Activated macrophage-targeted dextran-methotrexate/folate conjugate prevents deterioration of collagen-induced arthritis in mice

PEGylated retinoate prodrug self-assembled nanomicelles loaded with triptolide for targeting treatment of rheumatoid arthritis and side effect attenuation

Triptolide (TP, an active ingredient from Tripterygium wilfordii) demonstrates significant efficacy in treating rheumatoid arthritis, but its low bioavailability and multi-organ toxicity limit its application. Herein, we developed a PEGylated retinoate self-assembled nanomicelles (FA-TP@VA NPs) modified with folic acid (FA) for inflammatory macrophage-targeted delivery of TP. FA-TP@VA NPs showed an appropriate size (192.70 ± 4.37 nm), good physical stability and high drug loading (79.83 ± 5.11 % for retinoate prodrug and 6.78 ± 0.13 % for TP). FA-TP@VA NPs exhibited high cellular uptake in M1 macrophages via folate-receptor pathway, thereby inhibiting their growth. Compared with TP, FA-TP@VA NPs could effectively inhibit synovitis and erosion of bone and reduce swelling and deformation of paws by downregulation of the levels of IL-1β, IL-6, and TNF-α. In ICA mice, FA-TP@VA NPs could enhance drug-specific enrichment in inflamed joints, effectively suppress hepatic oxidative stress and reduce systemic toxicity induced by TP. Overall, FA-TP@VA NPs are a facile, carrier-free, and promising strategy for the precise treatment of rheumatoid arthritis and synergetic attenuation of side effect.

Natural polysaccharide-based nanodrug delivery systems for targeted treatment of rheumatoid arthritis: A review

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by persistent inflammation of the joints, leading to pain, disability, and systemic complications. Conventional treatments often exhibit limitations, including adverse effects and suboptimal bioavailability. To address these challenges, natural polysaccharides-mediated nano drug delivery is a promising vehicle for RA management. This review explores the potential of natural polysaccharides in RA, including chitosan, cellulose, albumin, hyaluronic acid, polylactic acid, alginate, etc. Their biodegradable and biocompatible nature renders them ideal nanomaterials for RA applications. These properties facilitate targeted delivery, improved cellular uptake, and sustained release of therapeutic agents, enhancing their pharmacological effects while minimizing systemic toxicity. Recent advances in nanotechnology have enabled the formulations of polysaccharides that can encapsulate a range of therapeutic agents, including conventional anti-inflammatory drugs and novel biologics. The review also highlights various formulation strategies to optimize the physicochemical properties of polysaccharide-based nano drug delivery systems, including surface modification and combinatorial therapies. Overall, natural polysaccharides represent a versatile and effective approach for developing innovative nano drug delivery systems, offering a promising strategy for the effective treatment of rheumatoid arthritis.

pH and ROS Dual-Sensitive Nanocarriers for the Targeted Co-Delivery and On-Demand Sequential Release of Tofacitinib and Glucosamine for Synergistic Rheumatoid Arthritis Treatment

Rheumatoid arthritis (RA) progression involves multiple cell types, and sequential drug action on target cells is necessary for RA treatment. Nanocarriers are widely used for RA treatment; however, the targeted delivery and on-demand release of multiple drugs remains challenging. Therefore, in this study, a dual-sensitive polymer is developed using chondroitin sulfate (CS) for the co-delivery of the cartilage repair agent, glucosamine (GlcN), and anti-inflammatory drug, tofacitinib (Tof). In the joint cavity, acidic pH facilitates the cleavage of GlcN from CS polymer to repair the cartilage damage. Subsequently, macrophage uptake via CS-CD44 binding and intracellular reactive oxygen species (ROS) mediate conversion of (methylsulfanyl)propylamine to a hydrophilic segment jointly triggered rapid Tof/GlcN release via micelle disassembly. The combined effects of Tof, GlcN, and ROS depletion promote the M1-to-M2 polarization shift to attenuate inflammation. The synergistic effects of these agents against RA are confirmed in vitro and in vivo. Overall, the dual pH/ROS-sensitive CS nanoplatform simultaneously delivers GlcN and Tof, providing a multifunctional approach for RA treatment with synergistic drug effects.

Advanced application of carbohydrate-based micro/nanoparticles for rheumatoid arthritis

Rheumatoid arthritis (RA) is a kind of synovitis and progressive joint destruction disease. Dysregulated immune cell activation, inflammatory cytokine overproduction, and subsequent reactive oxidative species (ROS) production contribute to the RA process. Carbohydrates, including cellulose, chitosan, alginate and dextran, are among the most abundant and important biomolecules in nature and are widely used in biomedicine. Carbohydrate-based micro/nanoparticles(M/NPs) as functional excipients have the ability to improve the bioavailability, solubility and stability of numerous drugs used in RA therapy. For on-demand therapy, smart reactive M/NPs have been developed to respond to a variety of chemical and physical stimuli, including light, temperature, enzymes, pH and ROS, alternating their physical and macroscopic properties, resulting in innovative new drug delivery systems. In particular, advanced products with targeted dextran or hyaluronic acid are exploiting multiple beneficial properties at the same time. In addition to those that respond, there are promising new derivatives in development with microenvironment and chronotherapy effects. In this review, we provide an overview of these recent developments and an outlook on how this class of agents will further shape the landscape of drug delivery for RA treatment.

Reactive Oxygen Species-Responsive Polymeric Prodrug Nanoparticles for Selective and Effective Treatment of Inflammatory Diseases

It is challenging to manage inflammatory diseases using traditional anti-inflammatory drugs due to their limited efficacy and systemic side effects, which are a result of their lack of selectivity, poor stability, and low solubility. Herein, it reports the development of a novel nanoparticle system, called ROS-CA-NPs, which is formed using polymer-cinnamaldehyde (CA) conjugates and is responsive to reactive oxygen species (ROS). ROS-CA-NPs exhibit excellent drug stability, tissue selectivity, and controlled drug release upon oxidative stress activation. Using mouse models of chronic rheumatoid arthritis and acute ulcerative colitis, this study demonstrates that the systemic administration of ROS-CA-NPs results in their accumulation at inflamed lesions and leads to greater therapeutic efficacy compared to traditional drugs. Furthermore, ROS-CA-NPs present excellent biocompatibility. The findings suggest that ROS-CA-NPs have the potential to be developed as safe and effective nanotherapeutic agents for a broad range of inflammatory diseases.

Advancement in nanotechnology for treatment of rheumatoid arthritis: scope and potential applications

Rheumatoid arthritis is a hyperactive immune disorder that results in severe inflammation in synovial joints, cartilage, and bone deterioration, resulting in immobilization of joints. Traditional approaches for the treatment of rheumatoid arthritis are associated with some limiting factors such as suboptimal patient compliance, inability to control the progression of disorder, and safety concerns. Therefore, innovative drug delivery carriers for efficient therapeutic delivery at inflamed synovial sites with better safety assessment are urgently needed to address these issues. From this perspective, nanotechnology is an outstanding alternative to traditional drug delivery approaches, and it has shown great promise in developing novel carriers to treat rheumatoid arthritis. Considering the current research and future application of nanocarriers, it is believed that nanocarriers can be a crucial element in rheumatoid arthritis treatment. This paper covers all currently available pathophysiological aspects of rheumatoid arthritis and treatment options. Future research for the reduction of synovial inflammation should focus on developing multifunction nanoparticles capable of delivering therapeutic agents with improved safety, efficacy, and cost-effectiveness to be commercialized.

Folate receptor-mediated targeted therapy for rheumatoid arthritis by methotrexate-phospholipid complex nano-emulsions

Rheumatoid arthritis (RA) is a common autoimmune and inflammatory disease. Activated macrophages in arthritic joints play a prominent role in the initiation and persistence of RA. Despite great progress in the clinical treatment of RA, poor response and high discontinuation due to systemic toxicity remain unsolved issues, especially the well-known methotrexate (MTX). Therefore, active targeted delivery of therapeutic drugs to pathogenic cells in arthritic joints is essential to increase in situ activity and decrease systemic toxicity. Here, we developed an MTX-loaded macrophage-targeted nano-emulsion (NE) based on the overexpression of folate receptor (FR) on activated macrophages, the inherent high affinity of FR for folate (FA), as well as the property of MTX and phospholipids to form complexes (MTX@PC). Intravenous injection of DID-labelled MTX@PC-FA NEs into adjuvant-induced arthritis (AIA) mice, in vivo images and flow cytometry results revealed that the NEs were highly targeted to inflamed joints and macrophages, respectively. Therapeutic studies suggested that this strategy was conducive to achieve high efficacy and low toxicity of MTX in the treatment of RA. Our research highlights MTX@PC-FA NEs as a potential treatment option for RA targeting the FR-expressed activated macrophages.

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.

Mannose-mediated nanodelivery of methotrexate to macrophages augments rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronic autoimmune disease that gravely jeopardizes the quality of life of numerous people. Methotrexate (MTX) is a disease-modifying anti-rheumatic drug commonly used in clinics; however, it suffers from slow onset, moderate efficacy, and adverse reactions such as renal dysfunction, myelosuppression, and bone erosion after long-term treatment. Here, we explored macrophage targeted delivery of MTX using mannose-installed chimaeric polymersomes (Man-PMTX) as an advanced treatment for RA. Man-PMTX exhibited high (∼18 wt%) and robust loading of MTX, uniform size of 51-55 nm, minimal hemolytic activity, and glutathione-actuated drug release property. Man-PMTX showed better uptake by activated macrophages than PMTX, and more repolarization of bone marrow-derived macrophages (BMDMs) to anti-inflammatory M2 type macrophages and less secretion of TNF-α and IL-1β compared with free MTX and PMTX. In vivo studies revealed that Man-PMTX showed significantly higher accumulation in inflammatory joints than in healthy joints and effectively treated RA by relieving inflammation, repolarizing macrophages from M1 type to M2 type, and mitigating proinflammatory cytokines. Accordingly, Man-PMTX effectively protected the synovium and bone from damage. Mannose-mediated nanodelivery of methotrexate to macrophages appears to be an attractive strategy to augment rheumatoid arthritis therapy.

Immunomodulatory nanosystems: An emerging strategy to combat viral infections

The viral infection spreads with the assistance of a host. Traditional antiviral therapies cannot provide long-term immunity against emerging and drug-resistant viral infections. Immunotherapy has evolved as an efficient approach for disease prevention and treatment, which include cancer, infections, inflammatory, and immune disorders. Immunomodulatory nanosystems can dramatically enhance therapeutic outcomes by combating many therapeutic challenges, such as poor immune stimulation and off-target adverse effects. Recently, immunomodulatory nanosystems have emerged as a potent antiviral strategy to intercept viral infections effectively. This review introduces major viral infections with their primary symptoms, route of transmission & targeted organ, and different stages of the viral life cycle with respective traditional blockers. The IMNs have an exceptional capacity for precisely modulating the immune system for therapeutic applications. The nano sized immunomodulatory systems permit the immune cells to interact with infectious agents enhancing lymphatic drainage and endocytosis by the over-reactive immune cells in the infected areas. Immune cells that can be modulated upon viral infection via various immunomodulatory nanosystems have been discussed. Advancement in theranostics can yield an accurate diagnosis, adequate treatment, and real-time screening of viral infections. Nanosystem-based drug delivery can continue to thrive in diagnosing, treating, and preventing viral infections. The curative medicine for remerging and drug-resistant viruses remains challenging, though certain systems have expanded our perception and initiated a new research domain in antiviral treatments.

Hybrid Cyanine/Methotrexate Nanoparticles for Synergistic PDT/Chemotherapy of Breast Cancer

Typically, nanomedicine was prepared using a nanocarrier to load cargo for specific purposes. In this work, a carrier-free nanosystem for imaging and photodynamic (PDT)/chemo combination therapy was developed using simple self-assembly of a dye and a chemotherapeutic agent. The resulting nanoparticles (I₂-IR783/MTX@NPs) exhibited a spherical morphology with a size of 240.6 ± 2.5 nm. I₂-IR783/MTX@NPs had substantial internalization in 4T1 murine breast cancer cells and showed a synergistic anticancer effect after NIR light irradiation. Additionally, the 3D tumor model exhibits the same phototoxicity of nanoparticles as a 2D cell culture. The PDT efficiency of the nanosystem in the physiological environment was confirmed by the detection of intracellular reactive oxygen species as well as the live/dead viability/cytotoxicity assay following NIR light exposure. In addition, optical coherence tomography (OCT) was used as an alternative tool to monitor the response after treatment. Therefore, I₂-IR783/MTX@NPs show great potential use in theranostic application for breast cancer PDT-chemotherapy.

Novel Biotherapeutics Targeting Biomolecular and Cellular Approaches in Diabetic Wound Healing

Wound healing responses play a major role in chronic inflammation, which affects millions of people around the world. One of the daunting tasks of creating a wound-healing drug is finding equilibrium in the inflammatory cascade. In this study, the molecular and cellular mechanisms to regulate wound healing are explained, and recent research is addressed that demonstrates the molecular and cellular events during diabetic wound healing. Moreover, a range of factors or agents that facilitate wound healing have also been investigated as possible targets for successful treatment. It also summarises the various advances in research findings that have revealed promising molecular targets in the fields of therapy and diagnosis of cellular physiology and pathology of wound healing, such as neuropeptides, substance P, T cell immune response cDNA 7, miRNA, and treprostinil growth factors such as fibroblast growth factor, including thymosin beta 4, and immunomodulators as major therapeutic targets.

Inflammation specific environment activated methotrexate-loaded nanomedicine to treat rheumatoid arthritis by immune environment reconstruction

Rheumatoid arthritis (RA), as an autoimmune inflammatory disease, is featured by enhanced vascular permeability, irreversible cartilage destroys and bone erosion. Although the pathogenesis of RA is still unclear, the immune environment, particularly the lymphatic system, which is instrumental to immune cell surveillance and interstitial fluid balance, plays vital roles in the process of RA. Herein, an inflammation specific environment activated methotrexate-encapsulated nanomedicine (MTX@NPs) was constructed for RA treatment, which accumulated in inflamed joints, and released MTX in the specific RA microenvironment. Notably, MTX@NPs could regulate the immune environment including reducing the expressions of inflammatory cytokines of macrophages and the inflammatory level of lymphatic epithelial cells (LECs), and ameliorating the lymphatic vessel contraction and drainage. In vitro and In vivo studies illustrated that MTX@NPs exhibited a high RA therapeutic efficacy and insignificant systemic toxicity owing to the suppression of the inflammation response and the improved lymphatic functions of RA joints. It suggests that the nanomedicine paves a potential way to the clinical practice of autoimmune diseases treatments via the regulation of immune environment and lymphatic functions. STATEMENT OF SIGNIFICANCE: Although 1.0% of the population in the world suffers from rheumatoid arthritis (RA), the pathogenesis of RA is still unclear and the therapeutic effect of the first-line clinical drugs is relatively low. Herein, we propose a specific RA-microenvironment triggered nanomedicine (MTX@NPs), which enhances RA treatment of a first-line antirheumatic drug (methotrexate, MTX) by immune environment reconstruction. The nanomedicine exhibits RA joints accumulation by EPR effect, and releases MTX under the specific RA environment, leading to the dramatical drop of M1-type macrophages and acceleration of lymphatic vessel contraction and drainage. Finally, the inflammatory cytokines in RA immune environment are reduced sharply, indicating the outstanding therapeutic efficacy of MTX@NPs to RA.

Development of pH-sensitive dextran-based methotrexate nanodrug for rheumatoid arthritis therapy through inhibition of JAK-STAT pathways

Rheumatoid arthritis (RA) is a chronic and symmetrical autoimmune disease that primarily characterized with articular synovial hyperplasia, joint swelling, cartilage and bone destruction. The in-depth understanding of the role of immune signaling pathway inhibitors provides inspiration for the construction of new and more effective strategy for RA therapy. In this study, by loading methotrexate (MTX) into an acetalated dextran biopolymer, AcDEX, we developed a pH-sensitive, MTX-loaded and molecularly targeted nanodrug MTX@pH-AcDEX NPs) to decrease the toxicity of MTX and simultaneously enhance its therapeutic effect. The resultant MTX@pH-AcDEX NPs showed the spherical morphology and notable pH-responsiveness with high drug loading of 88.32%. As demonstrated in vitro and in vivo, the reduced cytotoxicity of both RAW264.7 cells and LPS-activated RAW264.7 cells treated with MTX@pH-AcDEX NPs was found compared to free MTX. Upon intravenous administration into adjuvant-induced arthritis (AIA) rat model, the nanodrug had potent pharmacokinetic and pharmacodynamic profiles, which can accumulate in RA lesions and release MTX inhibitors for regulating the JAK-STAT pathways. As a result, the MTX@pH-AcDEX NPs achieved the cartilage and bone protective and a better anti-inflammatory effect with negligible systemic toxicity, suggesting the strong potential of safe and effective nanodrug for RA therapy as well as other autoimmune diseases.

Nanotechnology applications in rheumatology

Nanomedicine (NM) is the medical use of nanotechnology (NT). NT is the study and control of nanoscale structures (between approximately 1 and 100 nm). Nanomaterials are created by manipulating atoms and molecules at the nanoscale, resulting in novel physical and chemical properties. With its targeted tissue delivery capabilities, NT has enabled molecular modulation of the immune response and underlying inflammatory responses in individuals with rheumatic diseases (RD). NM has enabled targeted drug delivery, reduced adverse effects on non-target organs, raised drug concentration in synovial tissue, and slowed the progression of immune-mediated RD such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Thus, NM has evolved in rheumatology prevention, diagnosis, and therapy. Animal models have proven superior outcomes to conventional techniques of treating specific illnesses. Nanodiamond (ND) immunomodulatory applications have been proposed as an alternative to traditional nanoparticles in the diagnosis and treatment of RA due to their small size and ability to be removed from the body without causing harm to the patient's organs, such as the liver. However, human clinical NM needs more research. We conducted a literature review to assess the present role of NM in clinical rheumatology, describing its current and future applications in the diagnosis and treatment of rheumatic diseases.

Macrophage targeted triptolide micelles capable of cGAS-STING pathway inhibition for rheumatoid arthritis treatment

The abundant M1 macrophages in the joint synovium were the main factors that exacerbate rheumatoid arthritis (RA) by secreting various types of inflammatory cytokines. Here, we note that cGAS-STING, an important pro-inflammatory pathway, was significantly up-regulated in RA, enabling it be the potential target for RA therapy. Therefore, in this work, we developed M1 macrophages targeted micelles capable of cGAS-STING pathway inhibition for the smart treatment of RA. The folic acid (FA) and lauric acid (LA) were modified on dextran to obtain an amphiphilic polymer (FDL). Then, FDL was subsequently applied to encapsulate triptolide (TP) to form FDL@TP nanomicelles. The FDL@TP could target the joint and enhance the cell uptake of TP by M1 macrophages (overexpressing folate receptor-β), which also reduced the side effects of TP on normal tissues. In M1 macrophages, the released TP, acted as an anti-inflammatory and immunosuppressant, obviously down-regulated the expressions of cGAS and STING protein, and thus reduced the secretion of TNF-α, IL-1β, and IL-6. Importantly, compared with the same dose of free TP, FDL@TP could significantly enhance the anti-inflammatory effect. Therefore, FDL@TP nanomicelles were believed to be superior candidates for the clinical treatment of RA.

Efficacy and Immune Response Elicited by Gold Nanoparticle- Based Nanovaccines against Infectious Diseases

The use of nanoparticles for developing vaccines has become a routine process for researchers and pharmaceutical companies. Gold nanoparticles (GNPs) are chemical inert, have low toxicity, and are easy to modify and functionalize, making them an attractive choice for nanovaccine development. GNPs are modified for diagnostics and detection of many pathogens. The biocompatibility and biodistribution properties of GNPs render them ideal for use in clinical settings. They have excellent immune modulatory and adjuvant properties. They have been used as the antigen carrier for the delivery system to a targeted site. Tagging them with antibodies can direct the drug or antigen-carrying GNPs to specific tissues or cells. The physicochemical properties of the GNP, together with its dynamic immune response based on its size, shape, surface charge, and optical properties, make it a suitable candidate for vaccine development. The clear outcome of modulating dendritic cells, T and B lymphocytes, which trigger cytokine release in the host, indicates GNPs' efficiency in combating pathogens. The high titer of IgG and IgA antibody subtypes and their enhanced capacity to neutralize pathogens are reported in multiple studies on GNP-based vaccine development. The major focus of this review is to illustrate the role of GNPs in developing nanovaccines against multiple infectious agents, ranging from viruses to bacteria and parasites. Although the use of GNPs has its shortcomings and a low but detectable level of toxicity, their benefits warrant investing more thought and energy into the development of novel vaccine strategies.

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.

Design and Encapsulation of Immunomodulators onto Gold Nanoparticles in Cancer Immunotherapy

The aim of cancer immunotherapy is to reactivate autoimmune responses to combat cancer cells. To stimulate the immune system, immunomodulators, such as adjuvants, cytokines, vaccines, and checkpoint inhibitors, are extensively designed and studied. Immunomodulators have several drawbacks, such as drug instability, limited half-life, rapid drug clearance, and uncontrolled immune responses when used directly in cancer immunotherapy. Several strategies have been used to overcome these limitations. A simple and effective approach is the loading of immunomodulators onto gold-based nanoparticles (GNPs). As gold is highly biocompatible, GNPs can be administered intravenously, which aids in increasing cancer cell permeability and retention time. Various gold nanoplatforms, including nanospheres, nanoshells, nanorods, nanocages, and nanostars have been effectively used in cancer immunotherapy. Gold nanostars (GNS) are one of the most promising GNP platforms because of their unusual star-shaped geometry, which significantly increases light absorption and provides high photon-to-heat conversion efficiency due to the plasmonic effect. As a result, GNPs are a useful vehicle for delivering antigens and adjuvants that support the immune system in killing tumor cells by facilitating or activating cytotoxic T lymphocytes. This review represents recent progress in encapsulating immunomodulators into GNPs for utility in a cancer immunotherapeutic regimen.

Nanomedicines for the treatment of rheumatoid arthritis: State of art and potential therapeutic strategies

Increasing understanding of the pathogenesis of rheumatoid arthritis (RA) has remarkably promoted the development of effective therapeutic regimens of RA. Nevertheless, the inadequate response to current therapies in a proportion of patients, the systemic toxicity accompanied by long-term administration or distribution in non-targeted sites and the comprised efficacy caused by undesirable bioavailability, are still unsettled problems lying across the full remission of RA. So far, these existing limitations have inspired comprehensive academic researches on nanomedicines for RA treatment. A variety of versatile nanocarriers with controllable physicochemical properties, tailorable drug release pattern or active targeting ability were fabricated to enhance the drug delivery efficiency in RA treatment. This review aims to provide an up-to-date progress regarding to RA treatment using nanomedicines in the last 5 years and concisely discuss the potential application of several newly emerged therapeutic strategies such as inducing the antigen-specific tolerance, pro-resolving therapy or regulating the immunometabolism for RA treatments.

NIR-Responsive Spatiotemporally Controlled Cyanobacteria Micro-Nanodevice for Intensity-Modulated Chemotherapeutics in Rheumatoid Arthritis

The expression of hypoxia-inducible factor-1α (HIF-1α) is upregulated in hypoxic environments at the lesions of rheumatoid arthritis (RA), which promoted the polarization of proinflammatory M1 macrophages and inhibited the differentiation of anti-inflammatory M2 to deteriorate synovial inflammation. Since oxygen scarcity at the joints causes an imbalance of macrophages M1 and M2, herein, we designed a cyanobacteria micro-nanodevice that can be spatiotemporally controlled in vivo to continuously producing oxygen in the RA joints for the downregulation of the expression of HIF-1α, thereby reducing the amounts of M1 macrophages and inducing the polarization of M2 macrophages for chemically sensitized RA treatment. The forthputting of temperature-sensitive hydrogel guaranteed the safety of cyanobacteria micro-nanodevice in vivo. Furthermore, the oxygen produced by cyanobacteria micro-nanodevice in a sustained manner enhanced the therapeutic effect of the antirheumatic drug methotrexate (MTX) and discouraged inflammation and bone erosion at RA. This study provided a new approach for the RA treatment of spatiotemporal-controlled release of oxygen in vitro.

Construction of a pH-responsive, ultralow-dose triptolide nanomedicine for safe rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronicautoimmune disease, marked by joint swelling and pain, articular synovial hyperplasia, as well as cartilage and bone destruction. Triptolide (TP) is an anti-inflammatory molecule but its use to treat RA is limited due to poor solubility and extremely high toxicity. In this study, by encapsulating TP into a star-shaped amphiphilic block copolymer, POSS-PCL-b-PDMAEMA, we engineered a pH-sensitive TP-loaded nanomedicine (TP@NPs) to simultaneously reduce the toxicity of TP and improve its therapeutic efficacy. TP@NPs shows a uniform spherical structure with a hydrodynamic diameter of ~92 nm and notable pH-responsiveness. In vitro TP@NPs showed reduced cytotoxicity and cell apoptosis of treated RAW264.7 cells compared to free TP. And in vivo intravenous injection of indocyanine green-labeled NPs into a collagen-induced arthritis model in mice showed that the engineered compound had potent pharmacokinetic and pharmacodynamic profiles, while exhibiting significant cartilage-protective and anti-inflammatory effects with a better efficacy and neglible systemic toxicity even at an ultralow dose compared to free TP. These results suggest that TP@NPs may be a safe and effective therapy for RA and other autoimmune diseases.

Folate receptor-targeting mesoporous silica-coated gold nanorod nanoparticles for the synergistic photothermal therapy and chemotherapy of rheumatoid arthritis

The synergy of photothermal therapy (PTT) and chemotherapy is widely regarded as an effective treatment for complex diseases, such as cancer and inflammation. In this paper, we report the synthesis of a nanoscaled drug delivery system, which was composed of a gold nanorod (GNR) as the photothermal agent and a mesoporous silica shell as the methotrexate (MTX) reservoir, named FAGMs. Due to folate modification on the surface, FAGMs targeted specifically activated macrophages in rheumatoid arthritis (RA). Under 808 nm laser irradiation, FAGMs could kill macrophages by reaching sufficient local hyperthermia with excellent efficiency in the photothermal conversion of GNRs. Meanwhile, internal heating caused hydrogen bond fracture; thus, MTX released rapidly from FAGMs for localized synergistic PTT and chemotherapy. The FAGMs had a mean particle size of about 180 nm and a zeta potential of 14.36 mV. The release rate of MTX from FAGMs in vitro increased markedly under 808 nm laser irradiation. In a cellular uptake study, stronger fluorescence signals were observed in activated macrophages when treated with FAGMs, suggesting that folic acid molecules enabled the enhancement of endocytosis into activated macrophages. In rats with adjuvant-induced arthritis, synergistic treatment excellently inhibited the progression of RA. These results demonstrated that FAGMs could be promising for the treatment of RA.

Rational design of metal-organic frameworks to deliver methotrexate for targeted rheumatoid arthritis therapy

Methotrexate (MTX) has been used as an anchor drug for the treatment of rheumatoid arthritis (RA), while the patients with chronic MTX administration suffer from severe side-effects. To this end, targeted delivery of MTX by nanomedicine has attracted great interest. In this work, we aimed to employ metal-organic frameworks (MOFs) as nanocarrier to deliver MTX by virtue of its facile and green preparation and exceptionally high drug loading. While MTX could be easily and effectively loaded via different MOF construction strategies, such as direct coordination, physical encapsulation, and covalent conjugation, we found that most of the MTX loading MOFs showed premature and burst drug release, attributable to the unstable coordination between MTX and metals. To address this issue, we rationally designed the MOFs by conjugating MTX with tannic acid (TA) at 2:1 M ratio and then coordinating with ferric ion (Fe³⁺), followed by surface modification of hyaluronic acid (HA). The resulting MOFs achieved ultra-high drug loading (45%) and sustained drug release, and could selectively recognize the diseased cells for anti-inflammatory effect. The in vivo therapeutic evaluation suggested that the MOFs could enhance the anti-rheumatic activity of MTX while minimizing its toxic effects by targeted drug delivery, resulting in improved therapeutic index. This work provides a biocompatible nano-platform to deliver MTX for RA treatment, and importantly, calls for special attention to the gap between MOFs design and their biological applications, and the gap needs to be filled by careful evaluation of in vivo stability and burst drug release.

The double-edged sword effect of macrophage targeting delivery system in different macrophage subsets related diseases

Background

Monocyte/macrophage-targeting delivery systems (MTDSs) have been focused upon as an emerging routine for delivering drugs to treat various macrophage-related diseases. However, the ability of MTDSs to distinguish different macrophage-related diseases and their impact on macrophage function and disease progression have not been systematically revealed, which is important for actively targeted therapeutic or diagnostic strategies.

Results

Herein, we used dextran-modified polystyrene nanoparticles (DEX-PS) to demonstrate that modification of nanoparticles by dextran can specifically enhance their recognition by M2 macrophages in vitro, but it is obstructed by monocytes in peripheral blood according to in vivo assays. DEX-PS not only targeted and became distributed in tumors, an M2 macrophage-related disease, but was also highly distributed in an M1 macrophage-related disease, namely acute peritonitis. Thus, DEX-PS acts as a double-edged sword in these two different diseases by reeducating macrophages to a pro-inflammatory phenotype.

Conclusions

Our results suggest that MTDSs, even those designed based on differential expression of receptors on specific macrophage subtypes, lack the ability to distinguish different macrophage subtype-related diseases in vivo. In addition to the potential impact of these carrier materials on macrophage function, studies of MTDSs should pay greater attention to the distribution of nanoparticles in non-target macrophage-infiltrated disease sites and their impact on disease processes.

X-ray recharged long afterglow luminescent nanoparticles MgGeO3:Mn2+,Yb3+,Li+ in the first and second biological windows for long-term bioimaging

In this paper, we have designed long afterglow luminescent MgGeO₃:Mn²⁺,Yb³⁺,Li⁺ (MGO) nanoparticles in the first (NIR-I) and second (NIR-II) biological windows. Yb³⁺ ions served not only as the trap center to enhance the NIR-I long afterglow emission of Mn²⁺ at 680 nm, but also as an emitting center to produce a NIR-II long afterglow emission at ∼1000 nm. Furthermore, we have found the addition of Li⁺ can greatly increase the NIR-II afterglow emission of Yb³⁺ and the optimal amount of Mn²⁺, Yb³⁺ and Li⁺ was found to be 0.1, 0.5 and 0.5 mol%, respectively. The MGO nanoparticles synthesized using sol-gel methods showed a uniform morphology with a diameter of 50-100 nm, which were suitable for applications in bioimaging. More importantly, we have found MGO nanoparticles can be effectively excited to produce long persistent NIR-I and II luminescence using soft X-rays, suggesting that low dosage soft X-rays can also serve as a more powerful and deep tissue excitation source to recharge MGO nanoparticles. Furthermore, the MGO nanoparticles can also be re-excited to produce photo-stimulated emission under the irradiation of 650 and 808 nm NIR lasers. The in vivo imaging results have shown that MGO nanoparticles modified with folic acid (FA) can effectively realize super long-term targeted in vivo imaging of inflammation with a high sensitivity via recharging using soft X-rays and NIR lasers, which can provide not only an accurate diagnosis of inflammation, but also long-term monitoring of possible changes in the focus of inflammation in real time.

Surfactant-Free, Self-Assembled Nanomicelles-Based Transdermal Hydrogel for Safe and Targeted Delivery of Methotrexate against Rheumatoid Arthritis

Methotrexate (MTX) is the first line agent for therapy against rheumatoid arthritis (RA); however, orally its efficacy is hampered by poor solubility, less permeability, short plasma half-life, and reduced bioavailability. Meanwhile, parenteral formulations are associated with severe adverse effects. In an attempt to improve the efficacy of MTX, we synthesized polycaprolactone-polyethylene glycol-polycaprolactone (PCL-PEG-PCL) triblock copolymer by a ring-opening copolymerization reaction and used it as a carrier for the fabrication of MTX-loaded nanomicelles. Surfactant-free, self-assembled nanomicelles were prepared by nanoprecipitation technique and optimized through central composite design. The optimized nanomicelles exhibited a size distribution of 31 nm and an encapsulation efficiency of 91%. In vitro, the nanomicelles exhibited hemocompatibility, sustained release, and significantly high uptake in lipopolysaccharide activated macrophages. To facilitate application on the skin, optimized nanomicelles were loaded into a Carbopol 934-based hydrogel with eucalyptus oil as a penetration enhancer. Eucalyptus oil significantly improved the permeation of nanomicelles through the skin (p < 0.001). When the hydrogel was applied on the RA mice model, nanomicelles exhibited preferentially highest accumulation in the inflamed joints than other organs. As compared with the free MTX, MTX nanomicelles significantly improved the pharmacokinetic (4.34-fold greater half-life, 3.68-fold higher AUC_0-t, and 3.15-fold higher mean residence time) and pharmacodynamic profile ascertained through low inflammatory cytokines expression, improved oxidation protection, recovered behavioral responses, and radiological analysis. MTX nanomicelles-based hydrogel also significantly reduced the hepatotoxicity and did not activate the immune system. These results suggest that the MTX-loaded nanomicelles-based transdermal hydrogel can prove to be a promising agent against RA.

Avidin-biotin technology to synthesize multi-arm nano-construct for drug delivery

Here we describe methods for synthesizing a cationic, multi-arm Avidin (mAv) nano-construct that has a wide range of applications in drug delivery and imaging of negatively charged tissues. We use Avidin-biotin technology that gives the flexibility for conjugating biotinylated Dexamethasone to mAv by simple mixing at room temperature. We also describe methods to control hydrolysis rates of ester linkers to enable sustained (and tunable) drug release rates in therapeutic doses.•

Multi-arm structure provides multiple sites for covalent conjugation of drugs

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Use of Avidin-biotin reaction gives multi-arm nano-construct a modular design enabling conjugation and delivery of similar sized biotinylated drugs.

Significance of Ligand-Anchored Polymers for Drug Targeting in the Treatment of Colonic Disorders

Treatment of a variety of bowel diseases like Crohn's disease, ulcerative colitis, colonic cancers, colonic pathologies, and systemic delivery of drugs at the target sites can be done with the help of targeted drug delivery technique. Conventional colon specific drug delivery systems lack specificity and release significant amount of drug prior reaching the target site. Hence, efficient drug delivery system that ensures effective release of the drug at the colon is still a sought after research arena. Ligand anchored therapy is a strong and effective approach to execute drug delivery in selective target cells, for both, diagnostic, as well as therapeutic reasons. Compared to the regular drugs, such ligand anchored therapy provides added benefit of minimum toxicity and few side effects. Discovery of overexpressed receptors on diseased cells, as compared to healthy cells led to the emergence of active drug targeting. Further, drug resistance constitutes one of the major reasons of the failure of chemotherapy and presents a major obstacle for the effective treatment. The reason behind drug resistance is exposure of pathological cells/pathogens to sub-therapeutic levels of drugs due lack of specificity of therapeutics. Active targeting, specifically taken up by the target cells, can warrant exposure of pathological cells/pathogens to high drug load at the target and sparing non-target cells hence minimal damage to normal cells and least chance of drug resistance. Many ligands like antibodies, aptamers, peptides, folate, and transferrin have been discovered in the past few years. The design of nanocarriers can be incorporated with many different functions which enables functions like imaging and triggered intracellular drug release. The present review article focuses on advances in ligand anchored therapy and its significance on the progress of targeted nanocarriers. It will also establish novel concepts like multi-targeting and multi-functional nanocarriers for the treatment of colonic disorders.

Stimuli-responsive Drug Delivery Systems as an Emerging Platform for Treatment of Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is a systemic autoimmune disease accompanied by chronic inflammation. Due to the long-term infiltration in inflammatory sites, joints get steadily deteriorated, eventually resulting in functional incapacitation and disability. Despite the considerable effect, RA sufferers treated with current drug therapeutic efficacy are exposed to severe side effects. Application of Drug Delivery Systems (DDS) has improved these situations while the problem of limited drug exposure remains untackled. Stimuli-responsive DDS that are responsive to a variety of endogenous and exogenous stimuli, such as pH, redox status, and temperature, have emerged as a promising therapeutic strategy to optimize the drug release. Herein, we discussed the therapeutic regimes and serious side effects of current RA therapy, as well as focused on some of the potential stimuliresponsive DDS utilized in RA therapy. Besides, the prospective room in designing DDS for RA treatment has also been discussed.

Immunomodulatory Nanosystems

Immunotherapy has emerged as an effective strategy for the prevention and treatment of a variety of diseases, including cancer, infectious diseases, inflammatory diseases, and autoimmune diseases. Immunomodulatory nanosystems can readily improve the therapeutic effects and simultaneously overcome many obstacles facing the treatment method, such as inadequate immune stimulation, off-target side effects, and bioactivity loss of immune agents during circulation. In recent years, researchers have continuously developed nanomaterials with new structures, properties, and functions. This Review provides the most recent advances of nanotechnology for immunostimulation and immunosuppression. In cancer immunotherapy, nanosystems play an essential role in immune cell activation and tumor microenvironment modulation, as well as combination with other antitumor approaches. In infectious diseases, many encouraging outcomes from using nanomaterial vaccines against viral and bacterial infections have been reported. In addition, nanoparticles also potentiate the effects of immunosuppressive immune cells for the treatment of inflammatory and autoimmune diseases. Finally, the challenges and prospects of applying nanotechnology to modulate immunotherapy are discussed.

Trastuzumab-Coated Nanoparticles Loaded With Docetaxel for Breast Cancer Therapy

Docetaxel (DTX) is commonly used for breast cancer treatment. Tween 80 used for DTX dissolution in its clinical formulation causes severe hypersensitivity and other adverse reactions. In this study, trastuzumab (Tmab)-coated lipid-polymer hybrid nanoparticles (PLNs) were prepared, composed of poly (d, l-lactide-co-glycolide), PLGA; polyethylenimine (PEI); and lipids. The PLGA/PEI/lipid formed a hydrophobic core, while Tmab was electrostatically adsorbed on the surface of the PLNs as a ligand that targets human epidermal growth factor receptor 2 (HER2)-positive breast cancer cells. The resulting PLNs, electrostatically adsorbed Tmab-bearing PLGA/PEI/lipid nanoparticles (eTmab-PPLNs), had a mean particle size of 217.4 ± 13.36 nm, a ζ potential of 0.056 ± 0.315 mV, and good stability. In vitro, the eTmab-PPLNs showed increased cytotoxicity in HER2-postive BT474 cells but not in HER2-negative MCF7 cells. Studies of the ability of eTmab-PPLNs to target HER2 were performed. The uptake of eTmab-PPLNs was shown to be dependent on HER2 expression level. Therefore, eTmab-PPLNs provide a promising therapeutic for the treatment of breast cancer.

Secreted Protein Acidic and Rich in Cysteine Mediated Biomimetic Delivery of Methotrexate by Albumin-Based Nanomedicines for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is one of the most common chronic autoimmune diseases. Despite considerable advances in clinical treatment of RA, suboptimal response to therapy and treatment discontinuation are still unresolved challenges due to systemic toxicity. It is of crucial importance to actively target and deliver therapeutic agents to inflamed joints in order to promote in situ activity and decrease systemic toxicity. In this study, we found that SPARC (secreted protein acidic and rich in cysteine) was overexpressed in the synovial fluid and synovium of RA patients as well as mice with collagen-induced arthritis (CIA), which has been scarcely reported. Building upon the SPARC signature of RA joint microenvironment and the intrinsic high affinity of SPARC for albumin, we fabricated methotrexate-loaded human serum albumin nanomedicines (MTX@HSA NMs) and explored them as biomimetic drug delivery systems for RA therapy. Upon intravenous injection of chlorin e6-labeled MTX@HSA NMs into CIA mice, the fluorescence/magnetic resonance dual-modal imaging revealed higher accumulations and longer retention of MTX@HSA NMs in inflamed joints with respect to free MTX molecules. In vivo therapeutic evaluations suggested that the MTX@HSA NMs were able to attenuate the progression of RA with better efficacy and fewer side effects even at half  dose of administrated MTX in comparison with free MTX. By unraveling the mechanism driving the efficient accumulation of MTX@HSA NMs in RA joints and showing their ability to improve the safety and therapeutic efficacy of MTX, our work sheds light on the development of innovative anti-RA nanomedicines with a strong potential for clinical translation.

Multifunctional Nanosystem Based on Graphene Oxide for Synergistic Multistage Tumor-Targeting and Combined Chemo-Photothermal Therapy

Locating nanomedicines at the active sites plays a pivotal role in the nanoparticle-based cancer therapy field. Herein, a multifunctional nanotherapeutic is designed by using graphene oxide (GO) nanosheets with rich carboxyl groups as the supporter for hyaluronic acid (HA)-methotrexate (MTX) prodrug modification via an adipicdihydrazide cross-linker, achieving synergistic multistage tumor-targeting and combined chemo-photothermal therapy. As a tumor-targeting biomaterial, HA can increase affinity of the nanocarrier toward CD44 receptor for enhanced cellular uptake. MTX, a chemotherapeutic agent, can also serve as a tumor-targeting enhancer toward folate receptor based on its similar structure with folic acid. The prepared nanosystems possess a sheet shape with a dynamic size of approximately 200 nm and pH-responsive drug release. Unexpectedly, the physiological stability of HA-MTX prodrug-decorated GO nanosystems in PBS, serum, and even plasma is more excellent than that of HA-decorated GO nanosystems, while both of them exhibit an enhanced photothermal effect than GO nanosheets. More importantly, because of good blood compatibility as well as reduced undesired interactions with blood components, HA-MTX prodrug-decorated GO nanosystems exhibited remarkably superior accumulation at the tumor sites by passive and active targeting mechanisms, achieving highly effective synergistic chemo-photothermal therapeutic effect upon near-infrared laser irradiation, efficient ablation of tumors, and negligible systemic toxicity. Hence, the HA-MTX prodrug-decorated hybrid nanosystems have a promising potential for synergistic multistage tumor-targeting therapy.

Cellulase-Assisted Extraction, Characterization, and Bioactivity against Rheumatoid Arthritis of Astragalus Polysaccharides

This study investigated the effect of cellulase on the isolation of crude Astragalus polysaccharide (APS), analyzed the monosaccharide component of deproteinized APS, detected the molecular weights of purified APS, and examined the biological activities and the preliminary mechanism against rheumatoid arthritis (RA). Compared with water extraction method, cellulase-assisted extraction increased the yield of crude APS to 154% and polysaccharide contents to 121%. Crude APS was then purified by ethanol precipitation, Sevag deproteinization, and high-performance liquid chromatography (HPLC) analysis; monosaccharide contents of APS were different after cellulase-assisted method, especially galacturonic acid content which significantly increased. DEAE-52 cellulose column chromatography isolated three polysaccharide fractions, including a neutral polysaccharide (APS-water) and two acidic polysaccharides (APS-NaCl1 and APS-NaCl2). Using high-performance gel permeation chromatography (HPGPC), the molecular weights of APS-water, APS-NaCl1, and APS-NaCl2 were identified as 67.7 kDa, 234.1 kDa, and 189.4 kDa, respectively. Then their therapeutic effects and possible mechanism against RA were explored using type II collagen-induced arthritis (CIA) rat model. APS could significantly reduce paw swelling, serum concentration of IL-1β and TNF-α, and the expression levels of NF-κB-p65 and IκBα in synovial membranes in CIA rats. Our study indicated that cellulase significantly increases the yield and polysaccharide contents of crude APS, improves the product quality, and preserves the biological features against RA in CIA rats.

The folate receptor β as a macrophage-mediated imaging and therapeutic target in rheumatoid arthritis

Macrophages play a key role in the pathophysiology of rheumatoid arthritis (RA). Notably, positive correlations have been reported between synovial macrophage infiltration and disease activity as well as therapy outcome in RA patients. Hence, macrophages can serve as an important target for both imaging disease activity and drug delivery in RA. Folate receptor β (FRβ) is a glycosylphosphatidyl (GPI)-anchored plasma membrane protein being expressed on myeloid cells and activated macrophages. FRβ harbors a nanomolar binding affinity for folic acid allowing this receptor to be exploited for RA disease imaging (e.g., folate-conjugated PET tracers) and therapeutic targeting (e.g., folate antagonists and folate-conjugated drugs). This review provides an overview of these emerging applications in RA by summarizing and discussing properties of FRβ, expression of FRβ in relation to macrophage polarization, FRβ-targeted in vivo imaging modalities, and FRβ-directed drug targeting.

A Smart pH-Sensitive Delivery System for Enhanced Anticancer Efficacy via Paclitaxel Endosomal Escape

Micelles are highly attractive nano-drug delivery systems for targeted cancer therapy. While they have been demonstrated to significantly alleviate the side-effects of their cargo drugs, the therapy outcomes are usually suboptimal partially due to ineffective drug release and endosome entrapment. Stimulus-responsive nanoparticles have allowed controlled drug release in a smart fashion, and we want to use this concept to design novel micelles. Herein, we reported pH-sensitive paclitaxel (PTX)-loaded poly (ethylene glycol)-phenylhydrazone-dilaurate (PEG-BHyd-dC12) micelles (PEG-BHyd-dC12/PTX). The micelles were spherical, with an average particle size of ∼135 nm and a uniform size distribution. The pH-responsive properties of the micelles were certified by both colloidal stability and drug release profile, where the particle size was strikingly increased accompanied by faster drug release as pH decreased from 7.4 to 5.5. As a result, the micelles exhibited much stronger cytotoxicity than the pH-insensitive counterpart micelles against various types of cancer cells due to the hydrolysis of the building block polymers and subsequent rapid PTX release. Overall, these results demonstrate that the PEG-BHyd-dC12 micelle is a promising drug delivery system for cancer therapy.

Folate-Conjugated Cell Membrane Mimetic Polymer Micelles for Tumor-Cell-Targeted Delivery of Doxorubicin

Tumor-targeting nano-drug-delivery systems hold great potential to improve the therapeutic efficacy and alleviate the side effects of cancer treatments. Herein, folic acid (FA)-decorated amphiphilic copolymer of FA-P(MPC- co-MaPCL) (MPC: 2-methacryloxoethyl phosphorylcholine, MaPCL: poly(ε-caprolactone) macromonomer) is synthesized and its micelles are fabricated for doxorubicin (DOX) delivery. And non-FA-decorated P(MPC- co-MaPCL) micelles are used as the control. Dynamic light scattering and scanning electron microscopy measurements reveal that FA-P(MPC- co-MaPCL) and P(MPC- co-MaPCL) micelles are spherical with average diameters of 140 and 90 nm, respectively. The evaluation in vitro demonstrates that the blank micelles are nontoxic, while DOX-loaded FA-P(MPC- co-MaPCL) micelles show significant cytotoxicity to HeLa cells and slight cytotoxicity to L929 cells. Moreover, the cellular uptake of DOX-loaded FA-P(MPC- co-MaPCL) micelles in HeLa cells are 4.3-fold and 1.7-fold higher than that of DOX-loaded P(MPC- co-MaPCL) micelles and free DOX after 6 h of incubation, respectively. These results indicate the great potential of this system in anticancer target drug-delivery applications.

Polymer-drug conjugates in inflammation treatment

Inflammation is a vital defense mechanism of living organisms. However, persistent and chronic inflammation may lead to severe pathological processes and evolve into various chronic inflammatory diseases (CID), e.g. rheumatoid arthritis, multiple sclerosis, multiple sclerosis, systemic lupus erythematosus or inflammatory bowel diseases, or certain types of cancer. Their current treatment usually does not lead to complete remission. The application of nanotherapeutics may significantly improve CID treatment, since their accumulation in inflamed tissues has been described and is referred to as extravasation through leaky vasculature and subsequent inflammatory cell-mediated sequestration (ELVIS). Among nanotherapeutics, water-soluble polymer-drug conjugates may be highly advantageous in CID treatment due to the possibility of their passive and active targeting to the inflammation site and controlled release of active agents once there. The polymer-drug conjugate consists of a hydrophilic biocompatible polymer backbone along which the drug molecules are covalently attached via a biodegradable linker that enables controlled drug release. Their active targeting or bio-imaging can be achieved by introducing the cell-specific targeting moiety or imaging agents into the polymer conjugate. Here, we review the relationship between polymer conjugates and inflammation, including the benefits of the application of polymer conjugates in inflammation treatment, the anti-inflammatory activity of polymer drug conjugates and potential polymer-promoted inflammation and immunogenicity.

Hyaluronic Acid Coated Acid-Sensitive Nanoparticles for Targeted Therapy of Adjuvant-Induced Arthritis in Rats

Activated macrophages play a vital role in rheumatoid arthritis (RA) pathophysiology. CD44 is an overexpressed receptor on activated macrophages that is a potential target site for RA treatment. In this study, we prepared hyaluronic acid (HA) coated acid-sensitive polymeric nanoparticles (HAPNPs) composed of egg phosphatidylcholine, polyethylenimine, and poly (cyclohexane-1,4-diyl acetone dimethylene ketal) (PCADK) loaded with dexamethasone (Dex) for the treatment of RA. PCADK was used to form polymeric cores because of its acid-sensitivity. The HAPNPs were about 150 nm in size and had a zeta potential of -2.84 mV. The release rate of Dex from HAPNPs/Dex in vitro increased markedly when the pH decreased from 7.4 to 4.5, indicating that the HAPNPs were pH-sensitive. In a cellular uptake study, stronger fluorescence signals were observed in activated macrophages treated with HAPNPs, suggesting that HAPNPs could be effective nanodevices target to activated macrophages. In rats with adjuvant-induced arthritis, HAPNPs could inhibited the progression of RA. Taken together, these results suggest that the HAPNPs could be useful in RA therapy.

Ultrasound-triggered perfluorocarbon-derived nanobombs for targeted therapies of rheumatoid arthritis

The targeted US-triggered PFC-based “nanobombs” with US used to treat the RA in this work would offer a new treatment strategy and have a great potential for the application in the areas of theranostic agent and nanomedicine treatment.