various metal-based nanozymes have been developed for the treatment of IBD but their practical applications are seriously impaired by unstable ROS-eliminating properties and potential metal ion leakage in the digestive tract. Here, the authors for the first time propose metal-free melanin nanozymes (MeNPs) with excellent gastrointestinal stability and biocompatibility as a favorable therapy strategy for IBD. Moreover, MeNPs have extremely excellent natural and long-lasting characteristics of targeting IBD lesions. In view of the dominant role of ROS in IBD, the authors further reveal that oral administration of MeNPs can greatly alleviate the six major pathological features of IBD: oxidative stress, endoplasmic reticulum stress, apoptosis, inflammation, gut barrier disruption, and gut dysbiosis. Overall, this strategy highlights the great clinical application prospects of metal-free MeNPs via harnessing ROS scavenging at IBD lesions, offering a paradigm for antioxidant nanozyme in IBD or other inflammatory diseases.

A strategy of local hydrogen capture and catalytic hydrogenation for enhanced therapy of chronic liver diseases

Background: Chronic liver diseases (CLD) frequently derive from hepatic steatosis, inflammation and fibrosis, and become a leading inducement of cirrhosis and hepatocarcinoma. Molecular hydrogen (H₂) is an emerging wide-spectrum anti-inflammatory molecule which is able to improve hepatic inflammation and metabolic dysfunction, and holds obvious advantages in biosafety over traditional anti-CLD drugs, but existing H₂ administration routes cannot realize the liver-targeted high-dose delivery of H₂, severely limiting its anti-CLD efficacy. Method: In this work, a concept of local hydrogen capture and catalytic hydroxyl radical (·OH) hydrogenation is proposed for CLD treatment. The mild and moderate non-alcoholic steatohepatitis (NASH) model mice were intravenously injected with PdH nanoparticles firstly, and then daily inhaled 4% hydrogen gas for 3 h throughout the whole treatment period. After the end of treatment, glutathione (GSH) was intramuscularly injected every day to assist the Pd excretion. Results: In vitro and in vivo proof-of-concept experiments have confirmed that Pd nanoparticles can accumulate in liver in a targeted manner post intravenous injection, and play a dual role of hydrogen captor and ·OH filter to locally capture/store the liver-passing H₂ during daily hydrogen gas inhalation and rapidly catalyze the ·OH hydrogenation into H₂O. The proposed therapy significantly improves the outcomes of hydrogen therapy in the prevention and treatment of NASH by exhibiting a wide range of bioactivity including the regulation of lipid metabolism and anti-inflammation. Pd can be mostly eliminated after the end of treatment under the assistance of GSH. Conclusion: Our study verified a catalytic strategy of combining PdH nanoparticles and hydrogen inhalation, which exhibited enhanced anti-inflammatory effect for CLD treatment. The proposed catalytic strategy will open a new window to realize safe and efficient CLD treatment.

Challenges to Safe Nanomedicine Treatment

Nanotechnology has the potential to revolutionize the field of drug treatment by enabling the targeted delivery and controlled release of drugs at a cellular level [...].

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.

Kaempferol Reverses Acute Kidney Injury in Septic Model by Inhibiting NF-κB/AKT Signaling Pathway

Sepsis is the main cause of acute kidney injury (AKI), mainly due to systemic immune dysregulation. Kaempferol (KAE) is a natural flavonoid compound with multiple biological activities including anti-inflammatory, antioxidant, and antiapoptotic properties. In this study, we constructed a sepsis-induced AKI mouse model and an LPS-induced glomerular mesangial cell (HK-2) in vitro sepsis AKI model. We found that KAE ameliorated sepsis-induced renal pathological damage, reversed renal function damage, and inhibited p-p65 and p-AKT protein expression. In addition, KAE reversed LPS-induced proliferation and inhibited apoptosis in HK-2 cells. These studies suggest that KAE reverses sepsis by inhibiting activation of the NF-κB/AKT pathway to reverse acute kidney injury.

How to Best Protect Kidneys for Transplantation-Mechanistic Target

The increasing number of patients on the kidney transplant waiting list underlines the need to expand the donor pool and improve kidney graft utilization. By protecting kidney grafts adequately from the initial ischemic and subsequent reperfusion injury occurring during transplantation, both the number and quality of kidney grafts could be improved. The last few years have seen the emergence of many new technologies to abrogate ischemia-reperfusion (I/R) injury, including dynamic organ preservation through machine perfusion and organ reconditioning therapies. Although machine perfusion is gradually making the transition to clinical practice, reconditioning therapies have not yet progressed from the experimental setting, pointing towards a translational gap. In this review, we discuss the current knowledge on the biological processes implicated in I/R injury and explore the strategies and interventions that are being proposed to either prevent I/R injury, treat its deleterious consequences, or support the reparative response of the kidney. Prospects to improve the clinical translation of these therapies are discussed with a particular focus on the need to address multiple aspects of I/R injury to achieve robust and long-lasting protective effects on the kidney graft.

Nanosystems for oxidative stress regulation in the anti-inflammatory therapy of acute kidney injury

Acute kidney injury (AKI) is a clinical syndrome that results from a rapid decline in renal structure or renal functional impairment with the main pathological feature of sublethal and lethal damage to renal tubular cells. However, many potential therapeutic agents cannot achieve the desired therapeutic effect because of their poor pharmacokinetics and short retention time in the kidneys. With the recent emergence and progress of nanotechnology, nanodrugs with unique physicochemical properties could prolong circulation time, enhance efficient targeted delivery, and elevate the accumulation of therapeutics that can cross the glomerular filtration barrier and indicate comprehensive application prospects in the prevention and treatment of AKI. In this review, various types of nanosystems (such as liposomes, polymeric nanosystems, inorganic nanoparticles and cell-derived extracellular vesicles) are designed and applied to improve the pharmacokinetics of drug formation, which could further relieve the burden on the kidneys caused by the final cumulative dose of drugs in conventional treatments. Moreover, the passive or active targeting effect of nanosystems can also reduce the total therapeutic dose and off-target adverse effects on other organs. Nanodelivery systems for treating AKI that alleviate oxidative stress-induced renal cell damage and regulate the inflammatory kidney microenvironment are summarized.

Emerging Sonodynamic Therapy-Based Nanomedicines for Cancer Immunotherapy

Cancer immunotherapy effect can be greatly enhanced by other methods to induce immunogenic cell death (ICD), which has profoundly affected immunotherapy as a highly efficient paradigm. However, these treatments have significant limitations, either by causing damage of the immune system or limited to superficial tumors. Sonodynamic therapy (SDT) can induce ICD to promote immunotherapy without affecting the immune system because of its excellent spatiotemporal selectivity and low side effects. Nevertheless, SDT is still limited by low reactive oxygen species yield and the complex tumor microenvironment. Recently, some emerging SDT-based nanomedicines have made numerous attractive and encouraging achievements in the field of cancer immunotherapy due to high immunotherapeutic efficiency. However, this cross-cutting field of research is still far from being widely explored due to huge professional barriers. Herein, the characteristics of the tumor immune microenvironment and the mechanisms of ICD are firstly systematically summarized. Subsequently, the therapeutic mechanism of SDT is fully summarized, and the advantages and limitations of SDT are discussed. The representative advances of SDT-based nanomedicines for cancer immunotherapy are further highlighted. Finally, the application prospects and challenges of SDT-based immunotherapy in future clinical translation are discussed.