Dose-Dependent Efficacy of Gold Clusters on Rheumatoid Arthritis Therapy

Therapeutic and Diagnostic Agents based on Bioactive Endogenous and Exogenous Coordination Compounds

Metal-based coordination compounds have very special place in bioinorganic chemistry because of their different structural arrangements and significant application in medicine. Rapid progress in this field increasingly enables the targeted design and synthesis of metal-based pharmaceutical agents that fulfill valuable roles as diagnostic or therapeutic agents. Various coordination compounds have important biological functions, both those initially present in the body (endogenous) and those entering the organisms from the external environment (exogenous): vitamins, drugs, toxic substances, etc. In the therapeutic and diagnostic practice, both the essential for all living organisms and the trace metals are used in metal-containing coordination compounds. In the current review, the most important functional biologically active compounds were classified group by group according to the position of the elements in the periodic table.

Colon-Accumulated Gold Nanoclusters Alleviate Intestinal Inflammation and Prevent Secondary Colorectal Carcinogenesis via Nrf2-Dependent Macrophage Reprogramming

Inflammatory bowel disease (IBD) is one of the main factors leading to colitis-associated colorectal cancer (CAC). Therefore, it is critical to develop an effective treatment for IBD to prevent secondary colorectal carcinogenesis. M2 macrophages play crucial roles in the resolution phase of intestinal inflammation. However, traditional drugs rarely target intestinal M2 macrophages, and they are not easily cleared. Gold nanoclusters are known for their in vivo safety and intrinsic biomedical activities. In this study, a glutathione-protected gold nanocluster is synthesized and evaluated, namely, GA. Interestingly, GA specifically accumulates in the colon during IBD. Furthermore, GA not only promotes M2 differentiation of IL-4-treated peritoneal macrophages but also reprograms macrophage polarization from M1 to M2 in a pro-inflammatory environment. Mechanistically, this regulatory effect is exerted through activating the antioxidant Nrf2 signaling pathway, but not traditional STAT6. When applied in IBD mice, we found that GA elevates M2 macrophages and alleviates IBD in an Nrf2-dependent manner, evidenced by the abolished therapeutic effect upon Nrf2 inhibitor treatment. Most importantly, GA administration significantly suppresses AOM/DSS-induced CAC, without causing obvious tissue damage, providing critical evidence for the potential application of gold nanoclusters as nanomedicine for the treatment of IBD and CAC.

Treatment with silica-gold nanostructures decreases inflammation-related gene expression in collagen-induced arthritis

Gold salts have been used to treat rheumatoid arthritis (RA) since the 1940s, and, with advances in nanotechnology, the use of nanogold provides multiple options for anti-inflammatory therapies. This paper presents the synthesis and characterization of silica-gold nanostructures (SGNs) and their therapeutic effect in collagen-induced arthritis (CIA) in DBA/1 mice. At the end of the treatment, the synovial membranes, kidneys, livers, and spleens were dissected and analyzed by inductively coupled plasma mass spectroscopy (ICP) showing less than 0.0001 and 0.1% of the administered doses of Au and Si, respectively. Remains of the SGNs were visually identified in the synovial membrane by scanning electron microscopy (SEM), and the bone density of the hind paws was observed by computerized tomography (CT) indicating a reduction of porosity in the CIA-experimental group. The DNA microarray analysis carried out with RNA obtained from the hind paws showed 2628 differentially expressed genes (DEGs) by SGNs. The bioinformatic analysis showed that DEGs were significantly associated with several inflammatory signalling pathways including chemokines, cytokine-cytokine receptor interaction, PI3K-Akt, TNF, IL-17, NFκβ, MAPK, and RA. SGNs downregulated relevant inflammatory genes in the arthritic joints, including Tnf, Ifng, Il6, and Cxcl5; immunohistochemistry (IHC) confirmed the reduction of TNFα, IL-6, NFκβ, and VEGF in the joints due to the effect of SGNs. TNFα and IL-6 were also reduced in the serum of DBA/1 mice treated with SGNs.

Dose-Dependent Efficacy of Umbelliferone and Gelatin-Coated ZnO/ZnS Core-Shell Nanoparticles: A Novel Arthritis Agent for Severe Knee Arthritis

Rheumatoid arthritis (RA) is a well-known autoimmune disorder that affects 1% of the global population. Zinc (Zn) is crucial for bone homeostasis, when compared with normal human bone, Zn level found to be decreased in RA patients and collagen-induced arthritis (CIA) rats. Notably, Zn-based medicinal products play a prominent role in reducing disease symptoms and acute side effects of patients with bone-related diseases. In this study, we report the clinical efficiency of gelatin- (Gel-) coated ZnO-ZnS core-shell nanoparticles (CSNPs) with umbelliferon (Uf) drug (Uf-Gel-ZnO-ZnS CSNPs) on the normal and CIA-induced Wistar rats. The formed ZnO-ZnS CSNPs are spherical in shape, with an average particle diameter of 150 ± 7 nm. It showed strong cytocompatibility when tested on L929 and foreskin fibroblasts (BJ) cells by MTT assay. While comparing with free Uf, various doses (2.5 and 5 mg) of Uf-Gel-ZnO-ZnS CSNPs showed strong inhibition of CIA by attenuated proinflammatory cytokines such as interleukin-1β, IL-6, PEG2, and IL-17. The Uf-Gel-ZnO-ZnS CSNPs show more effectiveness in reducing joint swelling and also increase the level of antioxidant enzymes. In addition, CSNPs significantly reduced the infiltration of inflammatory cells in the knee joint. Thus, the current study concludes that Uf-Gel-ZnO-ZnS CSNPs feasibly reduce the incidence of arthritis in a dose-dependent manner by attenuation of inflammation.

Pharmacological Role of Functionalized Gold Nanoparticles in Disease Applications

Gold has always been regarded as a symbol of nobility, and its shiny golden appearance has always attracted the attention of many people. Gold has good ductility, molecular recognition properties, and good biocompatibility. At present, gold is being used in many fields. When gold particles are as small as several nanometers, their physical and chemical properties vary with their size in nanometers. The surface area of a nano-sized gold surface has a special effect. Therefore, gold nanoparticles can, directly and indirectly, give rise to different biological activities. For example, if the surface of the gold is sulfided. Various substances have a strong chemical reactivity and are easy to combine with sulfhydryl groups; hence, nanogold is often used in biomedical testing, disease diagnosis, and gene detection. Nanogold is easy to bind to proteins, such as antibodies, enzymes, or cytokines. In fact, scientists use nanogold to bind special antibodies, as a tool for targeting cancer cells. Gold nanoparticles are also directly cytotoxic to cancer cells. For diseases caused by inflammation and oxidative damage, gold nanoparticles also have antioxidant and anti-inflammatory effects. Based on these unique properties, gold nanoparticles have become the most widely studied metal nanomaterials. Many recent studies have further demonstrated that gold nanoparticles are beneficial for humans, due to their functional pharmacological properties in a variety of diseases. The content of this review will be the application of gold nanoparticles in treating or diagnosing pressing diseases, such as cancers, retinopathy, neurological diseases, skin disorders, bowel diseases, bone cartilage disorders, cardiovascular diseases, infections, and metabolic syndrome. Gold nanoparticles have shown very obvious therapeutic and application potential.

Platinum-based drugs for cancer therapy and anti-tumor strategies

Platinum-based drugs cisplatin, carboplatin, and oxaliplatin are widely used for chemotherapeutic eradication of cancer. However, the side effects of platinum drugs, such as lack of selectivity, high systemic toxicity, and drug resistance, seriously limit their clinical application. With advancements in nanotechnology and chemical synthesis, Pt-based anti-cancer drugs have made great progress in cancer therapy in recent years. Many strategies relied on the anti-cancer mechanism similar to cisplatin and achieved some success by modifying existing platinum drugs. Pt-based nanodrugs, such as platinum nanoclusters, have novel anti-cancer mechanisms and great potential in tumor-targeted therapy and have shown promising results in clinical application. In this review, we systematically explored the development of first-line platinum chemotherapy drugs in the clinic and their anti-cancer mechanisms. We also summarize the progress of Pt-based anti-cancer drug application in cancer therapy, emphasizing their modification to enhance the anti-tumor effect. Finally, we address challenges faced by platinum chemotherapy drugs, especially Pt nanocluster-based nanodrugs, in cancer treatment. The new platinum drugs and their targeted modifications undoubtedly provide a promising prospect for improving the current anti-cancer treatments.

Therapy of spinal cord injury by zinc modified gold nanoclusters via immune-suppressing strategies

Background

Spinal cord injury (SCI) is damage to the central nervous system (CNS) that causes devastating complications from chronic pain to breathing problems. Unfortunately, few effective and safe treatments are known to relieve the damages of SCI. Nanomedicines are used for the treatment of SCI with relatively few side effects, but only depending on the delivery of additional drugs, which increase complexity to the treatment. Considering the urgent need for saving SCI patients, it is important to develop promising nanobiotechnology for relieving their pains.

Methods

The clinical survey was used to investigate SCI patients, thereafter the therapy plan was designed. The receiver-operating characteristics (ROC) curves of the prediction model were built to find symptoms after SCI. The treatment plan (i.e. immunosuppressive strategy) was designed by manufacturing therapies based on gold nanoclusters (AuNCs). The response of the immune cells (macrophages) was studied accordingly. The western blot, reactive oxygen species (ROS) activity assay, enzyme-linked immunosorbent assay (ELISA), quantitative real-time PCR (RT-qPCR), and immunochemical staining were used for evaluation of the in vivo and in vitro therapeutic effects.

Results

We found increased monocytes/macrophages (M/Ms) levels in 114 SCI subjects (44.7% with severe SCI complications) by the clinical survey. Additionally, the enhanced macrophage level was found to be closely related to the walking disorder after SCI. Since macrophages were central effector cells of the immune system, we assumed that the immune-suppressing strategies could be used for SCI therapy. Thereafter, AuNCs were stabilized by dihydrolipoic acid (DHLA) enantiomers (including DL-DHLA, R-DHLA; A racemic mixture (R and S) was denoted as DL; R and S refer to Rectus and Sinister), obtaining DL-DHLA-AuNCs and R-DHLA-AuNCs, respectively. In addition, zinc-modified DL-DHLA and R-DHLA stabilized AuNCs (i.e., DL-DHLA-AuNCs-Zn and R-DHLA-AuNCs-Zn) were investigated. Among these AuNCs, R-DHLA-AuNCs-Zn showed the most remarkable therapeutic effect for promoting the polarization of pro-inflammatory macrophages and reducing neuronal ROS-induced apoptosis and inflammation in vitro and in vivo; the lesion size was decreased and the survival rate of ventral neurons is higher.

Conclusions

R-DHLA-AuNCs-Zn have comprehensive therapeutic capabilities, especially the immune-suppressing effects for the therapy of SCI, which is promising to relieve the pain or even recover SCI for the patients.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01035-8.

Mutual-reinforcing sonodynamic therapy against Rheumatoid Arthritis based on sparfloxacin sonosensitizer doped concave-cubic rhodium nanozyme

Rheumatoid arthritis (RA) is an autoimmune disease associated with synovitis and cartilage destruction. Ultrasound (US)-driven sonodynamic therapy (SDT) possess a good application prospect in RA therapy because of its non-invasiveness and strong tissue penetration capabilities, which can kill activated synovial inflammatory cells. Nevertheless, the tiny accumulation of sonosensitizers in the joints and the hypoxic synovial microenvironment severely limit the therapeutic effect of SDT. Hence, we developed a sonosensitizer spafloxacin (SPX) doped and human serum albumin (HSA) loaded concave-cubic rhodium (Rh) nanozyme (Rh/SPX-HSA) to realize mutual-reinforcing SDT during ultrasonic activation. On the one hand, SPX would cause mitochondrial dysfunction by inducing excessive reactive oxygen species (ROS) production, thus suppressing fibroblast-like synoviocyte (FLS) under US conditions. On the other hand, concave-cubic rhodium was utilized as a nanozyme with endogenous peroxidase (POD) and catalase (CAT)-like enzyme activities, which not only relieved the hypoxia of the joint to resist angiogenesis, but also enormously ascended the SDT efficacy by rising ¹O₂ levels. Interestingly, the activity of nanozymes was also improved by the ultrasonic cavitation effect, thereby realizing mutual-reinforcing SDT. Overall, our strategy provided Rh-based to achieve effective SDT under hypoxic microenvironment, which offered a promising prospect for highly efficient treatment of RA.

Nanomaterials Manipulate Macrophages for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is a chronic, progressive, and systemic inflammatory autoimmune disease, characterized by synovial inflammation, synovial lining hyperplasia and inflammatory cell infiltration, autoantibody production, and cartilage/bone destruction. Macrophages are crucial effector cells in the pathological process of RA, which can interact with T, B, and fibroblast-like synovial cells to produce large amounts of cytokines, chemokines, digestive enzymes, prostaglandins, and reactive oxygen species to accelerate bone destruction. Therefore, the use of nanomaterials to target macrophages has far-reaching therapeutic implications for RA. A number of limitations exist in the current clinical therapy for patients with RA, including severe side effects and poor selectivity, as well as the need for frequent administration of therapeutic agents and high doses of medication. These challenges have encouraged the development of targeting drug delivery systems and their application in the treatment of RA. Recently, obvious therapeutic effects on RA were observed following the use of various types of nanomaterials to manipulate macrophages through intravenous injection (active or passive targeting), oral administration, percutaneous absorption, intraperitoneal injection, and intra-articular injection, which offers several advantages, such as high-precision targeting of the macrophages and synovial tissue of the joint. In this review, the mechanisms involved in the manipulation of macrophages by nanomaterials are analyzed, and the prospect of clinical application is also discussed. The objective of this article was to provide a reference for the ongoing research concerning the treatment of RA based on the targeting of macrophages.

Biosynthesis of gold nanoparticles for the treatment of osteoarthritis alone or in combination with Diacerein® in a rat model

Gold (Au) compounds were used as an effective therapeutic agent for various inflammatory diseases; however, the use of Au compounds becomes limited because of its association with several side effects. Hence, gold nanoparticles (AuNPs) were developed as a new option for the medical proposes. However, the safety evaluation of gold nanoparticles (AuNPs) in osteoarthritis (OA) treatment remains vague. This study aimed to biosynthesize, characterize and evaluate the therapeutic effects of biosynthesized AuNPs and/or Diacerein^® (DIA) in experimental OA. OA was induced by a single injection of monosodium iodoacetate (3 mg/joint) in the intra-articular knee of female rats. Normal rats (N-rats) and OA-rats were treated orally for 5 weeks as follow: untreated N-rats; untreated OA-rats; N-rats received DIA (50 mg/kg b.w); N-rats received AuNPs (30 μg/kg b.w.); N-rats received AuNPs plus DIA; OA-rats received DIA; OA-rats received AuNPs, and OA-rats received AuNPs plus DIA. Blood, knee cartilage, liver and kidney samples were collected for biochemical and histological analysis. The synthesized AuNPs were nearly spherical with average size of 20 nm and zeta potential of 33 mV. AuNPs and DIA induced a significant improvement in serum inflammatory cytokines, biochemical parameters, estrogen level, hepatic and renal oxidative markers, hepatic DNA fragmentation, genomic template stability and cartilage joint histology of OA-rats. AuNPs were more effective than DIA and the combined treatment was more effective than the single treatment. It could be concluded that AuNPs are promising for the treatment of OA alone or in combination with DIA.

Catalytic Nanomaterials toward Atomic Levels for Biomedical Applications: From Metal Clusters to Single-Atom Catalysts

Single-atom catalysts (SACs) featuring the complete atomic utilization of metal, high-efficient catalytic activity, superior selectivity, and excellent stability have been emerged as a frontier in the catalytic field. Recently, increasing interests have been drawn to apply SACs in biomedical fields for enzyme-mimic catalysis and disease therapy. To fulfill the demand of precision and personalized medicine, precisely engineering the structure and active site toward atomic levels is a trend for nanomedicines, promoting the evolution of metal-based biomedical nanomaterials, particularly biocatalytic nanomaterials, from nanoparticles to clusters and now to SACs. This review outlines the syntheses, characterizations, and catalytic mechanisms of metal clusters and SACs, with a focus on their biomedical applications including biosensing, antibacterial therapy, and cancer therapy, as well as an emphasis on their in vivo biological safeties. Challenges and future perspectives are ultimately prospected for SACs in diverse biomedical applications.

Gold Clusters Attenuate Inflammation in Rat Mesangial Cells via Inhibiting the Activation of NF-κB Pathway

Sepsis-induced acute kidney injury (AKI) with high incidence and mortality rates remains a great challenge in the clinic; thus, novel therapies need to be developed urgently. This complication is associated with an overwhelming systemic inflammatory response. The aim of this study was to evaluate the potential effects and possible mechanisms of gold clusters on septic AKI in vitro. Rat mesangial HBZY-1 cells were treated with peptide-templated gold clusters under lipopolysaccharide (LPS) stimulation. The LPS-induced expression of pro-inflammatory cytokines was measured, including tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6). Our data showed that the LPS-induced transcription and secretion of these cytokines were suppressed by pretreatment of gold clusters in a dose-dependent manner. Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) also play key roles in septic AKI and both of them are induced upon LPS-stimulation in mesangial cells. Our results further showed that pretreatment with gold clusters dramatically inhibited the LPS-stimulated transcription and expression of COX2 and iNOS, and the subsequent prostaglandin E2 (PGE2) and nitric oxide (NO) production in HBZY-1 cells. Since these factors are involved in the NF-κB pathway upon LPS stimulation, the potential roles of gold clusters on the NF-κB pathway were further determined. We found that LPS-induced NF-κB activation was suppressed in gold clusters-pretreated HBZY-1 cells. These results demonstrated that gold clusters can attenuate LPS-induced inflammation in mesangial cells, probably via inhibiting the activation of the NF-κB pathway, suggesting a potential therapeutic approach for septic AKI.