Microneedle-Delivered PDA@Exo for Multifaceted Osteoarthritis Treatment via PI3K-Akt-mTOR Pathway

Recent advances in nanocrystals for arthritis drug delivery

INTRODUCTION

More than 500 million people worldwide suffer from arthritis, experiencing daily pain and inflammation. Current treatments for osteoarthritis (OA) and rheumatoid arthritis (RA) are palliative, offering only symptom relief. No disease-modifying OA drugs (DMOADs) capable of restoring joint functionality and regenerating the cartilage matrix have yet been approved by the FDA or EMA.

AREAS COVERED

This review highlights recent advances in nanocrystals (NCs) for arthritis drug delivery, including conventional nanosuspensions and novel transdermal microneedles. Special attention is given to intra-articular DMOADs formulated as NC-in-microparticles, designed to extend drug release over months. Papers and reviews with the mentioned contents and published over the last 5 years were included in the review process.

EXPERT OPINION

New DMOADs and disease-modifying antirheumatic drugs (DMARDs) are often poorly water-soluble, limiting their clinical progress. The versatility of NCs and nanosuspensions offers a potential advantage over other types of nanoparticles, as they can be adapted to various delivery systems, administration routes, and types of arthritis. Due to the avascular nature of cartilage, exploring the intra-articular route for OA management is essential. Implementing cartilage-targeted strategies or using stimuli-responsive hydrogels can further enhance their therapeutic potential.

Fish-derived biomaterials for tissue engineering: advances in scaffold fabrication and applications in regenerative medicine and cancer therapy

Fish-derived biomaterials, such as collagen, polyunsaturated fatty acids, and antimicrobial peptides, have emerged as promising candidates for scaffold development in stem cell therapies and tissue engineering due to their excellent biocompatibility and low immunogenicity. Although good bioactivity is a prerequisite for biomedical substitutes, scaffold design is necessary for the successful development of bioconstructs used in tissue regeneration. However, the limited processability of fish biomaterials poses a substantial challenge to the development of diverse scaffold structures. In this review, unlike previous reviews that primarily focused on the bioactivities of fish-derived components, we placed greater emphasis on scaffold fabrication and its applications in tissue regeneration. Specifically, we examined various cross-linking strategies to enhance the structural integrity of fish biomaterials and address challenges, such as poor processability, low mechanical strength, and rapid degradation. Furthermore, we demonstrated the potential of fish scaffolds in stem cell therapies, particularly their capacity to support stem cell growth and modulate the cellular microenvironment. Finally, this review provides future directions for the application of these scaffolds in cancer therapy.

Targeting Synovial Macrophages with Astaxanthin-Loaded Liposomes for Antioxidant Treatment of Osteoarthritis

Osteoarthritis (OA) is a chronic joint disease highly associated with an imbalance in the network of inflammatory factors and typically characterized by oxidative stress and cartilage damage. Moreover, the specificity of the joint structure makes it difficult for drugs to achieve good penetration and effective enrichment in the joint cavity. Therefore, therapeutic strategies that increase the specific targeting of drugs to inflammatory joint and incorporate antioxidative stress effects are important to improve the efficacy of OA. Here, we developed a folic acid-modified liposomal nanoparticle (AST@Lip-FA) loaded with the antioxidant astaxanthin (AST) to enhance the water solubility and stability of AST and to target the delivery of AST to the site of OA, leading to a significant improvement in therapeutic efficacy. In vitro experiments demonstrated that, due to the recognition by FA of the receptor folate receptor β on the surface of activated macrophages, the cellular uptake efficiency of AST@Lip-FA was increased. Meanwhile, intracellularly overexpressed inflammatory mediators such as reactive oxygen species and nitric oxide were efficiently removed by AST@Lip-FA. In addition, in the ACLT-induced OA mouse model, AST@Lip-FA was precisely enriched in the inflamed joints and achieved long-term retention, fully utilizing the anti-inflammatory, antioxidant, and cartilage-protecting effects of AST to effectively alleviate the progression of OA. In summary, AST@Lip-FA has an important prospect as a potential and effective therapeutic strategy for OA.