Preliminary histopathological study of intra-articular injection of a novel highly cross-linked hyaluronic acid in a rabbit model of knee osteoarthritis

Application of Injectable Hydrogels as Delivery Systems in Osteoarthritis and Rheumatoid Arthritis

Osteoarthritis and rheumatoid arthritis, though etiologically distinct, are both inflammatory joint diseases that cause progressive joint injury, chronic pain, and loss of function. Therefore, long-term treatment with a focus on relieving symptoms is needed. At present, the primary treatment for arthritis is drug therapy, both oral and intravenous. Although significant progress has been achieved for these treatment methods in alleviating symptoms, certain prominent drawbacks such as the substantial side effects and limited absorption of medications call for an urgent need for improved drug delivery methods. Injected hydrogels can be used as a delivery system to deliver drugs to the joint cavity in a controlled manner and continuously release them, thereby enhancing drug retention in the joint cavity to improve therapeutic effectiveness, which is attributed to the desirable attributes of the delivery system such as low immunogenicity, good biodegradability and biocompatibility. This review summarizes the types of injectable hydrogels and analyzes their applications as delivery systems in arthritis treatment. We also explored how hydrogels counteract inflammation, bone and cartilage degradation, and oxidative stress, while promoting joint cartilage regeneration in the treatment of osteoarthritis (OA) and rheumatoid arthritis (RA). This review also highlights new approaches to developing injectable hydrogels as delivery systems for OA and RA.

A Mechanically Resilient Soft Hydrogel Improves Drug Delivery for Treating Post-Traumatic Osteoarthritis in Physically Active Joints

Intra-articular delivery of disease-modifying osteoarthritis drugs (DMOADs) is likely to be most effective in early post-traumatic osteoarthritis (PTOA) when symptoms are minimal and patients are physically active. DMOAD delivery systems therefore must withstand repeated mechanical loading without affecting the drug release kinetics. Although soft materials are preferred for DMOAD delivery, mechanical loading can compromise their structural integrity and disrupt drug release. Here, we report a mechanically resilient soft hydrogel that rapidly self-heals under conditions resembling human running while maintaining sustained release of the cathepsin-K inhibitor L-006235 used as a proof-of-concept DMOAD. Notably, this hydrogel outperformed a previously reported hydrogel designed for intra-articular drug delivery, used as a control in our study, which neither recovered nor maintained drug release under mechanical loading. Upon injection into mouse knee joints, the hydrogel showed consistent release kinetics of the encapsulated agent in both treadmill-running and non-running mice. In a mouse model of aggressive PTOA exacerbated by treadmill running, L-006235 hydrogel markedly reduced cartilage degeneration. To our knowledge, this is the first hydrogel proven to withstand human running conditions and enable sustained DMOAD delivery in physically active joints, and the first study demonstrating reduced disease progression in a severe PTOA model under rigorous physical activity, highlighting the hydrogel's potential for PTOA treatment in active patients.

Hyaluronic acid carrier-based photodynamic therapy for head and neck squamous cell carcinoma

PURPOSE

Conventional photosensitizers for photodynamic therapy (PDT) typically have wide tissue distribution and poor water solubility. A hyaluronic acid (HA) polymeric nanoparticle with specific lymphatic uptake and highly water solubility was developed to deliver pyropheophorbide-a (PPa) for locally advanced head and neck squamous cell carcinoma (HNSCC) treatment.

METHODS AND RESULTS

PPa was chemically conjugated to the HA polymeric nanoparticle via an adipic acid dihydrazide (ADH) linker. The conjugates were injected subcutaneously in a region near the tumor. Near-infrared (NIR) imaging was used to monitor distribution, and diode laser was used to activate PPa. The singlet oxygen generation efficiency of PPa was not affected by conjugation to HA nanoparticles at a PPa loading degree of 1.89 w.t.%. HA-ADH-PPa inhibited human HNSCC MDA-1986 cell growth only when photo-irradiation was applied. After HA-ADH-PPa treatment and radiation, NU/NU mice bearing human HNSCC MDA-1986 tumors showed reduced tumor growth and significantly enhanced survival time compared with an untreated group (p < 0.05).

CONCLUSIONS

These results demonstrate that HA-ADH-PPa could be useful for in vivo locoregional photodynamic therapy of HNSCC.

VHPKQHR Peptide Modified Ultrasmall Paramagnetic Iron Oxide Nanoparticles Targeting Rheumatoid Arthritis for T1-Weighted Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) could be the ideal diagnostic modality for early rheumatoid arthritis (RA). Vascular cell adhesion molecule-1 (VCAM-1) is highly expressed in synovial locations in patients with RA, which could be a potential target protein for RA diagnosis. The peptide VHPKQHR (VHP) has a high affinity to VCAM-1. To make the contrast agent to target RA at an early stage, we used VHP and ultrasmall paramagnetic iron oxide (USPIO) to synthesize UVHP (U stands for USPIO) through a chemical reaction with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide. The size of UVHP was 6.7 nm; the potential was −27.7 mV, and the r₂/r₁ value was 1.73. Cytotoxicity assay exhibited that the cell survival rate was higher than 80% at even high concentrations of UVHP (Fe concentration 200 µg/mL), which showed the UVHP has low toxicity. Compared with no TNF-α stimulation, VCAM-1 expression was increased nearly 3-fold when mouse aortic endothelial cells (MAECs) were stimulated with 50 ng/mL TNF-α; cellular Fe uptake was increased very significantly with increasing UVHP concentration under TNF-α treatment; cellular Fe content was 17 times higher under UVHP with Fe concentration 200 µg/mL treating MAECs. These results indicate that UVHP can target overexpression of VCAM-1 at the cellular level. RA mice models were constructed with adjuvant-induced arthritis. In vivo MRI and biodistribution results show that the signal intensity of knee joints was increased significantly and Fe accumulation in RA model mice compared with normal wild-type mice after injecting UVHP 24 h. These results suggest that we have synthesized a simple, low-cost, and less toxic contrast agent UVHP, which targeted VCAM-1 for early-stage RA diagnosis and generates high contrast in T₁-weighted MRI.

Use of hyaluronic acid associated with triamcinolone acetonide or ozone gas in the treatment of induced osteoarthritis in rabbits

Purpose:

To evaluate the effects of the intra-articular application of hyaluronic acid associated with triamcinolone acetonide, and ozone gas in the treatment of induced osteoarthritis in rabbit’s stifles.

Methods:

Twenty-one Norfolk rabbits were submitted to cranial cruciate ligament transection of the left stifle. After six weeks of the surgery, the rabbits were randomized assigned into three groups: G1 (control) – saline solution (0.9%); G2 – hyaluronic acid associated with triamcinolone; G3 – ozone gas, submitted to three intra-articular applications every seven days.

Results:

Significant differences occurred: osteophytes at medial femoral condyle (G2 > G1, G2 > G3) on radiography exam; thickening of the medial condyle (G1 > G3, G2 > G3) on ultrasound exam; osteophytes at lateral tibial condyle (G2 > G1, G2 > G3), and medial femoral condyle (G1 > G2, G3 > G1) on computed tomography. Histologically, mean values of chondrocytes in the femur and tibia in G3 and G2 were statistically lower.

Conclusions:

The intra-articular injection of hyaluronic acid associated with triamcinolone accentuated degenerative joint disease by imaging and macroscopic evaluations, and by histological findings, this treatment and the ozone gas treatment showed similar effects and were inferior to the saline solution (0.9%).

Biocompatible Hydrogel for Intra-Articular Implantation Comprising Cationic and Anionic Polymers of Natural Origin: In Vivo Evaluation in a Rabbit Model

We describe the functional capability of a cross-linked hydrogel composed of sulfated glycosaminoglycans and a cationic cellulose by conducting trials on experimental animal models using intra-articular implants to treat an articular disease called osteoarthritis. Forty-eight mature New Zealand white rabbits were divided into three experimental groups: A, B, and C. Group A and B underwent unilateral anterior cruciate ligament transection (ACLT) of the right knee. Subsequently, both knees of group A were treated with the injectable formulation under study. Meanwhile, group B was treated with sterile PBS (placebo). The animals of group C were surgically operated in both knees: Commercial hyaluronic acid (HA) was implanted in the left knee, and the formulation under study was implanted in the right knee. After implantation, all specimens underwent several evaluations at 3, 6, and 12 months postoperatively. At 6 months, no significant differences were detected between the right and left knees of the different groups. However, significant differences were observed between both knees at 12 months in group C, with less cartilage damage in the right knees implanted with our hydrogel. Therefore, in vivo studies have demonstrated hydrogel safety, superior permanence, and less cartilage damage for long-term follow up 12 months after implantation for the formulation under study compared with commercial HA.

Intra-Articular Drug Delivery for Osteoarthritis Treatment

Osteoarthritis (OA) is the most prevalent degenerative joint disease affecting millions of people worldwide. Currently, clinical nonsurgical treatments of OA are only limited to pain relief, anti-inflammation, and viscosupplementation. Developing disease-modifying OA drugs (DMOADs) is highly demanded for the efficient treatment of OA. As OA is a local disease, intra-articular (IA) injection directly delivers drugs to synovial joints, resulting in high-concentration drugs in the joint and reduced side effects, accompanied with traditional oral or topical administrations. However, the injected drugs are rapidly cleaved. By properly designing the drug delivery systems, prolonged retention time and targeting could be obtained. In this review, we summarize the drugs investigated for OA treatment and recent advances in the IA drug delivery systems, including micro- and nano-particles, liposomes, and hydrogels, hoping to provide some information for designing the IA injected formulations.

Recent developments in natural and synthetic polymeric drug delivery systems used for the treatment of osteoarthritis

Osteoarthritis (OA), is a common musculoskeletal disorder that will progressively increase in older populations and is expected to be the most dominant cause of disability in the world population by 2030. The progression of OA is controlled by a multi-factorial pathway that has not been completely elucidated and understood yet. However, over the years, research efforts have provided a significant understanding of some of the processes contributing to the progression of OA. Both cartilage and bone degradation processes induce articular cells to produce inflammatory mediators that produce proinflammatory cytokines that block the synthesis of collagen type II and aggrecan, the major components of cartilage. Systemic administration and intraarticular injection of anti-inflammatory agents are the first-line treatments of OA. However, small anti-inflammatory molecules are rapidly cleared from the joint cavity which limits their therapeutic efficacy. To palliate this strong technological drawback, different types of polymeric materials such as microparticles, nanoparticles, and hydrogels, have been examined as drug carriers for the delivery of therapeutic agents to articular joints. The main purpose of this review is to provide a summary of recent developments in natural and synthetic polymeric drug delivery systems for the delivery of anti-inflammatory agents to arthritic joints. Furthermore, this review provides an overview of the design rules that have been proposed so far for the development of drug carriers used in OA therapy. Overall it is difficult to state clearly which polymeric platform is the most efficient one because many advantages and disadvantages could be pointed to both natural and synthetic formulations. That requires further research in the near future.

Active viscosupplements for osteoarthritis treatment

OBJECTIVE

Osteoarthritis is a chronic, painful and disabling disease which prevalence is increasing in developing countries. Patients with osteoarthritis present a reduced synovial fluid viscoelasticity due to a reduction in concentration and molecular weight of hyaluronic acid. Currently, the main treatment used to restore the compromised rheological properties of synovial fluid is the viscosupplementation by hyaluronic acid injections that can be combined with oral anti-inflammatory drugs for pain relief. Combination of viscosupplements with chemical agents or drugs is emerging as a new strategy to provide a double action of synovial fluid viscoelasticity recovery and the therapeutic effect of the bioactive principle.

METHODS

In this review, we present the latest research on the combination of viscosupplements with active molecules. We conducted a literature review of articles published in different web search engines and categorized according to the active molecule introduced into the viscosupplement.

RESULTS

Generally, the introduction of anti-inflammatory molecules have shown to improve pain relief although some cytotoxicity has been demonstrated especially for non-steroidal anti-inflammatory drugs. Other molecules such as antioxidant or disease modifying osteoarthritis drugs have been reported to improve viscosupplementation action. Drug delivery systems combined with hyaluronic acid could enhance the activity of the encapsulated molecules and provide better control over the drug release. Finally, biological approaches such as the use of stem cells or platelet-rich plasma seem to be the most promising strategies for cartilage recovery.

CONCLUSIONS

Combination therapy of viscosupplements with therapeutic agents, drug delivery systems or regenerative therapies can improve viscosupplementation outcome in terms of pain relief and joint functionality. However, further research is needed in order to reach more conclusive results.

A hyaluronic acid- and chondroitin sulfate-based medical device improves gastritis pain, discomfort, and endoscopic features

Gastritis is an inflammation of the gastric mucosa. In this study, we investigated the efficacy of a medical device, Esoxx®, based on hyaluronic acid and chondroitin sulfate on gastritis-related upper abdominal pain/discomfort and endoscopic features. Fifty patients, affected by gastritis, were randomised to receive the medical device or placebo. The primary endpoint was the medical device efficacy on upper abdominal pain/discomfort associated with gastritis and measured by Visual Analogue Scale (VAS). The secondary endpoints were the efficacy of the medical device on gastritis-related mucosal erosions, blood oozing, and hyperemia (redness)/edema, as assessed by endoscopy, and the patients’ rating of their compliance with the treatments. A significant reduction in VAS pain was observed in the treatment group after a 5-week treatment, if compared with placebo (p < 0.001). In summary, administration of a medical device, based on hyaluronic acid and chondroitin sulfate, improves gastritis-related upper abdominal pain/discomfort and decreases mucosal erosions, blood oozing, and hyperemia (redness)/edema at 5-week follow-up in patients affected by gastritis.

Investigational drugs for the treatment of osteoarthritis, an update on recent developments

INTRODUCTION

Osteoarthritis (OA) is the leading cause of pain, loss of function, and disability among elderly, with the knee the most affected joint. It is a heterogeneous condition characterized by complex and multifactorial etiologies which contribute to the broad variation in symptoms presentation and treatment responses that OA patients present. This poses a challenge for the development of effective treatment on OA.

AREAS COVERED

This review will discuss recent development of agents for the treatment of OA, updating our previous narrative review published in 2015. They include drugs for controlling local and systemic inflammation, regulating articular cartilage, targeting subchondral bone, and relieving pain.

EXPERT OPINION

Although new OA drugs such as monoclonal antibodies have shown marked effects and favorable tolerance, current treatment options for OA remain limited. The authors believe there is no miracle drug that can be used for all OA patients'; treatment and disease stage is crucial for the effectiveness of drugs. Therefore, early diagnosis, phenotyping OA patients and precise therapy would expedite the development of investigational drugs targeting at symptoms and disease progression of OA.

Origin and Efficacy of Hyaluronan Injections in Knee Osteoarthritis: Randomized, Double-Blind Trial

BACKGROUND Several hyaluronan preparations are available that have different dosage forms, origins, and concentrations. The objective of the study was to compare the efficacy of intra-articular chemically cross-linked hyaluronan (CCH) and avian-derived hyaluronan (ADH) injections in knee osteoarthritis (KOA) patients. MATERIAL AND METHODS In total, 258 patients were randomized into 2 groups of 129 each: patients who received CCH injection (CCH group) and patients who received ADH injection (ADH group). Radiographic Kellgren-Lawrence score, visual analog scale (VAS) pain score, Lequesne index score, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, single-limb stance (SLS) test, and timed "Up-and-Go" (TUG) test were performed. The Mann-Whitney U test or independent t-test following Bonferroni adjustment was performed for statistical analysis at 95% of confidence level. RESULTS The CCH group had improved VAS pain score (P<0.0001, q=54.803), total WOMAC score (P<0.0001, q=4.753), Lequesne index score (P<0.0001, q=3.208), and SLS time (P<0.0001, q=8.76) at the end of 6 months as compared to those in the ADH group. After 6 months of follow-up, the ADH group had improved TUG time (P=0.0148, q=3.385) as compared to baseline. Both groups of patients had the similar improvement in Kellgren-Lawrence score and mild to moderate adverse effects after 6 months. CONCLUSIONS CCH injection was superior to ADH injection.

Attenuation of inflammation and cartilage degradation by sulfasalazine-containing hyaluronic acid on osteoarthritis rat model

The aim of this study was to investigate the effects of a sulfasalazine-containing hyaluronic acid (SASP/HA) systems on in vitro anti-inflammation and the alleviation of cartilage degradation in both lipopolysaccharide (LPS)-stimulated synoviocytes and a rat model of monosodium iodoacetate (MIA)-induced osteoarthritis (OA). The SASP/HA resulted in long-term release of SASP from the SASP/HA for up to 60 days in a sustained manner. In vitro studies performed using real-time polymerase chain reaction (PCR) assay revealed that the SASP/HA was able to effectively and dose-dependently inhibit the mRNA expression levels of pro-inflammatory cytokines such as matrix metalloproteinases-3 (MMP-3), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in LPS-stimulated synoviocytes. In vivo studies showed that intra articular injection of SASP/HA greatly reduced the MIA-stimulated mRNA expression of MMP-3, COX-2, IL-6, and TNF-α in blood. Furthermore, these significant anti-inflammatory effects of SASP/HA contributed markedly to the alleviation of progression of MIA-induced OA and cartilage degradation, as demonstrated by X-ray, micro-computed tomography (micro-CT), gross findings, and histological evaluations. Therefore, our findings indicated that the long-term and sustained delivery of SASP using HA can play a therapeutic role in alleviating inflammation as well as protecting against cartilage damage in OA.

Hyaluronan in experimental injured/inflamed cartilage: In vivo studies

Joint disease is characterized by an imbalance between the synthesis and degradation of articular cartilage and subchondral bone accompanied by capsular fibrosis, osteophyte formation and varying degrees of inflammation of the synovial membrane. Many animal models have been developed to study arthritis and osteoarthritis that enable experimental conditions, diet and environmental risk factors to be carefully controlled. Animal-based studies have demonstrated the positive effects of exogenous HA on the preservation of joint cartilage in different models of arthritis and osteoarthritis. Although many promising effects of exogenous HA have been reported, there remains uncertainty as to its effectiveness in reversing cartilage injury and other manifestations of joint diseases because of difficulties in interpreting and unifying the results of these studies. A review of the literature of the last decade was conducted to report the results and to determine what we have learned from animal models in relation to joint inflammation induced by experimental models and HA treatment.

Corticosteroid transdermal delivery significantly improves arthritis pain and functional disability

Arthritis is characterized by pain and functional limitation affecting the patients' quality of life. We performed a clinical study to investigate the efficacy of a betamethasone valerate medicated plaster (Betesil) in improving pain and functional disability in patients with arthritis and osteoarthritis. We enrolled 104 patients affected by osteoarthritis (n = 40) or arthritis (n = 64) in different joints. Patients received diclofenac sodium cream (2 g, four times a day) or a 2.25-mg dose of Betesil applied to the painful joint every night before bedtime for 10 days. Pain and functional disability were assessed, by the Visual Analogue Scale (VAS) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) scores. Redness was assessed by clinical inspection, and edema by the "fovea sign" method. C-reactive protein (CRP) was also measured; CRP can be used to cost-effectively monitor the pharmacological treatment efficacy and is increased during the acute-phase response, returning to physiological values after tissue recovery and functional restoration. All measurements were at baseline and at 10-day follow-up. At 10-day follow-up, a greater improvement in VAS and WOMAC pain and WOMAC stiffness and functional limitation scores from baseline was observed in patients treated with Betesil compared with diclofenac (all p < 0.01). At 10-day follow-up, improvement in redness, edema, and CRP levels from baseline was also greater in patients treated with Betesil compared with diclofenac (all p < 0.01). This study demonstrates the safety and efficacy of transdermal delivery of betamethasone valerate in patients affected by arthritis and osteoarthritis.

Comparison between two different experimental models of osteoarthritis in rabbits. Intra-articular collagenase injection and anterior cruciate ligament transection

PURPOSE:

To compare two different experimental models of osteoarthritis in rabbits: intra-articular collagenase injection and anterior cruciate ligament transection.

METHODS:

Ten adult rabbits were randomly divided in two groups: COLL (collagenase group) and ACLT (anterior cruciate ligament transection). The COLL group was treated with 0.5 ml collagenase solution (2mg collagenase/0.5 ml sterile PBS), and the ACTL group was subjected to anterior cruciate ligament. After six and twelve weeks, respectively, the animals in the COLL and ACTL groups were euthanized. The gross appearance and histological examinations conducted in the cartilage articular surface was blindly scored according to the criteria developed by Yoshimi et al. (1994) and Mankin et al. (1971), respectively.

RESULTS:

The gross morphologic observation, macroscopic score and histological examinations have demonstrated that the ACTL group presented the highest scores, and lesions more severe than those in the COLL group.

CONCLUSIONS:

Both methods, anterior cruciate ligament transection and collagenase, applied to the stifle joint of the rabbits have effectively induced degenerative changes in the cartilage tissue, through statistically significant analysis (p≤0.05). The ACTL method has presented more severe lesions.

Protective effect of Shenmai injection on knee articular cartilage of osteoarthritic rabbits and IL-1β-stimulated human chondrocytes

Shenmai injection (SMI) has been widely used as a therapy to treat a number of diseases. However, its anti-osteoarthritic properties have not yet been fully investigated. In the present study, the protective effect of SMI on knee articular cartilage of anterior cruciate ligament transected rabbits and interleukin-1β (IL-1β)-stimulated human chondrocytes was investigated. For the in vivo study, knee osteoarthritis (KOA) was induced in female New Zealand white rabbits by anterior cruciate ligament transection (ACLT) in the knee of right hind limb. Rabbits either underwent sham surgery or ACLT surgery. Out of the rabbits receiving ACLT surgery, half of the rabbits received one 0.3 ml Shenmai intra-articular injection in the knee per week for four weeks, following ACLT surgery. The other rabbits received the same volume of normal saline solution. The cartilage was subsequently collected for histological evaluation. For the in vitro study, cultured human chondrocytes were treated with 10 ng/ml IL-1β in the presence or absence of 5 and 2% (v/v) SMI for 24 h. Nitric oxide (NO) and prostaglandin E2 (PGE2) levels in cell culture supernatant were assessed using a Griess reaction and ELISA respectively. The mRNA expression of cyclooxgenase-2 (COX-2), inducible nitric oxide synthase (iNOS), matrix metalloproteinase (MMP)-1, MMP-13 and tissue inhibitors of metalloproteinase-1 (TIMP-1) in chondrocytes were detected by reverse transcription-quantitative polymerase chain reaction. The results of the current study revealed that treatment with SMI ameliorated cartilage degradation in the ACLT rabbit model, and decreased levels of NO and PGE2. Furthermore, treatment with SMI decreased levels of COX-2, iNOS, MMP-1 and MMP-13 mRNA expression and increased TIMP-1 mRNA expression in IL-1β-stimulated human chondrocytes. These results indicate that SMI suppresses inflammation and ameliorated cartilage degradation, making it a potential and promising therapeutic option to treat KOA.

Efficacy and safety study on a new compound associating low and high molecular weight hyaluronic acid in the treatment of hip osteoarthritis

The combined use of low and high molecular weight hyaluronic acid (HA) has never been reported in the treatment of osteoarthritis (OA). The aim of this paper was to evaluate the efficacy of a new hybrid association of both preparations in patients suffering from hip OA and to compare the results with those obtained retrospectively from a cohort of patients treated with high molecular weight HA.

Twenty patients with moderate-severe hip OA (grade II–IV according to Kellgren-Lawrence score) were enrolled in the study group. After clinical and functional evaluation (Visual Analogue Scale [VAS] for pain, Lequesne Index, Harris Hip Score), each participant received an intra-articular ultrasound-guided injection of the new HA compound at baseline and after 40 days. The measures were repeated at three and six months. The data collected were retrospectively compared with those obtained in a cohort of 20 patients, matched for sex, age, and severity of hip OA, treated with high molecular weight hyaluronic acid.

The intra-group comparison showed a significant improvement in clinical and functional outcomes at three and six months in both cohorts, while the infra-group comparison showed better results in the patients treated with the study compound at six months (VAS at rest, P <0.04; VAS during activities, P <0.02; Harris Hip Score, P <0.001).

The present study is the first which demonstrates that a combination of low and high molecular weight HA is effective and safe in the management of patients suffering from hip OA and provides better therapeutic results in comparison to high molecular weight HA. We may infer that both HA preparations work synergically, enhancing their positive activities.

Intra-articular therapies for osteoarthritis

INTRODUCTION

Conventional medical therapies for osteoarthritis are mainly palliative in nature, aiming to control pain and symptoms. Traditional intra-articular therapies are not recommended in guidelines as first line therapy, but are potential alternatives, when conventional therapies have failed.

AREAS COVERED

Current and future intra-articular drug therapies for osteoarthritis are highlighted, including corticosteroids, hyaluronate, and more controversial treatments marketed commercially, namely platelet rich plasma and mesenchymal cell therapy. Intraarticular disease modifying osteoarthritis drugs are the future of osteoarthritis treatments, aiming at structural modification and altering the disease progression. Interleukin-1β inhibitor, bone morphogenic protein-7, fibroblast growth factor 18, bradykinin B2 receptor antagonist, human serum albumin, and gene therapy are discussed in this review. The evolution of drug development in osteoarthritis is limited by the ability to demonstrate effect. High quality trials are required to justify the use of existing intra-articular therapies and to advocate for newer, promising therapies.

EXPERT OPINION

Challenges in osteoarthritis therapy research are fundamentally related to the complexity of the pathological mechanisms of osteoarthritis. Novel drugs offer hope in a disease with limited medical therapy options. Whether these future intra-articular therapies will provide clinically meaningful benefits, remains unknown.

Ibuprofen-loaded porous microspheres suppressed the progression of monosodium iodoacetate-induced osteoarthritis in a rat model

The objectives of this study were (1) to fabricate ibuprofen-loaded porous microspheres (IBU/PMSs), (2) to evaluate the in vitro anti-inflammatory effects of the microspheres using LPS-induced inflammation in cultured synoviocytes, and (3) to evaluate the in vivo effect of the IBU/PMSs on the progression of monosodium iodoacetate (MIA)-induced osteoarthritis (OA) in a rat model. A dose-dependent in vitro anti-inflammatory effect on pro-inflammatory cytokine markers (matrix metallopeptidase-3 (MMP-3), matrix metallopeptidase-13 (MMP-13), cyclooxygenase-2 (COX-2), a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5)), interleukin-6 (IL-6), and tumor necrosis factor (TNF-α) was observed by confirming with real-time PCR analyses. In vivo, treatment with IBU/PMSs reduced MIA-stimulated mRNA expression of MMP-3, MMP-13, COX-2, ADAMTS-5, IL-6, and TNF-α in rat synoviocytes. In addition, we demonstrated that intra-articular IBU/PMSs suppressed the progression of MIA-induced OA in the rat model via anti-inflammatory mechanisms. In conclusion, IBU/PMSs are a promising therapeutic material to control the pain and progression of OA.

Docosahexenoic acid treatment ameliorates cartilage degeneration via a p38 MAPK-dependent mechanism

Osteoarthritis (OA) is a common chronic inflammatory disease, characterized by cartilage degradation. The aberrant expression of matrix metalloproteinase-13 (MMP-13) plays a vital role in the pathogenesis of OA. The anti‑inflammatory property of docosahexenoic acid (DHA) was previously revealed and showed that DHA retards the progress of many types of inflammatory disease. To evaluate the prophylactic function of DHA in OA, the effect of DHA on cartilage degeneration was assessed in interleukin‑1β (IL‑1β) stimulated human chondrosarcoma SW1353 cells or a rat model of adjuvant‑induced arthritis (AIA). The safe concentration range (0‑50 µg/ml in vitro) of DHA was determined by flow cytometry and MTT assay. The inhibitory effects of DHA on MMP‑13 mRNA and protein expression were confirmed by RT‑qPCR, ELISA and western blotting. Furthermore, findings of an in vivo study showed that DHA can increase the thickness of articular cartilage and decrease MMP‑13 expression in cartilage matrix in a rat AIA model. We also revealed the mechanism by which DHA ameliorates cartilage degeneration from OA. The DHA-mediated inhibition of MMP‑13 expression was partially attributed to the inactivation of the p38 mitogen‑activated protein kinases pathway by suppressing p‑p38 in IL-1β-stimulated SW1353 cells and a rat AIA model. Our findings suggested that DHA is a promising therapeutic agent that may be used for the prevention and treatment of OA.

Gallic acid can play a chondroprotective role against AGE-induced osteoarthritis progression

BACKGROUND

Advanced glycation end products (AGEs) are a group of stable covalent compounds generated by proteins, lipids, other macromolecules and sugar through a series of non-enzymatic reactions. As reported, AGEs can cause widespread pathophysiological responses through activation of AGE receptors (RAGEs) on the cell surface, and play an important role in the pathogenesis of osteoarthritis (OA). We hypothesized that the antioxidant and anti-glycan agent gallic acid (GA) can work against the effects of AGEs and can be used as a potential drug for the cure of OA.

METHODS

The present study first explored the negative functions of AGEs via AGE-treated chondrocytes isolated form rabbits. Then, we observed the protective role of GA in AGE-treated chondrocytes by measuring the reactive oxygen species (ROS), superoxide dismutase (SOD), collagen II, aggrecan, nitric oxide synthase (iNOs) and cyclooxygenase-2 (COX-2) in vitro. Finally, the changes in a cartilage lesion in a rabbit model of knee osteoarthritis was observed.

RESULTS

Exposure of chondrocytes to AGEs resulted in a reduction of ROS, SOD, collagen II and aggrecan, and an increase in iNOs and COX-2, which means exposure promoted OA lesions in a clinical setting. When AGE-treated chondrocytes were pretreated with GA, there were no significant changes in these key components compared to the normal chondrocytes. In vivo study showed cartilage degradation was reduced by GA as compared to the vehicle group.

CONCLUSION

The results of this study confirmed the chondroprotective role of GA and provide a potential drug for the relief of OA.

Acetylated derivative of glaucine inhibits joint inflammation in collagenase-induced arthritis

CONTEXT

Osteoarthritis (OA) has become by far the most common joint disorder. A number of studies using OA animal models have explored the effects of agents that can modulate bone metabolism.

OBJECTIVE

In the present study, we investigated the effect of acetylated derivative of plant alkaloid glaucine (ADG) on experimental OA in mice.

MATERIALS AND METHODS

Arthritis was induced by two intraarticular (i.a.) injections of collaganase. Histopathological changes were observed through hematoxylin and eosine (H&E), safranin O and toluidine blue staining. Differentiation of bone marrow (BM) cells was evaluated by tartarate-resistant acid phosphatase (TRAP) assay. The expression of phospho-Janus kinase 2 (pJAK2) and phospho signal transducer and activator of transcription3 (pSTAT3) expression in the joints was determined by immunohistochemistry.

RESULTS

We established that ADG significantly decreased cell infiltration (2.32 ± 0.14 versus 1.62 ± 0.13), cartilage loss (2.42 ± 0.12 versus 1.12 ± 0.10) and bone erosion (1.76 ± 0.13 versus 1.04 ± 0.14) in arthritic mice. It appeared that the substance inhibited in a dose-dependent manner osteoclast differentiation in vitro. ADG suppressed the expression of pJAK2 in the joint and partially affected the expression of pSTAT3.

CONCLUSION

Present results suggest that ADG is a suitable candidate for further development as an anti-arthritic agent.

Experimental and Clinical Efficacy of Two Hyaluronic Acid-based Compounds of Different Cross-Linkage and Composition in the Rejuvenation of the Skin

BACKGROUND

In the field of aesthetic medicine there is an increasing demand for safe and effective hyaluronic acid (HA) fillers to counteract the aging process.

METHODS AND AIMS

We designed a study to evaluate the safety and histological biocompatibility of Aliaxin® Global Performance, a cross-linked HA filler and Viscoderm® Skinkò E, a product composed of non-cross-linked HA and a complex including vitamins, antioxidants, amino acids and minerals injected into the skin of guinea pigs. Then, we translated our findings into the clinical setting, administering a combination of these compounds to patients seeking a facial rejuvenation procedure targeting moderate-to-severe wrinkles affecting the nasolabial folds.

RESULTS

The animal study showed that the two compounds did not induce any significant inflammatory reactions and increased collagen and elastic fibers in the skin. In the clinical setting, injection of Aliaxin® Global Performance, followed by Viscoderm® Skinkò E, resulted in a higher improvement in nasolabial fold hydration, trans-epidermal water loss and wrinkle aesthetic appearance, if compared with a protocol based on Aliaxin® Global Performance alone.

CONCLUSION

In summary, we show evidence on the safety and mechanism underlying two new HA-based compounds of different cross-linkage and composition, proposing that they can be safely used in combination in patients seeking facial rejuvenation procedures with long-lasting efficacy.

A randomized double-blind clinical trial on the treatment of knee osteoarthritis: the efficacy of polynucleotides compared to standard hyaluronian viscosupplementation

BACKGROUND

This randomized, double-blind, parallel-group clinical trial aims to assess the equivalence of intra-articular polynucleotides compared to standard hyaluronic acid (HA) viscosupplementation in the treatment of knee osteoarthritis (OA).

METHODS

75 patients affected by knee OA were assessed for eligibility and 72 were enrolled and randomized to receive either intra-articular polynucleotides (Condrotide-36 patients) or hyaluronic acid (Hyalubrix-36 patients) at the Orthopedic Institute "Gaetano Pini" (Milan). All patients underwent three intra-articular injections of Condrotide or Hyalubrix with an interval of 1week. Participants, care givers, and investigators responsible for outcome assessment were all blinded to group assignment. Primary outcome measurements (KOOS and pain level (1) at rest, (2) at weight-bearing and (3) during physical activity) were evaluated at baseline (T0) and after one (T1), two (T2), six (T6), ten (T10), and 26 (T26)weeks. Secondary measurements included the determination of COMP serum levels at T0, T6 and T26.

RESULTS

The reduction of pain and the increase of KOOS values from baseline were statistically significant for both treatments; nevertheless, for parameter KOOS "symptoms" the treatment with Condrotide showed significant results already after twoweeks (at T2 p=0.003) while the results obtained with Hyalubrix became significant only after 18 weeks (at T18 p=0.01). No significant adverse events were reported.

CONCLUSIONS

Condrotide is as effective as Hyalubrix in reducing knee OA symptoms but showed an earlier response on pain reduction and can therefore be considered a valid alternative to the use of HA in the treatment of OA, avoiding the adverse events of NSAIDs and of intra-articular corticosteroids.

Pulsed electromagnetic field therapy for management of osteoarthritis-related pain, stiffness and physical function: clinical experience in the elderly

BACKGROUND

Pulsed electromagnetic field (PEMF) therapy has shown promising therapeutic effectiveness on bone- and cartilage-related pathologies, being also safe for management of knee osteoarthritis.

AIM

The aim of this study was to investigate the clinical efficacy of a PEMF device for management of knee osteoarthritis in elderly patients.

MATERIALS AND METHODS

A total of 33 patients were screened, and 28 patients, aged between 60 and 83 and affected by bilateral knee osteoarthritis, were enrolled in this study. They received PEMF therapy on the right leg for a total of three 30-minute sessions per week for a period of 6 weeks, while the left leg did not receive any treatment and served as control. An intravenous drip containing ketoprofen, sodium clodronate, glucosamine sulfate, calcitonin, and ascorbic acid, for a total volume of 500 mL, was administered during PEMF therapy. At baseline and 3 months post-PEMF therapy, Visual Analog Scale (VAS) was used to assess knee pain and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) was used to measure knee pain, stiffness and physical function.

RESULTS

Changes in VAS and WOMAC scores were calculated for both knees as baseline minus post-treatment. A two sample Student's t-test, comparing change in knee-related VAS pain for PEMF-treated leg (49.8 ± 2.03) vs control leg (11 ± 1.1), showed a significant difference in favor of PEMF therapy (P < 0.001). A two sample Student's t-test comparing change in knee-related WOMAC pain, stiffness, and physical function for PEMF-treated leg (8.5 ± 0.4, 3.5 ± 0.2, 38.5 ± 2.08, respectively) vs control leg (2.6 ± 0.2; 1.6 ± 0.1; 4.5 ± 0.5 respectively), also showed a significant difference in favor of PEMF therapy (P < 0.001). No adverse reactions to therapy were observed.

CONCLUSION

The present study shows that PEMF therapy improves pain, stiffness and physical function in elderly patients affected by knee osteoarthritis.

A new highly viscoelastic hyaluronic acid gel: rheological properties, biocompatibility and clinical investigation in esthetic and restorative surgery

Nowadays there is an increased demand for safe and effective volume enhancing fillers to achieve soft tissue augmentation in order to overcome tissue defects and aging-associated skin changes. In the present study we characterized the rheological and biological properties of Variofill(®), a new highly viscoelastic hyaluronic acid gel, by investigating the local effects following subcutaneous implantation in the rat to detect the host-tissue reactions and biodegradation over 18 months. We also investigated, for the first time, the application of Variofill(®) in esthetic and restorative surgery in two medical case reports. In the first case report we successfully performed Variofill(®) treatment to improve facial scars in a patient previously involved in a car crash. In the second case report we carried out a novel procedure involving a high-dose (1000 ml) injection of Variofill(®) into the dermis and subcutis of the abdominal quadrants in order to allow a classic reconstructive procedure of the abdominal wall in a patient presenting a wide incisional hernia.