The Preparation of a Novel Poly(Lactic Acid)-Based Sustained H2S Releasing Microsphere for Rheumatoid Arthritis Alleviation

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.

Development of puerarin-loaded poly(lactic acid) microspheres for sustained ocular delivery: In vitro/vivo evaluation

Diabetic retinopathy, an ocular complication of diabetes, is an important cause of blindness in adults. Puerarin is considered to have promising potential for clinical use in treating diabetic retinopathy. In this study, we designed a novel puerarin-loaded poly(lactic acid) sustained-release microspheres suitable for ocular administration, and we assessed itsin vitro and in vivo properties. The preparation of puerarin-loaded microspheres was optimized by Box-Behnken response surface design. The encapsulation efficiency and drug loading of microspheres were 35.71% and 3.85%, respectively. The microspheres exhibited good dispersion and high safety, making it suitable for ocular drug delivery. In vitro release demonstrated that microspheres had a well-sustained release effectiveness, and its release behavior complied with the zero-order kinetic characteristics. The results of ocular tissue distribution revealed that the CmaxandAUC0-∞ of the microspheres group in the retina and choroid were considerably higher than those of the solution group and the intravenous injection group. This research revealed that intravitreal injection of microspheres can significantly prolong the half-life of puerarin in eye tissues and achieve sustained drug release. Therefore, intravitreal injection of microspheres has positive implications for the treatment of diabetic retinopathy.

Role of hydrogen sulfide in health and disease

In the past, hydrogen sulfide (H2S) was recognized as a toxic and dangerous gas; in recent years, with increased research, we have discovered that H2S can act as an endogenous regulatory transmitter. In mammals, H2S-catalyzing enzymes, such as cystathionine-β-synthase, cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase, are differentially expressed in a variety of tissues and affect a variety of biological functions, such as transcriptional and posttranslational modification of genes, activation of signaling pathways in the cell, and metabolic processes in tissues, by producing H2S. Various preclinical studies have shown that H2S affects physiological and pathological processes in the body. However, a detailed systematic summary of these roles in health and disease is lacking. Therefore, this review provides a thorough overview of the physiological roles of H2S in different systems and the diseases associated with disorders of H2S metabolism, such as ischemia-reperfusion injury, hypertension, neurodegenerative diseases, inflammatory bowel disease, and cancer. Meanwhile, this paper also introduces H2S donors and novel release modes, as well as the latest preclinical experimental results, aiming to provide researchers with new ideas to discover new diagnostic targets and therapeutic options.

Gas Therapy: Generating, Delivery, and Biomedical Applications

Oxygen (O2), nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and hydrogen (H2) with direct effects, and carbon dioxide (CO2) with complementary effects on the condition of various diseases are known as therapeutic gases. The targeted delivery and in situ generation of these therapeutic gases with controllable release at the site of disease has attracted attention to avoid the risk of gas poisoning and improve their performance in treating various diseases such as cancer therapy, cardiovascular therapy, bone tissue engineering, and wound healing. Stimuli-responsive gas-generating sources and delivery systems based on biomaterials that enable on-demand and controllable release are promising approaches for precise gas therapy. This work highlights current advances in the design and development of new approaches and systems to generate and deliver therapeutic gases at the site of disease with on-demand release behavior. The performance of the delivered gases in various biomedical applications is then discussed.

99mTc-labeled, tofacitinib citrate encapsulated chitosan microspheres loaded in situ gel formulations for intra-articular treatment of rheumatoid arthritis

Inflammatory diseases including rheumatoid arthritis are major health problems. Although different techniques and drugs are clinically available for the diagnosis and therapy of the disease, novel approaches regarding radiolabeled drug delivery systems are researched. Hence, in the present study, it was aimed to design, prepare, and characterize 99mTc-radiolabeled and tofacitinib citrate-encapsulated microsphere loaded poloxamer in situ gel formulations for the intra-articular treatment. Among nine different microsphere formulations, MS/TOFA-9 was chosen as the most proper one due to particle size, high encapsulation efficiency, and in vitro drug release behavior. Poloxamer 338 at a concentration of 15% was used to prepare in situ gel formulations. For intra-articular administration, microspheres were dispersed in an in situ gel containing 15% Poloxamer 338 and characterized in terms of gelation temperature, viscosity, rheological, mechanical, and spreadability properties. After the determination of the safe dose for MS/TOFA-9 and PLX-MS/TOFA-9 as 40 µL/mL in the cell culture study performed on healthy cells, the high anti-inflammatory effects were due to significant cellular inhibition of fibroblasts. In the radiolabeling studies with 99mTc, the optimum radiolabeling condition was determined as 200 ppm SnCl2 and 0.5 mg ascorbic acid, and both 99mTc-MS/TOFA-9 and 99mTc-PLX-MS/TOFA-9 exhibited high cellular binding capacity. In conclusion, although further in vivo experiments are required, PLX-MS/TOFA-9 was found to be a promising agent for intra-articular injection in rheumatoid arthritis.

Effect of Specific Surface Area and Hydrophobicity of Electrospun Nanofibers on the Sustained Release Performance of Diclofenac Sodium

Nanofibers produced by electrospinning are suitable options for slow-release materials. Diclofenac sodium (DS) is a nonsteroidal anti-inflammatory medication with a brief half-life that can serve as an effective sustained-release agent. This paper presents a novel method for producing DS-sustained release nanofibers by electrostatic spinning processes. During the preparation, the slow-release capabilities of biodegradable materials poly(lactic acid) (PLA) and polycaprolactone (PCL) are investigated. A composite drug-carrying scaffold is prepared to enhance the sustained-release performance. The sustained release ability is affected by the specific surface area of the nanofibers and the hydrophobicity of the polymer. The findings indicate that the composite nanofiber with a PLA/PCL ratio of 1:1 demonstrates the most effective sustained-release performance. The release rate is mostly influenced by the hydrophobicity of the polymer at this point. Sustained-release kinetic simulations were performed and revealed that the release of nanofibers follows a first-order release paradigm. This work presents a straightforward approach for creating a sustained-release formulation of DS.

Dissecting hair breakage in alopecia areata: the central role of dysregulated cysteine homeostasis

In the initial stages of Alopecia Areata (AA), the predominance of hair breakage or exclamation mark hairs serves as vital indicators of disease activity. These signs are non-invasive and are commonly employed in dermatoscopic examinations. Despite their clinical salience, the underlying etiology precipitating this hair breakage remains largely uncharted territory. Our exhaustive review of the existing literature points to a pivotal role for cysteine-a key amino acid central to hair growth-in these mechanisms. This review will probe and deliberate upon the implications of aberrant cysteine metabolism in the pathogenesis of AA. It will examine the potential intersections of cysteine metabolism with autophagy, ferroptosis, immunity, and psychiatric manifestations associated with AA. Such exploration could illuminate new facets of the disease's pathophysiology, potentially paving the way for innovative therapeutic strategies.

New Targets and Strategies for Rheumatoid Arthritis: From Signal Transduction to Epigenetic Aspect

Rheumatoid arthritis (RA) is a chronic autoimmune disease that can lead to joint damage and even permanent disability, seriously affecting patients' quality of life. At present, the complete cure for RA is not achievable, only to relieve the symptoms to reduce the pain of patients. Factors such as environment, genes, and sex can induce RA. Presently, non-steroidal anti-inflammatory drugs, DRMADs, and glucocorticoids are commonly used in treating RA. In recent years, some biological agents have also been applied in clinical practice, but most have side effects. Therefore, finding new mechanisms and targets for treating RA is necessary. This review summarizes some potential targets discovered from the perspective of epigenetics and RA mechanisms.

Local delivery of gaseous signaling molecules for orthopedic disease therapy

Over the past decade, a proliferation of research has used nanoparticles to deliver gaseous signaling molecules for medical purposes. The discovery and revelation of the role of gaseous signaling molecules have been accompanied by nanoparticle therapies for their local delivery. While most of them have been applied in oncology, recent advances have demonstrated their considerable potential in diagnosing and treating orthopedic diseases. Three of the currently recognized gaseous signaling molecules, nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S), are highlighted in this review along with their distinctive biological functions and roles in orthopedic diseases. Moreover, this review summarizes the progress in therapeutic development over the past ten years with a deeper discussion of unresolved issues and potential clinical applications.

Signaling pathways in rheumatoid arthritis: implications for targeted therapy

Rheumatoid arthritis (RA) is an incurable systemic autoimmune disease. Disease progression leads to joint deformity and associated loss of function, which significantly impacts the quality of life for sufferers and adds to losses in the labor force. In the past few decades, RA has attracted increased attention from researchers, the abnormal signaling pathways in RA are a very important research field in the diagnosis and treatment of RA, which provides important evidence for understanding this complex disease and developing novel RA-linked intervention targets. The current review intends to provide a comprehensive overview of RA, including a general introduction to the disease, historical events, epidemiology, risk factors, and pathological process, highlight the primary research progress of the disease and various signaling pathways and molecular mechanisms, including genetic factors, epigenetic factors, summarize the most recent developments in identifying novel signaling pathways in RA and new inhibitors for treating RA. therapeutic interventions including approved drugs, clinical drugs, pre-clinical drugs, and cutting-edge therapeutic technologies. These developments will hopefully drive progress in new strategically targeted therapies and hope to provide novel ideas for RA treatment options in the future.

Intelligent polymeric hydrogen sulfide delivery systems for therapeutic applications

Hydrogen sulfide (H₂S) plays an important role in regulating various pathological processes such as protecting mammalian cell from harmful injuries, promoting tissue regeneration, and regulating the process of various diseases caused by physiological disorders. Studies have revealed that the physiological effects of H₂S are highly associated with its concentrations. At relatively low concentration, H₂S shows beneficial functions. However, long-time and high-dose donation of H₂S would inhibit regular biological process, resulting in cell dysfunction and apoptosis. To regulate the dosage of H₂S delivery for precision medicine, H₂S delivery systems with intelligent characteristics were developed and a variety of biocompatibility polymers have been utilized to establish intelligent polymeric H₂S delivery systems, with the abilities to specifically target the lesions, smartly respond to pathological microenvironments, as well as real-timely monitor H₂S delivery and lesion conditions by incorporating imaging-capable moieties. In this review, we focus on the design, preparation, and therapeutic applications of intelligent polymeric H₂S delivery systems in cardiovascular therapy, inflammatory therapy, tissue regenerative therapy, cancer therapy and bacteria-associated therapy. Strategies for precise H₂S therapies especially imaging-guided H₂S theranostics are highlighted. Since H₂S donors with stimuli-responsive characters are vital components for establishing intelligent H₂S delivery systems, the development of H₂S donors is also briefly introduced.

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H₂S is an endogenous gasotransmitter that plays important role in regulating various physiological and pathological pathways.

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Controlled H₂S delivery is vital since the therapeutic effects of H₂S are highly associated with its concentrations.

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Intelligent polymeric H₂S delivery systems possess specific targeting, stimuli responsive and imaging guided capabilities, representing a strategic option for next generation of therapies.

Polymers Enhancing Bioavailability in Drug Delivery

A drug's bioavailability, i.e., the extent to and rate at which it enters the systemic circulation, thus accessing the site of action, is largely determined by the properties of the drug [...].

Chitosan-based biomaterials for the treatment of bone disorders

Bone is an alive and dynamic organ that is well-differentiated and originated from mesenchymal tissues. Bone undergoes continuous remodeling during the lifetime of an individual. Although knowledge regarding bones and their disorders has been constantly growing, much attention has been devoted to effective treatments that can be used, both from materials and medical performance points of view. Polymers derived from natural sources, for example polysaccharides, are generally biocompatible and are therefore considered excellent candidates for various biomedical applications. This review outlines the development of chitosan-based biomaterials for the treatment of bone disorders including bone fracture, osteoporosis, osteoarthritis, arthritis rheumatoid, and osteosarcoma. Different examples of chitosan-based formulations in the form of gels, micro/nanoparticles, and films are discussed herein. The work also reviews recent patents and important developments related to the use of chitosan in the treatment of bone disorders. Although most of the cited research was accomplished before reaching the clinical application level, this manuscript summarizes the latest achievements within chitosan-based biomaterials used for the treatment of bone disorders and provides perspectives for future scientific activities.

The Anti-Inflammation and Anti-Nociception Effect of Ketoprofen in Rats Could Be Strengthened Through Co-Delivery of a H2S Donor, S-Propargyl-Cysteine

PURPOSE

Ketoprofen (KETO) is a traditional non-steroidal anti-inflammatory drug (NSAIDs) with good analgesic and antipyretic effects. However, as NASIDs, the toxicity of KETO towards gastrointestinal (GI) system might limit its clinical use. S-propargyl-cysteine (SPRC) is an excellent endogenous H2S donor showed wide application in the field of anti-inflammation, anti-oxidative stress, or even the protection of cardiovascular system through the elevation of endogenous H2S concentration. As recently studies reported, co-administration of H2S donor might potentially mitigate the GI toxicity and relevant side effects induced by series of NSAIDs.

METHODS

In this study, we established a SPRC and KETO co-encapsulated poly (lactic-co-glycolic acid) microsphere (SK@MS), and its particle size, morphology, storage stability and in vitro release profile were firstly investigated. The elevation of endogenous H2S level of SK@MS was then calculated, and the pharmacodynamic study (anti-inflammation and analgesic effects) of SK@MS, SPRC, and KETO towards adjuvant induced arthritis (AIA) in rats were also studied. Finally, to test the potential side effect, the heart, liver, spleen, lung, kidney, stomach, small intestine, and large intestine were resected from rats and examined by H&E staining.

RESULTS

A monodispersed SK@MS could be observed under the SEM, and particle size was calculated around 25.12 μm. The loading efficiency (LE) for SPRC and KETO were 6.67% and 2.64%, respectively, while the encapsulation efficiency (EE) for SPRC and KETO were 37.20% and 68.28%, respectively. SK@MS showed a sustained release of SPRC and KETO in vitro, which was up-to 15 days. SK@MS could achieve a long-term elevation of the H2S concentration in vivo, while SPRC showed an instant H2S elevation and metabolize within 6 h. Interestingly, the KETO did not show any influence on the H2S concentration in vivo. After establishment of AIA model, neither SPRC nor KETO showed scarcely anti-inflammation and anti-nociception effect, while conversely, SK@MS showed an obvious mitigation towards paw edema and pain in AIA rats, which indicated an improved anti-inflammation and anti-nociception effect when co-delivery of SRC and KETO. Besides, low stimulation towards major organs in rats observed in any experimental group.

CONCLUSION

A monodispersed was successfully prepared in this study, and SK@MS showed a sustained SPRC and KETO release in vitro and H2S release in vivo. In the pharmacodynamics study, SK@MS not only exhibited an excellent anti-inflammation and analgesic effects in AIA rats but also showed low stimulation towards rats.