Targeted delivery of low-dose dexamethasone using PCL–PEG micelles for effective treatment of rheumatoid arthritis

Controlled Release of Drugs from Extracellular Matrix-Derived Peptide-Based Nanovesicles through Tailored Noncovalent Interactions

Elastin-collagen nanovesicles (ECnV) have emerged as a promising platform for drug delivery due to their tunable physicochemical properties and biocompatibility. The potential of nine distinct ECnVs to serve as drug-delivery vehicles was investigated in this study, and it was demonstrated that various small-molecule cargo (e.g., dexamethasone, methotrexate, doxorubicin) can be encapsulated in and released from a set of ECnVs, with extents of loading and rates of release dictated by the composition of the elastin domain of the ECnV and the type of cargo. Elastin-like peptides (ELPs) and collagen-like peptides (CLPs) of various compositions were produced; the secondary structure of the corresponding peptides was determined using CD, and the morphology and average hydrodynamic diameter (∼100 nm) of the ECnVs were determined using TEM and DLS. It was observed that hydrophobic drugs exhibited slower release kinetics than hydrophilic drugs, but higher drug loading was achieved for the more hydrophilic Dox. The collagen-binding ability of the ECnVs was demonstrated through a 2D collagen-binding assay, suggesting the potential for longer retention times in collagen-enriched tissues or matrices. Sustained release of drugs for up to 7 days was observed and, taken together with the collagen-binding data, demonstrates the potential of this set of ECnVs as a versatile drug delivery vehicle for longer-term drug release of a variety of cargo. This study provides important insights into the drug delivery potential of ECnVs and offers useful information for future development of ECnV-based drug delivery systems for the treatment of various diseases.

Coassembly Nanomedicine Mediated by Intermolecular Interactions Between Methotrexate and Baricitinib for Improved Rheumatoid Arthritis Treatment

The combination of anti-rheumatoid arthritis (RA) drugs methotrexate (MTX) and baricitinib (BTN) has been reported to improve RA treatment efficacy. However, study on the strategy of combination is elusive when considering the benefit of the synergy between MTX and BTN. In this study, we found that the N-heterocyclic rings in the MTX and BTN offer hydrogen bonds and π-π stacking interactions, driving the formation of exquisite vesicular morphology of nanovesicles, denoted as MB NVs. The MB NVs with the MTX/BTN weight ratio of 2:1, MB NVs (2:1), showed an improved anti-RA effect through the synergy between the anti-inflammatory and antiproliferative responses. This work presents that the intermolecular interactions between drug molecules could mediate the coassembly behavior into nanomedicine as well as the therapy synergy both in vitro and in vivo, which may provide further understanding on the rational design of combination nanomedicine for therapeutic purposes.

COVID-19 cooling: Nanostrategies targeting cytokine storm for controlling severe and critical symptoms

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to wreak havoc worldwide, the "Cytokine Storm" (CS, also known as the inflammatory storm) or Cytokine Release Syndrome has reemerged in the public consciousness. CS is a significant contributor to the deterioration of infected individuals. Therefore, CS control is of great significance for the treatment of critically ill patients and the reduction of mortality rates. With the occurrence of variants, concerns regarding the efficacy of vaccines and antiviral drugs with a broad spectrum have grown. We should make an effort to modernize treatment strategies to address the challenges posed by mutations. Thus, in addition to the requirement for additional clinical data to monitor the long-term effects of vaccines and broad-spectrum antiviral drugs, we can use CS as an entry point and therapeutic target to alleviate the severity of the disease in patients. To effectively combat the mutation, new technologies for neutralizing or controlling CS must be developed. In recent years, nanotechnology has been widely applied in the biomedical field, opening up a plethora of opportunities for CS. Here, we put forward the view of cytokine storm as a therapeutic target can be used to treat critically ill patients by expounding the relationship between coronavirus disease 2019 (COVID-19) and CS and the mechanisms associated with CS. We pay special attention to the representative strategies of nanomaterials in current neutral and CS research, as well as their potential chemical design and principles. We hope that the nanostrategies described in this review provide attractive treatment options for severe and critical COVID-19 caused by CS.

Theranostics: a multifaceted approach utilizing nano-biomaterials

Biomaterials play a vital role in targeting therapeutics. Over the years, several biomaterials have gained wide attention in the treatment and diagnosis of diseases. Scientists are trying to make more personalized treatments for different diseases, as well as discovering novel single agents that can be used for prognosis, medication administration, and keeping track of how a treatment works. Theranostics based on nano-biomaterials have higher sensitivity and specificity for disease management than conventional techniques. This review provides a concise overview of various biomaterials, including carbon-based materials like fullerenes, graphene, carbon nanotubes (CNTs), and carbon nanofibers, and their involvement in theranostics of different diseases. In addition, the involvement of imaging techniques for theranostics applications was overviewed. Theranostics is an emerging strategy that has great potential for enhancing the accuracy and efficacy of medicinal interventions. Despite the presence of obstacles such as disease heterogeneity, toxicity, reproducibility, uniformity, upscaling production, and regulatory hurdles, the field of medical research and development has great promise due to its ability to provide patients with personalised care, facilitate early identification, and enable focused treatment.

Visible light degradable micelles for intraocular corticosteroid delivery

Visible light responsive micellar drug delivery formulations are of notable interest for the treatment of ocular diseases, as their successful development would enable controlled drug release at the back of the eye, improving efficacy and reducing side-effects when compared to existing approaches. In this work, an aliphatic polycarbonate-based visible light responsive micelle formulation based on mPEG-b-poly(5-hydroxy-trimethylene carbonate) (PHTMC) was prepared wherein the pendant hydroxyl groups of the PHTMC repeating units were protected by blue light-labile [7-(diethylamino)coumarin-4-yl]methyl (DEACM). The photo-labile DEACM provided a photo-triggered release profile, as, upon the removal of these protecting groups by photo-irradiation, the micelles underwent structural disruption, leading to the release of the payload. The removal of DEACM also deprotected the pendant hydroxyl groups of PHTMC, leading to PHTMC backbone degradation via intramolecular cyclization.

Prodrug-based nanomedicines for rheumatoid arthritis

Most antirheumatic drugs with high toxicity exhibit a narrow therapeutic window due to their nonspecific distribution in the body, leading to undesirable side effects and reduced patient compliance. To in response to these challenges, prodrug-based nanoparticulate drug delivery systems (PNDDS), which combines prodrug strategy and nanotechnology into a single system, resulting their many advantages, including stability for prodrug structure, the higher drug loading capacity of the system, improving the target activity and bioavailability, and reducing their untoward effects. PNDDS have gained attention as a method for relieving arthralgia syndrome of rheumatoid arthritis in recent years. This article systematically reviews prodrug-based nanocarriers for rheumatism treatment, including Nano systems based on prodrug-encapsulated nanomedicines and conjugate-based nanomedicines. It provides a new direction for the clinical treatment of rheumatoid arthritis.

Therapeutic activity and biodistribution of a nano-sized polymer-dexamethasone conjugate intended for the targeted treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic inflammatory autoimmune disease caused by alteration of the immune system. Current therapies have several limitations and the use of nanomedicines represents a promising strategy to overcome them. By employing a mouse model of adjuvant induced arthritis, we aimed to evaluate the biodistribution and therapeutic effects of glucocorticoid dexamethasone conjugated to a nanocarrier based on biocompatible N-(2-hydroxypropyl) methacrylamide copolymers. We observed an increased accumulation of dexamethasone polymer nanomedicines in the arthritic mouse paw using non-invasive fluorescent in vivo imaging and confirmed it by the analysis of tissue homogenates. The dexamethasone conjugate exhibited a dose-dependent healing effect on arthritis and an improved therapeutic outcome compared to free dexamethasone. Particularly, significant reduction of accumulation of RA mediator RANKL was observed. Overall, our data suggest that the conjugation of dexamethasone to a polymer nanocarrier by means of stimuli-sensitive spacer is suitable strategy for improving rheumatoid arthritis therapy.

Plant-Based Approaches for Rheumatoid Arthritis Regulation: Mechanistic Insights on Pathogenesis, Molecular Pathways, and Delivery Systems

Rheumatoid arthritis (RA) is classified as a chronic inflammatory autoimmune disorder, associated with a varied range of immunological changes, synovial hyperplasia, cartilage destructions, as well as bone erosion. The infiltration of immune-modulatory cells and excessive release of proinflammatory chemokines, cytokines, and growth factors into the inflamed regions are key molecules involved in the progression of RA. Even though many conventional drugs are suggested by a medical practitioner such as DMARDs, NSAIDs, glucocorticoids, etc., to treat RA, but have allied with various side effects. Thus, alternative therapeutics in the form of herbal therapy or phytomedicine has been increasingly explored for this inflammatory disorder of joints. Herbal interventions contribute substantial therapeutic benefits including accessibility, less or no toxicity and affordability. But the major challenge with these natural actives is the need of a tailored approach for treating inflamed tissues by delivering these bioactive agentsat an appropriate dose within the treatment regimen for an extended periodof time. Drug incorporated with wide range of delivery systems such as liposomes, nanoparticles, polymeric micelles, and other nano-vehicles have been developed to achieve this goal. Thus, inclinations of modern treatment are persuaded on the way to herbal therapy or phytomedicines in combination with novel carriers is an alternative approach with less adverse effects. The present review further summarizes the significanceof use of phytocompounds, their target molecules/pathways and, toxicity and challenges associated with phytomolecule-based nanoformulations.

Tea polyphenol carrier-enhanced dexamethasone nanomedicines for inflammation-targeted treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by synovial inflammation, cartilage damage and bone erosion. In the progression of RA, the inflammatory mediators including ROS, NO, TNF-α, and IL-6 play important roles in the aggravation of inflammation. Hence, reducing the generation and release of inflammatory mediators is of great importance. However, the high dose and frequent administration of clinical anti-inflammatory drugs such as glucocorticoids (GCs) usually lead to severe side effects. The development of nanotechnology provides a promising strategy to overcome these issues. Here, polyphenol-based nanoparticles with inherent anti-oxidative and anti-inflammatory activities were developed and used as a kind of nanocarrier to deliver dexamethasone (Dex). The in vitro experiments confirmed that the nanoparticles and drugs could act synergistically for suppressing inflammatory mediators in the LPS/INF-γ-induced inflammatory cell model. After intravenous administration, the Dex-loaded nanoparticles with good biosafety showed effective accumulation in inflamed joints and improved therapeutic efficacy by inducing anesis of synovial inflammation and cartilage destruction over free Dex in a collagen-induced arthritis (CIA) mouse model. The results demonstrated that polyphenol-based nanoparticles with therapeutic functions may serve as an innovative platform to synergize with chemotherapeutic agents for enhanced treatment of inflammatory diseases.

Glucocorticoid Nanoparticles Show Full Therapeutic Efficacy in a Mouse Model of Acute Lung Injury and Concomitantly Reduce Adverse Effects

Glucocorticoids (GCs) are widely used to treat inflammatory disorders such as acute lung injury (ALI). Here, we explored inorganic-organic hybrid nanoparticles (IOH-NPs) as a new delivery vehicle for GCs in a mouse model of ALI. Betamethasone (BMZ) encapsulated into IOH-NPs (BNPs) ameliorated the massive infiltration of neutrophils into the airways with a similar efficacy as the free drug. This was accompanied by a potent inhibition of pulmonary gene expression and secretion of pro-inflammatory mediators, whereas the alveolar-capillary barrier integrity was only restored by BMZ in its traditional form. Experiments with genetically engineered mice identified myeloid cells and alveolar type II (AT II) cells as essential targets of BNPs in ALI therapy, confirming their high cell-type specificity. Consequently, adverse effects were reduced when using IOH-NPs for GC delivery. BNPs did not alter T and B cell numbers in the blood and also prevented the induction of muscle atrophy after three days of treatment. Collectively, our data suggest that IOH-NPs target GCs to myeloid and AT II cells, resulting in full therapeutic efficacy in the treatment of ALI while being associated with reduced adverse effects.

Highly Efficient Oral Iguratimod/Polyvinyl Alcohol Nanodrugs Fabricated by High-Gravity Nanoprecipitation Technique for Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA), a systemic autoimmune disease, poses a significant human health threat. Iguratimod (IGUR), a novel disease-modifying antirheumatic drug (DMARD), has attracted great attention for RA treatment. Due to IGUR's hydrophobic nature, there's a pressing need for effective pharmaceutical formulations to enhance bioavailability and therapeutic efficacy. The high-gravity nanoprecipitation technique (HGNPT) emerges as a promising approach for formulating poorly water-soluble drugs. In this study, IGUR nanodrugs (NanoIGUR) are synthesized using HGNPT, with a focus on optimizing various operational parameters. The outcomes revealed that HGNPT enabled the continuous production of NanoIGUR with smaller sizes (ranging from 300 to 1000 nm), more uniform shapes, and reduced crystallinity. In vitro drug release tests demonstrated improved dissolution rates with decreasing particle size and crystallinity. Notably, in vitro and in vivo investigations showcased NanoIGUR's efficacy in inhibiting synovial fibroblast proliferation, migration, and invasion, as well as reducing inflammation in collagen-induced arthritis. This study introduces a promising strategy to enhance and broaden the application of poorly water-soluble drugs.

Solvent exchange-motivated and tunable in situ forming implants sustaining triamcinolone acetonide release for arthritis treatment

Arthritis is a syndrome characterized by inflammation in the joints. Triamcinolone acetonide (TA) was used as an anti-inflammatory agent in the treatment of this disease. However, there are limitations to its clinical application, including rapid clearance from the joint cavity, potential joint damage from multiple injections, and adverse joint events. To address these drawbacks, we developed a tunable in situ forming implant loaded with TA. This injectable polymer solution utilized poly (lactic-co-glycolic acid) (PLGA) as an extended-release material. When injected into the joints, the solution solidifies into implants through a solvent exchange in the aqueous environment. The implants demonstrated robust retention at the injection site and released TA over several weeks even months through diffusion and erosion. By adding different proportions of low water-miscible plasticizers, the release period of the drug could be precisely adjusted. The plasticizers-optimized implants exhibited a tough texture, enhancing the therapeutic efficiency and drug safety in vivo. In arthritic model studies, the tunable TA-loaded implants significantly reduced swelling, pain, and motor discoordination, and also showed suppression of arthritis progression to some extent. These findings suggested that TA-loaded ISFI holds promise for managing inflammatory disorders in individuals with arthritis.

Enhanced Anti-Rheumatoid Arthritis Activity of Total Alkaloids from Picrasma Quassioides in Collagen-Induced Arthritis Rats by a Targeted Drug Delivery System

New drug delivery systems have rarely been used in the formulation of traditional Chinese medicine, especially those that are crude active Chinese medicinal ingredients. In the present study, hyaluronic acid decorated lipid-polymer hybrid nanoparticles were used to prepare a targeted drug delivery system (TDDS) for total alkaloid extract from Picrasma quassioides (TAPQ) to improve its targeting property and anti-inflammatory activity. Picrasma quassioides, a common-used traditional Chinese medicine (TCM), containing a series of hydrophobic total alkaloids including β-carboline and canthin-6-one alkaloids show great anti-inflammatory activity. However, its high toxicity (IC50= 8.088±0.903 μg/ml), poor water solubility (need to dissolve with 0.8% Tween-80) and poor targeting property severely limits its clinical application. Herein, hyaluronic acid (HA) decorated lipid-polymer hybrid nanoparticles loaded with TAPQ (TAPQ-NPs) were designed to overcome above mentioned deficiencies. TAPQ-NPs have good water solubility, strong anti-inflammatory activity and great joint targeting property. The in vitro anti-inflammatory activity assay showed that the efficacy of TAPQ-NPs was significantly higher than TAPQ(P<0.001). Animal experiments showed that the nanoparticles had good joint targeting property and had strong inhibitory activity against collagen-induced arthritis (CIA). These results indicate that the application of this novel targeted drug delivery system in the formulation of traditional Chinese medicine is feasible.

Direct Quantification of Serum Protein Interactions with PEGylated Micelle Nanocarriers

A large repertoire of nanocarrier (NC) technologies exists, each with highly specified advantages in terms of targetability, stability, and immunological inertness. The characterization of such NC properties within physiological conditions is essential for the development of optimized drug delivery systems. One method that is well established for reducing premature elimination by avoiding protein adsorption on NCs is surface functionalization with poly(ethylene glycol) (PEG), aptly called PEGylation. However, recent studies revealed that some PEGylated NCs have a delayed immune response, indicating the occurrence of protein-NC interactions. Obvious protein-NC interactions, especially in micellar systems, may have been overlooked as many early studies relied on techniques less sensitive to molecular level interactions. More sensitive techniques have been developed, but a major challenge is the direct measurement of interactions, which must be done in situ, as micelle assemblies are dynamic. Here, we report the use of pulsed-interleaved excitation fluorescence cross-correlation spectroscopy (PIE-FCCS) to interrogate the interactions between two PEG-based micelle models and serum albumin protein to compare protein adsorption differences based on linear or cyclic PEG architectures. First, by measuring micelle diffusion in isolated and mixed solutions, we confirmed the thermal stability of diblock and triblock copolymer micelle assemblies. Further, we measured the co-diffusion of micelles and serum proteins, the magnitudes of which increased with concentration and continued incubation. The results demonstrate that PIE-FCCS is capable of measuring direct interactions between fluorescently labeled NC and serum proteins, even at concentrations 500 times lower than those observed physiologically. This capability showcases the potential utility of PIE-FCCS in the characterization of drug delivery systems in biomimetic conditions.

Nanomedicines: intervention in inflammatory pathways of cancer

Inflammation is a complex defense process that maintains tissue homeostasis. However, this complex cascade, if lasts long, may contribute to pathogenesis of several diseases. Chronic inflammation has been exhaustively studied in the last few decades, for its contribution in development and progression of cancer. The intrinsic limitations of conventional anti-inflammatory and anti-cancer therapies triggered the development of nanomedicines for more effective and safer therapies. Targeting inflammation and tumor cells by nanoparticles, encapsulated with active therapeutic agents, offers a promising outcome with patient survival. Considerable technological success has been achieved in this field through exploitation of tumor microenvironment, and recognition of molecules overexpressed on endothelial cells or macrophages, through enhanced vascular permeability, or by rendering biomimetic approach to nanoparticles. This review focusses on the inflammatory pathways in progression of a tumor, and advancement in nanotechnologies targeting these pathways. We also aim to identify the gaps that hinder the successful clinical translation of nanotherapeutics with further clinical studies that will allow oncologist to precisely identify the patients who may be benefited from nanotherapy at time when promotion or progression of tumor initiates. It is postulated that the nanomedicines, in near future, will shift the paradigm of cancer treatment and improve patient survival.

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.

Development of triamcinolone acetonide-hyaluronic acid conjugates with selective targeting and less osteoporosis effect for rheumatoid arthritis treatments

Rheumatoid arthritis (RA) is a common systemic autoimmune disease in developed countries. In clinical treatment, steroids have been used as bridging and adjunctive therapy after disease-modifying anti-rheumatic drug administration. However, the severe side effects caused by the nonspecific targeting of organs followed by long-term administration have limited their usage in RA. In this study, poorly water-soluble triamcinolone acetonide (TA), a highly potent corticosteroid for intra-articular injection, is conjugated on hyaluronic acid (HA) for intravenous purposes with increased specific drug accumulation in inflamed parts for RA. Our results demonstrate that the designed HA/TA coupling reaction reveals >98 % conjugation efficiency in the dimethyl sulfoxide/water system, and the resulting HA-TA conjugates show lower osteoblastic apoptosis compared with that in free TA-treated osteoblast-like NIH3T3 cells. Furthermore, in a collagen-antibody-induced arthritis animal study, HA-TA conjugates enhanced the initiative targeting ability to inflame tissue and reduce the histopathological arthritic changes (score = 0). Additionally, the level of bone formation marker P1NP in HA-TA-treated ovariectomized mice (303.6 ± 40.6 pg/mL) is significantly higher than that in the free TA-treated group (143.1 ± 3.9 pg/mL), indicating the potential for osteoporotic reduction using an efficient HA conjugation strategy for the long-term administration of steroids against RA.

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.

pH-sensitive nano-polyelectrolyte complexes with arthritic macrophage-targeting delivery of triptolide

Since pro-inflammatory macrophages take on a critical significance in the pathophysiology of rheumatoid arthritis (RA), the therapeutics to affect macrophages may receive distinct anti-RA effects. However, the therapeutic outcomes are still significantly impeded, which is primarily due to the insufficient drug delivery at the arthritic site. In this study, the macrophage-targeting and pH stimuli-responsive nano-polyelectrolyte complexes were designed for the efficient targeted delivery of triptolide (TP/PNPs) on the arthritic site. The anionic and cationic amphiphilic copolymers, i.e., hyaluronic acid-g-vitamin E succinate (HA-VE) and the quaternized poly (β-amino ester) (QPBAE-C₁₈), were prepared and then characterized. The result indicated that TP/PNPs with the uniform particle size of ∼ 175 nm exhibited the high drug loading capacity and storage stability based on the polymeric charge interaction, in which DLC and DEE of TP/PNPs were obtained as 11.27 ± 0.44 % and 95.23 ± 2.34 %, respectively. Mediated by the "ELVIS" effect of NPs, CD44 receptor-mediated macrophage targeting, and pH-sensitive endo/lysosomal escape under the "proton sponge" effect, TP/PNPs exhibited the enhanced cellular internalization and cytotoxicity while mitigating the inflammation of LPS-activated RAW 264.7 cells. Even after 96-hour after administration, PNPs were preferentially accumulated in the inflammatory joints in a long term. It is noteworthy that after treatment for 14 days with 100 μg/kg of TP, TP/PNPs significantly facilitated arthritic symptom remission, protected cartilage, and mitigated inflammation of antigen-induced arthritis (AIA) rats, whereas the systematic side-effects of TP were reduced. In this study, an effective drug delivery strategy was proposed for the treatment of RA.

Exploring the role of exosomes in rheumatoid arthritis

In prosperous countries, autoimmune illnesses affect minimum 7% of the community. Rheumatoid Arthritis (RA) as an autoimmune illness is thought to be induced through a variety of genomic, physiological, and biological factors. Many experts in the field of nanomedicine have looked to stem cells as a viable strategy to repair human tissue; however, exosomes have demonstrated greater potential in recent years. Exosomes, produced from stem cells in particular, have exhibited a high propensity to give therapeutic effects. To resist local cellular stress, they are secreted in a paracrine manner from cells. As a result, exosomes produced from stem cells can provide enormous health uses. If treatment is not given, autoantibodies produce synovial inflammation and arthritis, which can lead to chronic inflammation, and impairment. Exosomes could be administered for the treatment of RA, by acting as therapeutic vectors. Exosomes are murine extracellular vesicles that influence biological mechanisms and signal transduction by transporting genetic and protein components. Diseases like RA and bone fractures could be treated using cell-free therapeutic strategies if exosomes could be isolated from stem cells efficiently and packaged with specific restorative substances. To get to this position, many breakthroughs must be achieved, and the following review summarises the most recent developments in stem cell-derived exosomes, with a focus on the important literature on exosome dynamics in RA.

H2O2/NIR-sensitive "two-step" nano theranostic system based hollow mesoporous copper sulfide/hyaluronic acid/JWH133 as an optimally designed delivery system for multidimensional treatment of RA

Cannabinoid receptors are widely distributed in many cells in Rheumatoid arthritis RA and strengthening factor to boost the development of RA diseases. Here, the hollow mesoporous copper sulfide (CuS) was used as the carrier skeleton and the cannabinoid type 2 (CB2) receptor agonist JWH133 was efficiently loaded inside of CuS through adsorption, then the outer layer was modified with hyaluronic acid (HA) to prevent the leakage of internal drugs. After the CuS-JWH133@HA nano carrier reached the target area, HA responsive cracked under RA microenvironment to realize the first step of accurate drug delivery of JWH133, and the thermally responsive CuS under near-infrared (NIR) promoted the release of internal drugs. Then, JWH133 specifically combined CB2 receptors on the surface of macrophage, synovial cells and osteoblasts to realize the second step of drug delivery. The inflammatory factors secreted by cells are significantly inhibited, and the activity of osteoblasts was significantly enhanced. Therapeutic effect by CuS-JWH133@HA of RA was well verified by decreasing levels of inflammation in vivo and improvement of inflamed and swollen joints of mice. The CuS-JWH133@HA nanocomposite showed satisfactory multidimensional therapeutic effect of RA in vitro and in vivo, which provided a novel idea for RA treatment.

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.

Flexible nano-liposomes-based transdermal hydrogel for targeted delivery of dexamethasone for rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is an inflammatory immune-mediated disease that can lead to synovitis, cartilage destruction, and even joint damage. Dexamethasone (DEX) is a commonly used agent for RA therapy on inflammation manage. However, the traditional administering DEX is hampered by low efficiency and obvious adverse effects. Therefore, in order to efficiently deliver DEX to RA inflamed joints and overcome existing deficiencies, we developed transdermal formation dextran sulfate (DS) modified DEX-loaded flexible liposome hydrogel (DS-FLs/DEX hydrogel), validated their transdermal efficiency, evaluated its ability to target activated macrophages, and its anti-inflammatory effect. The DS-FLs/DEX exhibited excellent biocompatibility, sustainable drug release, and high uptake by lipopolysaccharide (LPS)-activated macrophages. Furthermore, the DS-FLs/DEX hydrogel showed desired skin permeation as compared with regular liposome hydrogel (DS-RLs/DEX hydrogel) due to its good deformability. In vivo, when used the AIA rats as RA model, the DS-FLs/DEX hydrogel can effectively penetrate and accumulate in inflamed joints, significantly improve joint swelling in RA rats, and reduce the destructive effect of RA on bone. Importantly, the expression of inflammatory cytokines in joints was inhibited and the system toxicity did not activate under DS-FLs/DEX hydrogel treatment. Overall, these data revealed that the dextran sulfate (DS) modified DEX-loaded flexible liposome hydrogel (DS-FLs/DEX hydrogel) can prove to be an excellent drug delivery vehicle against RA.

Caffeic Acid Modified Nanomicelles Inhibit Articular Cartilage Deterioration and Reduce Disease Severity in Experimental Inflammatory Arthritis

Inflammation plays an important role in the development of rheumatoid arthritis (RA). NR4A1 is an anti-inflammatory orphan nuclear receptor involved in protection from inflammatory stimuli in RA. In this study we have explored the anti-inflammatory potential of the FDA-approved drug 9-aminoacridine (9AA) and the natural compound caffeic acid (CA) conjugated to nanomicelles for the treatment of RA. We have synthesized methoxy polyethylene glycol polycaprolactone block copolymer (mPEG-b-PCL) by ring opening polymerization of ε-caprolactone. Then, we conjugated the hydrophilic caffeic acid (CA) with mPEG-b-PCL micelles via Steglich esterification and incorporated the 9AA drug. These nanomicelles were formulated by the solvent evaporation method with a size distribution around 190 nm and showed maximum drug loading capacity along with sustained drug release behavior. Furthermore, we tested the therapeutic potential of the formulated 9AA-encapsulated CA-conjugated nanomicelles (9AA-NMs) against an experimental RA model. We observed promising results which showed alleviation of arthritic symptoms by reducing inflammation, joint damage, bone erosion, and swelling. Further, collagen destruction was significantly reduced in articular cartilage, as shown by safranin-O and toluidine blue staining. The protective mechanism might be due to the simultaneous inhibition of NF-κB by 9AA and CA, whereas the activation of NR4A1 by 9AA leads to the suppression of HIF-1α. This combined therapeutic effect of 9AA and CA has enhanced the therapeutic efficacy of 9AA-NM and markedly reduced the severity of inflammatory arthritis. Unlike existing drugs for pain management and with limited efficacy, 9AA-NM exerted a disease-relevant activation/blockade that alleviated inflammation and exhibited marked therapeutic efficacy against RA.

Production of paclitaxel-loaded PEG-b-PLA micelles using PEG for drug loading and freeze-drying

A new approach named PEG-assist is introduced for the production of drug-loaded polymeric micelles. The method is based on the use of PEG as the non-selective solvent for PEG-b-PLA in the fabrication procedure. Both hydration temperature and PEG molecular weight are shown to have a significant effect on the encapsulation efficiency of PTX in PEG_4kDa-b-PLA_2kDa micelles. The optimal procedure for fabrication includes the use of PEG_1kDa as the solvent at 60 °C, cooling the mixture to 40 °C, hydration at 40 °C, freezing at -80 °C and freeze-drying at -35 °C, 15 Pa. No significant difference (p > 0.05) in PTX encapsulation, average particle size and polydispersity index is observed between the samples before freeze-drying and after reconstitution of the freeze-dried cake. The prepared PTX formulations are stable at room temperature for at least 8 h. Scaling the batch size to 25× leads to no significant change (p > 0.05) in PTX encapsulation, average particle size and polydispersity index. PEG-assist method is applicable to other drugs such as 17-AAG, and copolymers of varied molecular weights. The use of no organic solvent, simplicity, cost-effectiveness, and efficiency makes PEG-assist a very promising approach for large scale production of drug-loaded polymeric micelles.

Recent advances in nanoparticle-based drug delivery systems for rheumatoid arthritis treatment

Nanotechnology has increasingly emerged as a promising tool for exploring new approaches, from treating complex conditions to early detection of the onset of multiple disease states. Tailored designer nanoparticles can now more comprehensively interact with their cellular targets and various pathogens due to a similar size range and tunable surface properties. The basic goal of drug delivery is to employ pharmaceuticals only where they are needed, with as few adverse effects and off-target consequences as possible. Rheumatoid arthritis (RA) is a chronic inflammatory illness that leads to progressive loss of bone and cartilage, resulting in acute impairment, decreased life expectancy, and increased death rates. Recent advancements in treatment have significantly slowed the progression of the disease and improved the lives of many RA sufferers. Some patients, on the other hand, attain or maintain illness remission without needing to continue immunosuppressive therapy. Furthermore, a large percentage of patients do not respond to current treatments or acquire tolerance to them. As a result, novel medication options for RA therapy are still needed. Nanocarriers, unlike standard medications, are fabricated to transport drugs directly to the location of joint inflammation, evading systemic and negative effects. As a result, researchers are reconsidering medicines that were previously thought to be too hazardous for systemic delivery. This article gives an overview of contemporary nanotechnology-based tactics for treating rheumatoid arthritis, as well as how the nanotherapeutic regimen could be enhanced in the future.

Inflammation-homing "living drug depot" for efficient arthritis treatment

Delivering therapeutic agents efficiently to inflamed joints remains an intractable problem in rheumatoid arthritis (RA) treatment due to the complicated physiological barriers. Circulating monocytes could selectively migrate to inflamed sites and differentiate into resident macrophages to aggravate RA. Therefore, a drug carrier that can be specifically internalized by circulating monocytes and switch monocytes into anti-inflammatory phenotype when reaching inflamed sites, might bypass the in vivo physiological barriers and achieve efficient RA therapy. Herein, we design a dextran sulfate (DS) functionalized nanoparticle (ZDNP) to selectively deliver anti-inflammatory agent dexamethasone (Dex) to circulating monocytes via the scavenger receptors on monocytes. Monocytes engulfing drug-loaded ZDNP could subsequently home to arthritic joints and act as a "living drug depot" to combat RA. Results revealed that ZDNP could be preferentially internalized by circulating monocytes when intravenously administrated in vivo. In a rat arthritic model, we found that circulating monocytes remarkably facilitated drug distribution and retention in inflamed joints. Moreover, monocytes engulfing drug-loaded nanoparticles exhibited favorable anti-inflammatory ability and M2-biased differentiation. Our work offers a facile approach to achieve site-directed anti-inflammatory therapy by taking advantage of the inflammation-homing ability of circulating monocytes. STATEMENT OF SIGNIFICANCE: Circulating monocytes can migrate to inflamed sites and then differentiate into macrophages to aggravate arthritis. Therefore, a drug carrier that can be specifically internalized by circulating monocytes and switch monocytes into anti-inflammatory phenotype when reaching inflamed sites may achieve efficient arthritis therapy. Here, we designed a monocyte-targeting nanoparticle (ZDNP) to selectively deliver anti-inflammatory Dex to circulating monocytes. When injected intravenously, ZDNP was effectively internalized by circulating monocytes via a scavenger receptor and subsequently was transported to arthritic joints, where monocytes engulfing the drug-loaded nanoparticles could switch to an anti-inflammatory phenotype to inhibit arthritis progress. We provide detailed evidence about the in vivo fate of ZDNP and unravel how monocytes act as a "living drug depot" to achieve site-directed arthritis therapy.

Simultaneous Release of Aflibercept and Dexamethasone from an Ocular Drug Delivery System

PURPOSE

Intravitreal injections of anti-vascular endothelial growth factors (anti-VEGF) are the current standard of care for patients with choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). There is a growing subset of patients that does not respond to anti-VEGF monotherapy treatment. Some patients, however, do respond to combination therapy of corticosteroids and anti-VEGF. This treatment requires monthly/bimonthly injections of anti-VEGF and semi-annual injections of corticosteroid. A drug delivery system (DDS) that simultaneously releases multiple drugs could benefit these patients by reducing the number of injections. The purpose of this study was to characterize the simultaneous release of aflibercept and dexamethasone from a biodegradable microparticle- and nanoparticle-hydrogel DDS.

METHODS

Dexamethasone-loaded nanoparticles and aflibercept-loaded microparticles were created using modified single- and double-emulsion techniques, respectively. Then, microparticles and nanoparticles were embedded into a thermoresponsive, biodegradable poly(ethylene glycol)-co-(L-lactic acid) diacrylate (PEG-PLLA-DA)-N-isopropylacrylamide (NIPAAm) hydrogel DDS. Drug release studies and characterization of DDS were conducted with varying doses of microparticles and nanoparticles.

RESULTS

The combination aflibercept-loaded microparticle- and dexamethasone-loaded nanoparticle- hydrogel (Combo-DDS) achieved a total release time of 224 days. Small decreases were seen in swelling ratio and equilibrium water content for Combo-DDS compared to monotherapy aflibercept-loaded microparticle-hydrogel DDS (AFL-DDS) and monotherapy dexamethasone-loaded nanoparticle-hydrogel DDS (DEX-DDS). Bioactivity of aflibercept was maintained in Combo-DDS compared to AFL-DDS.

CONCLUSIONS

The Combo-DDS was able to extend and control the release of both aflibercept and dexamethasone simultaneously from a single DDS. This may eliminate the need for separate dosing regiments of anti-VEGF and corticosteroids for wet AMD patients.

Immunomodulatory strategies for bone regeneration: A review from the perspective of disease types

Tissue engineering strategies for treating bone loss to date have largely focused on targeting stem cells or vascularization. Immune cells, including macrophages and T cells, can also indirectly enhance bone healing via cytokine secretion to interact with other bone niche cells. Bone niche cues and local immune environment vary depending on anatomical location, size of defects and disease types. As such, it is critical to evaluate the role of the immune system in the context of specific bone niche and different disease types. This review focuses on immunomodulation research for bone applications using biomaterials and cell-based strategies, with a unique perspective from different disease types. We first reviewed applications for prolonging orthopaedic implant lifetime and enhancing fracture healing, two clinical challenges where immunomodulatory strategies were initially developed for orthopedic applications. We then reviewed recent research progress in harnessing immunomodulatory strategies for regenerating critical-sized, long bone or cranial bone defects, and treating osteolytic bone diseases. Remaining gaps in knowledge, future directions and opportunities were also discussed.

Inflammation-targeted sialic acid-dexamethasone conjugates for reducing the side effects of glucocorticoids

As a potent glucocorticoid drug (GCs), Dexamethasone (Dex) is widely used clinically for the treatment of inflammatory diseases. However, such side effects as Cushing's syndrome and osteoporosis caused severe distress to patients. Herein, a sialic acid (SA)-modified dexamethasone conjugate (Dex-SA) was synthesized successfully to reduce side effects by targeting inflammatory diseases. The solubility of Dex-SA in water reached 58 times that of Dex, which meets the need for intravenous administration. The excellent stability of Dex-SA in plasma also laid a foundation for targeting disease sites. According to cellular uptake and biodistribution experiments, Dex-SA was more readily to be taken up by inflammatory cells and accumulated in diseased kidneys compared to Dex, which is attributed to the interaction of SA with E-selectin receptors overexpressed on the surface of inflammatory vascular endothelial cells. Besides, the pharmacodynamics studies of acute kidney injury showed that Dex-SA and Dex could produce comparable therapeutic effects. More importantly, Dex-SA was found to significantly reduce Dex-related side effects, as measured by blood glucose, red blood cells and immune cells, etc. At last, molecular docking results were obtained to confirm that Dex-SA could enter the cells by binding specifically with the E-selectin receptor, for combination with glucocorticoid receptors in the cytoplasm to exert pharmacological effects. Our study is expected to contribute a new strategy to the safe and effective targeting treatment of inflammatory diseases.

Polymer nanotherapeutics: A versatile platform for effective rheumatoid arthritis therapy

Rheumatoid arthritis is an aggressive and severely debilitating disorder that is characterized by joint pain and cartilage damage. It restricts mobility in patients, leaving them unable to carry out simple tasks. RA presents itself with severe lasting pain, swelling and stiffness in the joints and may cause permanent disability in patients. Treatment regimens currently employed for rheumatoid arthritis revolve around keeping clinical symptoms like joint pain, inflammation, swelling and stiffness at bay. The current therapeutic interventions in rheumatoid arthritis involve the use of non-steroidal anti-inflammatory drugs, glucocorticoids, disease-modifying anti-rheumatic drugs and newer biological drugs that are engineered for inhibiting the expression of pro-inflammatory mediators. These conventional drugs are plagued with severe adverse effects because of their higher systemic distribution, lack of specificity and higher doses. Oral, intra-articular, and intravenous routes are routinely used for drug delivery which is associated with decreased patient compliance, high cost, poor bioavailability and rapid systemic clearance. All these drawbacks have enticed researchers to create novel strategies for drug delivery, the main approach being nanocarrier-based systems. In this article, we aim to consolidate the remarkable contributions of polymeric carrier systems including microneedle technology and smart trigger-responsive polymeric carriers in the management of rheumatoid arthritis along with its detailed pathophysiology. This review also briefly describes the safety and regulatory aspects of polymer therapeutics.

Folic acid-conjugated magnetic triblock copolymer nanoparticles for dual targeted delivery of 5-fluorouracil to colon cancer cells

Background

In the current study, folic acid-conjugated PEG-PCL-PEG triblock copolymer were synthesized and loaded with 5-fluorouracil and magnetite nanoparticles (5-FU-SPION-PEG-PCL-PEG-FA) for targeted delivery of drug to HT29 human colon cancer cells and CT26 mouse colon cancer model. The nanoparticles were synthesized and characterized by nuclear magnetic resonance spectroscopy (NMR) and transmission electron microscopy (TEM). The cellular uptake of nanoparticles was assessed in vitro (on HUVEC and HT29) and in vivo (on CT26 colon tumor tissues). The cytotoxic effect of nanoparticles was assessed on human colon cell lines (HT29, Caco-2, HTC116, and SW480) and normal HUVEC cells. In addition, antitumor effects of nanoparticles were investigated based on tumor volume, survival time and protein expression of Bax and Bcl-2 on CT26 tumor-bearing BALB/c mice.

Results

Characterization of nanoparticles showed 5-FU-SPION-PEG-PCL-PEG-FA (5-FU-NPs-FA) nanoparticles had spherical shape with hydrodynamic diameter of 85 nm. The drug-release profile exhibited sustained pH-responsive release with cumulative release reaching approximately 23% after 24 h. Cellular uptake studies revealed that HT29 cancer cells absorb higher amount of 5-FU-NPs-FA as compared to HUVEC normal cells (P < 0.05). In addition, 5-FU-NPs-FA was found to be more antitumor efficient in comparison to free 5-FU based on Bax/Bcl2 ratio, survival rate of tumoral mouse and inhibitory tumor volume (P < 0.05).

Conclusions

The results suggested that 5-FU-NPs-FA could be considered as promising sustained drug delivery platform for in vitro and in vivo conditions, which may provide selective treatment of tumor cancer cells.

Graphical Abstarct

Targeted co-delivery biomimetic nanoparticles reverse macrophage polarization for enhanced rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease, which is characterized by synovial inflammation and autoimmunity. The main cause of the disease is the imbalance of the proportion of pro-inflammatory macrophages (M1-type) and anti-inflammatory macrophages (M2-type) in the synovial tissues of the joint. To restore this balance, in our study, the interleukin-10 encoding anti-inflammatory cytokines (IL-10 pDNA) and chemotherapeutic drug dexamethasone sodium phosphate (DSP) were co-loaded into human serum albumin (HSA) preparing pDNA/DSP-NPs to actively target macrophages in synovium tissue to promote M1-M2 polarization. Confocal laser scanning microscope and western blot were used to demonstrate the targeting ability of co-delivery nanoparticles. In vivo, the real-time fluorescence imaging system and HPLC were used to study the tissue distribution and pharmacokinetics of nanoparticles, and the results showed that the accumulation of nanoparticles in the inflammatory joint site was higher. Its pharmacodynamics were evaluated in collagen-induced arthritis (CIA) rat model, and it demonstrated that the pDNA/DSP-NPs significantly reduced the expression of serum inflammatory factors and alleviated joint swelling and bone erosion, suggesting the favorable therapeutic effect. The synergistic treatment effect of IL-10 pDNA and DSP in this system was achieved by reducing the secretion of pro-inflammatory factors (TNF-α, IL-1β) and increasing the expression of anti-inflammatory factors (IL-10) to promote the M1-M2 polarization of macrophages. Our strategy is promising for co-delivery of gene drugs and chemical drugs by biomimetic natural materials to promote macrophages polarization so that to achieve synergically treatment of inflammatory disease.

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.

Delivery of germacrone (GER) using macrophages-targeted polymeric nanoparticles and its application in rheumatoid arthritis

Macrophages can transform into M1 (pro-inflammatory) and M2 (anti-inflammatory) phenotypes, which mediate the immune/inflammatory response in rheumatoid arthritis (RA). Activated M1 phenotype macrophages and overexpression of folate (FA) receptors are abundant in inflammatory synovium and joints and promote the progression of RA. Germacrone (GER) can regulate the T helper 1 cell (Th1)/the T helper 2 cell (Th2) balance to delay the progression of arthritis. To deliver GER to inflammatory tissue cells to reverse M1-type proinflammatory cells and reduce inflammation, FA receptor-targeting nanocarriers loaded with GER were developed. In activated macrophages, FA-NPs/DiD showed significantly higher uptake efficiency than NPs/DiD. In vitro experiments confirmed that FA-NPs/GER could promote the transformation of M1 macrophages into M2 macrophages. In adjuvant-induced arthritis (AIA) rats, the biodistribution profiles showed selective accumulation at the inflammatory site of FA-NPs/GER, and significantly reduced the swelling and inflammation infiltration of the rat's foot. The levels of pro-inflammatory cytokines (TNF-α, IL-1β) in the rat's inflammatory tissue were significantly lower than other treatment groups, which indicated a significant therapeutic effect in AIA rats. Taken together, macrophage-targeting nanocarriers loaded with GER are a safe and effective method for the treatment of RA.

Macrophage-Targeted Hydroxychloroquine Nanotherapeutics for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is an autoimmune disease with unclear pathogenesis. Hydroxychloroquine (HCQ), despite its moderate anti-RA efficacy, is among the few clinical drugs used for RA therapy. Macrophages reportedly play a vital role in RA. Here, we designed and explored macrophage-targeted HCQ nanotherapeutics based on mannose-functionalized polymersomes (MP-HCQ) for RA therapy. Notably, MP-HCQ exhibited favorable properties of less than 50 nm size, glutathione-accelerated HCQ release, and M1 phenotype macrophage (M1M) targetability, leading to repolarization of macrophages to anti-inflammatory M2 phenotype (M2M), reduced secretion of pro-inflammatory cytokines (IL-6), and upregulation of anti-inflammatory cytokines (IL-10). The therapeutic studies in the zymosan-induced RA (ZIA) mouse model showed marked accumulation of MP-HCQ in the inflammation sites, ameliorated symptoms of RA joints, significantly reduced IL-6, TNF-α, and IL-1β, and increased IL-10 and TGF-β compared with free HCQ. The analyses of RA joints disclosed greatly amplified M2M and declined mature DCs, CD4⁺ T cells, and CD8⁺ T cells. In accordance, MP-HCQ significantly reduced the damage of RA joints, cartilages, and bones compared to free HCQ and non-targeted controls. Macrophage-targeted HCQ nanotherapeutics therefore appears as a highly potent treatment for RA.

Reactive Oxygen Species-Responsive Celastrol-Loaded : Bilirubin Nanoparticles for the Treatment of Rheumatoid Arthritis

Celastrol (CLT) has shown anti-rheumatic activity against rheumatoid arthritis, while its poor water solubility and high organ toxicity restrict its further therapeutic applications. To mitigate these challenges, a reactive oxygen species (ROS)-responsive nanoparticle was developed for celastrol delivery based on the excessive ROS at the pathologic sites, which was synthesized by conjugating bilirubin to a polyethylene glycol (PEG) chain. The PEGylated bilirubin self-assembled into nanoparticle (BRNP) in aqueous solution had a hydrodynamic diameter of around 68.6 nm, and celastrol was loaded into BRNP (CLT/BRNP) with a drug encapsulation efficiency of 72.6% and a loading capacity of 6.6%. In vitro study revealed that CLT/BRNP exhibited the capacity of scavenging intracellular ROS and down-regulating the level of nitric oxide after it was effectively internalized by activated macrophages. Furthermore, in adjuvant-induced arthritis rats, BRNP was accumulated preferentially at inflamed joints, alleviating the joint swelling and bone erosion, which significantly decreased the secretion of pro-inflammatory cytokines to suppress the RA progression. Importantly, CLT/BRNP markedly enhanced its anti-arthritic effect and attenuated the toxic effect compared with free celastrol. Taken together, our results suggested that CLT/BRNP could be used for targeted drug delivery in rheumatoid arthritis.

Acupoint nanocomposite hydrogel for simulation of acupuncture and targeted delivery of triptolide against rheumatoid arthritis

Background

Attenuating inflammatory response and relieving pain are two therapeutic therapeutical goals for rheumatoid arthritis (RA). Anti-inflammatory and analgesic drugs are often associated with many adverse effects due to nonspecific distribution. New drug delivery systems with practical targeting ability and other complementary strategies urgently need to be explored. To achieve this goal, an acupoint drug delivery system that can target deliver anti-inflammatory drugs and simulate acupuncture in relieving pain was constructed, which can co-deliver triptolide (TP) and 2-chloro-N (6)-cyclopentyl adenosine (CCPA).

Results

We have successfully demonstrated that acupoint nanocomposite hydrogel composed of TP-Human serum album nanoparticles (TP@HSA NPs) and CCPA could effectively treat RA. The result shows that CCPA-Gel can enhance analgesic effects specifically at the acupoint, while the mechanical and thermal pain threshold was 4.9 and 1.6 times compared with non-acupoint, respectively, and the nanocomposite gel further enhanced. Otherwise, the combination of acupoint and nanocomposite hydrogel exerted synergetic improvement of inflammation, bone erosion, and reduction of systemic toxicity. Furthermore, it could regulate inflammatory factors and restore the balance of Th17/Treg cells, which provided a novel and effective treatment strategy for RA. Interestingly, acupoint administration could improve the accumulation of the designed nanomedicine in arthritic paws (13.5% higher than those in non-acupoint at 48 h), which may explain the better therapeutic efficiency and low toxicity.

Conclusion

This novel therapeutic approach-acupoint nanocomposite hydrogel, builds a bridge between acupuncture and drugs which sheds light on the combination of traditional and modern medicine.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01157-z.

Targeted therapy of rheumatoid arthritis via macrophage repolarization

The polarization of macrophages plays a critical role in the physiological and pathological progression of rheumatoid arthritis (RA). Activated M1 macrophages overexpress folate receptors in arthritic joints. Hence, we developed folic acid (FA)-modified liposomes (FA-Lips) to encapsulate triptolide (TP) (FA-Lips/TP) for the targeted therapy of RA. FA-Lips exhibited significantly higher internalization efficiency in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells than liposomes (Lips) in the absence of folate. Next, an adjuvant-induced arthritis (AIA) rat model was established to explore the biodistribution profiles of FA-Lips which showed markedly selective accumulation in inflammatory paws. Moreover, FA-Lips/TP exhibited greatly improved therapeutic efficacy and low toxicity in AIA rats by targeting M1 macrophages and repolarizing macrophages from M1 to M2 subtypes. Overall, a safe FA-modified liposomal delivery system encapsulating TP was shown to achieve inflammation-targeted therapy against RA via macrophage repolarization.

Cellular Uptake of Three Different Nanoparticles in an Inflammatory Arthritis Scenario versus Normal Conditions

Nanoparticles (NPs) have wide potential applications in the biomedical field. To promote targeted and controlled delivery of encapsulated drugs, it is fundamentally important to understand the factors regulating NP uptake by different cells. Thus, the goal of the present study is to assess the internalization rates of different NPs under normal and proinflammatory states in primary human articular chondrocytes (hACs), human umbilical vein endothelial cells (EA), and human monocytes (THP-1). Here, we compared chitosan-hyaluronic acid (Ch-HA) polymeric NPs, methoxypolyethylene glycol amine-glutathione-palmitic acid (mPEG-GSH_n-PA) micelles, and cholesterol/l-α-phosphatidylcholine/DSPE-PEG-Mal (Chol/EPC/DSPE-PEG-Mal) unilamellar liposomes (LUVs). Our results reveal the importance of surface charge and chemistry in determining the levels of NP internalization. Under normal conditions, the cellular uptake was ≈30% for Ch-HA NPs and ≈100% for mPEG-GSH_n-PA micelles and Chol/EPC/DSPE-PEG-Mal LUVs. A proinflammatory cell state promoted a higher uptake of the Ch-HA NPs by EA cells (93% after 24 h). Since the therapeutic efficacy of the NP-loaded cargo is dependent on trafficking routes after cellular internalization, we tested their internalization pathways. Accordingly, caveolae-mediated endocytosis or energy-independent non-endocytic pathways, which circumvent lysosomal degradation, were accomplished in hACs and EA by LUVs and in M1 polarized macrophages by micelles. The present outcomes highlight the importance of considering cellular uptake and internalization pathways by the target cell when designing functional NPs for therapeutic applications.

OX40L blockade cellular nanovesicles for autoimmune diseases therapy

Current clinical agents for autoimmunity disorders treatment often cause substantial adverse effects and safety concerns, owing to non-specific immune modulation. Due to the prominent contribution of effector T cells in pathogenesis of rheumatoid arthritis (RA) and inflammatory bowel disease (IBD), and preferential location of co-stimulatory receptor-ligand pair OX40-OX40L at the inflamed sites, selectively targeting autoaggressive T cells by blockade OX40-OX40L, might represent an alternative strategy. Herein, we developed a new strategy to antagonize OX40-OX40L interaction by engineering a cell membrane derived nanovesicles (NVs) expressing OX40 receptors (OX40 NVs), and explored their potential for autoimmune disorders therapy. OX40 NVs showed specific binding capability to inflamed HUVECs in vitro, it also possessed distinct arthritic-targeting capacity in RA inflamed joints, and preferential accumulation in IBD inflamed colon. OX40 NVs efficiently suppressed the progression of both RA and IBD diseases through reducing CD4⁺OX40⁺ T cells population, and proinflammatory cytokines (i.e., TNF-α and IL-1β), while reinforcing Tregs immune-suppressive effect, with superior therapeutic efficacy than anti-OX40L. Additionally, dexamethasone (DEX) loading can further enhance the potential of OX40 NVs for RA treatment. Owing to their preferential localization to inflamed sites, and potent immune-suppression ability, targeting OX40-OX40L blockade by OX40 NVs for autoimmune therapy is highly promising.

Targeting immunosuppressor cells with nanoparticles in autoimmunity: How far have we come to?

Autoimmunity is the assault of immune response towards self-antigens, resulting to inflammation and tissue injury. It is staged into three phases and caused by malfunction of immune tolerance. In our body, immune tolerance is synchronized by several immunosuppressor cells such as regulatory T cells and B cells as well as myeloid-derived suppressor cells, which are prominently dysregulated in autoimmunity. Hence, targeting these cell populations serve as a significant potential in the therapy of autoimmunity. Nanotechnology with its advantageous properties is shown to be a remarkable tool as drug delivery system in this field. This review focused on the development of therapeutics in autoimmune diseases utilizing various nanoparticles formulation based on two targeting approaches in autoimmunity, passive and active targeting. Lastly, this review outlined the approved present nanomedicines as well as in clinical evaluations and issues regarding the lack of translation of these nanomedicines into the market, despite the abundant of positive experimental observations.

Polymeric microneedle-mediated transdermal delivery of melittin for rheumatoid arthritis treatment

Transdermal drug delivery systems for rheumatoid arthritis (RA) have been receiving increasing attention as they can potentially overcome drawbacks which exist in traditional oral or injection strategies, including low patient compliance and serious gastrointestinal side effects. However, transdermal delivery of RA drugs especially biological drugs suffers from low drug delivery efficiency due to the robust skin barrier. Herein, we fabricated melittin-loaded hyaluronic acid (HA) microneedles and investigated their capacity for inhibiting RA. We showed that melittin-loaded HA microneedles possessed high mechanical strength for successful delivery of melittin into the skin and effectively inhibited RA progression in adjuvant induced both rodent and murine models, as shown by results in histological, paw swelling and arthritis score. Furthermore, after modifying HA with cross-linkable groups, the fabricated microneedles with sustained release properties could further improve the therapeutic potency. Cytokine and T cell analysis in the paws and lymphatic organs indicated that the application of microneedles suppressed the levels of pro-inflammation cytokines including IL-17 and TNF-α, and increased the percentage of regulatory CD4 T cells. Our study revealed that polymeric microneedle-mediated transdermal delivery of melittin could serve as a new therapy with high compliance and good therapeutic efficacy for RA and other autoimmune diseases.

Targeting the resolution pathway of inflammation using Ac2-26 peptide-loaded PEGylated lipid nanoparticles for the remission of rheumatoid arthritis

Rheumatoid arthritis (RA) is a common autoimmune disease characterized by joint inflammation and immune dysfunction. Although various therapeutic approaches have been utilized for the treatment of RA in clinical applications, the low responsiveness of RA patients and undesired systemic toxicity are still unresolved problems. Targeting the resolution pathway of inflammation with pro-resolving mediators would evoke the protective actions of patient for combating the inflammation. Ac2-26, a 25-amino acid peptide derived from Annexin A (a pro-resolving mediator), has shown good efficacy in the treatment of inflammatory disorders. However, the low bioavailability of Ac2-26 peptides hinders their efficacy in vivo. In this paper, we formed PEGylated lipid nanoparticles (LDNPs) by the co-assembly of l-ascorbyl palmitate (L-AP) and N-(carbonyl methoxypolyethylene glycol-2000)-1,2-distearoyl-sn‑glycero-3-phosphoethanolamine (DSPE-PEG2k) to encapsulate and deliver Ac2-26 peptides to the arthritic rats. They showed good stability and biocompatibility. After being intravenously administrated, Ac2-26 peptide-loaded PEGylated lipid nanoparticles (ADNPs) showed the prolonged in vivo circulation time and enhanced accumulation in inflamed sites. In vivo therapeutic evaluations revealed that ADNPs could attenuate synovial inflammation and improve joint pathology. Therefore, the pro-resolving therapeutic strategy using ADNPs is effective in RA treatment.

Intra-Articular Injection of a Nanosuspension of Tetramethylpyrazine Dihydroxynaphthalenate for Stronger and Longer-Lasting Effects Against Osteoarthritis

Tetramethylpyrazine (TMP), isolated from the rhizome of the traditional Chinese medicinal plant Chuanxiong (Ligusticum wallichii Franchat) shows therapeutic efficacy against osteoarthritis. After intra-articular injection, the retention time of TMP in the joint cavity is short, which limits its treatment effect. To avoid this problem, the present study explored the preparation of a TMP nanosuspension (TMP-NS) based on hydrophobic ion pairing. TMP-NS showed a particle size of approximately 588 nm and, after intra-articular injection in rats, it had longer retention in the articular cavity, higher TMP concentrations in joints, and greater anti-osteoarthritic efficacy than TMP solution. TMP-NS didn't cause significant inflammation at the joint. These results suggest that TMP-NS may strengthen and prolong the therapeutic efficacy of TMP against osteoarthritis without systemic toxicity.

Glutathione Reductase-Sensitive Polymeric Micelles for Controlled Drug Delivery on Arthritic Diseases

Inflammation plays an essential role in arthritis development and progression. Despite the advances in the pharmaceutical field, current treatments still present low efficacy and severe side effects. Considering the high activity of the glutathione reductase (GR) enzyme in inflamed joints, a distinctive drug delivery system sensitive to the GR enzyme was designed for efficient drug delivery on arthritic diseases. A linear amphiphilic polymer composed of methoxypolyethylene glycol amine-glutathione-palmitic acid (mPEG-GSH_n-PA) was synthesized and the intermolecular oxidation of the thiol groups from GSHs retain the drug inside the resulting micelles. Stable polymeric micelles of 100 nm of size presented a loading capacity of dexamethasone (Dex) up to 65%. Although in physiological conditions the Dex release presented slow and sustained kinetics, in the presence of the GR enzyme, there was a burst release (stimuli-responsive properties). Biological assays demonstrated their cytocompatibility in contact with human articular chondrocytes, macrophages, and endothelial cells as well as their hemocompatibility. Importantly, in an in vitro model of inflammation, the polymeric micelles promoted a controlled drug release in the presence of GR, exhibiting a higher efficacy than the free Dex while reducing the negative effects of the drug into normal cells. In conclusion, this formulation is a promising approach to treat arthritic diseases and other inflammatory conditions.