Synergistic and receptor-mediated targeting of arthritic joints via intra-articular injectable smart hydrogels containing leflunomide-loaded lipid nanocarriers

Combined photodynamic therapy and hollow microneedle approach for effective non-invasive delivery of hypericin for the management of imiquimod-induced psoriasis

BACKGROUND

Conventional topical psoriasis treatments suffer from limited delivery to affected areas and skin irritation due to high local drug concentration.

PURPOSE

This study aims to prepare hypericin (HYP) loaded nanostructured lipid carriers (NLCs) and their application in psoriasis treatment through intradermal administration using hollow microneedles assisted by photodynamic therapy.

METHODS

The colloidal characteristics of NLCs, entrapment efficiency and morphology were evaluated. An ex-vivo skin distribution study was conducted along with testing the in vivo antipsoriatic activity in mice with the imiquimod-induced psoriasis model.

RESULTS

The particle size and zeta potential of HYP-NLCs were 167.70 nm and -18.1, respectively. The ex-vivo skin distribution study demonstrated the superior distribution of HYP-NLCs to a depth of 1480 µm within the skin layers relative to only 750 µm for free HYP. In vivo studies revealed that the levels of NF-KB, IL 6, MMP1, GSH, and catalase in the group treated with HYP-NLCs in the presence of light were comparable to the negative control.

CONCLUSIONS

The histopathological inspection of dissected skin samples reflected the superiority of HYP-NLCs over HYP ointment. This could be ascribed to the effect of nanoencapsulation on improving HYP properties besides the ability of hollow microneedles to ensure effective HYP delivery to the affected psoriatic area.

Melatonin hyalurosomes in collagen thermosensitive gel as a potential repurposing approach for rheumatoid arthritis management via the intra-articular route

Despite the fact that several rheumatoid arthritis treatments have been utilized, none of them achieved complete joint healing and has been accompanied by several side effects that compromise patient compliance. This study aims to provide an effective safe RA treatment with minimum side effects through the encapsulation of melatonin (MEL) in hyalurosomes and loading these hyalurosomes in collagen thermos-sensitive poloxamer 407 (PCO) hydrogels, followed by their intra-articular administration in AIA model rats. In vitro characterization of MEL-hyalurosomes and PCO hydrogel along with in vivo evaluation of the selected formulation were conducted. Particle size, PDI and EE % of the selected formulation were 71.5 nm, 0.09 and 90 %. TEM micrographs demonstrated that the particles had spherical shape with no aggregation signs. Loading PCO hydrogels with MEL-hyalurosomes did not cause significant changes in pH although it increased its viscosity and injection time. FTIR analysis showed that no interactions were noted among the delivery system components. In vivo results revealed the superior effect of MEL-hyalurosomes PCO hydrogel over MEL-PCO hydrogel and blank PCO hydrogels in improving joint healing, cartilage repair, pannus formation and cell infiltrations. Also, MEL-hyalurosomes PCO hydrogel group showed comparable levels of TNF-α, IL1, MDA, NRF2 and HO-1 with the negative control group. These findings highlight the MEL encapsulation role in augmenting its pharmacological effects along with the synergistic effect of hyaluronic acid in hyalurosomes and collagen in PCO hydrogel in promoting joint healing.

Hydrogel-based approaches to target hypersensitivity mechanisms underlying autoimmune disease

A robust adaptive immune response is essential for combatting pathogens. In the wrong context such as due to genetic and environmental factors, however, the same mechanisms crucial for self-preservation can lead to a loss of self-tolerance. Resulting autoimmunity manifests in the development of a host of organ-specific or systemic autoimmune diseases, hallmarked by aberrant immune responses and tissue damage. The prevalence of autoimmune diseases is on the rise, medical management of which focuses primarily on pharmacological immunosuppression that places patients at a risk of side effects, including opportunistic infections and tumorigenesis. Biomaterial-based drug delivery systems confer many opportunities to address challenges associated with conventional disease management. Hydrogels, in particular, can protect encapsulated cargo (drug or cell therapeutics) from the host environment, afford their presentation in a controlled manner, and can be tailored to respond to disease conditions or support treatment via multiplexed functionality. Moreover, localized delivery to affected sites by these approaches has the potential to concentrate drug action at the site, reduce off-target exposure, and enhance patient compliance by reducing the need for frequent administration. Despite their many benefits for the management of autoimmune disease, such biomaterial-based approaches focus largely on the downstream effects of hypersensitivity mechanisms and have a limited capacity to eradicate the disease. In contrast, direct targeting of mechanisms of hypersensitivity reactions uniquely enables prophylaxis or the arrest of disease progression by mitigating the basis of autoimmunity. One promising approach is to induce self-antigen-specific tolerance, which specifically subdues damaging autoreactivity while otherwise retaining the normal immune responses. In this review, we will discuss hydrogel-based systems for the treatment of autoimmune disease, with a focus on those that target hypersensitivity mechanisms head-on. As the field continues to advance, it will expand the range of therapeutic choices for people coping with autoimmune diseases, providing fresh prospects for better clinical outcomes and improved quality of life.

Enhancing anti-inflammatory effect of brucine nanohydrogel using rosemary oil: a promising strategy for dermal delivery in arthritic inflammation

Brucine (BRU), an active constituent of Strychnos nux-vomica L., is one of the potential agents to control subside swelling in arthritis. However, its hydrophobic nature, poor permeation, shorter half-life, narrow therapeutic window, and higher toxicity impede its clinical applications. Hence, this investigation was aimed to develop and evaluate novel BRU loaded β-cyclodextrin (β-CD) nanosponges (BRUNs) hydrogel consisting rosemary essential oil (RO), which have been tailored for delayed release, enhanced skin permeation, and reduced irritation, while retaining anti-oxidant and anti-inflammatory activities of this bioactive. Firstly, BRUNs were fabricated by melt technique and characterized appropriately. BRUNs6 demonstrated two fold enhancement in BRU solubility (441.692 ± 38.674) with minimum particle size (322.966 ± 54.456) having good PDI (0.571 ± 0.091) and zeta potential (-14.633 ± 6.357). In vitro release results demonstrated delayed release of BRU from BRUNs6 (67 ± 4.25%) over 24 h through molecular diffusion mechanism. Further, preserved anti-inflammatory (53.343 ± 0.191%) and antioxidant potential (60.269 ± 0.073%) of bioactive was observed in BRUNs6. Hence, this Ns batch was engrossed with Carbopol®934 hydrogel with RO and characterized. In vitro (release and anti-inflammatory activity), ex-vivo (skin permeability) and in vivo (carrageenan-induced inflammation) assays along with irritation study were conducted for fabricated hydrogels. Results revealed that in vitro release of BRU was further delayed from Ns hydrogel with RO (56.45 ± 3.01%) following Fickian mechanism. Considerable enhancement in skin permeability (60.221 ± 0.322 µg/cm2/h) and preservation of anti-inflammatory activity (94.736 ± 2.002%) was also observed in BRUNs6 hydrogel containing RO. The irritation of BRU was found reduced (half) after its entrapped in Ns. Further, as a proof of concept, BRUNs6 hydrogel with RO effectively reduced (75.757 ± 0.944%) carrageenan-induced inflammation in rat model in comparison to pure BRU (54.914 ± 1.081%). Hence, BRUNs hydrogel with RO can be considered as a promising alternative for dermal delivery of BRU in arthritis.

A review of hyaluronic acid-based therapeutics for the treatment and management of arthritis

Hyaluronic acid (HA), a biodegradable, biocompatible and non-immunogenic therapeutic polymer is a key component of the cartilage extracellular matrix (ECM) and has been widely used to manage two major types of arthritis, osteoarthritis (OA) and rheumatoid arthritis (RA). OA joints are characterized by lower concentrations of depolymerized (low molecular weight) HA, resulting in reduced physiological viscoelasticity, while in RA, the associated immune cells are over-expressed with various cell surface receptors such as CD44. Due to HA's inherent viscoelastic property and its ability to target CD44, there has been a surge of interest in developing HA-based systems to deliver various bioactives (drugs and biologics) and manage arthritis. Considering therapeutic benefits of HA in arthritis management and potential advantages of novel delivery systems, bioactive delivery through HA-based systems is beginning to display improved outcomes over bioactive only treatment. The benefits include enhanced bioactive uptake due to receptor-mediated targeting, prolonged retention of bioactives in the synovium, reduced expressions of proinflammatory mediators, enhanced cartilage regeneration, reduced drug toxicity due to sustained release, and improved and cost-effective treatment. This review provides an underlying rationale to prepare and use HA-based bioactive delivery systems for arthritis applications. With special emphasis given to preclinical/clinical results, this article reviews various bioactive-loaded HA-based particulate carriers (organic and inorganic), gels, scaffolds and polymer-drug conjugates that have been reported to treat and manage OA and RA. Furthermore, the review identifies several key challenges and provides valuable suggestions to address them. Various developments, strategies and suggestions described in this review may guide the formulation scientists to optimize HA-based bioactive delivery systems as an effective approach to manage and treat arthritis effectively.

Hypericin emulsomes combined with hollow microneedles as a non-invasive photodynamic platform for rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is a joint-destructive autoimmune disease that severely affects joint function. Despite the variability of treatment protocols, all of them are associated with severe side effects that compromise patient compliance. The main aim of the current study is to prepare localized effective RA treatment with reduced side effects by combining nanoencapsulation, photodynamic therapy (PDT) and hollow microneedles (Ho-MNs) to maximize the pharmacological effects of hypericin (HYP). To attain this, HYP-loaded emulsomes (EMLs) were prepared, characterized and administered through intradermal injection using AdminPen™ Ho-MNs combined with PDT in rats with an adjuvant-induced RA model. The prepared EMLs had a spherical shape and particle size was about 93.46 nm with an absolute entrapment efficiency. Moreover, confocal imaging indicated the interesting capability of Ho-MNs to deposit the HYP EMLs to a depth reaching 1560 µm into the subcutaneous tissue. In vivo, study results demonstrated that the group treated with HYP EMLs through Ho-MNs combined with PDT had no significant differences in joint diameter, TNF-α, IL1, HO-1, NRF2 and SD levels compared with the negative control group. Similarly, rats treated with the combination of HYP EMLs, Ho-MNs and PDT showed superior joint healing efficacy compared with the groups treated with HYP EMLs in dark, HYP ointment or HYP in microneedles in histopathological examination. These findings highlight the promising potential of photoactivated HYP EMLs when combined with Ho-MNs technology for RA management. The presented therapeutic EMLs-MNs platform could serve as a powerful game-changer in the development of future localized RA treatments.

Development of biomedical hydrogels for rheumatoid arthritis treatment

Rheumatoid Arthritis (RA) is an autoimmune disorder that hinders the normal functioning of bones and joints and reduces the quality of human life. Every year, millions of people are diagnosed with RA worldwide, particularly among elderly individuals and women. Therefore, there is a global need to develop new biomaterials, medicines and therapeutic methods for treating RA. This will improve the Healthcare Access and Quality Index and also relieve administrative and financial burdens on healthcare service providers at a global scale. Hydrogels are soft and cross-linked polymeric materials that can store a chunk of fluids, drugs and biomolecules for hydration and therapeutic applications. Hydrogels are biocompatible and exhibit excellent mechanical properties, such as providing elastic cushions to articulating joints by mimicking the natural synovial fluid. Hence, hydrogels create a natural biological environment within the synovial cavity to reduce autoimmune reactions and friction. Hydrogels also lubricate the articulating joint surfaces to prevent degradation of synovial surfaces of bones and cartilage, thus exhibiting high potential for treating RA. This work reviews the progress in injectable and implantable hydrogels, synthesis methods, types of drugs, advantages and challenges. Additionally, it discusses the role of hydrogels in targeted drug delivery, mechanistic behaviour and tribological performance for RA treatment.

The management of osteoarthritis symptomatology through nanotechnology: a patent review

Osteoarthritis is considered a degenerative joint disease that is characterised by inflammation, chronic pain, and functional limitation. The increasing development of nanotechnology in drug delivery systems has provided new ideas and methods for osteoarthritis therapy. This review aimed to evaluate patents that have developed innovations, therapeutic strategies, and alternatives using nanotechnology in osteoarthritis treatment. The results show patents deposited from 2015 to November 2021 in the online databases European Patent Office and World Intellectual Property Organisation. A total of 651 patents were identified for preliminary assessment and 16 were selected for full reading and discussion. The evaluated patents are focused on the intraarticular route, oral route, and topical route for osteoarthritis treatment. The intraarticular route presented a higher patent number, followed by the oral and topical routes, respectively. The development of new technologies allows us to envision a promising and positive future in osteoarthritis treatment.

Arthritic Microenvironment-Dictated Fate Decisions for Stem Cells in Cartilage Repair

The microenvironment and stem cell fate guidance of post-traumatic articular cartilage regeneration is primarily the focus of cartilage tissue engineering. In articular cartilage, stem cells are characterized by overlapping lineages and uneven effectiveness. Within the first 12 weeks after trauma, the articular inflammatory microenvironment (AIME) plays a decisive role in determining the fate of stem cells and cartilage. The development of fibrocartilage and osteophyte hyperplasia is an adverse outcome of chronic inflammation, which results from an imbalance in the AIME during the cartilage tissue repair process. In this review, the sources for the different types of stem cells and their fate are summarized. The main pathophysiological events that occur within the AIME as well as their protagonists are also discussed. Additionally, regulatory strategies that may guide the fate of stem cells within the AIME are proposed. Finally, strategies that provide insight into AIME pathophysiology are discussed and the design of new materials that match the post-traumatic progress of AIME pathophysiology in a spatial and temporal manner is guided. Thus, by regulating an appropriately modified inflammatory microenvironment, efficient stem cell-mediated tissue repair may be achieved.

Hyaluronic Acid in Rheumatology

Hyaluronic acid (HA), also known as hyaluronan, is an anionic glycosaminoglycan widely distributed throughout various tissues of the human body. It stands out from other glycosaminoglycans as it lacks sulfation and can attain considerable size: the average human synovial HA molecule weighs about 7 million Dalton (Da), equivalent to roughly 20,000 disaccharide monomers; although some sources report a lower range of 3-4 million Da. In recent years, HA has garnered significant attention in the field of rheumatology due to its involvement in joint lubrication, cartilage maintenance, and modulation of inflammatory and/or immune responses. This review aims to provide a comprehensive overview of HA's involvement in rheumatology, covering its physiology, pharmacology, therapeutic applications, and potential future directions for enhancing patient outcomes. Nevertheless, the use of HA therapy in rheumatology remains controversial with conflicting evidence regarding its efficacy and safety. In conclusion, HA represents a promising therapeutic option to improve joint function and alleviate inflammation and pain.

Preparation, Properties and Therapeutic Effect of a TPL Nanoparticle Thermosensitive Gel for Intra-Articular Injection

Most injectable preparations for the articular cavity are solution-type preparations that are frequently administered because of rapid elimination. In this study, triptolide (TPL), an effective ingredient in the treatment of rheumatoid arthritis (RA), was prepared in the form of a nanoparticle thermosensitive gel (TPL-NS-Gel). The particle size distribution and gel structure were investigated by TEM, laser particle size analysis and laser capture microdissection. The effect of the nanoparticle carrier material PLGA on the phase transition temperature was investigated by ¹H variable temperature NMR and DSC. The tissue distribution, pharmacokinetic behavior, four inflammatory factors and therapeutic effect were determined in a rat RA model. The results suggested that PLGA increased the gel phase transition temperature. The drug concentration of the TPL-NS-Gel group in joint tissues was higher than that in other tissues at different time points, and the retention time was longer than that of the TPL-NS group. After 24 days of administration, TPL-NS-Gel significantly improved the joint swelling and stiffness of the rat models, and the improvement degree was better than that of the TPL-NS group. TPL-NS-Gel significantly decreased the levels of hs-CRP, IL-1, IL-6 and TNF-α in serum and joint fluid. There was a significant difference between the TPL-NS-Gel and TPL-NS groups on Day 24 (p < 0.05). Pathological section results showed that inflammatory cell infiltration was lower in the TPL-NS-Gel group, and no other obvious histological changes were observed. Upon articular injection, the TPL-NS-Gel prolonged drug release, reduced the drug concentration outside the articular tissue and improved the therapeutic effect in a rat RA model. The TPL-NS-Gel can be used as a new type of sustained-release preparation for articular injection.

Development and Evaluation of Novel Leflunomide SPION Bioemulsomes for the Intra-Articular Treatment of Arthritis

Systemic treatments for rheumatoid arthritis are associated with many side effects. This study aimed to minimize the side effects associated with the systemic administration of leflunomide (LEF) by formulating LEF-loaded emulsomes (EMLs) for intra-articular administration. Additionally, EMLs were loaded with supramagnetic nanoparticles (SPIONs) to enhance joint localization, where a magnet was placed on the joint area after intra-articular administration. Full in vitro characterization, including colloidal characteristics, entrapment efficiency, and in vitro release were conducted besides the in vivo evaluation in rats with adjuvant-induced arthritis. In vivo study included joint diameter measurement, X-ray radiographic analysis, RT-PCR analysis, Western blotting, ELISA for inflammatory markers, and histopathological examination of dissected joints. The particle size and entrapment efficiency of the selected LEF SPION EMLs were 198.2 nm and 83.7%, respectively. The EMLs exhibited sustained release for 24 h. Moreover, in vivo evaluation revealed LEF SPION EMLs to be superior to the LEF suspension, likely due to the increase in LEF solubility by nanoencapsulation that improved the pharmacological effects and the use of SPION that ensured the localization of EMLs in the intra-articular cavity upon administration.

Advanced injectable hydrogels for cartilage tissue engineering

The rapid development of tissue engineering makes it an effective strategy for repairing cartilage defects. The significant advantages of injectable hydrogels for cartilage injury include the properties of natural extracellular matrix (ECM), good biocompatibility, and strong plasticity to adapt to irregular cartilage defect surfaces. These inherent properties make injectable hydrogels a promising tool for cartilage tissue engineering. This paper reviews the research progress on advanced injectable hydrogels. The cross-linking method and structure of injectable hydrogels are thoroughly discussed. Furthermore, polymers, cells, and stimulators commonly used in the preparation of injectable hydrogels are thoroughly reviewed. Finally, we summarize the research progress of the latest advanced hydrogels for cartilage repair and the future challenges for injectable hydrogels.

Hyaluronic acid coated teriflunomide (A771726) loaded lipid carriers for the oral management of rheumatoid arthritis

Systemic rheumatoid arthritis treatment has been associated with numerous side effects. We attempted to formulate hyaluronic acid (HA)-coated teriflunomide (TER)-loaded nanostructured lipid carriers (NLCs) that can target inflamed rheumatic joints following oral administration. In vitro evaluation including colloidal characteristics, drug release and stability studies were conducted. Also, cytotoxicity studies on THP1 and peripheral blood mononuclear cells besides testing the binding of HA coated TER-NLCs to CD44 receptors were carried out. Furthermore, pharmacokinetics following oral administration, anti-arthritic effects, hepato and nephrotoxicity of NLCs were assessed. Selected NLCs formulation was approximately 284.9 ± 3.8 nm in size with 96.89 ± 0.45% entrapment efficiency and provided a sustained release for 30 days. NLCs showed good stability that was confirmed by TEM examination. Cell culture studies revealed that HA-coated TER- NLCs showed superior cytotoxicity and binding affinity to CD44 receptors compared with TER suspension. In vivo studies demonstrated the superiority of NLCs in increasing TER bioavailability, reducing TNF-α serum levels and improving joint healing that was evidenced in both histopathological and X-ray radiographic examination. This may be attributed to the ability of HA-coated TER-NLCs to target rheumatic joints passively and actively by targeting CD44 receptors that are overexpressed in rheumatic joints.

Research progress in drug therapy of juvenile idiopathic arthritis

BACKGROUND

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children. With the gradual expansion of the incidence of JIA in the population, the pathogenesis and treatment of JIA were further explored and analyzed, and JIA has achieved some success in drug therapy.

DATA SOURCES

A systemic literature search was conducted on PubMed, Cochrane Library, EMBASE, ISI Web of Science, the US National Institutes of Health Ongoing Trials Register, and the EU Clinical Trials Register. Through the searching of clinical trials of JIA in recent years, we summarized the progress of the clinical treatment of JIA.

RESULTS

The main treatment drugs for JIA include non-steroidal anti-inflammatory drugs, glucocorticoids, disease-modifying antirheumatic drugs and biological agents. So far, a variety of biological agents targeting the cytokines and receptors involved in its pathogenesis have been gradually approved for JIA in many countries. The application of biological agents in JIA showed good efficacy and safety, bringing unprecedented experience to children and adolescents with JIA.

CONCLUSIONS

The potential and advantages of biologic agents in the treatment of JIA are significant, and the application of biologic agents in the treatment of JIA will be more and more common.