Immunomodulatory Microparticles Epigenetically Modulate T Cells and Systemically Ameliorate Autoimmune Arthritis

Advances in local drug delivery technologies for improved rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by an inflammatory microenvironment and cartilage erosion within the joint cavity. Currently, antirheumatic agents yield significant outcomes in RA treatment. However, their systemic administration is limited by inadequate drug retention in lesion areas and non-specific tissue distribution, reducing efficacy and increasing risks such as infection due to systemic immunosuppression. Development in local drug delivery technologies, such as nanostructure-based and scaffold-assisted delivery platforms, facilitate enhanced drug accumulation at the target site, controlled drug release, extended duration of the drug action, reduced both dosage and administration frequency, and ultimately improve therapeutic outcomes with minimized damage to healthy tissues. In this review, we introduced pathogenesis and clinically used therapeutic agents for RA, comprehensively summarized locally administered nanostructure-based and scaffold-assisted drug delivery systems, aiming at improving the therapeutic efficiency of RA by alleviating the inflammatory response, preventing bone erosion and promoting cartilage regeneration. In addition, the challenges and future prospects of local delivery for clinical translation in RA are discussed.

ABCD of IA: A multi-scale agent-based model of T cell activation in inflammatory arthritis

Biomaterial-based agents have been demonstrated to regulate the function of immune cells in models of autoimmunity. However, the complexity of the kinetics of immune cell activation can present a challenge in optimizing the dose and frequency of administration. Here, we report a model of autoreactive T cell activation, which are key drivers in autoimmune inflammatory joint disease. The model is termed a multi-scale Agent-Based, Cell-Driven model of Inflammatory Arthritis (ABCD of IA). Using kinetic rate equations and statistical theory, ABCD of IA simulated the activation and presentation of autoantigens by dendritic cells, interactions with cognate T cells and subsequent T cell proliferation in the lymph node and IA-affected joints. The results, validated with in vivo data from the T cell driven SKG mouse model, showed that T cell proliferation strongly correlated with the T cell receptor (TCR) affinity distribution (TCR-ad), with a clear transition state from homeostasis to an inflammatory state. T cell proliferation was strongly dependent on the amount of antigen in antigenic stimulus event (ASE) at low concentrations. On the other hand, inflammation driven by Th17-inducing cytokine mediated T cell phenotype commitment was influenced by the initial level of Th17-inducing cytokines independent of the amount of arthritogenic antigen. The introduction of inhibitory artificial antigen presenting cells (iaAPCs), which locally suppress T cell activation, reduced T cell proliferation in a dose-dependent manner. The findings in this work set up a framework based on theory and modeling to simulate personalized therapeutic strategies in IA.

The therapeutic potential of immunoengineering for systemic autoimmunity

Disease-modifying drugs have transformed the treatment options for many systemic autoimmune diseases. However, an evolving understanding of disease mechanisms, which might vary between individuals, is paving the way for the development of novel agents that operate in a patient-tailored manner through immunophenotypic regulation of disease-relevant cells and the microenvironment of affected tissue domains. Immunoengineering is a field that is focused on the application of engineering principles to the modulation of the immune system, and it could enable future personalized and immunoregulatory therapies for rheumatic diseases. An important aspect of immunoengineering is the harnessing of material chemistries to design technologies that span immunologically relevant length scales, to enhance or suppress immune responses by re-balancing effector and regulatory mechanisms in innate or adaptive immunity and rescue abnormalities underlying pathogenic inflammation. These materials are endowed with physicochemical properties that enable features such as localization in immune cells and organs, sustained delivery of immunoregulatory agents, and mimicry of key functions of lymphoid tissue. Immunoengineering applications already exist for disease management, and there is potential for this new discipline to improve disease modification in rheumatology.

Immunomodulatory Nanoparticles for Modulating Arthritis Flares

Disease-modifying drugs have improved the treatment for autoimmune joint disorders, such as rheumatoid arthritis, but inflammatory flares are a common experience. This work reports the development and application of flare-modulating poly(lactic-co-glycolic acid)-poly(ethylene glycol)-maleimide (PLGA-PEG-MAL)-based nanoparticles conjugated with joint-relevant peptide antigens, aggrecan70-84 and type 2 bovine collagen256-270. Peptide-conjugated PLGA-PEG-MAL nanoparticles encapsulated calcitriol, which acted as an immunoregulatory agent, and were termed calcitriol-loaded nanoparticles (CLNP). CLNP had a ∼200 nm hydrodynamic diameter with a low polydispersity index. In vitro, CLNP induced phenotypic changes in bone marrow derived dendritic cells (DC), reducing the expression of costimulatory and major histocompatibility complex class II molecules, and proinflammatory cytokines. Bulk RNA sequencing of DC showed that CLNP enhanced expression of Ctla4, a gene associated with downregulation of immune responses. In vivo, CLNP accumulated in the proximal lymph nodes after intramuscular injection. Administration of CLNP was not associated with changes in peripheral blood cell numbers or cytokine levels. In the collagen-induced arthritis and SKG mouse models of autoimmune joint disorders, CLNP reduced clinical scores, prevented bone erosion, and preserved cartilage proteoglycan, as assessed by high-resolution microcomputed tomography and histomorphometry analysis. The disease protective effects were associated with increased CTLA-4 expression in joint-localized DC and CD4+ T cells but without generalized suppression of T cell-dependent immune response. The results support the potential of CLNP as modulators of disease flares in autoimmune arthropathies.

Postbiotics in rheumatoid arthritis: emerging mechanisms and intervention perspectives

Rheumatoid arthritis (RA) is a prevalent chronic autoimmune disease that affects individuals of all age groups. Recently, the association between RA and the gut microbiome has led to the investigation of postbiotics as potential therapeutic strategies. Postbiotics refer to inactivated microbial cells, cellular components, or their metabolites that are specifically intended for the microbiota. Postbiotics not only profoundly influence the occurrence and development of RA, but they also mediate various inflammatory pathways, immune processes, and bone metabolism. Although they offer a variety of mechanisms and may even be superior to more conventional "biotics" such as probiotics and prebiotics, research on their efficacy and clinical significance in RA with disruptions to the intestinal microbiota remains limited. In this review, we provide an overview of the concept of postbiotics and summarize the current knowledge regarding postbiotics and their potential use in RA therapy. Postbiotics show potential as a viable adjunctive therapy option for RA.

Futuristic Novel Therapeutic Approaches in the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic inflammation and joint destruction, leading to significant morbidity and reduced quality of life. Although significant progress has been made in the management of RA over the past few decades, many patients still fail to respond adequately to currently available therapies. This article aims to review the current landscape of RA treatment and explore potential novel therapeutic approaches that hold promise for the future. Advances in our understanding of the underlying pathogenesis of the disease have led to the identification of new targets and the development of innovative treatment strategies. This review focuses on emerging therapies including small molecule inhibitors, targeted biologics, cell-based therapies, and gene editing technologies that have shown potential in preclinical and early clinical trials. Additionally, we discuss the challenges and opportunities associated with the use of these new approaches in the treatment of RA. By elucidating the future of novel therapeutic approaches, this article provides insights that can guide clinicians and researchers in their efforts to improve outcomes for patients with RA.

The Recent Applications of PLGA-Based Nanostructures for Ischemic Stroke

With the accelerated development of nanotechnology in recent years, nanomaterials have become increasingly prevalent in the medical field. The poly (lactic acid-glycolic acid) copolymer (PLGA) is one of the most commonly used biodegradable polymers. It is biocompatible and can be fabricated into various nanostructures, depending on requirements. Ischemic stroke is a common, disabling, and fatal illness that burdens society. There is a need for further improvement in the diagnosis and treatment of this disease. PLGA-based nanostructures can facilitate therapeutic compounds' passage through the physicochemical barrier. They further provide both sustained and controlled release of therapeutic compounds when loaded with drugs for the treatment of ischemic stroke. The clinical significance and potential of PLGA-based nanostructures can also be seen in their applications in cell transplantation and imaging diagnostics of ischemic stroke. This paper summarizes the synthesis and properties of PLGA and reviews in detail the recent applications of PLGA-based nanostructures for drug delivery, disease therapy, cell transplantation, and the imaging diagnosis of ischemic stroke.

Immunomodulatory Microparticles Epigenetically Modulate T Cells and Systemically Ameliorate Autoimmune Arthritis

Disease modifying antirheumatic drugs (DMARDs) have improved the prognosis of autoimmune inflammatory arthritides but a large fraction of patients display partial or nonresponsiveness to front-line DMARDs. Here, an immunoregulatory approach based on sustained joint-localized release of all-trans retinoic acid (ATRA), which modulates local immune activation and enhances disease-protective T cells and leads to systemic disease control is reported. ATRA imprints a unique chromatin landscape in T cells, which is associated with an enhancement in the differentiation of naïve T cells into anti-inflammatory regulatory T cells (Treg ) and suppression of Treg destabilization. Sustained release poly-(lactic-co-glycolic) acid (PLGA)-based biodegradable microparticles encapsulating ATRA (PLGA-ATRA MP) are retained in arthritic mouse joints after intra-articular (IA) injection. IA PLGA-ATRA MP enhance migratory Treg which in turn reduce inflammation and modify disease in injected and uninjected joints, a phenotype that is also reproduced by IA injection of Treg . PLGA-ATRA MP reduce proteoglycan loss and bone erosions in the SKG and collagen-induced arthritis mouse models of autoimmune arthritis. Strikingly, systemic disease modulation by PLGA-ATRA MP is not associated with generalized immune suppression. PLGA-ATRA MP have the potential to be developed as a disease modifying agent for autoimmune arthritis.