In Situ Forming Injectable Hydrogel For Encapsulation Of Nanoiguratimod And Sustained Release Of Therapeutics

Therapeutic delivery systems for rheumatoid arthritis based on hydrogel carriers

Rheumatoid arthritis (RA) is an autoimmune disease suffered by millions of people worldwide. It can significantly affect the patient's quality of life by damaging not only the joints but also organs such as the lungs and the heart. RA is normally treated using nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, disease-modifying antirheumatic drugs (DMARDs), and biologics. These active agents often cause side effects and offer low efficacy due to their lack of specificity and limited retention time. In an attempt to improve RA treatments, hydrogel-based systems have been proposed as drug delivery carriers. Due to their exceptional adaptability and biocompatibility, hydrogels have the potential of enhancing the delivery of RA therapy through different administration routes in an efficient and effective manner. In this review, we explore the application of hydrogel systems as potential carriers in RA treatment. Additionally, we discuss recent work in the field and highlight the required hydrogel properties, depending on the administration route. The outstanding potential of hydrogel systems as carriers for RA was demonstrated; however, there is extensive research yet to be done to improve available treatments for RA.

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.

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.

Hydrogels for the treatment of rheumatoid arthritis

Rheumatoid Arthritis is a universal disease that severely affects the normal function of human joints and the quality of life. Millions of people around the world are diagnosed with rheumatoid arthritis every year, carrying a substantial burden for both the individual and society. Hydrogel is a polymer material with good mechanical properties and biocompatibility, which shows great potential in the treatment of rheumatoid arthritis. With the progress of tissue engineering and biomedical material technology in recent years, more and more studies focus on the application of hydrogels in rheumatoid arthritis. We reviewed the progress of hydrogels applied in rheumatoid arthritis in recent years. Also, the needed comprehensive performance and current applications of therapeutic hydrogels based on the complex pathophysiological characteristics of rheumatoid arthritis are also concluded. Additionally, we proposed the challenges and difficulties in the application of hydrogels in rheumatoid arthritis and put forward some prospects for the future research.

Polymeric Hydrogels for Controlled Drug Delivery to Treat Arthritis

Rheumatoid arthritis (RA) and osteoarthritis (OA) are disabling musculoskeletal disorders that affect joints and cartilage and may lead to bone degeneration. Conventional delivery of anti-arthritic agents is limited due to short intra-articular half-life and toxicities. Innovations in polymer chemistry have led to advancements in hydrogel technology, offering a versatile drug delivery platform exhibiting tissue-like properties with tunable drug loading and high residence time properties This review discusses the advantages and drawbacks of polymeric materials along with their modifications as well as their applications for fabricating hydrogels loaded with therapeutic agents (small molecule drugs, immunotherapeutic agents, and cells). Emphasis is given to the biological potentialities of hydrogel hybrid systems/micro-and nanotechnology-integrated hydrogels as promising tools. Applications for facile tuning of therapeutic drug loading, maintaining long-term release, and consequently improving therapeutic outcome and patient compliance in arthritis are detailed. This review also suggests the advantages, challenges, and future perspectives of hydrogels loaded with anti-arthritic agents with high therapeutic potential that may alter the landscape of currently available arthritis treatment modalities.

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

Background

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

Results

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

Conclusion

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

Graphical Abstract

Supplementary Information

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

Hydrogels in the treatment of rheumatoid arthritis: drug delivery systems and artificial matrices for dynamic in vitro models

Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory disorder that mostly affects the synovial joints and can promote both cartilage and bone tissue destruction. Several conservative treatments are available to relieve pain and control the inflammation; however, traditional drugs administration are not fully effective and present severe undesired side effects. Hydrogels are a very attractive platform as a drug delivery system to guarantee these handicaps are reduced, and the therapeutic effect from the drugs is maximized. Furthermore, hydrogels can mimic the physiological microenvironment and have the mechanical behavior needed for use as cartilage in vitro model. The testing of these advanced delivery systems is still bound to animal disease models that have shown low predictability. Alternatively, hydrogel-based human dynamic in vitro systems can be used to model diseases, bypassing some of the animal testing problems. RA dynamic disease models are still in an embryonary stage since advances regarding healthy and inflamed cartilage models are currently giving the first steps regarding complexity increase. Herein, recent studies using hydrogels in the treatment of RA, featuring different hydrogel formulations are discussed. Besides, their use as artificial extracellular matrices in dynamic in vitro articular cartilage is also reviewed.

A novel dendritic mesoporous silica based sustained hydrogen sulfide donor for the alleviation of adjuvant-induced inflammation in rats

Purpose

S-propargyl-cysteine (SPRC), an excellent endogenous hydrogen sulfide (H₂S) donor, could elevate H₂S levels via the cystathionine γ-lyase (CSE)/H₂S pathway both in vitro and in vivo. However, the immediate release of H₂S in vivo and daily administration of SPRC potentially limited its clinical use.

Methods

To solve the fore-mentioned problem, in this study, the dendritic mesoporous silica nanoparticles (DMSN) was firstly prepared, and a sustained H₂S delivery system consisted of SPRC and DMSN (SPRC@DMSN) was then constructed. Their release profiles, both in vitro and in vivo, were investigated, and their therapeutical effect toward adjuvant-induced arthritis (AIA) rats was also studied.

Results

The spherical morphology of DMSN could be observed under scanning Electron Microscope (SEM), and the transmission electron microscope (TEM) images showed a central-radiational pore channel structure of DMSN. DMSN showed excellent SPRC loading capacity and attaining a sustained releasing ability than SPRC both in vitro and in vivo, and the prolonged SPRC releasing could further promote the release of H₂S in a sustained manner through CSE/H₂S pathway both in vitro and in vivo. Importantly, the SPRC@DMSN showed promising anti-inflammation effect against AIA in rats was also observed.

Conclusions

A sustained H₂S releasing donor consisting of SPRC and DMSN was constructed in this study, and this sustained H₂S releasing donor might be of good use for the treatment of AIA.

Imperative and effective reversion of synovial hyperplasia and cartilage destruction in rheumatoid arthritis through multiple synergistic effects of O2 and Ca2

Abnormal synovial hyperplasia and cartilage destruction in a joint cavity are the key causes affecting the pain and disability in rheumatoid arthritis (RA) and, unfortunately, there exists no effective treatment for them. This investigation reports an effective reversion of the above pathological characteristics in RA owing to the use of a prolonged O₂/Ca²⁺-supporting phototherapy hydrogel. The performed in vitro and in vivo experiments exhibit that the prolonged O₂-supporting not only promotes the direct cell-killing effects of singlet oxygen, but also persistently blocks the pathological feedback between the abnormal proliferation of fibroblast-like synoviocyte and the local oxygen depletion. Furthermore, the Ca²⁺, which is the other decomposition product of the O₂ donor, induces mitochondrial Ca²⁺ overload and endoplasmic reticulum Ca²⁺ disorder and triggers Ca²⁺-associated apoptosis and immunogenic cell death. In addition to these multiple synergistic effects on synovial hyperplasia, the prolonged Ca²⁺ support can also induce the regeneration of cartilage in RA affected joints. The present study may thus provide an effective therapeutic strategy for the prevention and reversion of joint lesions and the accompanying arthralgia and deformity in RA.

Antiarthritic effect of chitosan nanoparticle loaded with embelin against adjuvant-induced arthritis in Wistar rats

BACKGROUND

Rheumatoid arthritis (RA) is associated with joint damage. Effectiveness of embelin has been established in a wide variety of inflammatory disorders, but its utility as a therapeutic agent is limited by its poor absorption, rapid metabolism, and fast systemic elimination. To apprehend these limitations, we propose to use highly bioavailable embelin-loaded chitosan nanoparticles (CS-embelin NPs) for the treatment of RA.

METHODS

The rats were made arthritic using a subcutaneous injection with 0.1 ml complete Freund's adjuvant (CFA) into the footpad of the left hind paw. CS-embelin NPs (25 and 50 mg/kg) was administered from day 15 to day 28 after adjuvant injection. After the experimental period, the animals were sacrificed and various biochemical markers were assessed.

RESULTS

Arthritic score and paw swelling were significantly reduced after treatment with CS-embelin NPs. Arthritis-induced rats showed a significant increase in malondialdehyde (MDA) and nitric oxide (NO) with a concomitant reduction of antioxidants in the paw tissue. CS-embelin NPs (25 and 50 mg/kg) reduced MDA and NO levels and restored antioxidant levels to normalcy by mitigating oxidative stress. The arthritic rats exhibited elevated tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1beta (IL-1β) serum concentrations, upregulated TNF- α and IL-6 protein levels and upregulated nuclear factor-kB (NF-kB) mRNA expression in paw tissues. Treatment with CS-embelin NPs (25 and 50 mg/kg) significantly reduced serum levels and down-regulated inflammatory markers to normalcy, dose-dependently.

CONCLUSION

The results suggest that CS-embelin NPs displayed a protective effect against adjuvant-induced arthritis in rats mediated through antioxidant and anti-inflammatory effects.