Microneedles enhance topical delivery of 15-deoxy-Δ12,14-prostaglandin J2 and reduce nociception in temporomandibular joint of rats

Applications of hydrogels in tissue-engineered repairing of temporomandibular joint diseases

Epidemiological studies reveal that symptoms of temporomandibular joint disorders (TMDs) occur in 60-70% of adults. The inflammatory damage caused by TMDs can easily lead to defects in the articular disc, condylar cartilage, subchondral bone and muscle of the temporomandibular joint (TMJ) and cause pain. Despite the availability of various methods for treating TMDs, few existing treatment schemes can achieve permanent recovery. This necessity drives the search for new approaches. Hydrogels, polymers with high water content, have found widespread use in tissue engineering and regeneration due to their excellent biocompatibility and mechanical properties, which resemble those of human tissues. In the context of TMD therapy, numerous experiments have demonstrated that hydrogels show favorable effects in aspects such as articular disc repair, cartilage regeneration, muscle repair, pain relief, and drug delivery. This review aims to summarize the application of hydrogels in the therapy of TMDs based on recent research findings. It also highlights deficiencies in current hydrogel research related to TMD therapy and outlines the broad potential of hydrogel applications in treating TMJ diseases in the future.

Comparison of chemical-induced temporomandibular osteoarthritis rat models (monosodium iodoacetate versus collagenase type II) for the study of prolonged drug delivery systems

OBJECTIVE

To compare two agents that can induce a rat model of temporomandibular joint osteoarthritis (TMJOA) by chemical induction: monosodium iodoacetate (MIA) and collagenase type 2 (Col-2). We wished to ascertain the best agent for assessing drug-delivery systems (DDSs).

METHOD

Male Wistar rats underwent intra-articular injection with MIA or Col-2. They were manipulated for 30 days. The head withdrawal threshold (HWT), immunohistological assessment, and positron emission tomography (PET) were used to evaluate the relevance of our models.

RESULTS

For both the MIA and Col-2 groups, pain persisted for 30 days after injection. Change in the HWT showed that Col-2 elicited a strong action initially that decreased progressively. MIA had a constant action upon pain behavior. Histology of TMJ tissue from both groups showed progressive degradation of TMJ components.

CONCLUSIONS

MIA and Col-2 induced orofacial pain by their local chemical action on TMJs. However, based on a prolonged and greater sustained effect on the pain threshold, persistent histological changes, and imaging results, MIA appeared to be more suitable for creation of a rat model of TMJOA for the study of DDSs.

A new frontier in temporomandibular joint osteoarthritis treatment: Exosome-based therapeutic strategy

Temporomandibular joint osteoarthritis (TMJOA) is a debilitating degenerative disease with high incidence, deteriorating quality of patient life. Currently, due to ambiguous etiology, the traditional clinical strategies of TMJOA emphasize on symptomatic treatments such as pain relief and inflammation alleviation, which are unable to halt or reverse the destruction of cartilage or subchondral bone. A number of studies have suggested the potential application prospect of mesenchymal stem cells (MSCs)-based therapy in TMJOA and other cartilage injury. Worthy of note, exosomes are increasingly being considered the principal efficacious agent of MSC secretions for TMJOA management. The extensive study of exosomes (derived from MSCs, synoviocytes, chondrocytes or adipose tissue et al.) on arthritis recently, has indicated exosomes and their specific miRNA components to be potential therapeutic agents for TMJOA. In this review, we aim to systematically summarize therapeutic properties and underlying mechanisms of MSCs and exosomes from different sources in TMJOA, also analyze and discuss the approaches to optimization, challenges, and prospects of exosome-based therapeutic strategy.

Drug delivery systems for treatment of temporomandibular joint osteoarthritis

The number of people suffering from temporomandibular joint osteoarthritis (TMJOA) has been increasing. TMJOA cause joint noise, pain on TMJ and/or masticatory muscles, and restricted mandibular movement, which disturb eating, laughing and conversation, and impose serious lifestyle impediments. Chondrocyte apoptosis, extracellular matrix degradation, synovitis, and subchondral bone remodeling are the main pathological features of TMJOA. Various drug delivery systems are developed to controlled release at specific activation sites with high bioactivity and inhibit rapid dilution to enable long-term therapeutic response, which present great potential for the treatment of TMJOA. This review focuses on recently developed drug delivery systems by different administration in the TMJOA treatment, and summarizes their effects, duration, safety, and limitations, which would pave the way for development of TMJOA therapy.

Topical Administration of 15-Deoxy-Δ 12,14-Prostaglandin J2 Using a Nonionic Cream: Effect on UVB-Induced Skin Oxidative, Inflammatory, and Histopathological Modifications in Mice

UVB radiation is certainly one of the most important environmental threats to which we are subjected to. This fact highlights the crucial protective role of the skin. However, the skin itself may not be capable of protecting against UVB depending on irradiation intensity and time of exposition. Sun blockers are used to protect our skin, but they fail to fully protect it against oxidative and inflammatory injuries initiated by UVB. To solve this issue, topical administration of active molecules is an option. 15-Deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ₂) is an arachidonic acid-derived lipid with proresolution and anti-inflammatory actions. However, as far as we are aware, there is no evidence of its therapeutic use in a topical formulation to treat the deleterious events initiated by UVB, which was the aim of the present study. We used a nonionic cream to vehiculate 15d-PGJ₂ (30, 90, and 300 ng/mouse) (TFcPGJ₂) in the skin of hairless mice. UVB increased skin edema, myeloperoxidase activity, metalloproteinase-9 activity, lipid peroxidation, superoxide anion production, gp91^phox and COX-2 mRNA expression, cytokine production, sunburn and mast cells, thickening of the epidermis, and collagen degradation. UVB also diminished skin ability to reduce iron and scavenge free radicals, reduced glutathione (GSH), sulfhydryl proteins, and catalase activity. TFcPGJ₂ inhibited all these pathological alterations in the skin caused by UVB. No activity was observed with the unloaded topical formulation. The protective outcome of TFcPGJ₂ indicates it is a promising therapeutic approach against cutaneous inflammatory and oxidative pathological alterations.

Systematic review of studies on drug-delivery systems for management of temporomandibular-joint osteoarthritis

INTRODUCTION

Temporomandibular-joint osteoarthritis (TMJOA) management is a major challenge. Minimally invasive therapies (based mainly on injections) have been developed to increase local efficacy and limit adverse systemic effects. However, the requirement for repeat injections due to a short duration of action and expensive healthcare costs have pushed researchers to develop, via tissue engineering, drug-delivery systems (DDSs). In this literature systematic review, we aim to provide an overview of studies that tested DDSs on a TMJOA model.

MATERIAL AND METHODS

We searched on PubMed for articles published from November 1965 to March 2021 on DDSs using a TMJOA model. We highlighted the different DDSs and the active molecule employed. Route of drug administration, model type, test duration, and efficacy duration were assessed. To evaluate the quality of each study, a protocol bias was tested using QUADAS-2™.

RESULTS

Of the 10 studies that were full text-screened, four used a poly(lactic-co-glycolic acid)-based delivery system. The other DDSs employed chitosan-based hydrogels, microneedles patches, nanostructured lipid carriers, or poloxamer micelles. Hyaluronic acid, nonsteroidal anti-inflammatory drugs, and analgesics were used as active molecules in five studies. The main way to administer DDSs was intra-articular injection and the most used model was the rat.

DISCUSSION

Various DDSs and active molecules have been studied on a TMJOA model that could aid TMJOA management. Further works using longer test durations are necessary to validate these advances.

Marine polymeric microneedles for transdermal drug delivery

Transdermal drug delivery is considered one of the most attractive routes for administration of pharmaceutic and cosmetic active ingredients due to the numerous advantages, especially over oral and intravenous methodologies. However, some limitations still exist mainly regarding the need to improve the drugs permeation across the skin. For this, several strategies have been described, considering the application of chemical permeation enhancers, drugs' nanoformulations and physical methods. Of these, microneedles have been proposed in the last years as promising strategies to enhance transdermal drug delivery. In this review, different types of microneedles are described, and the most commonly used methods of fabrication systematized, as well as the materials typically used and their main therapeutical applications. A special attention is paid to polymeric microneedles, particularly those made from sustainable marine polysaccharides like chitosan, alginate and hyaluronic acid. The applications of marine based polymeric microneedle devices for transdermal drug delivery are examined in detail and the perspectives of translation from the clinical trials to the market demonstrated.

Microneedles Coated with Tramadol Exhibit Antinociceptive Effect in a Rat Model of Temporomandibular Hypernociception

Coated microneedles have emerged as a promising drug delivery system for inflammatory pain treatment. We have previously shown that tramadol injection into the rat temporomandibular joint (TMJ) induces an antinociceptive and anti-inflammatory effect. In this study, microneedles coated with tramadol were investigated as a platform to treat TMJ pain. Male Wistar rats were administered tramadol using an intra-TMJ injection or with microneedles coated with tramadol, followed by 1.5% formalin nociceptive challenge administered 15 minutes later. The nociceptive behavior of rats was evaluated, and their periarticular tissues were removed after euthanasia for analysis. The duration of antinociceptive effect was determined by performing the formalin challenge at different time points extending up to 6 days post tramadol administration. Microneedles coated with tramadol produced an antinociceptive effect similar to injection of tramadol into the rat TMJ. Surprisingly, tramadol delivery using coated microneedles produced a more durable antinociceptive effect lasting as much as 2 days post tramadol delivery as compared with an antinociceptive effect lasting under 2 hours from intra-TMJ injection of tramadol. The proinflammatory cytokines tumor necrosis factor-α and interleukin-1β (IL-1β) were found to be reduced, whereas the anti-inflammatory cytokine IL-10 was found to be elevated in tramadol-treated groups. In conclusion, microneedles coated with tramadol can offer a therapeutic option for pain control of inflammatory disorders in the TMJ.

15d-PGJ2-loaded nanocapsules ameliorate experimental gout arthritis by reducing pain and inflammation in a PPAR-gamma-sensitive manner in mice

Gout arthritis (GA) is a painful inflammatory disease in response to monosodium urate (MSU) crystals in the joints. 15deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ₂) is a natural activator of PPAR-γ with analgesic, anti-inflammatory, and pro-resolution properties. Thus, we aimed to evaluate the effect and mechanisms of action of 15d-PGJ₂ nanocapsules (NC) in the model of GA in mice, since a reduction of 33-fold in the dose of 15d-PGJ₂ has been reported. Mice were treated with 15d-PGJ₂-loaded NC, inert NC, free 15d-PGJ₂ (without NC), or 15d-PGJ₂-loaded NC+ GW9662, a PPAR-γ inhibitor. We show that 15d-PGJ₂-loaded NC provided analgesic effect in a dose that the free 15d-PGJ₂ failed to inhibiting pain and inflammation. Hence, 15d-PGJ₂-loaded NC reduced MSU-induced IL-1β, TNF-α, IL-6, IL-17, and IL-33 release and oxidative stress. Also, 15d-PGJ₂-loaded NC decreased the maturation of IL-1β in LPS-primed BMDM triggered by MSU. Further, 15d-PGJ₂-loaded NC decreased the expression of the components of the inflammasome Nlrp3, Asc, and Pro-caspase-1, as consequence of inhibiting NF-κB activation. All effects were PPAR-γ-sensitive. Therefore, we demonstrated that 15d-PGJ₂-loaded NC present analgesic and anti-inflammatory properties in a PPAR-γ-dependent manner inhibiting IL-1β release and NF-κB activation in GA. Concluding, 15d-PGJ₂-loaded NC ameliorates MSU-induced GA in a PPAR-γ-sensitive manner.

Therapeutic applications and pharmacoeconomics of microneedle technology

INTRODUCTION

Microneedle (MN) arrays contain a backing plate with multiple microscopic projections to puncture the skin and can be used to deliver drug in a minimally invasive way. Advantages of MNs are numerous including administration of large molecules, avoiding first-pass metabolism, ease of administration, lack of pain, site-specific drug targeting, and dose reduction due to increased absorption efficacy. The growth in the transdermal market has been fueled by an increasing number of chronic disease patients and a demand for easy and pain-free drug administration.

AREAS COVERED

This paper highlights the use of MNs as a drug delivery system and discusses their potential market impact from a cost perspective. A number of clinical trials have been conducted and are listed to illustrate the potential applications of MNs for therapeutic use. Furthermore, the cosmetic market has made use of the MN technology, indicating that MNs can be used safely, efficaciously, and on a commercial scale. Furthermore, the cost-effectiveness of MNs is discussed.

EXPERT COMMENTARY

For MNs to become commercially available for therapeutic use, a number of factors will need to be considered: safety, ease of use, manufacturing and storage, uptake, effectiveness, and regulatory requirements.