Effect of magnetic nanoparticles size on rheumatoid arthritis targeting and photothermal therapy

Deep-insights: Nanoengineered gel-based localized drug delivery for arthritis management

Arthritis is an inflammatory joint disorder that progressively impairs function and diminishes quality of life. Conventional therapies often prove ineffective, as oral administration lacks specificity, resulting in off-target side effects like hepatotoxicity and GIT-related issues. Intravenous administration causes systemic side effects. The characteristic joint-localized symptoms such as pain, stiffness, and inflammation make the localized drug delivery suitable for managing arthritis. Topical/transdermal/intra-articular routes have become viable options for drug delivery in treating arthritis. However, challenges with those localized drug delivery routes include skin barrier and cartilage impermeability. Additionally, conventional intra-articular drug delivery also leads to rapid clearance of drugs from the synovial joint tissue. To circumvent these limitations, researchers have developed nanocarriers that enhance drug permeability through skin and cartilage, influencing localized action. Gel-based nanoengineered therapy employs a gel matrix to incorporate the drug-encapsulated nanocarriers. This approach combines the benefits of gels and nanocarriers to enhance therapeutic effects and improve patient compliance. This review emphasizes deep insights into drug delivery using diverse gel-based novel nanocarriers, exploring their various applications embedded in hyaluronic acid (biopolymer)-based gels, carbopol-based gels, and others. Furthermore, this review discusses the influence of nanocarrier pharmacokinetics on the localization and therapeutic manipulation of macrophages mediated by nanocarriers. The ELVIS (extravasation through leaky vasculature and inflammatory cell-mediated sequestration) effect associated with arthritis is advantageous in drug delivery. Simply put, the ELVIS effect refers to the extravasation of nanocarriers through leaky vasculatures, which finally results in the accumulation of nanocarriers in the joint cavity.

Nano-based Therapeutics for Rheumatoid Arthritis: Recent Patents and Development

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease marked by inflammation of synovium and generation of autoantibodies. Bone and cartilage are frequently damaged along with weakening of tendons and ligaments resulting in disability. An effective RA treatment needs a multi-disciplinary approach which relies upon pathophysiology that is still partially understood. In RA patients, inflammation was induced by pro-inflammatory cytokines including IL-1, IL-6 & IL-10. The conventional dosage regimens for treating RA have drawbacks such as ineffectiveness, greater doses, frequent dosing, relatively expensive and serious adverse effects. To formulate an effective treatment plan for RA, research teams have recently focused on producing several nanoformulations containing anti-inflammatory APIs with an aim to target the inflamed area. Nanomedicines have recently gained popularity in the treatment of RA. Interestingly, unbelievable improvements have been observed in current years in diagnosis and management of RA utilizing nanotechnology. Various patents and clinical trial data have been reported in relevance to RA treatment.

Target-Engineered Liposomes Decorated with Nanozymes Alleviate Liver Fibrosis by Remodeling the Liver Microenvironment

Liver fibrosis is a pathological repair response that occurs after sustained liver damage, and prompt intervention is necessary to prevent liver fibrosis from developing into a potentially life-threatening condition. In long-term liver injury, damaged hepatocytes produce excessive amounts of reactive oxygen species (ROS), which activate hepatic stellate cells (HSCs). This activation leads to excessive accumulation of extracellular matrix proteins in liver tissue. Additionally, liver macrophages contribute to the inflammatory microenvironment in the hepatic fibrotic process, exacerbating liver fibrosis through ROS production and the secretion of pro-inflammatory factors. To address the dysregulation of the hepatic microenvironment associated with liver fibrosis, we developed cerium oxide nanozymes using hyaluronic acid (HA) as a template and decorated them on the surface of liposomes loaded with oleanolic acid (OA). We named this prepared and obtained target-engineered liposome HCOL. The inherent superoxide dismutase (SOD) and catalase (CAT) activities of HCOL enabled it to effectively scavenge ROS in HSCs and alleviate the hypoxic conditions characteristic of fibrotic livers. Furthermore, HCOL reduced the concentrations of ROS in macrophages, promoting a shift in macrophage polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype. This transition increased the production of the anti-inflammatory cytokine interleukin 10 (IL-10), which contributed to the mitigation of the inflammatory microenvironment. Consequently, this therapeutic approach proves effective in decelerating the advancement of liver fibrosis.

Nanomaterials in the treatment and diagnosis of rheumatoid arthritis: Advanced approaches

Rheumatoid arthritis (RA), a chronic inflammatory condition that affects persons between the ages of 20 and 40, causes synovium inflammation, cartilage loss, and joint discomfort as some of its symptoms. Diagnostic techniques for RA have traditionally been split into two main categories: imaging and serological tests. However, significant issues are associated with both of these methods. Imaging methods are costly and only helpful in people with obvious symptoms, while serological assays are time-consuming and require specialist knowledge. The drawbacks of these traditional techniques have led to the development of novel diagnostic approaches. The unique properties of nanomaterials make them well-suited as biosensors. Their compact dimensions are frequently cited for their outstanding performance, and their positive impact on the signal-to-noise ratio accounts for their capacity to detect biomarkers at low detection limits, with excellent repeatability and a robust dynamic range. In this review, we discuss the use of nanomaterials in RA theranostics. Scientists have recently synthesized, characterized, and modified nanomaterials and biomarkers commonly used to enhance RA diagnosis and therapy capabilities. We hope to provide scientists with the promising potential that nanomaterials hold for future theranostics and offer suggestions on further improving nanomaterials as biosensors, particularly for detecting autoimmune disorders.

Macrophages-mediated delivery of protoporphyrin for sonodynamic therapy of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease characterized by infiltration of inflammatory cells, hyperplasia of synovium, and destruction of the joint cartilage. Owing to the low drug delivery efficiency and limited immunosuppression effect, complete cure for RA remains a formidable challenge. Here, we show that live macrophages (Mφs) carrying protoporphyrin-loaded Fe3O4 nanoparticles can migrate to the RA tissues and inhibit the inflammation by sonodynamic therapy. The inflammation of RA leads to the release of cytokines, which guides the migration of the Mφs into the RA tissues, realizing precise delivery of therapeutics. The following sonodynamic therapy induced by ultrasound and protoporphyrin destructs the proliferating synovial cells and also infiltrated inflammatory cells, demonstrating significant therapeutic effect for RA. Meanwhile, the cytokines and relapse of RA can be remarkably suppressed because of the efficient damage to the resident inflammatory cells.

Development and functional evaluation of a hyaluronic acid coated nano-formulation with kaempferol as a novel intra-articular agent for Knee Osteoarthritis treatment

Knee osteoarthritis (OA) involves articular cartilage degradation driven mainly by inflammation. Kaempferol (KM), known for its anti-inflammatory property, holds potential for OA treatment. This study investigated the potential of hyaluronic acid (HA)-coated gelatin nanoparticles loaded with KM (HA-KM GNP) for treating knee OA. KM was encapsulated into gelatin nanoparticles (KM GNP) and then coated with HA to form HA-KM GNPs. Physical properties were characterized, and biocompatibility and cellular uptake were assessed in rat chondrocytes. Anti-inflammatory and chondrogenic properties were evaluated using IL-1β-stimulated rat chondrocytes, compared with HA-coated nanoparticles without KM (HA GNP) and KM alone. Preclinical efficacy was tested in an anterior cruciate ligament transection (ACLT)-induced knee OA rat model treated with intra-articular injection of HA-KM GNP. Results show spherical HA-KM GNPs (88.62 ± 3.90 nm) with positive surface charge. Encapsulation efficiency was 98.34 % with a sustained release rate of 18 % over 48 h. Non-toxic KM concentration was 2.5 μg/mL. In IL-1β-stimulated OA rat chondrocytes, HA-KM GNP significantly down-regulated RNA expression of IL-1β, TNF-α, COX-2, MMP-9, and MMP-13, while up-regulating SOX9 compared to HA GNP, and KM. In vivo imaging demonstrated significantly higher fluorescence intensity within rat knee joints for 3 hours post HA-KM GNP injection compared with KM GNP (185.2% ± 34.1% vs. 45.0% ± 16.7%). HA-KM GNP demonstrated significant effectiveness in reducing subchondral sclerosis, attenuating inflammation, inhibiting matrix degradation, restoring cartilage thickness, and reducing the severity of OA in the ACLT rat model. In conclusion, HA-KM GNP holds promise for knee OA therapy.

Advanced strategies for CRISPR/Cas9 delivery and applications in gene editing, therapy, and cancer detection using nanoparticles and nanocarriers

Cancer remains one of the deadliest diseases, and is characterised by the uncontrolled growth of modified human cells. Unlike infectious diseases, cancer does not originate from foreign agents. Though a variety of diagnostic procedures are available; their cost-effectiveness and accessibility create significant hurdles. Non-specific cancer symptoms further complicate early detection, leading to belated recognition of certain cancer. The lack of reliable biomarkers hampers effective treatment, as chemotherapy, radiation therapy, and surgery often result in poor outcomes and high recurrence rates. Genetic and epigenetic mutations play a crucial role in cancer pathogenesis, necessitating the development of alternate treatment methods. The advent of CRISPR/Cas9 technology has transformed molecular biology and exhibits potential for gene modification and therapy in various cancer types. Nonetheless, obstacles such as safe transport, off-target consequences, and potency must be overcome before widespread clinical use. Notably, this review delves into the multifaceted landscape of cancer research, highlighting the pivotal role of nanoparticles in advancing CRISPR/Cas9-based cancer interventions. By addressing the challenges associated with cancer diagnosis and treatment, this integrated approach paves the way for innovative solutions and improved patient outcomes.

Phototherapy techniques for the management of musculoskeletal disorders: strategies and recent advances

Musculoskeletal disorders (MSDs), which include a range of pathologies affecting bones, cartilage, muscles, tendons, and ligaments, account for a significant portion of the global burden of disease. While pharmaceutical and surgical interventions represent conventional approaches for treating MSDs, their efficacy is constrained and frequently accompanied by adverse reactions. Considering the rising incidence of MSDs, there is an urgent demand for effective treatment modalities to alter the current landscape. Phototherapy, as a controllable and non-invasive technique, has been shown to directly regulate bone, cartilage, and muscle regeneration by modulating cellular behavior. Moreover, phototherapy presents controlled ablation of tumor cells, bacteria, and aberrantly activated inflammatory cells, demonstrating therapeutic potential in conditions such as bone tumors, bone infection, and arthritis. By constructing light-responsive nanosystems, controlled drug delivery can be achieved to enable precise treatment of MSDs. Notably, various phototherapy nanoplatforms with integrated imaging capabilities have been utilized for early diagnosis, guided therapy, and prognostic assessment of MSDs, further improving the management of these disorders. This review provides a comprehensive overview of the strategies and recent advances in the application of phototherapy for the treatment of MSDs, discusses the challenges and prospects of phototherapy, and aims to promote further research and application of phototherapy techniques.

Ångstrom-scale silver particles ameliorate collagen-induced and K/BxN-transfer arthritis in mice via the suppression of inflammation and osteoclastogenesis

OBJECTIVE

Nanoparticles (NPs) hold a great promise in combating rheumatoid arthritis, but are often compromised by their toxicities because the currently used NPs are usually synthesized by chemical methods. Our group has previously fabricated Ångstrom-scale silver particles (AgÅPs) and demonstrated the anti-tumor and anti-sepsis efficacy of fructose-coated AgÅPs (F-AgÅPs). This study aimed to uncover the efficacy and mechanisms of F-AgÅPs for arthritis therapy.

METHODS

We evaluated the efficacy of F-AgÅPs in collagen-induced arthritis (CIA) mice. We also compared the capacities of F-AgÅPs, the commercial AgNPs, and the clinical drug methotrexate (MTX) in protecting against K/BxN serum-transfer arthritis (STA) mice. Moreover, we evaluated the effects of F-AgÅPs and AgNPs on inflammation, osteoclast formation, synoviocytes migration, and matrix metalloproteinases (MMPs) production in vitro and in vivo. Meanwhile, the toxicities of F-AgÅPs and AgNPs in vitro and in vivo were also tested.

RESULTS

F-AgÅPs significantly prevented bone erosion, synovitis, and cartilage damage, attenuated rheumatic pain, and improved the impaired motor function in mouse models of CIA or STA, the anti-rheumatic effects of which were comparable or stronger than AgNPs and MTX. Further studies revealed that F-AgÅPs exhibited similar or greater inhibitory abilities than AgNPs to suppress inflammation, osteoclast formation, synoviocytes migration, and MMPs production. No obvious toxicities were observed in vitro and in vivo after F-AgÅPs treatment.

CONCLUSIONS

F-AgÅPs can effectively alleviate arthritis without notable toxicities and their anti-arthritic effects are associated with the inhibition of inflammation, osteoclastogenesis, synoviocytes migration, and MMPs production. Our study suggests the prospect of F-AgÅPs as an efficient and low-toxicity agent for arthritis therapy.

Multifunctional nanoparticles encapsulating methotrexate and curcumin for holistic management of rheumatoid arthritis: in-vitro and pre-clinical assessment

PURPOSE

Bovine serum albumin (BSA) nanoparticles (BSA-MTX-CUR-NPs) encapsulating methotrexate (MTX) and curcumin (CUR) was developed with an aim to co-deliver the drugs at the inflamed joint so as to maximize the therapeutic efficacy and alleviate toxic side effects associated with MTX.

METHODS

Nanoparticle albumin-bound technology was used to formulate nanoparticles, followed by characterization for its particle size, polydispersity index, encapsulation efficiency, zeta potential, surface morphology, in-vitro drug release and drug release kinetics. Further, we investigated the pharmacokinetics and pharmacodynamics of the developed nanoparticles in the adjuvant-induced arthritis model.

RESULTS

BSA-MTX-CUR-NPs exhibited particle size of 163.05 ± 1.708 nm, polydispersity index of 0.195 ± 0.0024 and % encapsulation efficiency of 68.23 ± 0.640% for MTX and 75.71 ± 0.216% for CUR with controlled release pattern for both the drugs. The scanning electron microscopy revealed nanoparticles exhibited a spherical shape. DSC study confirmed the absence of incompatibility between the drugs and the excipients. Half-life and area under the curve were significantly higher for MTX in the nanoparticulate form in comparison to free MTX. Pharmacodynamic studies revealed that BSA-MTX-CUR-NPs possessed better disease-modifying effects in comparison to free MTX.

CONCLUSION

Hence, it can be concluded that albumin nanoparticles constitute a viable method for delivering MTX and CUR to inflamed joints simultaneously, because of the strong affinity of albumin and enhanced permeability and retention effect at the inflamed joint. This combinational therapy of MTX & CUR in nanoparticulate form has the potential for the holistic management of rheumatoid arthritis.

Tailoring Magnetite-Nanoparticle-Based Nanocarriers for Gene Delivery: Exploiting CRISPRa Potential in Reducing Conditions

Gene delivery has emerged as a promising alternative to conventional treatment approaches, allowing for the manipulation of gene expression through gene insertion, deletion, or alteration. However, the susceptibility of gene delivery components to degradation and challenges associated with cell penetration necessitate the use of delivery vehicles for effective functional gene delivery. Nanostructured vehicles, such as iron oxide nanoparticles (IONs) including magnetite nanoparticles (MNPs), have demonstrated significant potential for gene delivery applications due to their chemical versatility, biocompatibility, and strong magnetization. In this study, we developed an ION-based delivery vehicle capable of releasing linearized nucleic acids (tDNA) under reducing conditions in various cell cultures. As a proof of concept, we immobilized a CRISPR activation (CRISPRa) sequence to overexpress the pink1 gene on MNPs functionalized with polyethylene glycol (PEG), 3-[(2-aminoethyl)dithio]propionic acid (AEDP), and a translocating protein (OmpA). The nucleic sequence (tDNA) was modified to include a terminal thiol group and was conjugated to AEDP's terminal thiol via a disulfide exchange reaction. Leveraging the natural sensitivity of the disulfide bridge, the cargo was released under reducing conditions. Physicochemical characterizations, including thermogravimetric analysis (TGA) and Fourier-transform infrared (FTIR) spectroscopy, confirmed the correct synthesis and functionalization of the MNP-based delivery carriers. The developed nanocarriers exhibited remarkable biocompatibility, as demonstrated by the hemocompatibility, platelet aggregation, and cytocompatibility assays using primary human astrocytes, rodent astrocytes, and human fibroblast cells. Furthermore, the nanocarriers enabled efficient cargo penetration, uptake, and endosomal escape, with minimal nucleofection. A preliminary functionality test using RT-qPCR revealed that the vehicle facilitated the timely release of CRISPRa vectors, resulting in a remarkable 130-fold overexpression of pink1. We demonstrate the potential of the developed ION-based nanocarrier as a versatile and promising gene delivery vehicle with potential applications in gene therapy. The developed nanocarrier is capable of delivering any nucleic sequence (up to 8.2 kb) once it is thiolated using the methodology explained in this study. To our knowledge, this represents the first MNP-based nanocarrier capable of delivering nucleic sequences under specific reducing conditions while preserving functionality.

Intra-articular nanoparticles based therapies for osteoarthritis and rheumatoid arthritis management

Osteoarthritis (OA) and rheumatoid arthritis (RA) are chronic and progressive inflammatory joint diseases that affect a large population worldwide. Intra-articular administration of various therapeutics is applied to alleviate pain, prevent further progression, and promote cartilage regeneration and bone remodeling in both OA and RA. However, the effectiveness of intra-articular injection with traditional drugs is uncertain and controversial due to issues such as rapid drug clearance and the barrier afforded by the dense structure of cartilage. Nanoparticles can improve the efficacy of intra-articular injection by facilitating controlled drug release, prolonged retention time, and enhanced penetration into joint tissue. This review systematically summarizes nanoparticle-based therapies for OA and RA management. Firstly, we explore the interaction between nanoparticles and joints, including articular fluids and cells. This is followed by a comprehensive analysis of current nanoparticles designed for OA/RA, divided into two categories based on therapeutic mechanisms: direct therapeutic nanoparticles and nanoparticles-based drug delivery systems. We highlight nanoparticle design for tissue/cell targeting and controlled drug release before discussing challenges of nanoparticle-based therapies for efficient OA and RA treatment and their future clinical translation. We anticipate that rationally designed local injection of nanoparticles will be more effective, convenient, and safer than the current therapeutic approach.

Central composite design-based optimization, fabrication, and pharmacodynamic assessment of sulfasalazine-loaded lipoidal nanoparticle-based hydrogel for the management of rheumatoid arthritis

Rheumatoid arthritis is a progressive, chronic, immunological, and inflammatory disorder that is distinguished by joint inflammation, joint tenderness, and synovial joint destruction. The study aimed to fabricate sulfasalazine-loaded solid lipid nanoparticle (SLN)-based gels for rheumatoid arthritis management. The SLNs were fabricated with the melt emulsification technique by employing central composite design (CCD) for SLNs optimization. The optimized formulation of SLNs (FF-1) showed particle size and drug entrapment efficiency of 117.25 nm ± 1.67 and 94.05% ± 1.05, respectively. To scrutinize the outcome of the independent variable on responses; model graphs and the polynomial equation obtained from the Design-Expert were used. The surface morphology studies of SLNs revealed a smooth surface with a slightly asymmetric shape. In vitro drug release of the optimized formulation (FF1) had shown a maximum release of up to ~ 91.89% ± 2.12 over 24 h. The optimized FF1 formulation was subsequently gelled using 1% w/v Carbopol 934 and subjected to ex vivo permeation that displayed 8.01 mg/cm² ± 0.24 and 7.49 mg/cm² ± 0.86 amount of drug permeated up to 24 h and 10 h from SLNs gel and plain gel, respectively. In vivo studies manifested a considerable reduction in the paw thickness (*p < 0.0001) and an arthritic score (*p < 0.0001) of the sulfasalazine SLN gel as compared to plain gel. Further, pro-inflammatory cytokines, viz. TNF-α, IL-1, and IL-6 levels, were significantly inhibited (p < 0.0001) by sulfasalazine SLN-based gel that exhibited substantial anti-inflammatory effects. In conclusion, sulfasalazine-loaded SLN-based gel showed sustained release of drug for up to 24 h and can be considered suitable as a topical application for rheumatoid arthritis management.

A comprehensive review of advanced drug delivery systems for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA), a chronic autoimmune disease, is characterized by articular pain and swelling, synovial hyperplasia, and cartilage and bone destruction. Conventional treatment strategies for RA involve the use of anti-rheumatic drugs, which warrant high-dose, frequent, and long-term administration, resulting in serious adverse effects and poor patient compliance. To overcome these problems and improve clinical efficacy, drug delivery systems (DDS) have been designed for RA treatment. These systems have shown success in animal models of RA. In this review, representative DDS that target RA through passive or active effects on inflammatory cells are discussed and highlighted using examples. In particular, DDS allowing controlled and targeted drug release based on a variety of stimuli, intra-articular DDS, and transdermal DDS for RA treatment are described. Thus, this review provides an improved understanding of these DDS and paves the way for the development of novel DDS for efficient RA treatment.

Bioinspired Construction of Annulus Fibrosus Implants with a Negative Poisson's Ratio for Intervertebral Disc Repair and Restraining Disc Herniation

Inspired by the negative Poisson's ratio (NPR) effects of the annulus fibrosus (AF) in intervertebral discs (IVDs), we designed a re-entrant honeycomb model and then 3D printed it into a poly(ε-caprolactone) (PCL) scaffold with NPR effects, which was followed by in situ polymerization of polypyrrole (PPy), thus constructing a PPy-coated NPR-structured PCL scaffold (-vPCL-PPy) to be used as the AF implant for the treatment of lumbar herniated discs. Mechanical testing and finite element (FE) simulation indicated that the NPR composite implant could sustain axial spine loading and resist nucleus pulposus (NP) swelling while displaying uniform stress diffusion under NP swelling and contraction. More interestingly, the NPR-structured composite scaffold could also apply a reacting force to restrain NP herniation owing to the NPR effect. In addition, the in vitro biological assessment and in vivo implantation demonstrated that the NPR composite scaffold exhibited good biocompatibility and exerted the ability to restore the physiological function of the disc segments.

Redox Homeostasis Strategy for Inflammatory Macrophage Reprogramming in Rheumatoid Arthritis Based on Ceria Oxide Nanozyme-Complexed Biopolymeric Micelles

The synovial tissues under rheumatoid arthritis conditions are usually infiltrated by inflammatory cells, particularly M1 macrophages with aberrant redox homeostasis, which causes rapid deterioration of articular structure and function. Herein, we created an ROS-responsive micelle (HA@RH-CeO_X) through the in situ host-guest complexation between ceria oxide nanozymes and hyaluronic acid biopolymers, which precisely delivered nanozyme and clinically approved rheumatoid arthritis drug Rhein (RH) to proinflammatory M1 macrophage populations in inflamed synovial tissues. The abundant cellular ROS could cleave the thioketal linker to trigger the release of RH and Ce. Specifically, the Ce³⁺/Ce⁴⁺ redox pair could present SOD-like enzymatic activity to rapidly decompose ROS and alleviate the oxidative stress in M1 macrophages, while RH could inhibit the TLR4 signaling in M1 macrophages, both of which could act in a concerted manner to induce their repolarization into anti-inflammatory M2 phenotype to ameliorate local inflammation and promote cartilage repair. Notably, rats bearing rheumatoid arthritis showed a drastic increase in the M1-to-M2 macrophage ratio from 1:0.48 to 1:1.91 in the inflamed tissue and significantly reduced inflammatory cytokine levels including TNF-α and IL-6 following the intra-articular injection of HA@RH-CeO_X, accompanied by efficient cartilage regeneration and restored articular function. Overall, this study revealed an approach to in situ modulate the redox homeostasis in inflammatory macrophages and reprogram their polarization states through micelle-complexed biomimetic enzymes, which offers alternative opportunities for the treatment of rheumatoid arthritis.

Nanomedicine is more than a supporting role in rheumatoid arthritis therapy

Rheumatoid arthritis(RA) is an autoimmune disorder that affects the joints. Various medications successfully alleviate the symptoms of RA in clinical. Still, few therapy strategies can cure RA, especially when joint destruction begins, and there is currently no effective bone-protective treatment to reverse the articular damage. Furthermore, the RA medications now used in clinical practice accompany various adverse side effects. Nanotechnology can improve the pharmacokinetics of traditional anti-RA drugs and therapeutic precision through targeting modification. Although the clinical application of nanomedicines for RA is in its infancy, preclinical research is rising. Current anti-RA nano-drug studies mainly focus on the following: drug delivery systems, nanomedicines with anti-inflammatory and anti-arthritic properties, biomimetic design with better biocompatibility and therapeutic features, and nanoparticle-dominated energy conversion therapies. These therapies have shown promising therapeutic benefits in animal models, indicating that nanomedicines are a potential solution to the current bottleneck in RA treatment. This review will summarize the present state of anti-RA nano-drug research.

Recent Advances in Polymer-Based Nanomaterials for Non-Invasive Photothermal Therapy of Arthritis

To date, nanomaterials have been widely used for the treatment and diagnosis of rheumatoid arthritis. Amongst various nanomaterials, polymer-based nanomaterials are becoming increasingly popular in nanomedicine due to their functionalised fabrication and easy synthesis, making them biocompatible, cost-effective, biodegradable, and efficient nanocarriers for the delivery of drugs to a specific target cell. They act as photothermal reagents with high absorption in the near-infrared region that can transform near-infrared light into localised heat with fewer side effects, provide easier integration with existing therapies, and offer increased effectiveness. They have been combined with photothermal therapy to understand the chemical and physical activities behind the stimuli-responsiveness of polymer nanomaterials. In this review article, we provide detailed information regarding the recent advances in polymer nanomaterials for the non-invasive photothermal treatment of arthritis. The synergistic effect of polymer nanomaterials and photothermal therapy has enhanced the treatment and diagnosis of arthritis and reduced the side effects of drugs in the joint cavity. In addition, further novel challenges and future perspectives must be resolved to advance polymer nanomaterials for the photothermal therapy of arthritis.

Nanomaterial-assisted theranosis of bone diseases

Bone-related diseases refer to a group of skeletal disorders that are characterized by bone and cartilage destruction. Conventional approaches can regulate bone homeostasis to a certain extent. However, these therapies are still associated with some undesirable problems. Fortunately, recent advances in nanomaterials have provided unprecedented opportunities for diagnosis and therapy of bone-related diseases. This review provides a comprehensive and up-to-date overview of current advanced theranostic nanomaterials in bone-related diseases. First, the potential utility of nanomaterials for biological imaging and biomarker detection is illustrated. Second, nanomaterials serve as therapeutic delivery platforms with special functions for bone homeostasis regulation and cellular modulation are highlighted. Finally, perspectives in this field are offered, including current key bottlenecks and future directions, which may be helpful for exploiting nanomaterials with novel properties and unique functions. This review will provide scientific guidance to enhance the development of advanced nanomaterials for the diagnosis and therapy of bone-related diseases.

Iron oxide nanoparticles served as the primary carrier to increase drug loading in macrophages

The specific chemotaxis of macrophages to inflammatory site makes them good candidate for inflammation drug delivery. However, the loading capacity of free drug is low. The goal of the manuscript is to enhance the loading capacity by encapsulating drug onto iron oxide nanoparticles (IONPs) and investigate the size effect on the cellular uptake. IONPs with different sizes (10 nm, 70 nm, and 200 nm) were synthesized. The loading capacities of model drug protoporphyrin IX (PPIX) on different sized IONPs were studied, showing similar loading capacity. However, the cellular internalization of PPIX loaded IONPs (Fe₃O₄-PPIX) was quite different. 70 nm IONPs indicated maximum uptake by the macrophages. The results also demonstrate that the IONPs could significantly improve the loading capacity when compared with free drug. All the three sized nanoparticles demonstrated minimal effects on cellular viability and would not induce the polarization of macrophages. This study not only provides an efficient method to increase the drug loading capacity in macrophages, but also indicates the optimal size of nanoparticles for cellular uptake.

Recent Insights into NIR-Light-Responsive Materials for Photothermal Cell Treatments

Controlling cells using photo-responsive materials is highly indispensable in the current biomedical sector. Considering the potential side effects of nanoparticles, it has become a challenge to control cells with photo-responsive materials. Recent studies have described several methods for controlling cell behavior using nanoparticles subjected to the near-infrared (NIR) laser light operating at the wavelength of 808 nm to 980 nm and at the power densities of 0.33 to 0.72 W·cm^-2. The challenge here is the preparation of biocompatible nanoparticles for both in vivo and in vitro studies and understanding cell behavior with an external light source recommended for biological application. Earlier studies have well documented many approaches and associated mechanisms for controlling cell behavior and the interaction between nanoparticles, cells, and appropriate external light sources. In this review, various nanomaterials such as metal nanomaterials and carbon-based nanomaterials are compared systematically regarding the effects of controlling cell behavior and inflammation by studying their mechanisms, route of administration, dose, and adverse effects such as toxicity and the interaction of nanoparticles with a specific wavelength of the light. Future directions should focus on stable and efficient light-responsive materials with minimal cytotoxicity.

Chemo-photothermal therapeutic effect of chitosan-gelatin hydrogels containing methotrexate and melanin on a collagen-induced arthritis mouse model

Heat stimulation can promote osteoblast differentiation and bone formation. Combining photothermal therapy and chemotherapy is an effective strategy for treating rheumatoid arthritis (RA). Herein, we prepared chitosan/gelatin/β-glycerophosphate-melanin-methotrexate (CMM) hydrogel that could be used to perform simultaneous chemotherapy and photothermal therapy for patients with RA. The CMM solution was successfully converted to a gel state at body temperature. Due to intrinsic photothermal properties of melanin, CMM hydrogel exhibited effective temperature increase both in vitro and in vivo with increasing time of near-infrared (NIR) laser irradiation. After NIR laser irradiation, 50 % of methotrexate was rapidly released from the hydrogel within 3 h. Its release rate showed an instantaneous increase with additional NIR laser irradiation. After CMM hydrogel was injected directly into the paw joint of each collagen-induced arthritis (CIA) mouse followed by irradiation with a NIR laser (808 nm, 0.5 W/cm², 3 min), swelling and redness at the inflamed area were significantly alleviated at 14 days after treatment. Micro-CT analysis confirmed that treated joints of mice were similar to normal joints. Hence, CMM hydrogel could be used as an attractive RA therapeutic agent for simultaneous chemo-photothermal therapy.

ICAM-1 targeted thermal-sensitive micelles loaded with tofacitinib for enhanced treatment of rheumatoid arthritis via microwave assistance

Rheumatoid arthritis (RA) is an immune-mediated inflammatory disease without effective treatment. Tofacitinib (TOF) is a JAK inhibitor that can be used for RA therapy, but it still faces the problems of nonspecific distribution and relatively low therapeutic effect. Herein, ICAM-1-modified TOF-loaded P(AN-co-AAm)-PEG micelles (AI-TM) were developed, which can result in an enhanced RA therapy when combining with microwave hyperthermia (MH). It was found that AI-TM could rapidly release the encapsulated TOF under a thermal condition of >43 °C, which was due to the fact that the polymeric micelles has an upper critical solution temperature (UCST) of 43 °C. AI-TM could specifically distribute into the inflamed joints of RA mice, which is associated with the high affinity between anti-ICAM-1 and overexpressed ICAM-1 receptors. Moreover, the combination of AI-TM and MH could result in a remarkably enhanced anti-rheumatic activity, which was related to the RA-targeted ability of AI-TM, the rapid TOF release under MH, and the combined effect between TOF and MH treatment. Our study definitely provides a novel strategy for effective treatment of RA.

Dexamethasone-Loaded Radially Mesoporous Silica Nanoparticles for Sustained Anti-Inflammatory Effects in Rheumatoid Arthritis

Radially mesoporous silica nanoparticles (RMSNs) with protonated amine functionality are proposed to be a dexamethasone (Dex) carrier that could achieve a sustained anti-inflammatory effect in rheumatoid arthritis (RA). High-capacity loading and a sustained release of target drugs were achieved by radially oriented mesopores and surface functionality. The maximum loading efficiency was confirmed to be about 76 wt%, which is about two times greater than that of representative mesopores silica, SBA-15. In addition, Dex-loaded RMSNs allow a sustained-release profile with about 92% of the loaded Dex for 100 h in vitro, resulting in 2.3-fold better delivery efficiency of Dex than that of the SBA-15 over the same period. In vivo evaluation of the inhibitory effects on inflammation in a RA disease rat model showed that, compared with the control groups, the group treated with Dex-loaded RMSNs sustained significant anti-inflammatory effects and recovery of cartilage over a period of 8 weeks. The in vivo effects were confirmed via micro-computed tomography, bone mineral density measurements, and modified Mankin scoring. The proposed Dex-loaded RMSNs prolonged the life of the in vivo concentrations of therapeutic agents and maximized their effect, which should encourage its application.

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.

Biomimetic Hybrid Membrane-Coated Xuetongsu Assisted with Laser Irradiation for Efficient Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a systemic autoimmune disease underlying a cascade of chronic inflammatory processes. Over the past decades, the response rate of effective RA treatments has remained scarce despite numerous advancements in the current therapeutic interventions, owing largely to the associated off-target adverse events and poor accumulation in the inflamed joints. Recently, there is a high interest in the development of targeted drug delivery system by using nanotechnology, as it can provide a handle to improve the therapy efficacy of RA. Here, multifunctional HA@RFM@PB@SE nanoparticles (HRPS NPs) are developed by loading schisanlactone E (SE, also called with xuetongsu), an anti-RA compound isolated from Tujia ethnomedicine xuetong, into Prussian blue nanoparticles (PB NPs) and further camouflage of RBC-RAFLS hybrid membrane with HA modification onto PB@SE NPs (PS NPs). We demonstrated that the modification of RFM makes PB NPs ideal decoys for targeting inflammatory mediators of arthritis due to the homing effects of the parental cells. Moreover, the encapsulation of RFM on the PB@SE NPs extended the blood circulation time and improved its targeting ability, which accordingly achieved optimal accumulation of SE in arthritic rat paws. In vitro and in vivo assay demonstrated the outstanding performance of HRPS NPs for synergistic chemo-/photothermal therapy of RA without side effects to healthy tissues. Molecular mechanism exploration indicated that the ultrastrong inhibition of synovial hyperplasia and bone destruction was partly via suppressing NF-κB signaling pathway and the expression of matrix metalloproteinases. In summary, the nanodrug delivery system showed controllable release behavior, targeted accumulation at arthritic sites and systemic regulation of immunity, hence improved therapeutic efficacy and clinical outcomes of the disease without attenuating safety.

[Retracted] Multifunctional Therapeutic Approach of Nanomedicines against Inflammation in Cancer and Aging

Cancer is a fatal disorder that affects people across the globe, yet existing therapeutics are ineffective. The development of submicrometer transport for optimizing the biodistribution of systemically provided medications is the focus of nanomedicine. Nanoparticle‐ (NP‐) based treatments may enable the development of novel therapeutic approaches to combat this deadly disorder. In multifunctional, multimodal imaging, and drug delivery carriers, NPs generally play a major role. They have emerged as potential strategies for the invention of innovative therapeutic procedures in the last decade. The exponential growth of nanotechnologies in recent years has increased public awareness of the application of these innovative therapeutic approaches. Many tumor‐targeted nanomedicines have been studied in cancer therapy, and there is clear evidence for a significant improvement in the therapeutic index of antineoplastic drugs. Age‐related factors such as metabolic and physiological alterations in old age and inadequate animal models are currently understudied in nanomedicine and pharmacology. This review highlighted the most important targeting approaches, as well as public awareness, therapeutic advancements, and future prospects in age‐related metabolic variations, and tumor‐targeted nanomedicine studies.

The influence of IONPs core size on their biocompatibility and activity in in vitro cellular models

Although the key factor affecting the biocompatibility of IONPs is the core size, there is a lack of regular investigation concerning the impact of the parameter on the toxicity of these nanomaterials. Therefore, such studies were carried out in this paper. Their purpose was to compare the influence of PEG-coated-magnetite NPs with the core of 5, 10 and 30 nm on six carefully selected cell lines. The proliferation rate, viability, metabolic activity, migration activity, ROS levels and cytoskeleton architecture of cells have been evaluated for specified incubation periods. These were 24 and 72-h long incubations with IONPs administered in two doses: 5 and 25 µg Fe/ml. A decrease in viability was observed after exposure to the tested NPs for all the analyzed cell lines. This effect was not connected with core diameter but depended on the exposure time to the nanomaterials. IONPs increased not only the proliferation rate of macrophages-being phagocytic cells-but also, under certain conditions stimulated tumor cell divisions. Most likely, the increase in proliferation rate of macrophages contributed to the changes in the architecture of their cytoskeleton. The growth in the level of ROS in cells had been induced mainly by the smallest NPs. This effect was observed for HEK293T cells and two cancerous lines: U87MG (at both doses tested) and T98G (only for the higher dose). This requires further study concerning both potential toxicity of such IONPs to the kidneys and assessing their therapeutic potential in the treatment of glioblastoma multiforme.

Targeted extracellular vesicle delivery systems employing superparamagnetic iron oxide nanoparticles

In the past decade, the study of extracellular vesicles (EVs), especially exosomes (50-150 nm) have attracted growing interest in numerous areas of cancer and tissue regeneration due to their unique biological features. A low isolation yield and insufficient targeting abilities limit their therapeutic applicability. Recently, superparamagnetic iron oxide nanoparticles (SPIONs) with magnetic navigation have been exploited to enhance the targeting ability of EVs. To construct targeted EV delivery systems engineered by SPIONs, several groups have pioneered the use of different techniques, such as electroporation, natural incubation, and cell extrusion, to directly internalize SPIONs into EVs. Furthermore, some endogenous ligands, such as transferrins, antibodies, aptamers, and streptavidin, were shown to enable modification of SPIONs, which increases binding with EVs. In this review, we summarized recent advances in targeted EV delivery systems engineered by SPIONs and focused on the key methodological approaches and the current applications of magnetic EVs. This report aims to address the existing challenges and provide comprehensive insights into targeted EV delivery systems. STATEMENT OF SIGNIFICANCE: Targeted extracellular vesicle (EV) delivery systems engineered by superparamagnetic iron oxide nanoparticles (SPIONs) have attracted wide attention and research interest in recent years. Such strategies employ external magnet fields to manipulate SPION-functionalized EVs remotely, aiming to enhance their accumulation and penetration in vivo. Although iron oxide nanoparticle laden EVs are interesting, they are controversial at present, hampering the progress in their clinical application. A thorough integration of these studies is needed for an advanced insight and rational design of targeted EV delivery systems. In this review, we summarize the latest advances in the design strategies of targeted EV delivery systems engineered by SPIONs with a focus on their key methodological approaches, current applications, limitation and future perspectives, which may facilitate the development of natural theranostic nanoplatforms.

Thermochemotherapy Meets Tissue Engineering for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is an autoimmune disease that progresses from inflammation to cartilage destruction. Inspired by the similar characteristics of inflammatory granulation tissue to those of tumors, the newly emerged tumor therapy called thermochemotherapy is proposed to treat RA. Meanwhile, the repair of cartilage injury via tissue engineering is paid attention simultaneously. A first‐line antirheumatic drug (MTX; methotrexate) and transforming growth factor β1 (TGF‐β1) are loaded in nano‐Fe3O4 composite chitosan‐polyolefin to construct a multifunctional hydrogel (DN‐Fe‐MTX‐TGFβ1). The mechanical properties of the hydrogel are equivalent to that of articular cartilage to guarantee its role as a scaffold. A long‐term release ability and the magnetocaloric properties of the hydrogel assure its effect to provide sustained local thermochemotherapy. The effective ability of the hydrogel for both anti‐inflammation and cartilage repair is demonstrated. This work indicates a promising way to combine thermochemotherapy and tissue engineering for the effective treatment of RA for the first time.

From traditional to novel treatment of arthritis: a review of recent advances in nanotechnology-based thermal therapy

Arthritis has been a heavy burden on the economy and society at large. Recently, nanomaterials that can convert near-infrared light into localized heat have demonstrated better targeting to arthritic joints, fewer side effects, ease of combined application with current therapeutics and enhanced efficacy for arthritis treatment. In this review, the authors summarize traditional thermal therapies for arthritis treatment and their molecular mechanisms and discuss the advantages and applications of nanotechnology-based thermal therapies for arthritis treatment. In conclusion, nanotechnology-based thermal therapies are effective alternatives or adjuvant strategies to the current pharmacological treatment of arthritis. Future clinical translation of thermal therapies could benefit from research elucidating their mechanisms and standardizing their parameters to optimize efficacy.

Treatment of rheumatoid arthritis by phototherapy: advances and perspectives

Rheumatoid arthritis (RA) is an inflammatory disease that is prevalent worldwide and seriously threatens human health. Though traditional drug therapy can alleviate RA symptoms and slow progression, high dosage and frequent administration would cause unfavorable side effects. Phototherapy including photodynamic therapy (PDT) and photothermal therapy (PTT) has demonstrated distinctive potential in RA treatment. Under light irradiation, phototherapy can convert light into heat, or generate ROS, to promote necrosis or apoptosis of RA inflammatory cells, thus reducing the concentration of related inflammatory factors and relieving the symptoms of RA. In this review, we will summarize the development in the application of phototherapy in the treatment of rheumatoid arthritis.

Integrated nanomaterials for non-invasive photothermal therapy of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic inflammatory autoimmune disease that causes swelling, redness, and arthralgia of multiple joints. Despite significant research and development on the treatment modalities for RA, there is still no established effective treatment option for eradicating joint damage and inflammation. In recent years, photothermal therapy (PTT) has emerged as a practical approach to treat RA. In this review, we outline various factors that affect the effective treatment of RA. Moreover, we discuss various PTT-based nanomaterials that can be used to treat RA.

Continuous size fractionation of magnetic nanoparticles by using simulated moving bed chromatography

The size fractionation of magnetic nanoparticles is a technical problem, which until today can only be solved with great effort. Nevertheless, there is an important demand for nanoparticles with sharp size distributions, for example for medical technology or sensor technology. Using magnetic chromatography, we show a promising method for fractionation of magnetic nanoparticles with respect to their size and/or magnetic properties. This was achieved by passing magnetic nanoparticles through a packed bed of fine steel spheres with which they interact magnetically because single domain ferro-/ferrimagnetic nanoparticles show a spontaneous magnetization. Since the strength of this interaction is related to particle size, the principle is suitable for size fractionation. This concept was transferred into a continuous process in this work using a so-called simulated moving bed chromatography. Applying a suspension of magnetic nanoparticles within a size range from 20 to 120 nm, the process showed a separation sharpness of up to 0.52 with recovery rates of 100%. The continuous feed stream of magnetic nanoparticles could be fractionated with a space-time-yield of up to 5 mg/(L∙min). Due to the easy scalability of continuous chromatography, the process is a promising approach for the efficient fractionation of industrially relevant amounts of magnetic nanoparticles.

Ceria-based nanotheranostic agent for rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that affects 1-2% of the human population worldwide, and effective therapies with targeted delivery for local immune suppression have not been described. We address this problem by developing a novel theranostic nanoparticle for RA and assessed its therapeutic and targeting effects under image-guidance. Methods: Albumin-cerium oxide nanoparticles were synthesized by the biomineralization process and further conjugated with near-infrared, indocyanine green (ICG) dye. Enzymatic-like properties and reactive oxygen species (ROS) scavenging activities, as well as the ability to reprogram macrophages, were determined on a monocyte cell line in culture. The therapeutic effect and systemic targeting potential were evaluated in collagen-induced arthritis (CIA) mouse model using optical/optoacoustic tomographic imaging. Results: Small nanotheranostics with narrow size distribution and high colloidal stability were fabricated and displayed high ROS scavenging and enzymatic-like activity, as well as advanced efficacy in a converting pro-inflammatory macrophage phenotype into anti-inflammatory phenotype. When administrated into affected animals, these nanoparticles accumulated in inflamed joints and revealed a therapeutic effect similar to the gold-standard therapy for RA, methotrexate. Conclusions: The inflammation-targeting, inherent contrast and therapeutic activity of this new albumin-cerium oxide nanoparticle may make it a relevant agent for assessing severity in RA, and other inflammatory diseases, and controlling inflammation with image-guidance. The design of these nanotheranostics will enable potential clinical translation as systemic therapy for RA.

Stimuli-responsive polymeric nanomaterials for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a long-term inflammatory disease derived from an autoimmune disorder of the synovial membrane. Current therapeutic strategies for RA mainly aim to hamper the macrophages' proliferation and reduce the production of pro-inflammatory cytokines. Therefore, the accumulation of therapeutic agents targeted at the inflammatory site should be a crucial therapeutic strategy. Nowadays, the nanocarrier system incorporated with stimuli-responsive property is being intensively studied, showing the potentially tremendous value of specific therapy. Stimuli-responsive (i.e., pH, temperature, light, redox, and enzyme) polymeric nanomaterials, as an important component of nanoparticulate carriers, have been intensively developed for various diseases treatment. A survey of the literature suggests that the use of targeted nanocarriers to deliver therapeutic agents (nanotherapeutics) in the treatment of inflammatory arthritis remains largely unexplored. The lack of suitable stimuli-sensitive polymeric nanomaterials is one of the limitations. Herein, we provide an overview of drug delivery systems prepared from commonly used stimuli-sensitive polymeric nanomaterials and some inorganic agents that have potential in the treatment of RA. The current situation and challenges are also discussed to stimulate a novel thinking about the development of nanomedicine.

Magnetic nanoparticles: A new diagnostic and treatment platform for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory condition characterized by articular synovitis that eventually leads to the destruction of cartilage and bone in the joints with resulting pain and disability. The current therapies for RA are divided into 4 categories: non-steroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, nonbiological disease-modifying anti-rheumatic drugs (DMARDs), and biological DMARDs. Each drug grouping is beset with significant setbacks that not only include limited drug bioavailability and high clearance, but also varying degrees of drug toxicity to normal tissues. Recently, nanotechnology has provided a promising tool for the development of novel therapeutic and diagnostic systems in the area of malignant and inflammatory diseases. Among these, magnetic nanoparticles (MNPs) have provided an attractive carrier option for delivery of therapeutic agents. Armed with an extra magnetic probe, MNPs are capable of more accurately targeting the local lesion with avoidance of unpleasant systemic side effects. This review aims to provide an introduction to the applications of magnetic nanoparticles in RA, focusing on the latest advances, challenges, and opportunities for future development.

Targeted delivery of β-glucosidase-loaded magnetic nanoparticles: effect of external magnetic field duration and intensity

Aim: The effect of applied magnetic field duration and intensity on the delivery of β-glucosidase-loaded magnetic nanoparticles was evaluated. Materials & methods: The prepared β-glucosidase-loaded magnetic nanoparticles were targeted to subcutaneous tumors with an external magnetic field. Iron concentration and enzyme activity in tumor tissue were analyzed via electron spin resonance detection, Prussian blue staining and enzyme activity measurement. Results: The increase in magnetic nanoparticles quantity and enzyme activity in tumor tissue was not synchronous with the magnetic targeting duration. In addition, accumulation of magnetic nanoparticles and the increase in enzyme activity were not synchronous with the magnetic field intensity. Conclusion: The results suggested that appropriate magnetic field conditions should be considered for targeted delivery of bioactivity proteins based on magnetic nanoparticles.

Energy Conversion-Based Nanotherapy for Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) is characterized by synovial hyperplasia and cartilage/bone destruction, which results in a high disability rate on human health and a huge burden on social economy. At present, traditional therapies based on drug therapy still cannot cure RA, in accompany with the potential serious side effects. Based on the development of nanobiotechnology and nanomedicine, energy conversion-based nanotherapy has demonstrated distinctive potential and performance in RA treatment. This strategy employs specific nanoparticles with intrinsic physiochemical properties to target lesions with the following activation by diverse external stimuli, such as light, ultrasound, microwave, and radiation. These nanoagents subsequently produce therapeutic effects or release therapeutic factors to promote necrotic apoptosis of RA inflammatory cells, reduce the concentration of related inflammatory factors, relieve the symptoms of RA, which are expected to ultimately improve the life quality of RA patients. This review highlights and discusses the versatile biomedical applications of energy conversion-based nanotherapy in efficient RA treatment, in together with the deep clarification of the facing challenges and further prospects on the final clinical translations of these energy conversion-based nanotherapies against RA.

Trigger-responsive engineered-nanocarriers and image-guided theranostics for rheumatoid arthritis

Rheumatoid Arthritis (RA), one of the leading causes of disability due to progressive autoimmune destruction of synovial joints, affects ∼1% of the global population. Standard therapy helps in reducing inflammation and delaying the progression of RA but is limited by non-responsiveness on long-term use and several side-effects. The conventional nanocarriers (CNCs), to some extent, minimize toxicity associated with free drug administration while improving the therapeutic efficacy. However, the uncontrolled release of the encapsulated drug even at off-targeted organs limits the application of CNCs. To overcome these challenges, trigger-responsive engineered nanocarriers (ENCs) have been recently explored for RA treatment. Unlike CNCs, ENCs enable precise control over on-demand drug release due to endogenous triggers in arthritic paws like pH, enzyme level, oxidative stress, or exogenously applied triggers like near-infrared light, magnetic field, ultrasonic waves, etc. As the trigger is selectively applied to the inflamed joint, it potentially reduces toxicity at off-target locations. Moreover, ENCs have been strategically coupled with imaging probe(s) for simultaneous monitoring of ENCs inside the body and facilitate an 'image-guided-co-trigger' for site-specific action in arthritic paws. In this review, the progress made in recently emerging 'trigger-responsive' and 'image-guided theranostics' ENCs for RA treatment has been explored with emphasis on the design strategies, mechanism, current status, challenges, and translational perspectives.

Nanomedicine for the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that results in severe inflammatory microenvironments in the joint tissues. In clinics, disease-modifying antirheumatic drugs (DMARDs) are generally prescribed to patients with RA, but their long-term use often shows toxicity in some organs such as the gastrointestinal system, skin, and kidneys and immunosuppression-mediated infection. Nanomedicine has emerged as a new therapeutic strategy to efficiently localize the drugs in inflamed joints for the treatment of RA. In this Review, we introduce recent research in the area of nanomedicine for the treatment of RA and discuss how the nanomedicine can be used to deliver therapeutic agents to the inflamed joints and manage the progression of RA, particularly focusing on targeted delivery, controlled drug release, and immune modulation.

Modular Acid-Activatable Acetone-Based Ketal-Linked Nanomedicine by Dexamethasone Prodrugs for Enhanced Anti-Rheumatoid Arthritis with Low Side Effects

Given the physically encapsulated payloads with drug burst release and/or low drug loading, it is critical to initiate an innovative prodrug strategy to optimize the design of modular nanomedicines. Here, we designed modular pH-sensitive acetone-based ketal-linked prodrugs of dexamethasone (AKP-dexs) and formulated them as nanoparticles. We comprehensively studied the relationships between AKP-dex structure and properties, and we selected two types of AKP-dex-loaded nanoparticles for in vivo studies on the basis of their size, drug loading, and colloidal stability. In a collagen-induced arthritis rat model, these AKP-dex-loaded nanoparticles showed higher accumulation in inflamed joints and better therapeutic efficacy than free dexamethasone phosphate with less-severe side effects. AKP-dex-loaded nanoparticles may be useful for treating other inflammatory diseases and thus have great translational potential. Our findings represent an important step toward the development of practical applications for acetone-based ketal-linked prodrugs and are useful in the design of modular nanomedicines.

Recent Advances in Nanotheranostics for Treat-to-Target of Rheumatoid Arthritis

Early diagnosis, standardized treatment, and regular monitoring are the clinical treatment principle of rheumatoid arthritis (RA). The overarching principles and recommendations of treat-to-target (T2T) in RA advocate remission as the optimum aim, especially for patients with very early disease who are initiating therapy with anti-RA medications. However, traditional anti-RA drugs cannot selectively target the inflammatory areas and may cause serious side effects due to its short biological half-life and poor bioavailability. These limitations have significantly driven the research and application of nanomaterial-based drugs in theranostics of RA. Nanomedicines have appropriate sizes and easily modified surfaces which can enhance their biological compatibility and prolong circulation time of drug-loading systems in vivo. Traditional T2T regimens cannot evaluate the efficacy of drugs in real time, while clinical drug nanosizing can realize the integration of diagnosis and treatment of RA. This review bridges clinically proposed T2T concepts and nanomedicine in an integrated system for RA early-stage diagnosis and treatment. The most advanced progress in various nanodrug delivery systems for theranostics of RA is summarized, establishing a clear path and a new perspective for further optimization of T2T. Finally, the key facing challenges are discussed and prospects are addressed.