Recent advances in nanotherapeutics for the treatment and prevention of acute kidney injury

Rutin loaded bilosomes for enhancing the oral activity and nephroprotective effects of rutin in potassium dichromate induced acute nephrotoxicity in rats

Rutin, a flavone glycoside, has shown to have a significant beneficial kidney protection effect in drug-induced nephropathy. However, its poor solubility and low oral bioavailability have limited its pharmacological applications. This study aimed at formulating rutin-loaded bilosomes to enhance the renal protective effect of rutin for oral application. Rutin-loaded bilosomes were developed using thin-film hydration technique. The prepared formulations were characterized by entrapment efficiency percentage (EE%), vesicular size (VS) and zeta potential (ZP) measurement. The developed formula exhibited moderate EE%, ranging from 20.02 ± 2.85 to 48.57 ± 3.57%, suitable VS results that ranged from 502.1 ± 36 to 665.1 ± 45 nm and high ZP values (≤ -41.4 ± 7.27 mV). Transmission electron microscopy revealed the spherical shape of the developed bilosomes. The in-vitro release study revealed prolonged release of rutin from bilosomes, relative to free drug. F2, prepared using the molar ratio span 60: cholesterol: sodium cholate 1:1:0.5, was selected for further investigations as it showed the highest EE%, smallest VS, optimum ZP, and persistent release profile. In-vivo studies were performed on drug-induced nephropathy in rats. Acute renal failure was induced using a single dose of potassium dichromate (PDC; 15 mg/kg; i.p). The selected formulation, F2, alleviated kidney dysfunction, oxidative stress and inflammation via decreasing MDA, TNF-α and TGF-β and increasing GSH. In addition, F2 promoted Akt/PI3K activation against PDC-induced acute renal failure. Histopathology results came in accordance with in-vivo results. Thus, bilosomes could be considered a potential delivery system for enhancing the oral delivery and kidney protection activity of rutin.

Enhancing Osteogenic Potential: Controlled Release of Dopamine D1 Receptor Agonist SKF38393 Compared to Free Administration

Osteoporosis is the most common metabolic bone disorder and is characterized by decreased bone density, which has a relationship with the quality of life among the aging population. Previous research has found that activation of the dopamine D1 receptor can improve bone mass formation. SKF38393 is an agonist of dopamine D1 receptors. However, as a small-molecule drug, SKF38393 is unstable and releases quickly. The aim of this study was to prototype polylactic-co-glycolic acid (PLGA)/SKF38393 microspheres and assess their potential osteogenic effects compared to those under the free administration of SKF38393. The cytocompatibility of PLGA/SKF38393 was determined via CCK-8 and live/dead cell staining; the osteogenic effects in vitro were determined with ALP and alizarin red staining, qRT-PCR, and Western blotting; and the in vivo effects were assessed using 25 Balb/c mice. We also used a PCR array to explore the possible signaling pathway changes after employing PLGA/SKF38393. Our experiments demonstrated that the osteogenic effect of D1Rs activated by the PLGA/SKF38393 microsphere was better than that under free administration, both in vitro and in vivo. According to the PCR array, this result might be associated with six signaling pathways (graphical abstract). Ultimately, in this study, we prototyped PLGA/SKF38393, demonstrated its effectiveness, and preliminarily analyzed its mechanism of action.

Anti-DNA antibody-targeted D-peptide nanoparticles ameliorate lupus nephritis in MRL/lpr mice

Peptide ALW (ALWPPNLHAWVP) targeting anti-dsDNA antibodies has shown promising therapeutic effects in alleviating lupus nephritis, but is potentially limited by poor stability and non-kidney targeting. We recently developed a D-form modified ALW, called D-ALW, which has the capacity to widely inhibit pathogenic polyclonal anti-dsDNA antibody reactions. Further modification of D-ALW using PEG-PLGA nanoparticles to enhance good kidney-targeting ability and extend half-life. Here, we demonstrate that the D-form modified ALW maintains higher binding and inhibition efficiencies and achieves higher stability. Most importantly, D-ALW nanoparticles exhibit excellent kidney-targeting ability and prolong the half-life of the peptides in BALB/c mice. Additionally, compared to D-ALW, D-ALW nanoparticles significantly reduce the glomerular deposition of IgG and C3, improve renal histopathologies, such as glomerular proliferation and inflammatory cells infiltration, and markedly prolong lifespan in MRL/lpr lupus-prone mice. Overall, these results establish that the D-ALW nanoparticles offer synergistic benefits in both safety and efficacy, providing long-term renal preservation and treatment advantages in lupus nephritis.

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.

Protein and peptide-based renal targeted drug delivery systems

Renal diseases have become an increasingly concerned public health problem in the world. Kidney-targeted drug delivery has profound transformative potential on increasing renal efficacy and reducing extra-renal toxicity. Protein and peptide-based kidney targeted drug delivery systems have garnered more and more attention due to its controllable synthesis, high biocompatibility and low immunogenicity. At the same time, the targeting methods based on protein/peptide are also abundant, including passive renal targeting based on macromolecular protein and active targeting mediated by renal targeting peptide. Here, we review the application and the drug loading strategy of different proteins or peptides in targeted drug delivery, including the ferritin family, albumin, low molecular weight protein (LMWP), different peptide sequence and antibodies. In addition, we summarized the factors influencing passive and active targeting in drug delivery system, the main receptors related to active targeting in different kidney diseases, and a variety of nano forms of proteins based on the controllable synthesis of proteins.

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.

Biotherapy of experimental acute kidney injury: emerging novel therapeutic strategies

Acute kidney injury (AKI) is a complex and heterogeneous disease with high incidence and mortality, posing a serious threat to human life and health. Usually, in clinical practice, AKI is caused by crush injury, nephrotoxin exposure, ischemia-reperfusion injury, or sepsis. Therefore, most AKI models for pharmacological experimentation are based on this. The current research promises to develop new biological therapies, including antibody therapy, non-antibody protein therapy, cell therapy, and RNA therapy, that could help mitigate the development of AKI. These approaches can promote renal repair and improve systemic hemodynamics after renal injury by reducing oxidative stress, inflammatory response, organelles damage, and cell death, or activating cytoprotective mechanisms. However, no candidate drugs for AKI prevention or treatment have been successfully translated from bench to bedside. This article summarizes the latest progress in AKI biotherapy, focusing on potential clinical targets and novel treatment strategies that merit further investigation in future pre-clinical and clinical studies.

RIPK1 and RIPK3 inhibitors: potential weapons against inflammation to treat diabetic complications

Diabetes mellitus is a metabolic disease that is characterized by chronic hyperglycemia due to a variety of etiological factors. Long-term metabolic stress induces harmful inflammation leading to chronic complications, mainly diabetic ophthalmopathy, diabetic cardiovascular complications and diabetic nephropathy. With diabetes complications being one of the leading causes of disability and death, the use of anti-inflammatories in combination therapy for diabetes is increasing. There has been increasing interest in targeting significant regulators of the inflammatory pathway, notably receptor-interacting serine/threonine-kinase-1 (RIPK1) and receptor-interacting serine/threonine-kinase-3 (RIPK3), as drug targets for managing inflammation in treating diabetes complications. In this review, we aim to provide an up-to-date summary of current research on the mechanism of action and drug development of RIPK1 and RIPK3, which are pivotal in chronic inflammation and immunity, in relation to diabetic complications which may be benefit for explicating the potential of selective RIPK1 and RIPK3 inhibitors as anti-inflammatory therapeutic agents for diabetic complications.

Neutrophil Membrane-Inspired Nanorobots Act as Antioxidants Ameliorate Ischemia Reperfusion-Induced Acute Kidney Injury

Ischemia/reperfusion (I/R) injury causes excessive oxidative events and initiates destructive inflammatory responses, and it is an important promoter to the pathology of various pathema states. Ferroptosis is an iron-dependent type of nonapoptotic cell death accompanied by the accumulation of membrane lipid peroxide and consumption of polyunsaturated fatty acid, and it plays a key role in I/R injury diseases. Moreover, the excessive production of inflammatory cytokines contributes to the development of acute kidney injury. Here, we reported neutrophil membrane-coated copper-based nanoparticles (N-Cu5.4O@DFO NPs) for I/R kidney injury treatment. The highly biocompatible and stable N-Cu5.4O@DFO NPs showed excellent antioxidant and iron ion scavenging abilities in vitro. Our finding showed that the N-Cu5.4O@DFO NPs strategy could significantly accumulate in the inflammatory kidney, reduce oxidative damage events and inflammatory response, and finally achieve synergistic therapy against renal I/R injury. This work promotes the development of nanoantioxidant agents with multiple antioxidant properties for the therapy of other I/R injury diseases.

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.

Self-assembled hyaluronic acid-coated nanocomplexes for targeted delivery of curcumin alleviate acute kidney injury

Acute kidney injury (AKI) is a pathological process with high morbidity, and drug resistance is easy to occur due to untargeted drug therapy. Curcumin can repair acute kidney injury. The expression of the CD44 receptor in renal tubular epithelial cells is abnormally elevated during AKI, and hyaluronic acid (HA) has the ability to bind specifically to the CD44 receptor. In this study, we developed a hyaluronic acid-coated liposome (HALP) nanocomplexes that targeted renal epithelial cells and its effect of relieving AKI was investigated. HALP was formed by self-assembly through the electrostatic interaction of curcumin-loaded cationic liposomes (LP) with hyaluronic acid and responds to the release of curcumin in the acidic microenvironment of lesions to treat AKI. HALP had good stability and biocompatibility. The in vitro results showed that compared to LP, HALP exhibited higher antioxidant, anti-inflammatory, and anti-apoptotic capacities. The AKI model suggested that HALP could not only target and accumulate in the injured kidney but also had an excellent ability to reduce the inflammatory response, which decreased tubular necrosis and restored kidney function.

Kidney-Targeted Nanoparticles Loaded with the Natural Antioxidant Rosmarinic Acid for Acute Kidney Injury Treatment

Acute kidney injury (AKI) is a common clinical disease with high morbidity and mortality, and with a lack of effective drugs for treatment. Oxidative stress is very important in the occurrence and progression of AKI, and antioxidants use is one of the promising treatments. Rosmarinic acid (RA) is a ubiquitous natural polyphenol with powerful antioxidant and anti-inflammatory activities. Due to its inherent characteristic with poor water solubility and inferior bioavailability, its clinical application is impeded. Hence, the authors design a nanoparticle for effectively delivering RA, which is a chemical complex of RA and fourth-generation poly-amidoamine-based amphiphilic polymer (G4-PAMAM). The nanoparticle is modified with l-serine due to the specific interaction between kidney injury molecule-1 (Kim-1) and serine, which eventually generates a promising AKI kidney-targeting nanoparticle (S-G-R). The S-G-R is rapidly cumulated and long-term retained in ischemia-reperfusion-induced AKI kidneys, especially in the damaged renal tubular cells. The S-G-R exhibits more excellent antioxidative and antiapoptotic effects in vitro and has a more outstanding ability to improve the renal function, repair damaged renal tissue, and decrease oxidative stress, inflammatory response and apoptosis of tubular cells in vivo. Overall, this study might develop a safe and effective targeting strategy for the therapy of AKI.

Molecular mechanisms underlying the renal protective effects of coenzyme Q10 in acute kidney injury

Coenzyme Q10 (CoQ10), an endogenous antioxidant, has been reported frequently to exert an outstanding protective effect on multiple organ injury, including acute kidney injury (AKI). In this study, we aim to summarize all the current evidence of the protective action of CoQ10 against AKI as there are presently no relevant reviews in the literature. After a systematic search, 20 eligible studies, either clinical trials or experimental studies, were included and further reviewed. CoQ10 treatment exhibited a potent renal protective effect on various types of AKI, such as AKI induced by drugs (e.g., ochratoxin A, cisplatin, gentamicin, L-NAME, and nonsteroidal anti-inflammatory drug), extracorporeal shock wave lithotripsy (ESWL), sepsis, contrast media, and ischemia–reperfusion injury. The renal protective role of CoQ10 against AKI might be mediated by the antiperoxidative, anti-apoptotic, and anti-inflammatory potential of CoQ10. The molecular mechanisms for the protective effects of CoQ10 might be attributed to the regulation of multiple essential genes (e.g., caspase-3, p53, and PON1) and signaling cascades (e.g., Nrf2/HO-1 pathway). This review highlights that CoQ10 may be a potential strategy in the treatment of AKI.

From AKI to CKD: Maladaptive Repair and the Underlying Mechanisms

Acute kidney injury (AKI) is defined as a pathological condition in which the glomerular filtration rate decreases rapidly over a short period of time, resulting in changes in the physiological function and tissue structure of the kidney. An increasing amount of evidence indicates that there is an inseparable relationship between acute kidney injury and chronic kidney disease (CKD). With the progress in research in this area, researchers have found that the recovery of AKI may also result in the occurrence of CKD due to its own maladaptation and other potential mechanisms, which involve endothelial cell injury, inflammatory reactions, progression to fibrosis and other pathways that promote the progress of the disease. Based on these findings, this review summarizes the occurrence and potential mechanisms of maladaptive repair in the progression of AKI to CKD and explores possible treatment strategies in this process so as to provide a reference for the inhibition of the progression of AKI to CKD.

Novel Drug Delivery Technologies and Targets for Renal Disease

The burden of acute and chronic kidney diseases to the health care system is exacerbated by the high mortality that this disease carries paired with the still limited availability of comprehensive therapies. A reason partially resides in the complexity of the kidney, with multiple potential target cell types and a complex structural environment that complicate strategies to protect and recover renal function after injury. Management of both acute and chronic renal disease, irrespective of the cause, are mainly focused on supportive treatments and renal replacement strategies when needed. Emerging preclinical evidence supports the feasibility of drug delivery technology for the kidney, and recent studies have contributed to building a robust catalog of peptides, proteins, nanoparticles, liposomes, extracellular vesicles, and other carriers that may be fused to therapeutic peptides, proteins, nucleic acids, or small molecule drugs. These fusions can display a precise renal uptake, an enhanced circulating time, and a directed intraorgan biodistribution while protecting their cargo to improve therapeutic efficacy. However, several hurdles that slow the transition towards clinical applications are still in the way, such as solubility, toxicity, and sub-optimal renal targeting. This review will discuss the feasibility and current limitations of drug delivery technologies for the treatment of renal disease, offering an update on their potential and the future directions of these promising strategies.

Role of serum β2-microglobulin, glycosylated hemoglobin, and vascular endothelial growth factor levels in diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN) is a common complication of type 1 and type 2 diabetes that can lead to kidney damage and high blood pressure. Increasing evidence support the important roles of microproteins and cytokines, such as β2-microglobulin (β2-MG), glycosylated hemoglobin (HbA1c), and vascular endothelial growth factor (VEGF), in the pathogenesis of this disease. In this study, we identified novel therapeutic options for this disease.

AIM

To analyze the guiding significance of β2-MG, HbA1c, and VEGF levels in patients with DN.

METHODS

A total of 107 patients with type 2 diabetes mellitus complicated with nephropathy and treated in our hospital from May 2018 to February 2021 were included in the study. Additionally, 107 healthy individuals and 107 patients with simple diabetes mellitus were selected as the control groups. Changes in β2-MG, HbA1c, and VEGF levels in the three groups as well as the different proteinuria exhibited by the three groups were examined.

RESULTS

Changes in β2-MG, HbA1c, and VEGF levels in the disease, healthy, and simple diabetes groups were significantly different (P < 0.05). The expression of these factors from high to low were evaluated in different groups by pairwise comparison. In the disease group, high to low changes in β2-MG, HbA1c, and VEGF levels were noted in the massive proteinuria, microproteinuria, and normal urinary protein groups, respectively. Changes in these factors were positively correlated with disease progression.

CONCLUSION

The expression of serum β2-MG, HbA1c, and VEGF was closely correlated with DN progression, and disease progression could be evaluated by these factors.

Renal Nano-drug delivery for acute kidney Injury: Current status and future perspectives

Acute kidney injury (AKI) causes considerable morbidity and mortality, particularly in the case of post-cardiac infarction or kidney transplantation; however, the site-specific accumulation of small molecule reno-protective agents for AKI has often proved ineffective due to dynamic fluid and solute excretion and non-selectivity, which impedes therapeutic efficacy. This article reviews the current status and future trajectories of renal nanomedicine research for AKI management from pharmacological and clinical perspectives, with a particular focus on appraising nanosized drug carrier (NDC) use for the delivery of reno-protective agents of different pharmacological classes and the effectiveness of NDCs in improving renal tissue targeting selectivity and efficacy of said agents. This review reveals the critical shift in the role of the small molecule reno-protective agents in AKI pharmacotherapy - from prophylaxis to treatment - when using NDCs for delivery to the kidney. We also highlight the need to identify the accumulation sites of NDCs carrying reno-protective agents in renal tissues during in vivo assessments and detail the less-explored pharmacological classes of reno-protective agents whose efficacies may be improved via NDC-based delivery. We conclude the paper by outlining the challenges and future perspectives of NDC-based reno-protective agent delivery for better clinical management of AKI.