Sustained intra-cartilage delivery of low dose dexamethasone using a cationic carrier for treatment of post traumatic osteoarthritis

Avidin-biotin technology to synthesize multi-arm nano-construct for drug delivery

Here we describe methods for synthesizing a cationic, multi-arm Avidin (mAv) nano-construct that has a wide range of applications in drug delivery and imaging of negatively charged tissues. We use Avidin-biotin technology that gives the flexibility for conjugating biotinylated Dexamethasone to mAv by simple mixing at room temperature. We also describe methods to control hydrolysis rates of ester linkers to enable sustained (and tunable) drug release rates in therapeutic doses.•

Multi-arm structure provides multiple sites for covalent conjugation of drugs

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Use of Avidin-biotin reaction gives multi-arm nano-construct a modular design enabling conjugation and delivery of similar sized biotinylated drugs.

Post-traumatic osteoarthritis following ACL injury

Post-traumatic osteoarthritis (PTOA) develops after joint injury. Specifically, patients with anterior cruciate ligament (ACL) injury have a high risk of developing PTOA. In this review, we outline the incidence of ACL injury that progresses to PTOA, analyze the role of ACL reconstruction in preventing PTOA, suggest possible mechanisms thought to be responsible for PTOA, evaluate current diagnostic methods for detecting early OA, and discuss potential interventions to combat PTOA. We also identify important directions for future research. Although much work has been done, the incidence of PTOA among patients with a history of ACL injury remains high due to the complexity of ACL injury progression to PTOA, the lack of sensitive and easily accessible diagnostic methods to detect OA development, and the limitations of current treatments. A number of factors are thought to be involved in the underlying mechanism, including structural factors, biological factors, mechanical factors, and neuromuscular factor. Since there is a clear "start point" for PTOA, early detection and intervention is of great importance. Currently, imaging modalities and specific biomarkers allow early detection of PTOA. However, none of them is both sensitive and easily accessible. After ACL injury, many patients undergo surgical reconstruction of ACL to restore joint stability and prevent excessive loading. However, convincing evidence is still lacking for the superiority of ACL-R to conservative management in term of the incidence of PTOA. As for non-surgical treatment such as anti-cytokine and chemokine interventions, most of them are investigated in animal studies and have not been applied to humans. A complete understanding of mechanisms to stratify the patients into different subgroups on the basis of risk factors is critical. And the improvement of standardized and quantitative assessment techniques is necessary to guide intervention. Moreover, treatments targeted toward different pathogenic pathways may be crucial to the management of PTOA in the future.

Sustained low-dose dexamethasone delivery via a PLGA microsphere-embedded agarose implant for enhanced osteochondral repair

Articular cartilage defects are a common source of joint pain and dysfunction. We hypothesized that sustained low-dose dexamethasone (DEX) delivery via an acellular osteochondral implant would have a dual pro-anabolic and anti-catabolic effect, both supporting the functional integrity of adjacent graft and host tissue while also attenuating inflammation caused by iatrogenic injury. An acellular agarose hydrogel carrier with embedded DEX-loaded poly(lactic-co-glycolic) acid (PLGA) microspheres (DLMS) was developed to provide sustained release for at least 99 days. The DLMS implant was first evaluated in an in vitro pro-inflammatory model of cartilage degradation. The implant was chondroprotective, as indicated by maintenance of Young's modulus (EY) (p = 0.92) and GAG content (p = 1.0) in the presence of interleukin-1β insult. In a subsequent preliminary in vivo experiment, an osteochondral autograft transfer was performed using a pre-clinical canine model. DLMS implants were press-fit into the autograft donor site and compared to intra-articular DEX injection (INJ) or no DEX (CTL). Functional scores for DLMS animals returned to baseline (p = 0.39), whereas CTL and INJ remained significantly worse at 6 months (p < 0.05). DLMS knees were significantly more likely to have improved OARSI scores for proteoglycan, chondrocyte, and collagen pathology (p < 0.05). However, no significant improvements in synovial fluid cytokine content were observed. In conclusion, utilizing a targeted DLMS implant, we observed in vitro chondroprotection in the presence of IL-1-induced degradation and improved in vivo functional outcomes. These improved outcomes were correlated with superior histological scores but not necessarily a dampened inflammatory response, suggesting a primarily pro-anabolic effect. STATEMENT OF SIGNIFICANCE: Articular cartilage defects are a common source of joint pain and dysfunction. Effective treatment of these injuries may prevent the progression of osteoarthritis and reduce the need for total joint replacement. Dexamethasone, a potent glucocorticoid with concomitant anti-catabolic and pro-anabolic effects on cartilage, may serve as an adjuvant for a variety of repair strategies. Utilizing a dexamethasone-loaded osteochondral implant with controlled release characteristics, we demonstrated in vitro chondroprotection in the presence of IL-1-induced degradation and improved in vivo functional outcomes following osteochondral repair. These improved outcomes were correlated with superior histological cartilage scores and minimal-to-no comorbidity, which is a risk with high dose dexamethasone injections. Using this model of cartilage restoration, we have for the first time shown the application of targeted, low-dose dexamethasone for improved healing in a preclinical model of focal defect repair.

Multi-arm Avidin nano-construct for intra-cartilage delivery of small molecule drugs

Targeted drug delivery to joint tissues like cartilage remains a challenge that has prevented clinical translation of promising osteoarthritis (OA) drugs. Local intra-articular (IA) injections of drugs suffer from rapid clearance from the joint space and slow diffusive transport through the dense, avascular cartilage matrix comprised of negatively charged glycosaminoglycans (GAGs). Here we apply drug carriers that leverage electrostatic interactions with the tissue's high negative fixed charge density (FCD) for delivering small molecule drugs to cartilage cell and matrix sites. We demonstrate that a multi-arm cationic nano-construct of Avidin (mAv) with 28 sites for covalent drug conjugation can rapidly penetrate through the full thickness of cartilage in high concentration and have long intra-cartilage residence time in both healthy and arthritic cartilage via weak-reversible binding with negatively charged aggrecans. mAv's intra-cartilage mean uptake was found to be 112× and 33× the equilibration bath concentration in healthy and arthritic (50% GAG depleted) cartilage, respectively. mAv was conjugated with Dexamethasone (mAv-Dex), a broad-spectrum glucocorticoid, using a combination of hydrolysable ester linkers derived from succinic anhydride (SA), 3,3-dimethylglutaric anhydride (GA) and phthalic anhydride (PA) in 2:1:1 M ratio that enabled 50% drug release within 38.5 h followed by sustained release in therapeutic doses over 2 weeks. A single 10 μM low dose of controlled release mAv-Dex (2:1:1) effectively suppressed IL-1α-induced GAG loss, cell death and inflammatory response significantly better than unmodified Dex over 2 weeks in cartilage explant culture models of OA. With this multi-arm design, <1 μM Avidin was needed - a concentration which has been shown to be safe, preventing further GAG loss and cytotoxicity. A charge-based cartilage homing drug delivery platform like this can elicit disease modifying effects as well as facilitate long-term symptomatic pain and inflammation relief by enhancing tissue specificity and prolonging intra-cartilage residence time of OA drugs. This nano-construct thus has high translational potential for enabling intra-cartilage delivery of a broad array of small molecule OA drugs and their combinations to chondrocytes, enabling OA treatment with a single injection of low drug doses and eliminating toxicity issues associated with multiple high dose injections.

Biomaterial-engineered intra-articular drug delivery systems for osteoarthritis therapy

Osteoarthritis (OA) is a progressive and degenerative disease, which is no longer confined to the elderly. So far, current treatments are limited to symptom relief, and no valid OA disease-modifying drugs are available. Additionally, OA relative joint is challenging for drug delivery, since the drugs experience rapid clearance in joint, showing a poor bioavailability. Existing therapeutic drugs, like non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids, are not conducive for long-term use due to adverse effects. Though supplementations, including chondroitin sulfate and glucosamine, have shown beneficial effects on joint tissues in OA, their therapeutic use is still debatable. New emerging agents, like Kartogenin (KGN) and Interleukin-1 receptor antagonist (IL-1 ra), without a proper formulation, still will not work. Therefore, it is urgent to establish a suitable and efficient drug delivery system for OA therapy. In this review, we pay attention to various types of drug delivery systems and potential therapeutic drugs that may escalate OA treatments.

Interleukin-1 receptor antagonist (IL-1Ra) is more effective in suppressing cytokine-induced catabolism in cartilage-synovium co-culture than in cartilage monoculture

Background

Most in vitro studies of potential osteoarthritis (OA) therapies have used cartilage monocultures, even though synovium is a key player in mediating joint inflammation and, thereby, cartilage degeneration. In the case of interleukin-1 (IL-1) inhibition using its receptor antagonist (IL-1Ra), like chondrocytes, synoviocytes also express IL-1 receptors that influence intra-articular IL-1 signaling and IL-1Ra efficacy. The short residence time of IL-1Ra after intra-articular injection requires the application of frequent dosing, which is clinically impractical and comes with increased risk of infection; these limitations motivate the development of effective drug delivery strategies that can maintain sustained intra-articular IL-1Ra concentrations with only a single injection. The goals of this study were to assess how the presence of synovium in IL-1-challenged cartilage-synovium co-culture impacts the time-dependent biological response of single and sustained doses of IL-1Ra, and to understand the mechanisms underlying any co-culture effects.

Methods

Bovine cartilage explants with or without synovium were treated with IL-1α followed by single or multiple doses of IL-1Ra. Effects of IL-1Ra in rescuing IL-1α-induced catabolism in cartilage monoculture and cartilage-synovium co-culture were assessed by measuring loss of glycosaminoglycans (GAGs) and collagen using DMMB (dimethyl-methylene blue) and hydroxyproline assays, respectively, nitric oxide (NO) release using Griess assay, cell viability by fluorescence staining, metabolic activity using Alamar blue, and proteoglycan biosynthesis by radiolabel incorporation. Day 2 conditioned media from mono and co-cultures were analyzed by mass spectrometry and cytokine array to identify proteins unique to co-culture that contribute to biological crosstalk.

Results

A single dose of IL-1Ra was ineffective, and a sustained dose was necessary to significantly suppress IL-1α-induced catabolism as observed by enhanced suppression of GAG and collagen loss, NO synthesis, rescue of chondrocyte metabolism, viability, and GAG biosynthesis rates. The synovium exhibited a protective role as the effects of single-dose IL-1Ra were significantly enhanced in cartilage-synovium co-culture and were accompanied by release of anti-catabolic factors IL-4, carbonic anhydrase-3, and matrilin-3. A total of 26 unique proteins were identified in conditioned media from co-cultures, while expression levels of many additional proteins important to cartilage homeostasis were altered in co-culture compared to monocultures; principal component analysis revealed distinct clustering between co-culture and cartilage and synovium monocultures, thereby confirming significant crosstalk.

Conclusions

IL-1Ra suppresses cytokine-induced catabolism in cartilage more effectively in the presence of synovium, which was associated with endogenous production of anti-catabolic factors. Biological crosstalk between cartilage and synovium is significant; thus, their co-cultures should better model the intra-articular actions of potential OA therapeutics. Additionally, chondroprotective effects of IL-1Ra require sustained drug levels, underscoring the need for developing drug delivery strategies to enhance its joint residence time following a single intra-articular injection.

A Jack of All Trades: Impact of Glucocorticoids on Cellular Cross-Talk in Osteoimmunology

Glucocorticoids (GCs) are known to have a strong impact on the immune system, metabolism, and bone homeostasis. While these functions have been long investigated separately in immunology, metabolism, or bone biology, the understanding of how GCs regulate the cellular cross-talk between innate immune cells, mesenchymal cells, and other stromal cells has been garnering attention rather recently. Here we review the recent findings of GC action in osteoporosis, inflammatory bone diseases (rheumatoid and osteoarthritis), and bone regeneration during fracture healing. We focus on studies of pre-clinical animal models that enable dissecting the role of GC actions in innate immune cells, stromal cells, and bone cells using conditional and function-selective mutant mice of the GC receptor (GR), or mice with impaired GC signaling. Importantly, GCs do not only directly affect cellular functions, but also influence the cross-talk between mesenchymal and immune cells, contributing to both beneficial and adverse effects of GCs. Given the importance of endogenous GCs as stress hormones and the wide prescription of pharmaceutical GCs, an improved understanding of GC action is decisive for tackling inflammatory bone diseases, osteoporosis, and aging.

Identification of peptide coatings that enhance diffusive transport of nanoparticles through the tumor microenvironment

In solid tumors, increasing drug penetration promotes their regression and improves the therapeutic index of compounds. However, the heterogeneous extracellular matrix (ECM) acts as a steric and interaction barrier that hinders effective transport of therapeutics, including nanomedicines. Specifically, the interactions between the ECM and surface physicochemical properties of nanomedicines (e.g. charge, hydrophobicity) affect their diffusion and penetration. To address the challenges using existing surface chemistries, we used peptide-presenting phage libraries as a high-throughput approach to screen and identify peptides as coatings with desired physicochemical properties that improve diffusive transport through the tumor microenvironment. Through iterative screening against the ECM and identification by next-generation DNA sequencing and analysis, we selected individual clones and quantify their transport by diffusion assays. Here, we identified a net-neutral charge, hydrophilic peptide P4 that facilitates significantly higher diffusive transport of phage than negative control through in vitro tumor ECM. Through alanine mutagenesis, we confirmed that the hydrophilicity, charge, and spatial ordering impact diffusive transport. The P4 phage clone exhibited almost 200-fold improved uptake in ex vivo pancreatic tumor xenografts compared to the negative control. Nanoparticles coated with P4 exhibited ∼40-fold improvement in diffusivity in pancreatic tumor tissues, and P4-coated particles demonstrated less hindered diffusivity through the ECM compared to functionalized control particles. By leveraging the power of molecular diversity using phage display, we can greatly expand the chemical space of surface chemistries that can improve the transport of nanomedicines through the complex tumor microenvironment to ultimately improve their efficacy.

Catering to chondrocytes

An innovative strategy for delivering drugs to chondrocytes in situ offers new avenues for treating osteoarthritis (Geiger et al, this issue).

Molecular Response of Rabbit Menisci to Surgically Induced Hemarthrosis and a Single Intra-Articular Dexamethasone Treatment

Anterior cruciate ligament reconstructive surgery can restore biomechanical stability, however, such surgery cannot reliably prevent the onset of post-traumatic osteoarthritis. The aim of this study was to elucidate the molecular response that occurs within the menisci following a surgical injury that allows bleeding into the joint space, and then to investigate the effect of dexamethasone (DEX) on this molecular response. Cell viability studies following acute controlled exposure to blood and blood plus DEX were also conducted. Forty-eight New Zealand white rabbits were randomly allocated into control, sham, surgical, and surgical  + DEX groups (each group n  =  6). Animals were sacrificed at 48 h and 9 weeks, and menisci were harvested. The messenger RNA (mRNA) expression levels for key inflammatory, and degradative proteins, as well as mRNA levels for autophagy pathway molecules were quantified, and statistically significant changes were described. Meniscal cell viability was calculated by incubating groups of medial and lateral menisci in autologous blood, or autologous blood plus DEX for 48 h (each group n  =  4; total of eight medial and eight lateral menisci), and then conducting a histological live/dead assay. Results indicated a significant reduction in only medial meniscal cell viability when the tissue was exposed to blood in combination with DEX. A single administration of DEX following surgery significantly suppresses the elevated molecular expression for key inflammatory and degradative markers within menisci at 48 h and 9 weeks post-surgery. In vitro, autologous blood did not affect cell viability, but addition of DEX uniquely impacted the medial menisci. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2043-2052, 2019.

Cartilage penetrating cationic peptide carriers for applications in drug delivery to avascular negatively charged tissues

Drug delivery to avascular, negatively charged tissues like cartilage remains a challenge. The constant turnover of synovial fluid results in short residence time of administered drugs in the joint space and the dense negatively charged matrix of cartilage hinders their diffusive transport. Drugs are, therefore, unable to reach their cell and matrix targets in sufficient doses, and fail to elicit relevant biological response, which has led to unsuccessful clinical trials. The high negative fixed charge density (FCD) of cartilage, however, can be used to convert cartilage from a barrier to drug entry into a depot by making drugs positively charged. Here we design cartilage penetrating and binding cationic peptide carriers (CPCs) with varying net charge, spatial distribution and hydrophobicity to deliver large-sized therapeutics and investigate their electro-diffusive transport in healthy and arthritic cartilage. We showed that CPC uptake increased with increasing net charge up to +14 but dropped as charge increased further due to stronger binding interactions that hindered CPC penetrability and uptake showing that weak-reversible binding is key to enable their penetration through full tissue thickness. Even after 90% GAG depletion, while CPC +14 uptake reduced by over 50% but still had a significantly high value of 148× showing that intra-tissue long-range charge-based binding is further stabilized by short-range H-bond and hydrophobic interactions. The work presents an approach for rational design of cationic carriers based on tissue FCD and properties of macromolecules to be delivered. These design rules can be extended to drug delivery for other avascular, negatively charged tissues. STATEMENT OF SIGNIFICANCE: Osteoarthritis (OA) remains an untreatable disease partly due to short joint residence time of drugs and a lack of delivery methods that can effectively target the dense, avascular, highly negatively charged cartilage tissue. In this study, we designed cartilage penetrating and binding cationic peptide carriers (CPCs) that, due to their optimal charge provide adequate electrical driving force to rapidly transport OA drugs into cartilage and reach their cell and matrix targets in therapeutic doses before drugs exit the joint space. This way cartilage is converted from being a barrier to drug entry into a drug depot that can provide sustained drug release for several weeks. This study also investigates synergistic effects of short-range H-bond and hydrophobic interactions in combination with long-range electrostatic interactions on intra-cartilage solute transport. The work provides rules for rational design of cartilage penetrating charge-based carriers depending on the net charge of tissue (normal versus arthritic), macromolecule to be delivered and whether the application is in drug delivery or tissue imaging.

Bioactive factors for cartilage repair and regeneration: Improving delivery, retention, and activity

Articular cartilage is a remarkable tissue whose sophisticated composition and architecture allow it to withstand complex stresses within the joint. Once injured, cartilage lacks the capacity to self-repair, and injuries often progress to joint wide osteoarthritis (OA) resulting in debilitating pain and loss of mobility. Current palliative and surgical management provides short-term symptom relief, but almost always progresses to further deterioration in the long term. A number of bioactive factors, including drugs, corticosteroids, and growth factors, have been utilized in the clinic, in clinical trials, or in emerging research studies to alleviate the inflamed joint environment or to promote new cartilage tissue formation. However, these therapies remain limited in their duration and effectiveness. For this reason, current efforts are focused on improving the localization, retention, and activity of these bioactive factors. The purpose of this review is to highlight recent advances in drug delivery for the treatment of damaged or degenerated cartilage. First, we summarize material and modification techniques to improve the delivery of these factors to damaged tissue and enhance their retention and action within the joint environment. Second, we discuss recent studies using novel methods to promote new cartilage formation via biofactor delivery, that have potential for improving future long-term clinical outcomes. Lastly, we review the emerging field of orthobiologics, using delivered and endogenous cells as drug-delivering "factories" to preserve and restore joint health. Enhancing drug delivery systems can improve both restorative and regenerative treatments for damaged cartilage. STATEMENT OF SIGNIFICANCE: Articular cartilage is a remarkable and sophisticated tissue that tolerates complex stresses within the joint. When injured, cartilage cannot self-repair, and these injuries often progress to joint-wide osteoarthritis, causing patients debilitating pain and loss of mobility. Current palliative and surgical treatments only provide short-term symptomatic relief and are limited with regards to efficiency and efficacy. Bioactive factors, such as drugs and growth factors, can improve outcomes to either stabilize the degenerated environment or regenerate replacement tissue. This review highlights recent advances and novel techniques to enhance the delivery, localization, retention, and activity of these factors, providing an overview of the cartilage drug delivery field that can guide future research in restorative and regenerative treatments for damaged cartilage.

Cartilage-targeting dexamethasone prodrugs increase the efficacy of dexamethasone

Intra-articular administration of glucocorticoids such as dexamethasone is a common treatment for osteoarthritic inflammation and pain. Despite its potent anti-inflammatory properties, multiple barriers hinder the drug's effectiveness in the articular space. In particular, the high turnover rate of the synovial fluid and the dense cartilage extracellular matrix (ECM) lead to poor drug penetration into cartilage. In order to increase the infiltration and retention time, two dexamethasone prodrugs were developed. Firstly, dexamethasone was conjugated to polycationic chitosan, which led to deep and sustained infiltration of the drug into full thickness cartilage, due to its strong electrostatic interactions with the high negative fixed charges of the cartilage ECM. Secondly, dexamethasone was conjugated to a collagen type II-binding peptide, WYRGRL, and this prodrug was shown to be retained in the deep zones of cartilage through specific interactions with cartilage-specific collagen type II bundles. In both cases, active dexamethasone was released from the carrier by ester linkage hydrolysis. Complexing dexamethasone with either chitosan or collagen type II-affinity carriers increased its binding and therapeutic efficacy inside cartilage, compared to the free drug. Both dexamethasone conjugates significantly reduced levels of inflammatory markers and slowed the loss of glycosaminoglycans in an ex vivo model. A single dose of a cartilage-targeting dexamethasone prodrug represents a promising alternative to the repetitive glucocorticoid injections needed to compensate for its rapid clearance from the joint cavity.

Green fluorescent proteins engineered for cartilage-targeted drug delivery: Insights for transport into highly charged avascular tissues

Osteoarthritis (OA), the most common form of arthritis, is a multi-factorial disease that primarily affects cartilage as well as other joint tissues such as subchondral bone. The lack of effective drug delivery, due to the avascular nature of cartilage and the rapid clearance of intra-articularly delivered drugs via the synovium, remains a major challenge in the development of disease modifying drugs for OA. Cationic delivery carriers can significantly enhance the uptake, penetration and retention of drugs in cartilage by interacting with negatively charged matrix proteoglycans. In this study, we used "supercharged" green fluorescent proteins (GFPs), engineered to have a wide range of net positive charge and surface charge distributions, to characterize the effects of carrier charge on transport into cartilage in isolation of other factors such as carrier size and shape. We quantified the uptake, extent of cartilage penetration and cellular uptake of the GFP variants into living human knee cartilage and bovine cartilage explants. Based on these results, we identified optimal net charges of GFP carriers for potential drug targets located within cartilage extracellular matrix as well as the resident live chondrocytes. These cationic GFPs did not have adverse effects on cartilage in terms of measured cell viability and metabolism, cartilage cell biosynthesis and matrix degradation at doses needed for drug delivery. In addition to quantifying the kinetics of GFP uptake, we developed a predictive mathematical model for transport of the GFP variants that exhibited the highest uptake and penetration into cartilage. This model was further used to predict the transport behavior of GFPs during scale-up to in vivo applications such as intra-articular injection into human knees. The insights gained from this study set the stage for development of cartilage-targeted delivery systems to prevent cartilage degeneration, improve tissue regeneration and reduce inflammation that may cause degradation of other joint tissues affected by OA.

Cartilage diseases

Hyaline cartilages, fibrocartilages and elastic cartilages play multiple roles in the human body including bearing loads in articular joints and intervertebral discs, providing joint lubrication, forming the external ears and nose, supporting the trachea, and forming the long bones during development and growth. The structure and organization of cartilage's extracellular matrix (ECM) are the primary determinants of normal function. Most diseases involving cartilage lead to dramatic changes in the ECM which can govern disease progression (e.g., in osteoarthritis), cause the main symptoms of the disease (e.g., dwarfism caused by genetically inherited mutations) or occur as collateral damage in pathological processes occurring in other nearby tissues (e.g., osteochondritis dissecans and inflammatory arthropathies). Challenges associated with cartilage diseases include poor understanding of the etiology and pathogenesis, delayed diagnoses due to the aneural nature of the tissue and drug delivery challenges due to the avascular nature of adult cartilages. This narrative review provides an overview of the clinical and pathological features as well as current treatment options available for various cartilage diseases. Late breaking advances are also described in the quest for development and delivery of effective disease modifying drugs for cartilage diseases including osteoarthritis, the most common form of arthritis that affects hundreds of millions of people worldwide.

Interleukin-6 Neutralization by Antibodies Immobilized at the Surface of Polymeric Nanoparticles as a Therapeutic Strategy for Arthritic Diseases

Arthritic diseases are disabling conditions affecting millions of patients worldwide. Pro-inflammatory cytokines, particularly interleukin-6 (IL-6), plays a crucial role in inflammation and cartilage destruction. Although the beneficial effects of antibody therapy, its efficacy is limited. Therefore, this work proposes the immobilization of antibodies at the surface of biodegradable polymeric nanoparticles (NPs) to capture and neutralize IL-6. Our system is intended to protect, extend and enhance the therapeutic efficacy after delivery. Chitosan-hyaluronic acid NPs are synthesized as a stable monodisperse population. After determining the maximum immobilization capacity (10 μg/mL), the capture ability was confirmed. Biological assays demonstrate the NPs cytocompatibility with human articular chondrocytes (hACs) and human macrophages. hACs stimulated with macrophage conditioned medium shows the beneficial role of IL-6 capture and neutralization. Biofunctionalized NPs exhibit a prolonged action and stronger efficacy than the free antibody. In conclusion, this system can be an effective and long lasting treatment for arthritic diseases.