Lubricating Microneedles System with Multistage Sustained Drug Delivery for the Treatment of Osteoarthritis

A customized partitioned microneedle array based on functionalized glycol chitosan for prolonged blood glucose regulation and prevention of diabetic neuropathy

Efficient glycemic control serves as the cornerstone of diabetes and its complication treatments, necessitating additional symptomatic medications or nutritional supplements tailored to various complications. However, different diseases and medications require specific treatment regimens and drug delivery methods. For instance, conventional subcutaneous insulin injections suffer from uncontrollable release rates and onset times. This study has developed a segmented microneedle array that integrates two controlled-release mechanisms within a single array. Different drugs are loaded into distinct regions, allowing for modular and simultaneous timed-release therapies. The posterior segment of the microneedle tip releases insulin via a glucose-sensitive mechanism, enabling real-time intelligent glycemic regulation and effective glycemic control for up to 43.7 h, which is nearly 8 times longer than subcutaneous injections. The anterior segment releases vitamin B9 via a sustained-release mechanism, which has potential preventive and reparative effects on diabetic neuropathy, providing a gentler and more sustained nutrient supply. The regionalized design of the microneedles significantly enhances drug delivery efficiency and the intelligent customization of drug release, especially in managing diabetic neuropathy.

Polymeric Microneedles for Transdermal Delivery of Human Placental Tissue for the Treatment of Osteoarthritis

Biologics targeting matrix-degrading proteases, cartilage repair, and inflammation are emerging as promising approaches for osteoarthritis (OA) treatment. Recent research highlights biologic-human placental tissue (HPT) as a potential OA therapy due to its biocompatibility, abundant protein biofactors, and ability to reduce cartilage degradation by suppressing protease expression. Microneedles (MNs) are receiving growing attention for enhancing transdermal delivery of biologics as an alternative to conventional subcutaneous injections. The lyophilized human placental extract (LHP) loaded polymeric MNs are fabricated using a micromolding technique for transdermal delivery. Ex vivo release studies reveal that MNs exhibit a gradual and consistent release of LHP, indicating a sustained delivery profile. LHP-MNs are nontoxic and anti-inflammatory in nature against human skin cells and interleukin (IL-1β) induced synovial cells. Furthermore, the in vivo study shows that LHP-MNs substantially improve behavioral parameters in OA rat models and lower serum concentrations of tumor necrosis factor- α (TNF-α) and cartilage oligomeric matrix protein (COMP) biomarkers, thereby alleviating knee and ankle joint injuries. Histopathological analysis indicates that LHP-MNs significantly preserve cartilage integrity. The study results suggest that employing polymeric MNs for transdermal delivery of LHP can be a promising treatment approach for OA, with the added benefit of excellent patient compliance.

Resveratrol nanocrystals based dissolving microneedles with highly efficient for rheumatoid arthritis

Rheumatoid arthritis (RA) is a common immune disease characterized mainly by erosive arthritis with extensive clinical sequelae. Resveratrol (Res) has pharmacological effects in the treatment of RA, but it has not been widely used in the clinic due to its poor water solubility and low bioavailability. In this study, a drug delivery system (Res-NC MNs) of dissolved microneedles (MNs) loaded with Res nanocrystals (NC) was designed for the treatment of RA. Res-NC MNs can improve the drawbacks of long-term oral drug delivery with toxic side effects and low compliance associated with intra-articular drug delivery. In this study, Res-NC was prepared by media milling and loaded into soluble microneedles prepared from hyaluronic acid (HA) by vacuum casting for the treatment of RA. HA has high mechanical strength and can penetrate the cuticle layer of the skin for effective drug delivery. In in vivo pharmacodynamic experiments, Res-NC MNs achieved better therapeutic efficacy in the treatment of RA compared with oral Res. These findings suggest that Res-NC MNs may be an effective and promising drug delivery strategy for the treatment of RA.

Injectable microspheres filled with copper-containing bioactive glass improve articular cartilage healing by regulating inflammation and recruiting stem cells

Osteoarthritis (OA) is a frequent chronic illness in orthopedics that poses a major hazard to patient health. In situ cell therapy is emerging as a therapeutic option, but its efficacy is influenced by both the inflammatory milieu and the amount of stem cells, limiting its use. In this study, we designed a novel injectable porous microsphere (PM) based on microfluidic technology that can support in situ mesenchymal stem cells (MSCs) therapy by combining polylactic-glycolic acid copolymer, kartogenin, polydopamine, stromal cell-derived factor-1, and copper-doped bioactive glass (CuBG). The ex vivo tests demonstrated that PMs@CuBG microspheres were biocompatible and facilitated the transformation of synovial macrophages from pro-inflammatory M1 to anti-inflammatory M2 phenotypes by releasing CuBG to reduce joint inflammation. At the same time, the microspheres are able to recruit MSCs into the joint cavity and encourage their differentiation into chondrocytes, thereby treating articular cartilage injury. The in vivo rat experimental results show that intra-articular injection of PMs@CuBG in rats with OA improves OARSI scores, aggrecan content and the ratio of col-2α-positive cells, indicating a reparative effect on damaged cartilage within the joint. As a result, PMs@CuBG microspheres are predicted to provide a novel and successful approach to in situ cell therapy for OA.

Hyaluronic Acid Receptor-Mediated Nanomedicines and Targeted Therapy

Hyaluronic acid (HA) is a naturally occurring polysaccharide found in the extracellular matrix with broad applications in disease treatment. HA possesses good biocompatibility, biodegradability, and the ability to interact with various cell surface receptors. Its wide range of molecular weights and modifiable chemical groups make it an effective drug carrier for drug delivery. Additionally, the overexpression of specific receptors for HA on cell surfaces in many disease states enhances the accumulation of drugs at pathological sites through receptor binding. In this review, the modification of HA with drugs, major receptor proteins, and the latest advances in receptor-targeted nano drug delivery systems (DDS) for the treatment of tumors and inflammatory diseases are summarized. Furthermore, the functions of HA with varying molecular weights of HA in vivo and the selection of drug delivery methods for different diseases are discussed.

Hyaluronic Acid-Based Microparticles with Lubrication and Anti-Inflammation for Alleviating Temporomandibular Joint Osteoarthritis

The pathogenesis of temporomandibular joint osteoarthritis (TMJOA) is closely associated with mechanical friction, which leads to the up-regulation of inflammatory mediators and the degradation of articular cartilage. Injectable drug-loaded microparticles have attracted widespread interest in intra-articular treatment of TMJOA by providing lubrication and facilitating localized drug delivery. Herein, a hyaluronic acid-based microparticle is developed with excellent lubrication properties, drug loading capacity, antioxidant activity, and anti-inflammatory effect for the treatment of TMJOA. The microparticles are facilely prepared by the self-assembly of 3-aminophenylboronic acid-modified hyaluronic acid (HP) through hydrophobic interaction in an aqueous solution, which can further encapsulate diol-containing drugs through dynamic boronate ester bonds. The resulting microparticles demonstrate excellent injectability, lubrication properties, radical scavenging efficiency, and antibacterial activity. Additionally, the drug-loaded microparticles exhibit a favorable cytoprotective effect on chondrocyte cells in vitro under an oxidative stress microenvironment. In vivo experiments validate that intra-articular injection of drug-loaded microparticles effectively alleviates osteoporosis-like damage, suppresses inflammatory response, and facilitates matrix regeneration in the treatment of TMJOA. The HP microparticles demonstrate excellent injectability and encapsulation capacity for diol-containing drugs, highlighting its potential as a versatile drug delivery vehicle in the intra-articular treatment of TMJOA.