p47phox siRNA-Loaded PLGA Nanoparticles Suppress ROS/Oxidative Stress-Induced Chondrocyte Damage in Osteoarthritis

Unraveling the molecular landscape of osteoarthritis: A comprehensive review focused on the role of non-coding RNAs

Osteoarthritis (OA) poses a significant global health challenge, with its prevalence anticipated to increase in the coming years. This review delves into the emerging molecular biomarkers in OA pathology, focusing on the roles of various molecules such as metabolites, noncoding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Advances in omics technologies have transformed biomarker identification, enabling comprehensive analyses of the complex pathways involved in OA pathogenesis. Notably, ncRNAs, especially miRNAs and lncRNAs, exhibit dysregulated expression patterns in OA, presenting promising opportunities for diagnosis and therapy. Additionally, the intricate interplay between epigenetic modifications and OA progression highlights the regulatory role of epigenetics in gene expression dynamics. Genome-wide association studies have pinpointed key genes undergoing epigenetic changes, providing insights into the inflammatory processes and chondrocyte hypertrophy typical of OA. Understanding the molecular landscape of OA, including biomarkers and epigenetic mechanisms, holds significant potential for developing innovative diagnostic tools and therapeutic strategies for OA management.

Rejuvenating aged microglia by p16ink4a-siRNA-loaded nanoparticles increases amyloid-β clearance in animal models of Alzheimer's disease

Age-dependent accumulation of amyloid plaques in patients with sporadic Alzheimer's disease (AD) is associated with reduced amyloid clearance. Older microglia have a reduced ability to phagocytose amyloid, so phagocytosis of amyloid plaques by microglia could be regulated to prevent amyloid accumulation. Furthermore, considering the aging-related disruption of cell cycle machinery in old microglia, we hypothesize that regulating their cell cycle could rejuvenate them and enhance their ability to promote more efficient amyloid clearance. First, we used gene ontology analysis of microglia from young and old mice to identify differential expression of cyclin-dependent kinase inhibitor 2A (p16ink4a), a cell cycle factor related to aging. We found that p16ink4a expression was increased in microglia near amyloid plaques in brain tissue from patients with AD and 5XFAD mice, a model of AD. In BV2 microglia, small interfering RNA (siRNA)-mediated p16ink4a downregulation transformed microglia with enhanced amyloid phagocytic capacity through regulated the cell cycle and increased cell proliferation. To regulate microglial phagocytosis by gene transduction, we used poly (D,L-lactic-co-glycolic acid) (PLGA) nanoparticles, which predominantly target microglia, to deliver the siRNA and to control microglial reactivity. Nanoparticle-based delivery of p16ink4a siRNA reduced amyloid plaque formation and the number of aged microglia surrounding the plaque and reversed learning deterioration and spatial memory deficits. We propose that downregulation of p16ink4a in microglia is a promising strategy for the treatment of Alzheimer's disease.

Current therapies for osteoarthritis and prospects of CRISPR-based genome, epigenome, and RNA editing in osteoarthritis treatment

Osteoarthritis (OA) is one of the most common degenerative joint diseases worldwide, causing pain, disability, and decreased quality of life. The balance between regeneration and inflammation-induced degradation results in multiple etiologies and complex pathogenesis of OA. Currently, there is a lack of effective therapeutic strategies for OA treatment. With the development of CRISPR-based genome, epigenome, and RNA editing tools, OA treatment has been improved by targeting genetic risk factors, activating chondrogenic elements, and modulating inflammatory regulators. Supported by cell therapy and in vivo delivery vectors, genome, epigenome, and RNA editing tools may provide a promising approach for personalized OA therapy. This review summarizes CRISPR-based genome, epigenome, and RNA editing tools that can be applied to the treatment of OA and provides insights into the development of CRISPR-based therapeutics for OA treatment. Moreover, in-depth evaluations of the efficacy and safety of these tools in human OA treatment are needed.

Engineering approaches for RNA-based and cell-based osteoarthritis therapies

Osteoarthritis (OA) is a chronic, debilitating disease that substantially impairs the quality of life of affected individuals. The underlying mechanisms of OA are diverse and are becoming increasingly understood at the systemic, tissue, cellular and gene levels. However, the pharmacological therapies available remain limited, owing to drug delivery barriers, and consist mainly of broadly immunosuppressive regimens, such as corticosteroids, that provide only short-term palliative benefits and do not alter disease progression. Engineered RNA-based and cell-based therapies developed with synthetic chemistry and biology tools provide promise for future OA treatments with durable, efficacious mechanisms of action that can specifically target the underlying drivers of pathology. This Review highlights emerging classes of RNA-based technologies that hold potential for OA therapies, including small interfering RNA for gene silencing, microRNA and anti-microRNA for multi-gene regulation, mRNA for gene supplementation, and RNA-guided gene-editing platforms such as CRISPR-Cas9. Various cell-engineering strategies are also examined that potentiate disease-dependent, spatiotemporally regulated production of therapeutic molecules, and a conceptual framework is presented for their application as OA treatments. In summary, this Review highlights modern genetic medicines that have been clinically approved for other diseases, in addition to emerging genome and cellular engineering approaches, with the goal of emphasizing their potential as transformative OA treatments.

Peptide-mediated targeted delivery of SOX9 nanoparticles into astrocytes ameliorates ischemic brain injury

Astrocytes are highly activated following brain injuries, and their activation influences neuronal survival. Additionally, SOX9 expression is known to increase in reactive astrocytes. However, the role of SOX9 in activated astrocytes following ischemic brain damage has not been clearly elucidated yet. Therefore, in the present study, we investigated the role of SOX9 in reactive astrocytes using a poly-lactic-co-glycolic acid (PLGA) nanoparticle plasmid delivery system in a photothrombotic stroke animal model. We designed PLGA nanoparticles to exclusively enhance SOX9 gene expression in glial fibrillary acidic protein (GFAP)-immunoreactive astrocytes. Our observations indicate that PLGA nanoparticles encapsulated with GFAP:SOX9:tdTOM reduce ischemia-induced neurological deficits and infarct volume through the prostaglandin D2 pathway. Thus, the astrocyte-targeting PLGA nanoparticle plasmid delivery system provides a potential opportunity for stroke treatment. Since the only effective treatment currently available is reinstating the blood supply, cell-specific gene therapy using PLGA nanoparticles will open a new therapeutic paradigm for brain injury patients in the future.

Epigallocatechin Gallate Potentiates the Anticancer Effect of AFP-siRNA-Loaded Polymeric Nanoparticles on Hepatocellular Carcinoma Cells

To develop a potential cancer treatment, we formulated a novel drug delivery platform made of poly(lactic-co-glycolic) acid (PLGA) and used a combination of an emerging siRNA technology and an extracted natural substance called catechins. The synthesized materials were characterized to determine their properties, including morphology, hydrodynamic size, charge, particle stability, and drug release profile. The therapeutic effect of AFP-siRNA and epigallocatechin gallate (EGCG) was revealed to have remarkable cytotoxicity towards HepG2 when in soluble formulation. Notably, the killing effect was enhanced by the co-treatment of AFP-siRNA-loaded PLGA and EGCG. Cell viability significantly dropped to 59.73 ± 6.95% after treatment with 12.50 μg/mL of EGCG and AFP-siRNA-PLGA. Meanwhile, 80% of viable cells were observed after treatment with monotherapy. The reduction in the survival of cells is a clear indication of the complementary action of both active EGCG and AFP-siRNA-loaded PLGA. The corresponding cell death was involved in apoptosis, as evidenced by the increased caspase-3/7 activity. The combined treatment exhibited a 2.5-fold increase in caspase-3/7 activity. Moreover, the nanoparticles were internalized by HepG2 in a time-dependent manner, indicating the appropriate use of PLGA as a carrier. Accordingly, a combined system is an effective therapeutic strategy.

Targeting the Main Sources of Reactive Oxygen Species Production: Possible Therapeutic Implications in Chronic Pain

Humans have long been combating chronic pain. In clinical practice, opioids are first- choice analgesics, but long-term use of these drugs can lead to serious adverse reactions. Finding new, safe and effective pain relievers that are useful treatments for chronic pain is an urgent medical need. Based on accumulating evidence from numerous studies, excess reactive oxygen species (ROS) contribute to the development and maintenance of chronic pain. Some antioxidants are potentially beneficial analgesics in the clinic, but ROS-dependent pathways are completely inhibited only by scavenging ROS directly targeting cellular or subcellular sites. Unfortunately, current antioxidant treatments donot achieve this effect. Furthermore, some antioxidants interfere with physiological redox signaling pathways and fail to reverse oxidative damage. Therefore, the key upstream processes and mechanisms of ROS production that lead to chronic pain in vivo must be identified to discover potential therapeutic targets related to the pathways that control ROS production in vivo. In this review, we summarize the sites and pathways involved in analgesia based on the three main mechanisms by which ROS are generated in vivo, discuss the preclinical evidence for the therapeutic potential of targeting these pathways in chronic pain, note the shortcomings of current research and highlight possible future research directions to provide new targets and evidence for the development of clinical analgesics.

Targeting regulated chondrocyte death in osteoarthritis therapy

In vivo articular cartilage degeneration is an essential hallmark of osteoarthritis (OA), involving chondrocyte senescence, extracellular matrix degradation, chondrocyte death, cartilage loss, and bone erosion. Among them, chondrocyte death is one of the major factors leading to cartilage degeneration. Many studies have reported that various cell death modes, including apoptosis, ferroptosis, and autophagy, play a key role in OA chondrocyte death. Currently, there is insufficient understanding of OA pathogenesis, and there remains a lack of treatment methods to prevent OA and inhibit its progression. Studies suggest that OA prevention and treatment are mainly directed to arrest premature or excessive chondrocyte death. In this review, we a) discuss the forms of death of chondrocytes and the associations between them, b) summarize the critical factors in chondrocyte death, c) discuss the vital role of chondrocyte death in OA, d) and, explore new approaches for targeting the regulation of chondrocyte death in OA treatment.

The emerging potential of siRNA nanotherapeutics in treatment of arthritis

RNA interference (RNAi) using small interfering RNA (siRNA) has shown potential as a therapeutic option for the treatment of arthritis by silencing specific genes. However, siRNA delivery faces several challenges, including stability, targeting, off-target effects, endosomal escape, immune response activation, intravascular degradation, and renal clearance. A variety of nanotherapeutics like lipidic nanoparticles, liposomes, polymeric nanoparticles, and solid lipid nanoparticles have been developed to improve siRNA cellular uptake, protect it from degradation, and enhance its therapeutic efficacy. Researchers are also investigating chemical modifications and bioconjugation to reduce its immunogenicity. This review discusses the potential of siRNA nanotherapeutics as a therapeutic option for various immune-mediated diseases, including rheumatoid arthritis, osteoarthritis, etc. siRNA nanotherapeutics have shown an upsurge of interest and the future looks promising for such interdisciplinary approach-based modalities that combine the principles of molecular biology, nanotechnology, and formulation sciences.

Use of Poly Lactic-co-glycolic Acid Nano and Micro Particles in the Delivery of Drugs Modulating Different Phases of Inflammation

Chronic inflammation contributes to the pathogenesis of many diseases, including apparently unrelated conditions such as metabolic disorders, cardiovascular diseases, neurodegenerative diseases, osteoporosis, and tumors, but the use of conventional anti-inflammatory drugs to treat these diseases is generally not very effective given their adverse effects. In addition, some alternative anti-inflammatory medications, such as many natural compounds, have scarce solubility and stability, which are associated with low bioavailability. Therefore, encapsulation within nanoparticles (NPs) may represent an effective strategy to enhance the pharmacological properties of these bioactive molecules, and poly lactic-co-glycolic acid (PLGA) NPs have been widely used because of their high biocompatibility and biodegradability and possibility to finely tune erosion time, hydrophilic/hydrophobic nature, and mechanical properties by acting on the polymer's composition and preparation technique. Many studies have been focused on the use of PLGA-NPs to deliver immunosuppressive treatments for autoimmune and allergic diseases or to elicit protective immune responses, such as in vaccination and cancer immunotherapy. By contrast, this review is focused on the use of PLGA NPs in preclinical in vivo models of other diseases in which a key role is played by chronic inflammation or unbalance between the protective and reparative phases of inflammation, with a particular focus on intestinal bowel disease; cardiovascular, neurodegenerative, osteoarticular, and ocular diseases; and wound healing.

Epigallocatechin-3-gallate (EGCG) based metal-polyphenol nanoformulations alleviates chondrocytes inflammation by modulating synovial macrophages polarization

The activation of M1-type macrophages are dominant cells secreting proinflammatory present within the inflamed synovium in the progression of osteoarthritis (OA). Increased oxidative stress, such as redundant ROS and hydrogen peroxide (H2O2), are important factors in driving macrophages to polarize into M1 type. In this study, metal-polyphenol nanoformulations (Cu-Epigallocatechin-3-gallate (Cu-EGCG) nanosheets) were synthesized through the coordination interaction between EGCG and copper ions, which possessed the antioxidant effect of EGCG and anti-inflammatory of Cu2+. Results showed that Cu-EGCG nanosheets were biocompatible and the Cu2+ could be sustained released from the nanoparticles. Cu-EGCG nanosheets with multienzyme-like antioxidative activity could effectively scavenge the excessive intracellular ROS, leading to significantly decreased expression of the pro-inflammatory cytokines, which could reduce the expression of M1-type macrophages and exhibit excellent promotion on shifting macrophages to M2 phenotypes. Moreover, the secreted factor from the cell supernatant of Cu-EGCG treated macrophages exhibited anti-inflammatory potential in chondrocytes of inflamed synovial joints. This study suggests a novel strategy for OA therapy by using metal-polyphenol nanoformulations targeting macrophages.

PINK1 siRNA-loaded poly(lactic-co-glycolic acid) nanoparticles provide neuroprotection in a mouse model of photothrombosis-induced ischemic stroke

PTEN-induced kinase 1 (PINK1) is a well-known critical marker in the pathway for mitophagy regulation as well as mitochondrial dysfunction. Evidence suggests that mitochondrial dynamics and mitophagy flux play an important role in the development of brain damage from stroke pathogenesis. In this study, we propose a treatment strategy using nanoparticles that can control PINK1. We used a murine photothrombotic ischemic stroke (PTS) model in which clogging of blood vessels is induced with Rose Bengal (RB) to cause brain damage. We targeted PINK1 with poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles loaded with PINK1 siRNA (PINK1 NPs). After characterizing siRNA loading in the nanoparticles, we assessed the efficacy of PINK1 NPs in mice with PTS using immunohistochemistry, 1% 2,3,5-triphenyltetrazolium chloride staining, measurement of motor dysfunction, and Western blot. PINK1 was highly expressed in microglia 24 h after PTS induction. PINK1 siRNA treatment increased phagocytic activity, migration, and expression of an anti-inflammatory state in microglia. In addition, the PLGA nanoparticles were selectively taken up by microglia and specifically regulated PINK1 expression in those cells. Treatment with PINK1 NPs prior to stroke induction reduced expression of mitophagy-inducing factors, infarct volume, and motor dysfunction in mice with photothrombotic ischemia. Experiments with PINK1-knockout mice and microglia depletion with PLX3397 confirmed a decrease in stroke-induced infarct volume and behavioral dysfunction. Application of nanoparticles for PINK1 inhibition attenuates RB-induced photothrombotic ischemic injury by inhibiting microglia responses, suggesting that a nanomedical approach targeting the PINK1 pathway may provide a therapeutic avenue for stroke treatment.

Nanomaterial-based Reactive Oxygen Species Scavengers for Osteoarthritis Therapy

Reactive oxygen species (ROS) play distinct but important roles in physiological and pathophysiological processes. Recent studies on osteoarthritis (OA) have suggested that ROS plays a crucial role in its development and progression, serving as key mediators in the degradation of the extracellular matrix, mitochondrial dysfunction, chondrocyte apoptosis, and OA progression. With the continuous development of nanomaterial technology, the ROS-scavenging ability and antioxidant effects of nanomaterials are being explored, with promising results already achieved in OA treatment. However, current research on nanomaterials as ROS scavengers for OA is relatively non-uniform and includes both inorganic and functionalized organic nanomaterials. Although the therapeutic efficacy of nanomaterials has been reported to be conclusive, there is still no uniformity in the timing and potential of their use in clinical practice. This paper reviews the nanomaterials currently used as ROS scavengers for OA treatment, along with their mechanisms of action, with the aim of providing a reference and direction for similar studies, and ultimately promoting the early clinical use of nanomaterials for OA treatment. STATEMENT OF SIGNIFICANCE: Reactive oxygen species (ROS) play an important role in the pathogenesis of osteoarthritis (OA). Nanomaterials serving as promising ROS scavengers have gained increasing attention in recent years. This review provides a comprehensive overview of ROS production and regulation, as well as their role in OA pathogenesis. Furthermore, this review highlights the applications of various types of nanomaterials as ROS scavengers in OA treatment and their mechanisms of action. Finally, the challenges and future prospects of nanomaterial-based ROS scavengers in OA therapy are discussed.

Research progress on the mechanism of interleukin-1β on epiphyseal plate chondrocytes

Epiphyseal plate injury, a common problem in pediatric orthopedics, may result in poor bone repair or growth defects. Epiphyseal plate, also known as growth plate is a layer of hyaline cartilage tissue between the epiphysis and metaphyseal and has the ability to grow longitudinally. Under normal physiological conditions, the epiphyseal plate has a certain axial resistance to stress, but it is fragile in growth phase and can be damaged by excessive stress, leading to detachment or avulsion of the epiphysis, resulting in life-long devastating consequences for patients. There is an obvious inflammatory response in the phase of growth plate injury, the limited physiological inflammatory response locally favors tissue repair and the organism, but uncontrolled chronic inflammation always leads to tissue destruction and disease progression. Interleukin-1β (IL-1β), as representative inflammatory factors, not only affect the inflammatory phase response to bone and soft tissue injury, but have a potentially important role in the later repair phase, though the exact mechanism is not fully understood. At present, epiphyseal plate injuries are mainly treated by corrective and reconstructive surgery, which is highly invasive with limited effectiveness, thus new therapeutic approaches are urgently needed, so a deeper understanding and exploration of the pathological mechanisms of epiphyseal plate injuries at the cellular molecular level is an entry point. In this review, we fully introduced the key role of IL-1 in the progression of epiphyseal plate injury and repair, deeply explored the mechanism of IL-1 on the molecular transcript level and endocrine metabolism of chondrocytes from multiple aspects, and summarized other possible mechanisms to provide theoretical basis for the clinical treatment and in-depth study of epiphyseal plate injury in children.

Echinacoside alleviates osteoarthritis in rats by activating the Nrf2-HO-1 signaling pathway

OBJECTIVE

Osteoarthritis (OA) is a progressive disease characterized by degeneration of cartilage and echinacoside (Ech) has anti-inflammatory and antioxidant effects in various human diseases. This study aimed to reveal the effect and potential mechanism of Ech on OA.

MATERIALS AND METHODS

The in vitro OA model was established by rat chondrocytes treated with IL-1β, and the in vivo OA model was established by anterior cruciate ligament transaction. The effect of Ech on the viability, inflammatory response, extracellular matrix (ECM) degradation, and oxidative stress of IL-1β-treated rat chondrocytes were evaluated by Cell Counting Kit-8 assay, enzyme-linked immunosorbent assay, quantitative real-time PCR, Western blot, and immunofluorescence assay. Meanwhile, the mechanism of Ech was assessed using Western blot, Cell Counting Kit-8 assay, enzyme-linked immunosorbent assay, and immunofluorescence analysis. Moreover, the function of Ech in vivo was analyzed in rat models of OA.

RESULTS

Functionally, Ech enhanced the viability of rat chondrocytes, repressed the inflammatory response and ECM degradation of rat chondrocytes induced by IL-1β with restrained oxidative stress. Mechanically, Ech repressed IL-1β-induced chondrocyte injury by activating the Nrf2/HO-1 signaling pathway. Meanwhile, Ech alleviated the degree of articular cartilage injury in rats and exerted protective effects on the rat model of OA in vivo.

DISCUSSION AND CONCLUSIONS

Ech alleviated OA in rats by activating the Nrf2-HO-1 signaling pathway.

Functional biomaterials for osteoarthritis treatment: From research to application

Osteoarthritis (OA) is a common disease that endangers millions of middle-aged and elderly people worldwide. Researchers from different fields have made great efforts and achieved remarkable progress in the pathogenesis and treatment of OA. However, there is still no cure for OA. In this review, we discuss the pathogenesis of OA and summarize the current clinical therapies. Moreover, we introduce various natural and synthetic biomaterials for drug release, cartilage transplantation, and joint lubricant during the OA treatment. We also present our perspectives and insights on OA treatment in the future. We hope that this review will foster communication and collaboration among biological, clinical, and biomaterial researchers, paving the way for OA therapeutic breakthroughs.

Polymeric Nanoparticles for Drug Delivery in Osteoarthritis

Osteoarthritis (OA) is a degenerative musculoskeletal disorder affecting the whole synovial joint and globally impacts more than one in five individuals aged 40 and over, representing a huge socioeconomic burden. Drug penetration into and retention within the joints are major challenges in the development of regenerative therapies for OA. During the recent years, polymeric nanoparticles (PNPs) have emerged as promising drug carrier candidates due to their biodegradable properties, nanoscale structure, functional versatility, and reproducible manufacturing, which makes them particularly attractive for cartilage penetration and joint retention. In this review, we discuss the current development state of natural and synthetic PNPs for drug delivery and OA treatment. Evidence from in vitro and pre-clinical in vivo studies is used to show how disease pathology and key cellular pathways of joint inflammation are modulated by these nanoparticle-based therapies. Furthermore, we compare the biodegradability and surface modification of these nanocarriers in relation to the drug release profile and tissue targeting. Finally, the main challenges for nanoparticle delivery to the cartilage are discussed, as a function of disease state and physicochemical properties of PNPs such as size and surface charge.

Inhibition of NADPH Oxidases Prevents the Development of Osteoarthritis

Increased oxidative stress in osteoarthritis (OA) cartilage mediates catabolic signal transduction leading to extracellular matrix degradation and chondrocyte apoptosis. This study aimed to explore the contribution of NADPH oxidase (NOX), a major source of cellular reactive oxygen species (ROS), to the catabolic process of chondrocytes and to OA. The inhibition of NOX isoforms with a pan-NOX inhibitor, APX-115, significantly decreased IL-1β-induced ROS production in primary chondrocytes and, most potently, suppressed the expression of oxidative stress marker genes and catabolic proteases compared with the inhibition of other ROS sources. Catabolic stimuli by IL-1β treatment and in post-traumatic OA conditions upregulated the expression of NOX2 and NOX4 in chondrocytes. In the post-traumatic OA model, the pharmacologic inhibition of NOX protected mice against OA by modulating the oxidative stress and the expression of MMP-13 and Adamts5 in chondrocytes. Mechanistically, NOX inhibition suppresses Rac1, p38, and JNK MAPK signaling consistently and restores oxidative phosphorylation in IL-1β-treated chondrocytes. In conclusion, NOX inhibition prevented the development of OA by attenuating the catabolic signaling and restoring the mitochondrial metabolism and can thus be a promising class of drug for OA.

Paradoxical role of reactive oxygen species in bone remodelling: implications in osteoporosis and possible nanotherapeutic interventions

Osteoporosis is a metabolic bone disorder that affects both sexes and is the most common cause of fractures. Osteoporosis therapies primarily inhibit osteoclast activity, and are seldom designed to trigger new bone growth thereby frequently causing severe systemic adverse effects. Physiologically, the intracellular redox state depends on the ratio of pro-oxidants, oxidizing agents (reactive oxygen species, ROS) and antioxidants. ROS is the key contributor to oxidative stress in osteoporosis as changes in redox state are responsible for dynamic bone remodeling and bone regeneration. Imbalances in ROS generation vs. antioxidant systems play a pivotal role in pathogenesis of osteoporosis, stimulating osteoblasts and osteocytes towards osteoclastogenesis. ROS prevents mineralization and osteogenesis, causing increased turnover of bone loss. Alternatively, antioxidants either directly or indirectly, contribute to activation of osteoblasts leading to differentiation and mineralization, thereby reducing osteoclastogenesis. Owing to the unpredictability of immune responsiveness and reported adverse effects, despite promising outcomes from drugs against oxidative stress, treatment in clinics targeting osteoclast has been limited. Nanotechnology-mediated interventions have gained remarkable superiority over other treatment modalities in regenerative medicine. Nanotherapeutic approaches exploit the antioxidant properties of nanoparticles for targeted drug delivery to trigger bone repair, by enhancing their osteogenic and anti-osteoclastogenic potentials to influence the biocompatibility, mechanical properties and osteoinductivity. Therefore, exploiting nanotherapeutics for maintaining the differentiation and proliferation of osteoblasts and osteoclasts is quintessential.

Targeting spinal microglia with fexofenadine-loaded nanoparticles prolongs pain relief in a rat model of neuropathic pain

Targeting microglial activation is emerging as a clinically promising drug target for neuropathic pain treatment. Fexofenadine, a histamine receptor 1 antagonist, is a clinical drug for the management of allergic reactions as well as pain and inflammation. However, the effect of fexofenadine on microglial activation and pain behaviors remains elucidated. Here, we investigated nanomedicinal approach that targets more preferentially microglia and long-term analgesics. Fexofenadine significantly abolished histamine-induced microglial activation. The fexofenadine-encapsulated poly(lactic-co-glycolic acid) nanoparticles (Fexo NPs) injection reduced the pain sensitivity of spinal nerve ligation rats in a dose-dependent manner. This alleviation was sustained for 4 days, whereas the effective period by direct fexofenadine injection was 3 h. Moreover, Fexo NPs inhibited microglial activation, inflammatory signaling, cytokine release, and a macrophage phenotype shift towards the alternative activated state in the spinal cord. These results show that Fexo NPs exhibit drug repositioning promise as a long-term treatment modality for neuropathic pain.

Nanomedicine and regenerative medicine approaches in osteoarthritis therapy

Osteoarthritis (OA), the most common chronic joint disease, is a degenerative disease that affects 7% of the worldwide population, more than 500 million people all over the world. OA is the main factor of disability in elderly people which decreases the quality of life of patients. It is characterized by joint pain, low bone density, and deterioration of the joint structure. Despite ongoing novel advances in drug discovery and drug delivery, OA therapy is still a big challenge since there is no available effective treatment and the existing therapies mainly focus on pain and symptomatic management rather than improving and/or suppressing its progression. This review aims to summarize the currently available and novel emerging therapies for OA including regenerative medicine and nanotechnology-based materials and formulations at the clinical and experimental levels. Applications of regenerative medicine and novel technologies such as nanotechnology in OA treatments have opened a new window to support OA patients by offering treatments that could halt or delay OA progression satisfactorily or provide an effective cure in near future. Nanomedicine and regenerative medicine suggest novel alternatives in the regeneration of cartilage, repair of bone damage, and control of chronic pain in OA therapy.

Protective effect of a novel polyherbal formulation on experimentally induced osteoarthritis in a rat model

Osteoarthritis (OA) is a musculoskeletal disorder mainly found in elderly individuals. Modern treatment of OA, like nonsteroidal anti-inflammatory drugs, corticosteroids, hyaluronic acid injections, etc., is linked to long-term side effects. We evaluated the anti-osteoarthritic properties of a novel joint health formula (JHF) containing Bisdemethoxycurcumin enriched curcumin, 3-O-Acetyl-11-keto-beta-Boswellic acid-enriched Boswellia, and Ashwagandha in monosodium iodoacetate (MIA)-induced knee OA in rats. Twenty-eight female rats were distributed into four groups: Control, OA, OA + JHF (100 mg/kg), and OA + JHF (200 mg/kg). JHF decreased the right joint diameters but increased the paw area and stride length compared to the OA group with no treatment. JHF significantly reduced the arthritic conditions after four weeks of supplementation (p < 0.05). JHF significantly decreased TNF-α, IL-1β, IL-10, COMP, and CRP in the serum of osteoarthritic rats (p < 0.0001). We observed reduced lipid peroxidation but increased SOD, GSH-Px, and CAT activities in response to JHF treatment in OA animals. JHF down-regulated MMP-3, COX-2, and LOX-5 and improved the histological structure of the knee joint of osteoarthritic rats. JHF demonstrated a protective effect against osteoarthritis, possibly due to anti-inflammatory and antioxidant activity in experimentally induced osteoarthritis in rats, and could be an effective option in the management of OA.

Perampanel Reduces Brain Damage via Induction of M2 Microglia in a Neonatal Rat Stroke Model

Purpose

Ischemic stroke is a leading cause of death and disability worldwide. Additionally, neonatal ischemia is a common cause of neonatal brain injury, resulting in cerebral palsy with subsequent learning disabilities and epilepsy. However, there is currently a lack of effective treatments available for patients with perinatal ischemic stroke. In this study, we investigated the effect of perampanel (PER)-loaded poly lactic-co-glycolic acid (PLGA) by targeting microglia in perinatal stroke.

Methods

After formation of focal ischemic stroke by photothrombosis in P7 rats, PER-loaded PLGA was injected intrathecally. Proinflammatory markers (TNF-α, IL-1β, IL-6, COX2, and iNOS) and M2 polarization markers (Ym1 and Arg1) were evaluated. We investigated whether PER increased M2 microglial polarization in vitro.

Results

PER-loaded PLGA nanoparticles decreased the pro-inflammatory cytokines compared to the control group. Furthermore, they increased M2 polarization.

Conclusion

PER-loaded PLGA nanoparticles decreased the size of the infarct and increased motor function in a perinatal ischemic stroke rat model. Pro-inflammatory cytokines were also reduced compared to the control group. Finally, this development of a drug delivery system targeting microglia confirms the potential to develop new therapeutic agents for perinatal ischemic stroke.

Intra-articular Injection of Lornoxicam and MicroRNA-140 Co-loaded Cationic Liposomes Enhanced the Therapeutic Treatment of Experimental Osteoarthritis

Osteoarthritis is a chronic joint disease characterized by chronic inflammation, progressive destruction of articular cartilage, and subchondral bone sclerosis. When compared to individual treatment, the combined administration of genes and small-molecule drugs for osteoarthritis may not only provide superior inflammation control and pain relief, but may also repair cartilage damage. Here, cationic liposomes (CL) were used to deliver small hydrophobic drugs and microRNA into chondrocytes to treat osteoarthritis. Lornoxicam cationic liposomes (Lnxc-CL) were prepared by film dispersion, and loaded with microRNA-140 (miR-140) by electrostatic interaction to obtain cationic liposomes co-loaded with lornoxicam and miR-140 (Lnxc-CL/miR-140). The prepared Lnxc-CL/miR-140 had a particle size of 286.6 ± 7.3 nm, polydispersity index (PDI) of 0.261 ± 0.029 and zeta potential of 26.5 ± 0.5 mV and protected miR-140 from RNase degradation for 24 h. Lnxc-CL/miR-140 was evaluated for its ability to regulate gene expression in chondrocytes in vitro and to provide in vivo therapeutic effects for knee osteoarthritis in rats. The results of in vitro uptake experiments and polymerase chain reaction (PCR) analysis showed that Lnxc-CL/miR-140 efficiently delivered miR-140 into chondrocytes and up-regulated the expression of miR-140 and COL2A1 mRNA. Pharmacodynamics studies demonstrated that Lnxc-CL/miR-140 effectively treated osteoarthritis by eliminating joint inflammation and repairing damaged cartilage cells, with superior therapeutic effects compared to Lnxc or miR-140 alone. Overall, the findings of this study support the co-delivery of Lnxc and miR-140 with cationic liposomes as a potential new therapeutic strategy for the treatment of osteoarthritis.

A review on interplay between small RNAs and oxidative stress in cancer progression

Oxidative stress has been known to be the underlying cause in many instances of cancer development. The new aspect of cancer genesis that has caught the attention of many researchers worldwide is its connection to non-coding RNAs (ncRNAs). ncRNAs may not be protein coding, but in light of the more recent discovery of their wide range of functions, the term 'dark matter of the genome' has been rendered inapplicable. There is an extensive mention of colon cancer as an example, where some of these ncRNAs and their manipulations have seen significant progress. As of now, the focus is on discovering a non-invasive, cost-effective method for diagnosis that is easier to monitor and can be conducted before visible symptoms indicate cancer in a patient, by which time it may already be too late. The concept of liquid biopsies has revolutionized recent diagnostic measures. It has been possible to detect circulating parts of the cancer genome or other biomarkers in the patients' bodily fluids, resulting in the effective management of the disease. This has led these ncRNAs to be considered effective therapeutic targets and extrinsic modifications in several tumor types, proven to be effective as therapy. However, there is a vast scope for further understanding and pertinent application of our acquired knowledge and expanding it in enhancing the utilization of ncRNAs for a better prognosis, quicker diagnosis, and improved management of cancer. This review explores the prognosis of cancer and related mutations by scrutinizing small ncRNAs in the disease.

GPR43 regulation of mitochondrial damage to alleviate inflammatory reaction in sepsis

Sepsis is a common critical illness in ICU and always a great difficulty in clinical treatment. GPR43 (G protein-coupled receptor 43) participates in regulating appetite and gastrointestinal peptide secretion to modulate fat decomposition and formation. However, the biological contribution of GPR43 on inflammation of sepsis has not been previously investigated. We investigated the mechanisms of GPR43 gene, which plays a possible role in distinguishing sepsis and contributes to the pathogenesis of sepsis-induced inflammatory reaction. Furthermore, we performed studies with mice induced to sepsis by Cecal Ligation and Puncture (CLP), Knockout GPR43 (GPR43-/-) mice, and Wild Type (WT) mice induced with CLP. In addition, lung tissues and cell samples were analyzed by histology, Quantitative Polymerase Chain Reaction (Q-PCR), Enzyme-linked Immunosorbent (ELISA) Assay, and western blot. GPR43 agonist could significantly reduce inflammation reactions and trigger lung injury in mice with sepsis. As for GPR43-/- mice, the risks of sepsis-induced inflammatory reactions and corresponding lung injury were promoted. On the one hand, the up-regulation of GPR43 gene reduced ROS mitochondrial damage to inhibit inflammatory reactions via the inactivation of NLRP3 Inflammasome by PPARγ/ Nox1/EBP50/ p47phox signal channel. On the other hand, the down-regulation of GPR43 promoted inflammatory reactions in vitro model through the acceleration of ROS-dependently mitochondrial damage by PPARγ/ Nox1/EBP50/ p47phox/ NLRP3 signal channel. These findings indicate that the inhibition of GPR43 as a possible important factor of sepsis may shed lights on the mechanism of sepsis-induced inflammation reaction.

IKBKB siRNA-Encapsulated Poly (Lactic-co-Glycolic Acid) Nanoparticles Diminish Neuropathic Pain by Inhibiting Microglial Activation

Activation of nuclear factor-kappa B (NF-κB) in microglia plays a decisive role in the progress of neuropathic pain, and the inhibitor of kappa B (IκB) is a protein that blocks the activation of NF-κB and is degraded by the inhibitor of NF-κB kinase subunit beta (IKBKB). The role of IKBKB is to break down IκB, which blocks the activity of NF-kB. Therefore, it prevents the activity of NK-kB. This study investigated whether neuropathic pain can be reduced in spinal nerve ligation (SNL) rats by reducing the activity of microglia by delivering IKBKB small interfering RNA (siRNA)-encapsulated poly (lactic-co-glycolic acid) (PLGA) nanoparticles. PLGA nanoparticles, as a carrier for the delivery of IKBKB genes silencer, were used because they have shown potential to enhance microglial targeting. SNL rats were injected with IKBKB siRNA-encapsulated PLGA nanoparticles intrathecally for behavioral tests on pain response. IKBKB siRNA was delivered for suppressing the expression of IKBKB. In rats injected with IKBKB siRNA-encapsulated PLGA nanoparticles, allodynia caused by mechanical stimulation was reduced, and the secretion of pro-inflammatory mediators due to NF-κB was reduced. Delivering IKBKB siRNA through PLGA nanoparticles can effectively control the inflammatory response and is worth studying as a treatment for neuropathic pain.

Polymer particles for the intra-articular delivery of drugs to treat osteoarthritis

Osteoarthritis (OA) is a leading cause of chronic disability. It is a progressive disease, involving pathological changes to the entire joint, resulting in joint pain, stiffness, swelling, and loss of mobility. There is currently no disease-modifying pharmaceutical treatment for OA, and the treatments that do exist suffer from significant side effects. An increasing understanding of the molecular pathways involved in OA is leading to many potential drug targets. However, both current and new therapies can benefit from a targeted approach that delivers drugs selectively to joints at therapeutic concentrations, while limiting systemic exposure to the drugs. Delivery systems including hydrogels, liposomes, and various types of particles have been explored for intra-articular drug delivery. This review will describe progress over the past several years in the development of polymer-based particles for OA treatment, as well as their in vitro, in vivo, and clinical evaluation. Systems based on biopolymers such as polysaccharides and polypeptides, as well as synthetic polyesters, poly(ester amide)s, thermoresponsive polymers, poly(vinyl alcohol), amphiphilic polymers, and dendrimers will be described. We will discuss the role of particle size, biodegradability, and mechanical properties in the behavior of the particles in the joint, and the challenges to be addressed in future research.

From Pathogenesis to Therapy in Knee Osteoarthritis: Bench-to-Bedside

Osteoarthritis (OA) is currently the most widespread musculoskeletal condition and primarily affects weight-bearing joints such as the knees and hips. Importantly, knee OA remains a multifactorial whole-joint disease, the appearance and progression of which involves the alteration of articular cartilage as well as the synovium, subchondral bone, ligaments, and muscles through intricate pathomechanisms. Whereas it was initially depicted as a predominantly aging-related and mechanically driven condition given its clear association with old age, high body mass index (BMI), and joint malalignment, more recent research identified and described a plethora of further factors contributing to knee OA pathogenesis. However, the pathogenic intricacies between the molecular pathways involved in OA prompted the study of certain drugs for more than one therapeutic target (amelioration of cartilage and bone changes, and synovial inflammation). Most clinical studies regarding knee OA focus mainly on improvement in pain and joint function and thus do not provide sufficient evidence on the possible disease-modifying properties of the tested drugs. Currently, there is an unmet need for further research regarding OA pathogenesis as well as the introduction and exhaustive testing of potential disease-modifying pharmacotherapies in order to structure an effective treatment plan for these patients.

ROS-Sensitive Nanoparticles Co-delivering Dexamethasone and CDMP-1 for the Treatment of Osteoarthritis Through Chondrogenic Differentiation Induction and Inflammation Inhibition

Objective: Osteoarthritis (OA) is a common subtype of arthritis. To date, treatment of OA focuses primarily on alleviating pain and improving joint function. The lack of a vascular system within synovial joints and the rapid removal of agents due to synovial exchange hinder continuous delivery of OA drugs. However, these obstacles are being addressed by promising nanoscale drugs.

Methods: We synthesize and assemble a hydrogen peroxide [H₂O₂, belongs to the category of active oxygen species (ROS)]-sensitive nanomicelle, which is loaded with the anti-inflammation drug dexamethasone and chondrogenic differentiation factor cartilage-derivedmor-phogeneticprotein-1. The micelle can induce bone marrow mesenchymal stem cells to repair cartilage while inhibiting joint inflammation.

Results: The prepared nanoparticles were of uniform size and displayed an obvious core-shell structure. Under H₂O₂ stimulation, the shell layer could be removed gradually. The drug-loaded micelle effectively inhibited proliferation of activated macrophages, induced macrophage apoptosis with an anti-inflammatory effect, and caused the BMSCs to differentiate into chondrocytes.

Conclusion: This work provides an experimental and theoretical basis for further development of a drug-loaded micelle in the healing of osteoarthritis.

Recent advances in targeted drug delivery for treatment of osteoarthritis

PURPOSE OF REVIEW

Osteoarthritis is associated with severe joint pain, inflammation, and cartilage degeneration. Drugs injected directly into intra-articular joint space clear out rapidly providing only short-term benefit. Their transport into cartilage to reach cellular targets is hindered by the tissue's dense, negatively charged extracellular matrix. This has limited, despite strong preclinical data, the clinical translation of osteoarthritis drugs. Recent work has focused on developing intra-joint and intra-cartilage targeting drug delivery systems (DDS) to enable long-term therapeutic response, which is presented here.

RECENT FINDINGS

Synovial joint targeting hybrid systems utilizing combinations of hydrogels, liposomes, and particle-based carriers are in consideration for pain-inflammation relief. Cartilage penetrating DDS target intra-cartilage constituents like aggrecans, collagen II, and chondrocytes such that drugs can reach their cellular and intra-cellular targets, which can enable clinical translation of disease-modifying osteoarthritis drugs including gene therapy.

SUMMARY

Recent years have witnessed significant increase in both fundamental and clinical studies evaluating DDS for osteoarthritis. Steroid encapsulating polymeric microparticles for longer lasting pain relief were recently approved for clinical use. Electrically charged biomaterials for intra-cartilage targeting have shown promising disease-modifying response in preclinical models. Clinical trials evaluating safety of viral vectors are ongoing whose success can pave the way for gene therapy as osteoarthritis treatment.

Current Nanoparticle-Based Technologies for Osteoarthritis Therapy

Osteoarthritis (OA) is a common chronic joint disease that is characterized by joint pain and stiffness, and limitation of motion and the major cause of disability, which reduces life quality of patients and brings a large economic burden to the family and society. Current clinical treatment is mostly limited to symptomatic treatment aimed at pain alleviation and functional improvement, rather than suppressing the progression of OA. Nanotechnology is a promising strategy for the treatment of OA. In this review, we summarize the current experimental progress that focuses on technologies such as liposomes, micelles, dendrimers, polymeric nanoparticles (PNPs), exosomes, and inorganic nanoparticles (NPs) for their potential treatment of OA.

Poly(lactic-co-glycolic acid) nanomaterial-based treatment options for pain management: a review

Neuropathic pain is one of the most intense types of chronic pain; it constitutes a pervasive complaint throughout the public health system. With few effective treatments, it remains a significant challenge. Commercially available drugs for neuropathic pain are still limited and have disappointing efficacy. Therefore, chronic neuropathic pain imposes a tremendous burden on patients' quality of life. Recently, the introduction and application of nanotechnology in multiple fields has accelerated the development of new drugs. This review highlights the application of poly(lactic-co-glycolic acid) nanomaterial-based vehicles for drug delivery and how they improve the therapeutic outcomes for neuropathic pain treatment. Finally, future developments for pain research and effective management are presented.

Preventive Effects of Neuroprotective Agents in a Neonatal Rat of Photothrombotic Stroke Model

Neonatal ischemic stroke has a higher incidence than childhood stroke. Seizures are the first sign for the need for clinical assessment in neonates, but many questions remain regarding treatments and follow-up modalities. In the absence of a known pathophysiological mechanism, only supportive care is currently provided. Stroke-induced microglia activation and neuroinflammation are believed to play a central role in the pathological progression of neonatal ischemic stroke. We induced a photothrombotic infarction with Rose Bengal in neonatal rats to investigate the effects of pre- and post-treatment with Aspirin (ASA), Clopidogrel (Clop), and Coenzyme Q10 (CoQ10), which are known for their neuroprotective effects in adult stroke. Pre-stroke medication ameliorates cerebral ischemic injury and reduces infarct volume by reducing microglia activation, cellular reactive oxygen species (ROS) production, and cytokine release. Post-stroke administration of ASA, Clop, and CoQ10 increased motor function and reduced the volume of infarction, and the statistical evidence was stronger than that seen in the pre-stroke treatment. In this study, we demonstrated that ASA, Clop, and CoQ10 treatment before and after the stroke reduced the scope of stroke lesions and increased behavioral activity. It suggests that ASA, Clop, and CoQ10 medication could significantly have neuroprotective effects in the neonates who have suffered strokes.

CX3CR1-Targeted PLGA Nanoparticles Reduce Microglia Activation and Pain Behavior in Rats with Spinal Nerve Ligation

Activation of CX3CR1 in microglia plays an important role in the development of neuropathic pain. Here, we investigated whether neuropathic pain could be attenuated in spinal nerve ligation (SNL)-induced rats by reducing microglial activation through the use of poly(D,L-lactic-co-glycolic acid) (PLGA)-encapsulated CX3CR1 small-interfering RNA (siRNA) nanoparticles. After confirming the efficacy and specificity of CX3CR1 siRNA, as evidenced by its anti-inflammatory effects in lipopolysaccharide-stimulated BV2 cells in vitro, PLGA-encapsulated CX3CR1 siRNA nanoparticles were synthesized by sonication using the conventional double emulsion (W/O/W) method and administered intrathecally into SNL rats. CX3CR1 siRNA-treated rats exhibited significant reductions in the activation of microglia in the spinal dorsal horn and a downregulation of proinflammatory mediators, as well as a significant attenuation of mechanical allodynia. These data indicate that the PLGA-encapsulated CX3CR1 siRNA nanoparticles effectively reduce neuropathic pain in SNL-induced rats by reducing microglial activity and the expression of proinflammatory mediators. Therefore, we believe that PLGA-encapsulated CX3CR1 siRNA nanoparticles represent a valuable new treatment option for neuropathic pain.

p66shc siRNA-Encapsulated PLGA Nanoparticles Ameliorate Neuropathic Pain Following Spinal Nerve Ligation

p66shc, a member of the shc adaptor protein family, has been shown to participate in regulation of mitochondrial homeostasis, apoptosis, and autophagosome formation. The present study was performed to investigate whether p66shc siRNA-encapsulated poly(d,l-lactic-co-glycolic acid) nanoparticles (p66shc siRNA-PLGA NPs) can attenuate spinal nerve ligation (SNL)-induced neuropathic pain in rats. The SNL-induced pain behavior was decreased in the p66shc siRNA-PLGA NP-treated group compared with the scrambled siRNA-PLGA NP-treated group. In the L5 spinal cord of the p66shc siRNA-PLGA NP-treated group, expression levels of phosphorylated p66shc, cleaved caspase-3, p62, and PINK1, as well as microglial activation, were also decreased. In addition, p66shc knockdown using p66shc siRNA reduced the expression levels of cleaved caspase-3, p62, and PINK1, as well as proinflammatory mediators in the H₂O₂-treated HT22 neuronal cells. These results suggest that downregulation of p66shc expression in the spinal cord using p66shc siRNA-PLGA NPs could reduce the SNL-induced neuropathic pain by attenuating the SNL-induced aberrant autophagic, mitophagic, and neuroinflammatory processes in rats.

miRNA 146a-5p-loaded poly(d,l-lactic-co-glycolic acid) nanoparticles impair pain behaviors by inhibiting multiple inflammatory pathways in microglia

Aims: We investigated whether miRNA (miR) 146a-5p-loaded nanoparticles (NPs) can attenuate neuropathic pain behaviors in the rat spinal nerve ligation-induced neuropathic pain model by inhibiting activation of the NF-κB and p38 MAPK pathways in spinal microglia. Materials & methods: After NP preparation, miR NPs were assessed for their physical characteristics and then injected intrathecally into the spinal cords of rat spinal nerve ligation rats to test their analgesic effects. Results: miR NPs reduced pain behaviors for 11 days by negatively regulating the inflammatory response in spinal microglia. Conclusion: The anti-inflammatory effects of miR 146a-5p along with nanoparticle-based materials make miR NPs promising tools for treating neuropathic pain.