The Role of Polymeric Biomaterials in the Treatment of Articular Osteoarthritis

Efficacy of new active viscosupplements on the behavior of an experimental model of osteoarthritis

OBJECTIVE

To evaluate with an animal model of osteoarthritis (New Zealand rabbits) the effectiveness of treatment with active viscosupplements (hyaluronic acid loaded with nanoparticles (NPs) that encapsulate anti-inflammatory compounds or drugs.

MATERIAL AND METHODS

Experimental study composed of 5 groups of rabbits in which section of the anterior cruciate ligament and resection of the internal meniscus were performed to trigger degenerative changes and use it as a model of osteoarthritis. The groups were divided into osteoarthrosis without treatment (I), treatment with commercial hyaluronic acid (HA) (II), treatment with HA with empty nanoparticles (III), treatment with HA with nanoparticles encapsulating dexamethasone (IV) and treatment with HA with nanoparticles that encapsulate curcumin (V). In groups II to V, the infiltration of the corresponding compound was carried out spaced one week apart. Macroscopic histological analysis was performed using a scale based on the Outerbridge classification for osteoarthritis.

RESULTS

We observed that this osteoarthritis model is reproducible and degenerative changes similar to those found in humans are observed. The groups that were infiltrated with hyaluronic acid with curcumin-loaded nanoparticles (V), followed by the dexamethasone group (IV) presented macroscopically less fibrillation, exposure of subchondral bone and sclerosis (better score on the scale) than the control groups (I) (osteoarthritis without treatment), group (II) treated with commercial hyaluronic acid and hyaluronic acid with nanoparticles without drug (III).

CONCLUSIONS

The use of active viscosupplements could have an additional effect to conventional hyaluronic acid treatment due to its antioxidant and anti-inflammatory effect. The most promising group was hyaluronic acid with nanoparticles that encapsulate curcumin and the second group was the one that encapsulates dexamethasone.

[Translated article] Efficacy of new active viscosupplements on the behaviour of an experimental model of osteoarthritis

OBJECTIVE

To evaluate with an animal model of osteoarthritis (New Zealand rabbits) the effectiveness of treatment with active viscosupplements (hyaluronic acid loaded with nanoparticles (NPs) that encapsulate anti-inflammatory compounds or drugs.

MATERIAL AND METHODS

Experimental study composed of 5 groups of rabbits in which section of the anterior cruciate ligament and resection of the internal meniscus were performed to trigger degenerative changes and use it as a model of osteoarthritis. The groups were divided into osteoarthrosis without treatment (I), treatment with commercial hyaluronic acid (HA) (II), treatment with HA with empty nanoparticles (III), treatment with HA with nanoparticles encapsulating dexamethasone (IV) and treatment with HA with nanoparticles that encapsulate curcumin (V). In groups II-V, the infiltration of the corresponding compound was carried out spaced one week apart. Macroscopic histological analysis was performed using a scale based on the Outerbridge classification for osteoarthritis.

RESULTS

We observed that this osteoarthritis model is reproducible and degenerative changes similar to those found in humans are observed. The groups that were infiltrated with hyaluronic acid with curcumin-loaded nanoparticles (V), followed by the dexamethasone group (IV) presented macroscopically less fibrillation, exposure of subchondral bone and sclerosis (better score on the scale) than the control groups (I) (osteoarthritis without treatment), group (II) treated with commercial hyaluronic acid and hyaluronic acid with nanoparticles without drug (III).

CONCLUSIONS

The use of active viscosupplements could have an additional effect to conventional hyaluronic acid treatment due to its antioxidant and anti-inflammatory effect. The most promising group was hyaluronic acid with nanoparticles that encapsulate curcumin and the second group was the one that encapsulates dexamethasone.

Structured Polymers Enable the Sustained Delivery of Glucocorticoids within the Intra-Articular Space

Intra-articular glucocorticoid injections are effective in controlling inflammation and pain in arthritides but restricted by short duration of action and risk of joint degeneration. Controlled drug release using biocompatible hydrogels offers a unique solution, but limitations of in situ gelation restrict their application. Gellan sheared hydrogels (GSHs) retain the advantages of hydrogels, however their unique microstructures lend themselves to intra-articular application - capable of shear thinning under force but restructuring at rest to enhance residence. This study examined GSHs for extended intra-articular glucocorticoid delivery of prednisolone (10 mg mL-1); demonstrating links between material mechanics, steroid release, and preclinical assessment of efficacy in synoviocyte culture and transgenic(TNF)197Gkl (TNFtg) murine model of arthritis. GSHs demonstrated sustained release, with typical Fickian profiles over 18 days. Moreover, systems showed good stability under extended culture, with inherent cell-compatibility and suppression of inflammatory synoviocyte activation. In TNFtg animals, GSHs suppressed synovitis (70.08%, p < 0.05), pannus formation (45.01%, p < 0.05), and increased articular cartilage (82.23%, p < 0.05) relative to vehicle controls. The extended profile of steroid release from injectable GSH formulations holds promise in the treatment and management of inflammatory arthritides such as rheumatoid and osteoarthritis, representing a step-change in intra-articular drug delivery to suppress long-term joint inflammation.

Therapeutic Controlled Release Strategies for Human Osteoarthritis

Osteoarthritis is a progressive, irreversible debilitating whole joint disease that affects millions of people worldwide. Despite the availability of various options (non-pharmacological and pharmacological treatments and therapy, orthobiologics, and surgical interventions), none of them can definitively cure osteoarthritis in patients. Strategies based on the controlled release of therapeutic compounds via biocompatible materials may provide powerful tools to enhance the spatiotemporal delivery, expression, and activities of the candidate agents as a means to durably manage the pathological progression of osteoarthritis in the affected joints upon convenient intra-articular (injectable) delivery while reducing their clearance, dissemination, or side effects. The goal of this review is to describe the current knowledge and advancements of controlled release to treat osteoarthritis, from basic principles to applications in vivo using therapeutic recombinant molecules and drugs and more innovatively gene sequences, providing a degree of confidence to manage the disease in patients in a close future.

Innovative Biotherapies and Nanotechnology in Osteoarthritis: Advancements in Inflammation Control and Cartilage Regeneration

Osteoarthritis (OA) is among the most prevalent degenerative joint disorders worldwide, particularly affecting the aging population and imposing significant disability and economic burdens. The disease is characterized by progressive degradation of articular cartilage and chronic inflammation, with no effective long-term treatments currently available to address the underlying causes of its progression. Conventional therapies primarily manage symptoms such as pain and inflammation but fail to repair damaged tissues. Emerging biotherapies and regenerative medicine approaches offer promising alternatives by addressing cartilage repair and inflammation control at the molecular level. This review explores the recent advancements in biotherapeutic strategies, including mesenchymal stem cell (MSC) therapy, growth factors, and tissue engineering, which hold the potential for promoting cartilage regeneration and modulating the inflammatory microenvironment. Additionally, the integration of nanotechnology has opened new avenues for targeted drug delivery systems and the development of innovative nanomaterials that can further enhance the efficacy of biotherapies by precisely targeting inflammation and cartilage damage. This article concludes by discussing the current clinical applications, the ongoing clinical trials, and the future research directions necessary to confirm the safety and efficacy of these advanced therapies for OA management. With these advancements, biotherapies combined with nanotechnology may revolutionize the future of OA treatment by offering precise and effective solutions for long-term disease management and improved patient outcomes.

New insights into the mechanisms and therapeutic strategies of chondrocyte autophagy in osteoarthritis

Osteoarthritis (OA) is a chronic joint disease with an unclear cause characterized by secondary osteophytes and degenerative changes in the articular cartilage. More than 250 million people are expected to be affected by it by 2050, putting a tremendous socioeconomic strain on the entire world. OA cannot currently be treated with any effective medications that change the illness. Over time, chondrocytes undergo gradual metabolic, structural, and functional changes as a result of aging or abuse. The degenerative progression of osteoarthritis is significantly influenced by the imbalance of chondrocyte homeostasis. By continuously recycling and rebuilding macromolecules or organelles, autophagy functions as a crucial regulatory system to maintain homeostasis during an individual's growth and development. This review uses chondrocytes as its starting point and establishes a strong connection between autophagy and osteoarthritis in order to thoroughly examine the mechanisms behind chondrocyte autophagy in osteoarthritis. Biomarkers of chondrocyte autophagy will be identified, and prospective targeted medications and novel treatment approaches for slowing or preventing the course of OA will be developed based on chondrocyte senescence, autophagy, and apoptosis in OA. KEY MESSAGES: Currently, OA has not been treated with any drugs that can effectively cure it. We hope that by exploring specific targets in the course of osteoarthritis, we can promote the progress of treatment strategies. The degenerative progression of osteoarthritis is significantly influenced by the imbalance of chondrocyte balance. Through the continuous recovery and reconstruction of macromolecules or organelles, autophagy is an important regulatory system for maintaining homeostasis during individual growth and development. In this paper, the close relationship between autophagy and osteoarthritis was established with chondrocytes as the starting point, in order to further explore the mechanism of chondrocyte autophagy in osteoarthritis. The development process of osteoarthritis was studied from the perspective of chondrocytes, and the change of autophagy level had a significant impact on osteoarthritis. Chondrocyte autophagy is mainly determined by intracellular mitochondrial autophagy, so we are committed to finding relevant molecules. Through PI3K/AKT- and MAPK-related pathways, the biomarkers of chondrocyte autophagy were identified, and chondrocyte senescence, autophagy, and apoptosis based on osteoarthritis provided a constructive idea for the development of prospective targeted drugs and new therapies to slow down or prevent the progression of osteoarthritis.

Poly(ethylene Glycol) Methyl Ether Methacrylate-Based Injectable Hydrogels: Swelling, Rheological, and In Vitro Biocompatibility Properties with ATDC5 Chondrogenic Lineage

Here, we present the synthesis of a series of chemical homopolymeric and copolymeric injectable hydrogels based on polyethylene glycol methyl ether methacrylate (PEGMEM) alone or with 2-dimethylamino ethyl methacrylate (DMAEM). The objective of this study was to investigate how the modification of hydrogel components influences the swelling, rheological attributes, and in vitro biocompatibility of the hydrogels. The hydrogels' networks were formed via free radical polymerization, as assured by 1H nuclear magnetic resonance spectroscopy (1H NMR). The swelling of the hydrogels directly correlated with the monomer and the catalyst amounts, in addition to the molecular weight of the monomer. Rheological analysis revealed that most of the synthesized hydrogels had viscoelastic and shear-thinning properties. The storage modulus and the viscosity increased by increasing the monomer and the crosslinker fraction but decreased by increasing the catalyst. MTT analysis showed no potential toxicity of the homopolymeric hydrogels, whereas the copolymeric hydrogels were toxic only at high DMEAM concentrations. The crosslinker polyethylene glycol dimethacrylate (PEGDMA) induced inflammation in ATDC5 cells, as detected by the significant increase in nitric oxide synthase type II activity. The results suggest a range of highly tunable homopolymeric and copolymeric hydrogels as candidates for cartilage regeneration.

In Vitro Analysis of Human Cartilage Infiltrated by Hydrogels and Hydrogel-Encapsulated Chondrocytes

Osteoarthritis (OA) is a degenerative joint disease causing loss of articular cartilage and structural damage in all joint tissues. Given the limited regenerative capacity of articular cartilage, methods to support the native structural properties of articular cartilage are highly anticipated. The aim of this study was to infiltrate zwitterionic monomer solutions into human OA-cartilage explants to replace lost proteoglycans. The study included polymerization and deposition of methacryloyloxyethyl-phosphorylcholine- and a novel sulfobetaine-methacrylate-based monomer solution within ex vivo human OA-cartilage explants and the encapsulation of isolated chondrocytes within hydrogels and the corresponding effects on chondrocyte viability. The results demonstrated that zwitterionic cartilage-hydrogel networks are formed by infiltration. In general, cytotoxic effects of the monomer solutions were observed, as was a time-dependent infiltration behavior into the tissue accompanied by increasing cell death and penetration depth. The successful deposition of zwitterionic hydrogels within OA cartilage identifies the infiltration method as a potential future therapeutic option for the repair/replacement of OA-cartilage extracellular suprastructure. Due to the toxic effects of the monomer solutions, the focus should be on sealing the OA-cartilage surface, instead of complete infiltration. An alternative treatment option for focal cartilage defects could be the usage of monomer solutions, especially the novel generated sulfobetaine-methacrylate-based monomer solution, as bionic for cell-based 3D bioprintable hydrogels.