In vivo therapeutic efficacy of TNFα silencing by folate-PEG-chitosan-DEAE/siRNA nanoparticles in arthritic mice

COVID-19 cooling: Nanostrategies targeting cytokine storm for controlling severe and critical symptoms

As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to wreak havoc worldwide, the "Cytokine Storm" (CS, also known as the inflammatory storm) or Cytokine Release Syndrome has reemerged in the public consciousness. CS is a significant contributor to the deterioration of infected individuals. Therefore, CS control is of great significance for the treatment of critically ill patients and the reduction of mortality rates. With the occurrence of variants, concerns regarding the efficacy of vaccines and antiviral drugs with a broad spectrum have grown. We should make an effort to modernize treatment strategies to address the challenges posed by mutations. Thus, in addition to the requirement for additional clinical data to monitor the long-term effects of vaccines and broad-spectrum antiviral drugs, we can use CS as an entry point and therapeutic target to alleviate the severity of the disease in patients. To effectively combat the mutation, new technologies for neutralizing or controlling CS must be developed. In recent years, nanotechnology has been widely applied in the biomedical field, opening up a plethora of opportunities for CS. Here, we put forward the view of cytokine storm as a therapeutic target can be used to treat critically ill patients by expounding the relationship between coronavirus disease 2019 (COVID-19) and CS and the mechanisms associated with CS. We pay special attention to the representative strategies of nanomaterials in current neutral and CS research, as well as their potential chemical design and principles. We hope that the nanostrategies described in this review provide attractive treatment options for severe and critical COVID-19 caused by CS.

Cationic nanoparticles-based approaches for immune tolerance induction in vivo

The development of autoimmune diseases and the rejection of transplanted organs are primarily caused by an exaggerated immune response to autoantigens or graft antigens. Achieving immune tolerance is crucial for the effective treatment of these conditions. However, traditional therapies often have limited therapeutic efficacy and can result in systemic toxic effects. The emergence of nanomedicine offers a promising avenue for addressing immune-related diseases. Among the various nanoparticle formulations, cationic nanoparticles have demonstrated significant potential in inducing immune tolerance. In this review, we provide an overview of the underlying mechanism of autoimmune disease and organ transplantation rejection. We then highlight the recent advancements and advantages of utilizing cationic nanoparticles for inducing immune tolerance in the treatment of autoimmune diseases and the prevention of transplant rejection.

Lipid mediators obtained from docosahexaenoic acid by soybean lipoxygenase attenuate RANKL-induced osteoclast differentiation and rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease characterized by persistent inflammation and joint destruction. A lipid mediator (LM, namely, 17S-monohydroxy docosahexaenoic acid, resolvin D5, and protectin DX in a ratio of 3:47:50) produced by soybean lipoxygenase from DHA, exhibits anti-inflammatory activity. In this study, we determined the effect of LM on collagen antibody-induced arthritis (CAIA) in mice and receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation in RAW264.7 cells. LM effectively downregulated the expression of tartrate-resistant acid phosphatase (TRAP) and cathepsin K, inhibited osteoclast formation, and suppressed the NF-κB signaling pathway in vitro. In vivo, LM at 10 μg/kg/day significantly decreased paw swelling and inhibited progression of arthritis in CAIA mice. Moreover, proinflammatory cytokine (tumor necrosis factor-α, interleukin (IL)-6, IL-1β, IL-17, and interferon-γ) levels in serum were decreased, whereas IL-10 levels were increased following LM treatment. Furthermore, LM alleviated joint inflammation, cartilage erosion, and bone destruction in the ankles, which may be related to matrix metalloproteinase and Janus kinase (JAK)-signal transducer and activators of transcription (STAT) signaling pathway. Our findings suggest that LM attenuates arthritis severity, restores serum imbalances, and modifies joint damage. Thus, LM represents a promising therapy for relieving RA symptoms.

A review of chitosan in gene therapy: Developments and challenges

Gene therapy, as a revolutionary treatment, has been gaining more and more attention. The key to gene therapy is the selection of suitable vectors for protection of exogenous nucleic acid molecules and enabling their specific release in target cells. While viral vectors have been widely used in researches, non-viral vectors are receiving more attention due to its advantages. Chitosan (CS) has been widely used as non-viral organic gene carrier because of its good biocompatibility and its ability to load large amounts of nucleic acids. This paper summarizes and evaluates the potential of chitosan and its derivatives as gene delivery vector materials, along with factors influencing transfection efficiency, performance evaluation, ways to optimize infectious efficiency, and the current main research development directions. Additionally, it provides an outlook on its future prospects.

RNA Interference Ex Vivo

RNA interference (RNAi) is a widely used technique to regulate the expression of genes and proteins with a high degree of specificity that is not easily accessed by traditional pharmacological approaches. For preclinical research on rheumatoid arthritis (RA), silencing of target genes in primary immune cells can be easily achieved by the application of small interfering RNA (siRNA) and synthetic short hairpin RNA (shRNA). Cellular and systemic administration of siRNA or shRNA has been a significant advance in preclinical research on RA. In this chapter, the basic techniques for gene silencing in human-derived peripheral T cells using liposome-dependent siRNA transfection and lentiviral-mediated shRNA delivery, aiming at gene silencing of therapeutic targets, are introduced.

Drug Delivery System Approaches for Rheumatoid Arthritis Treatment: A Review

Rheumatoid arthritis (RA) is a chronic autoimmune disease that has traditionally been treated using a variety of pharmacological compounds. However, the effectiveness of these treatments is often limited due to challenges associated with their administration. Oral and parenteral routes of drug delivery are often restricted due to issues such as low bioavailability, rapid metabolism, poor absorption, first-pass effect, and severe side effects. In recent years, nanocarrier-based delivery methods have emerged as a promising alternative for overcoming these challenges. Nanocarriers, including nanoparticles, dendrimers, micelles, nanoemulsions, and stimuli-sensitive carriers, possess unique properties that enable efficient drug delivery and targeted therapy. Using nanocarriers makes it possible to circumvent traditional administration routes' limitations. One of the key advantages of nanocarrier- based delivery is the ability to overcome resistance or intolerance to traditional antirheumatic therapies. Moreover, nanocarriers offer improved drug stability, controlled release kinetics, and enhanced solubility, optimizing the therapeutic effect. They can also protect the encapsulated drug, prolonging its circulation time and facilitating sustained release at the target site. This targeted delivery approach ensures a higher concentration of the therapeutic agent at the site of inflammation, leading to improved therapeutic outcomes. This article explores potential developments in nanotherapeutic regimens for RA while providing a comprehensive summary of current approaches based on novel drug delivery systems. In conclusion, nanocarrier-based drug delivery systems have emerged as a promising solution for improving the treatment of rheumatoid arthritis. Further advancements in nanotechnology hold promise for enhancing the efficacy and safety of RA therapies, offering new hope for patients suffering from this debilitating disease.

Overcoming delivery barriers for RNA therapeutics in the treatment of rheumatoid arthritis

RNA therapeutics can manipulate gene expression or protein production, making them suitable for treating a wide range of diseases. Theoretically, any disease that has a definite biological target would probably find feasible therapeutic approach from RNA-based therapeutics. Numerous clinical trials using RNA therapeutics fighting against cancer, infectious diseases or inherited diseases have been reported and achieved desirable therapeutic efficacy. So far, encouraging findings from various animal experimental studies have also confirmed the great potential of RNA-based therapies in the treatment of rheumatic arthritis (RA). However, the in vivo multiple physiological barriers still seriously compromise the therapeutic efficacy of RNA drugs. Thus, safe and effective delivery strategies for RNA therapeutics are quite essential for their further and wide application in RA therapy. In this review, we will discuss the recent progress achieved using RNA-based therapeutics and focus on delivery strategies that can overcome the in vivo delivery barriers in RA treatment. Furthermore, discussion about the existing problems in current RNA delivery systems for RA therapy has been also included here.

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.

Arthritic Microenvironment-Dictated Fate Decisions for Stem Cells in Cartilage Repair

The microenvironment and stem cell fate guidance of post-traumatic articular cartilage regeneration is primarily the focus of cartilage tissue engineering. In articular cartilage, stem cells are characterized by overlapping lineages and uneven effectiveness. Within the first 12 weeks after trauma, the articular inflammatory microenvironment (AIME) plays a decisive role in determining the fate of stem cells and cartilage. The development of fibrocartilage and osteophyte hyperplasia is an adverse outcome of chronic inflammation, which results from an imbalance in the AIME during the cartilage tissue repair process. In this review, the sources for the different types of stem cells and their fate are summarized. The main pathophysiological events that occur within the AIME as well as their protagonists are also discussed. Additionally, regulatory strategies that may guide the fate of stem cells within the AIME are proposed. Finally, strategies that provide insight into AIME pathophysiology are discussed and the design of new materials that match the post-traumatic progress of AIME pathophysiology in a spatial and temporal manner is guided. Thus, by regulating an appropriately modified inflammatory microenvironment, efficient stem cell-mediated tissue repair may be achieved.

Nanoparticles and cytokine response

Synthetic nanoparticles (NPs) are non-viral equivalents of viral gene delivery systems that are actively explored to deliver a spectrum of nucleic acids for diverse range of therapies. The success of the nanoparticulate delivery systems, in the form of efficacy and safety, depends on various factors related to the physicochemical features of the NPs, as well as their ability to remain "stealth" in the host environment. The initial cytokine response upon exposure to nucleic acid bearing NPs is a critical component of the host response and, unless desired, should be minimized to prevent the unintended consequences of NP administration. In this review article, we will summarize the most recent literature on cytokine responses to nanoparticulate delivery systems and identify the main factors affecting this response. The NP features responsible for eliciting the cytokine response are articulated along with other factors related to the mode of therapeutic administration. For diseases arising from altered cytokine pathophysiology, attempts to silence the individual components of cytokine response are summarized in the context of different diseases, and the roles of NP features on this respect are presented. We finish with the authors' perspective on the possibility of engineering NP systems with controlled cytokine responses. This review is intended to sensitize the reader with important issues related to cytokine elicitation of non-viral NPs and the means of controlling them to design improved interventions in the clinical setting.

Abnormal changes of bone metabolism markers with age in children with cerebral palsy

Cerebral palsy (CP) is a broad range of diseases with permanent and nonprogressive motor impairments, carrying a high cost for both the individual and the society. The characteristics of low bone mineral density and high risk of fractures suggest that bone metabolism disorders are present in CP. This study aims to investigate the association between indicators of bone metabolism and children with CP. A total of 139 children (75 children with CP and 64 healthy controls) were included in this cross-sectional study. Participants were divided into three age groups (0-2 years, 2.1-4 years, and 4.1-7 years). All children with CP were diagnosed according to clinical criteria and furtherly divided into clinical subtypes. The levels of total procollagen type I N-terminal propeptide (TPINP), N-MID osteocalcin (OC), beta-crosslaps (β-CTX), 25-hydroxyvitamin D (25-OHD) and parathyroid hormone (PTH) in the serum were measured with corresponding detection kits according to the manufacturer's instructions. Serum levels of TPINP and 25-OHD were lower with older age, whereas β-CTX and PTH were higher with older age. In the CP group, TPINP (age 0-2 years and 2.1-4 years) and OC (age 2.1-4 years) levels were higher, while β-CTX (age 2.1-4 years and 4.1-7 years) and PTH (age 2.1-4 years) values were lower than the control group. In addition, there were no statistically significant differences in the levels of these indicators among the CP subgroups with different clinical characteristics. Our study shows that bone turnover markers, indicators of bone metabolism, in children with CP differ significantly from healthy controls. The indicators we studied changed with age, and they did not correlate with disease severity.

Biomedical applications of nanomaterials in the advancement of nucleic acid therapy: Mechanistic challenges, delivery strategies, and therapeutic applications

In the past few decades, substantial advancement has been made in nucleic acid (NA)-based therapies. Promising treatments include mRNA, siRNA, miRNA, and anti-sense DNA for treating various clinical disorders by modifying the expression of DNA or RNA. However, their effectiveness is limited due to their concentrated negative charge, instability, large size, and host barriers, which make widespread application difficult. The effective delivery of these medicines requires safe vectors that are efficient & selective while having non-pathogenic qualities; thus, nanomaterials have become an attractive option with promising possibilities despite some potential setbacks. Nanomaterials possess ideal characteristics, allowing them to be tuned into functional bio-entity capable of targeted delivery. In this review, current breakthroughs in the non-viral strategy of delivering NAs are discussed with the goal of overcoming challenges that would otherwise be experienced by therapeutics. It offers insight into a wide variety of existing NA-based therapeutic modalities and techniques. In addition to this, it provides a rationale for the use of non-viral vectors and a variety of nanomaterials to accomplish efficient gene therapy. Further, it discusses the potential for biomedical application of nanomaterials-based gene therapy in various conditions, such as cancer therapy, tissue engineering, neurological disorders, and infections.

Biomaterial-based gene therapy

Gene therapy, a medical approach that involves the correction or replacement of defective and abnormal genes, plays an essential role in the treatment of complex and refractory diseases, such as hereditary diseases, cancer, and rheumatic immune diseases. Nucleic acids alone do not easily enter the target cells due to their easy degradation in vivo and the structure of the target cell membranes. The introduction of genes into biological cells is often dependent on gene delivery vectors, such as adenoviral vectors, which are commonly used in gene therapy. However, traditional viral vectors have strong immunogenicity while also presenting a potential infection risk. Recently, biomaterials have attracted attention for use as efficient gene delivery vehicles, because they can avoid the drawbacks associated with viral vectors. Biomaterials can improve the biological stability of nucleic acids and the efficiency of intracellular gene delivery. This review is focused on biomaterial-based delivery systems in gene therapy and disease treatment. Herein, we review the recent developments and modalities of gene therapy. Additionally, we discuss nucleic acid delivery strategies, with a focus on biomaterial-based gene delivery systems. Furthermore, the current applications of biomaterial-based gene therapy are summarized.

Nanomedicines: intervention in inflammatory pathways of cancer

Inflammation is a complex defense process that maintains tissue homeostasis. However, this complex cascade, if lasts long, may contribute to pathogenesis of several diseases. Chronic inflammation has been exhaustively studied in the last few decades, for its contribution in development and progression of cancer. The intrinsic limitations of conventional anti-inflammatory and anti-cancer therapies triggered the development of nanomedicines for more effective and safer therapies. Targeting inflammation and tumor cells by nanoparticles, encapsulated with active therapeutic agents, offers a promising outcome with patient survival. Considerable technological success has been achieved in this field through exploitation of tumor microenvironment, and recognition of molecules overexpressed on endothelial cells or macrophages, through enhanced vascular permeability, or by rendering biomimetic approach to nanoparticles. This review focusses on the inflammatory pathways in progression of a tumor, and advancement in nanotechnologies targeting these pathways. We also aim to identify the gaps that hinder the successful clinical translation of nanotherapeutics with further clinical studies that will allow oncologist to precisely identify the patients who may be benefited from nanotherapy at time when promotion or progression of tumor initiates. It is postulated that the nanomedicines, in near future, will shift the paradigm of cancer treatment and improve patient survival.

Research Advances in Nucleic Acid Delivery System for Rheumatoid Arthritis Therapy

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that affects the lives of nearly 1% of the total population worldwide. With the understanding of RA, more and more therapeutic drugs have been developed. However, lots of them possess severe side effects, and gene therapy may be a potential method for RA treatment. A nanoparticle delivery system is vital for gene therapy, as it can keep the nucleic acids stable and enhance the efficiency of transfection in vivo. With the development of materials science, pharmaceutics and pathology, more novel nanomaterials and intelligent strategies are applied to better and safer gene therapy for RA. In this review, we first summarized the existing nanomaterials and active targeting ligands used for RA gene therapy. Then, we introduced various gene delivery systems for RA treatment, which may enlighten the relevant research in the future.

The function of immunomodulation and biomaterials for scaffold in the process of bone defect repair: A review

The process of bone regeneration involves the interaction of the skeletal, blood, and immune systems. Bone provides a solid barrier for the origin and development of immune cells in the bone marrow. At the same time, immune cells secrete related factors to feedback on the remodeling of the skeletal system. Pathological or traumatic injury of bone tissue involves changes in blood supply, cell behavior, and cytokine expression. Immune cells and their factors play an essential role in repairing foreign bodies in bone injury or implantation of biomaterials, the clearance of dead cells, and the regeneration of bone tissue. This article reviews the bone regeneration application of the bone tissue repair microenvironment in bone cells and immune cells in the bone marrow and the interaction of materials and immune cells.

Advances in Lipid-Based Codelivery Systems for Cancer and Inflammatory Diseases

Combination therapy targeting multiple therapeutic targets is a favorable strategy to achieve better therapeutic outcomes in cancer and inflammatory diseases. Codelivery is a subfield of drug delivery that aims to achieve combined delivery of diverse therapeutic cargoes within the same delivery system, thereby ensuring delivery to the same site and providing an opportunity to tailor the release kinetics as desired. Among the wide range of materials being investigated in the design of codelivery systems, lipids have stood out on account of their low toxicity, biocompatibility, and ease of formulation scale-up. This review highlights the advances of the last decade in lipid-based codelivery systems focusing on the codelivery of drug-drug, drug-nucleic acid, nucleic acid-nucleic acid, and protein therapeutic-based combinations for targeted therapy in cancer and inflammatory diseases.

DEAE/Catechol-Chitosan Conjugates as Bioactive Polymers: Synthesis, Characterization, and Potential Applications

This work provides the first description of the synthesis and characterization of water-soluble chitosan (Cs) derivatives based on the conjugation of both diethylaminoethyl (DEAE) and catechol groups onto the Cs backbone (Cs-DC) in order to obtain a Cs derivative with antioxidant and antimicrobial properties. The degree of substitution [DS (%)] was 35.46% for DEAE and 2.53% for catechol, determined by spectroscopy. Changes in the molecular packing due to the incorporation of both pendant groups were described by X-ray diffraction and thermogravimetric analysis. For Cs, the crystallinity index was 59.46% and the maximum decomposition rate appeared at 309.3 °C, while for Cs-DC, the values corresponded to 16.98% and 236.4 °C, respectively. The incorporation of DEAE and catechol groups also increases the solubility of the polymer at pH > 7 without harming the antimicrobial activity displayed by the unmodified polymer. The catecholic derivatives increase the radical scavenging activity in terms of the half-maximum effective concentration (EC₅₀). An EC₅₀ of 1.20 μg/mL was found for neat hydrocaffeic acid (HCA) solution, while for chitosan-catechol (Cs-Ca) and Cs-DC solutions, concentrations equivalent to free HCA of 0.33 and 0.41 μg/mL were required, respectively. Cell culture results show that all Cs derivatives have low cytotoxicity, and Cs-DC showed the ability to reduce the activity of reactive oxygen species by 40% at concentrations as low as 4 μg/mL. Polymeric nanoparticles of Cs derivatives with a hydrodynamic diameter (D_h) of around 200 nm, unimodal size distributions, and a negative ζ-potential were obtained by ionotropic gelation and coated with hyaluronic acid in aqueous suspension, providing the multifunctional nanoparticles with higher stability and a narrower size distribution.

Role of macrophage polarization in osteoarthritis (Review)

Osteoarthritis (OA) is a disease involving the whole joint that seriously reduces the living standards of individuals. Traditional treatments include physical therapy, administration of anti-inflammatory and analgesic drugs and injection of glucocorticoids or hyaluronic acid into the joints. However, these methods have limited efficacy and it is difficult to reverse the progression of OA, therefore it is urgent to find new effective treatment methods. Immune microenvironment is significant in the occurrence and development of OA. Recent studies have shown that macrophages are important targets for the treatment of OA. Macrophages are polarized into M1 pro-inflammatory phenotype and M2 anti-inflammatory phenotype under stimulation of different factors, which release and regulate inflammatory response and cartilage growth. Accumulating studies have tried to alleviate OA by regulating macrophage homeostasis. The present study summarized the related studies, discuss the mechanism of various therapeutic reagents on OA, expound the molecular mechanism of drug effect on OA and attempted to provide clues for the treatment of OA.

Chitosan-based biomaterials for the treatment of bone disorders

Bone is an alive and dynamic organ that is well-differentiated and originated from mesenchymal tissues. Bone undergoes continuous remodeling during the lifetime of an individual. Although knowledge regarding bones and their disorders has been constantly growing, much attention has been devoted to effective treatments that can be used, both from materials and medical performance points of view. Polymers derived from natural sources, for example polysaccharides, are generally biocompatible and are therefore considered excellent candidates for various biomedical applications. This review outlines the development of chitosan-based biomaterials for the treatment of bone disorders including bone fracture, osteoporosis, osteoarthritis, arthritis rheumatoid, and osteosarcoma. Different examples of chitosan-based formulations in the form of gels, micro/nanoparticles, and films are discussed herein. The work also reviews recent patents and important developments related to the use of chitosan in the treatment of bone disorders. Although most of the cited research was accomplished before reaching the clinical application level, this manuscript summarizes the latest achievements within chitosan-based biomaterials used for the treatment of bone disorders and provides perspectives for future scientific activities.

Nucleic Acids for Potential Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a common systemic inflammatory autoimmune disease that severely affects the life quality of patients. Current therapeutics in clinic mainly focus on alleviating the development of RA or relieving the pain of patients. The emerging biological disease-modifying antirheumatic drugs (DMARDs) require long-term treatment to achieve the expected efficacy. With the development of bionanotechnology, nucleic acids fulfill characters as therapeutics or nanocarriers and can therefore be alternatives to combat RA. This review summarizes the therapeutic RNAs developed through RNA interference (RNAi), nucleic acid aptamers, DNA nanostructures-based drug delivery systems, and nucleic acid vaccines for the applications in RA therapy and diagnosis. Furthermore, prospects of nucleic acids for RA therapy are intensively discussed as well.

Polymer nanotherapeutics to correct autoimmunity

The immune system maintains homeostasis and protects the body from pathogens, mutated cells, and other harmful substances. When immune homeostasis is disrupted, excessive autoimmunity will lead to diseases. To inhibit the unexpected immune responses and reduce the impact of treatment on immunoprotective functions, polymer nanotherapeutics, such as nanomedicines, nanovaccines, and nanodecoys, were developed as part of an advanced strategy for precise immunomodulation. Nanomedicines transport cytotoxic drugs to target sites to reduce the occurrence of side effects and increase the stability and bioactivity of various immunomodulating agents, especially nucleic acids and cytokines. In addition, polymer nanomaterials carrying autoantigens used as nanovaccines can induce antigen-specific immune tolerance without interfering with protective immune responses. The precise immunomodulatory function of nanovaccines has broad prospects for the treatment of immune related-diseases. Besides, nanodecoys, which are designed to protect the body from various pathogenic substances by intravenous administration, are a simple and relatively noninvasive treatment. Herein, we have discussed and predicted the application of polymer nanotherapeutics in the correction of autoimmunity, including treating autoimmune diseases, controlling hypersensitivity, and avoiding transplant rejection.

Short interfering RNA (siRNA)-Based Therapeutics for Cartilage Diseases

Articular cartilage injury, as a hallmark of arthritic diseases, is difficult to repair and causes joint pain, stiffness, and loss of mobility. Over the years, the most significant problems for the drug-based treatment of arthritis have been related to drug administration and delivery. In recent years, much research has been devoted to developing new strategies for repairing or regenerating the damaged osteoarticular tissue. The RNA interference (RNAi) has been suggested to have the potential for implementation in targeted therapy in which the faulty gene can be edited by delivering its complementary Short Interfering RNA (siRNA) at the post-transcriptional stage. The successful editing of a specific gene by the delivered siRNA might slow or halt osteoarthritic diseases without side effects caused by chemical inhibitors. However, cartilage siRNA delivery remains a challenging objective because cartilage is an avascular and very dense tissue with very low permeability. Furthermore, RNA is prone to degradation by serum nucleases (such as RNase H and RNase A) due to an extra hydroxyl group in its phosphodiester backbone. Therefore, successful delivery is the first and most crucial requirement for efficient RNAi therapy. Nanomaterials have emerged as highly advantage tools for these studies, as they can be engineered to protect siRNA from degrading, address barriers in siRNA delivery to joints, and target specific cells. This review will discuss recent breakthroughs of different siRNA delivery technologies for cartilage diseases.

Nanomedicine-based delivery strategies for nucleic acid gene inhibitors in inflammatory diseases

Thanks to their abilities to modulate the expression of virtually any genes, RNA therapeutics have attracted considerable research efforts. Among the strategies focusing on nucleic acid gene inhibitors, antisense oligonucleotides and small interfering RNAs have reached advanced clinical trial phases with several of them having recently been marketed. These successes were obtained by overcoming stability and cellular delivery issues using either chemically modified nucleic acids or nanoparticles. As nucleic acid gene inhibitors are promising strategies to treat inflammatory diseases, this review focuses on the barriers, from manufacturing issues to cellular/subcellular delivery, that still need to be overcome to deliver the nucleic acids to sites of inflammation other than the liver. Furthermore, key examples of applications in rheumatoid arthritis, inflammatory bowel, and lung diseases are presented as case studies of systemic, oral, and lung nucleic acid delivery.

The pathophysiology of immunoporosis: innovative therapeutic targets

BACKGROUND

The physiological balance between bone resorption and bone formation is now known to be mediated by a cascade of events parallel to the classic osteoblast-osteoclast interaction. Thus, osteoimmunology now encompasses the role played by other cell types, such as cytokines, lymphocytes and chemokines, in immunological responses and how they help modulate bone metabolism. All these factors have an impact on the RANK/RANKL/OPG pathway, which is the major pathway for the maturation and resorption activity of osteoclast precursor cells, responsible for osteoporosis development. Recently, immunoporosis has emerged as a new research area in osteoimmunology dedicated to the immune system's role in osteoporosis.

METHODS

The first part of this review presents theoretical concepts on the factors involved in the skeletal system and osteoimmunology. Secondly, existing treatments and novel therapeutic approaches to treat osteoporosis are summarized. These were selected from to the most recent studies published on PubMed containing the term osteoporosis. All data relate to the results of in vitro and in vivo studies on the osteoimmunological system of humans, mice and rats.

FINDINGS

Treatments for osteoporosis can be classified into two categories. They either target osteoclastogenesis inhibition (denosumab, bisphosphonates), or they aim to restore the number and function of osteoblasts (romozumab, abaloparatide). Even novel therapies, such as resolvins, gene therapy, and mesenchymal stem cell transplantation, fall within this classification system.

CONCLUSION

This review presents alternative pathways in the pathophysiology of osteoporosis, along with some recent therapeutic breakthroughs to restore bone homeostasis.

Nanoparticle-Cartilage Interaction: Pathology-Based Intra-articular Drug Delivery for Osteoarthritis Therapy

Osteoarthritis is the most prevalent chronic and debilitating joint disease, resulting in huge medical and socioeconomic burdens. Intra-articular administration of agents is clinically used for pain management. However, the effectiveness is inapparent caused by the rapid clearance of agents. To overcome this issue, nanoparticles as delivery systems hold considerable promise for local control of the pharmacokinetics of therapeutic agents. Given the therapeutic programs are inseparable from pathological progress of osteoarthritis, an ideal delivery system should allow the release of therapeutic agents upon specific features of disorders. In this review, we firstly introduce the pathological features of osteoarthritis and the design concept for accurate localization within cartilage for sustained drug release. Then, we review the interactions of nanoparticles with cartilage microenvironment and the rational design. Furthermore, we highlight advances in the therapeutic schemes according to the pathology signals. Finally, armed with an updated understanding of the pathological mechanisms, we place an emphasis on the development of "smart" bioresponsive and multiple modality nanoparticles on the near horizon to interact with the pathological signals. We anticipate that the exploration of nanoparticles by balancing the efficacy, safety, and complexity will lay down a solid foundation tangible for clinical translation.

Nanomedicines for the treatment of rheumatoid arthritis: State of art and potential therapeutic strategies

Increasing understanding of the pathogenesis of rheumatoid arthritis (RA) has remarkably promoted the development of effective therapeutic regimens of RA. Nevertheless, the inadequate response to current therapies in a proportion of patients, the systemic toxicity accompanied by long-term administration or distribution in non-targeted sites and the comprised efficacy caused by undesirable bioavailability, are still unsettled problems lying across the full remission of RA. So far, these existing limitations have inspired comprehensive academic researches on nanomedicines for RA treatment. A variety of versatile nanocarriers with controllable physicochemical properties, tailorable drug release pattern or active targeting ability were fabricated to enhance the drug delivery efficiency in RA treatment. This review aims to provide an up-to-date progress regarding to RA treatment using nanomedicines in the last 5 years and concisely discuss the potential application of several newly emerged therapeutic strategies such as inducing the antigen-specific tolerance, pro-resolving therapy or regulating the immunometabolism for RA treatments.

Folate Receptor-Mediated siRNA Delivery: Recent Developments and Future Directions for RNAi Therapeutics

RNA interference (RNAi), a gene regulatory process mediated by small interfering RNAs (siRNAs), has made remarkable progress as a potential therapeutic agent against various diseases. However, RNAi is associated with fundamental challenges such as poor systemic delivery and susceptibility to the nucleases. Targeting ligand-bound delivery vehicles has improved the accumulation of drug at the target site, which has resulted in high transfection efficiency and enhanced gene silencing. Recently, folate receptor (FR)-mediated targeted delivery of siRNAs has garnered attention due to their enhanced cellular uptake and high transfection efficiency toward tumor cells. Folic acid (FA), due to its small size, low immunogenicity, high in vivo stability, and high binding affinity toward FRs, has attracted much attention for targeted siRNA delivery. FRs are overexpressed in a large number of tumors, including ovarian, breast, kidney, and lung cancer cells. In this review, we discuss recent advances in FA-mediated siRNA delivery to treat cancers and inflammatory diseases. This review summarizes various FA-conjugated nanoparticle systems reported so far in the literature, including liposome, silica, metal, graphene, dendrimers, chitosan, organic copolymers, and RNA nanoparticles. This review will help in the design and development of potential delivery vehicles for siRNA drug targeting to tumor cells using an FR-mediated approach.

To Conjugate or to Package? A Look at Targeted siRNA Delivery Through Folate Receptors

RNA interference (RNAi) applications have evolved from experimental tools to study gene function to the development of a novel class of gene-silencing therapeutics. Despite decades of research, it was not until August 2018 that the US FDA approved the first-ever RNAi drug, marking a new era for RNAi therapeutics. Although there are many limitations associated with the inherent structure of RNA, delivery to target cells and tissues remains the most challenging. RNAs are unable to diffuse across cellular membranes due to their large size and polyanionic backbone and, therefore, require a delivery vector. RNAi molecules can be conjugated to a targeting ligand or packaged into a delivery vehicle. Alnylam has used both strategies in their FDA-approved formulations to achieve efficient delivery to the liver. To harness the full potential of RNAi therapeutics, however, we must be able to target additional cells and tissues. One promising target is the folate receptor α, which is overexpressed in a variety of tumors despite having limited expression and distribution in normal tissues. Folate can be conjugated directly to the RNAi molecule or used to functionalize delivery vehicles. In this review, we compare both delivery strategies and discuss the current state of research in the area of folate-mediated delivery of RNAi molecules.

Evidence Supporting the Safety of Pegylated Diethylaminoethyl-Chitosan Polymer as a Nanovector for Gene Therapy Applications

PURPOSE

Diethylaminoethyl-chitosan (DEAE-CH) is a derivative with excellent potential as a delivery vector for gene therapy applications. The aim of this study is to evaluate its toxicological profile for potential future clinical applications.

METHODS

An endotoxin-free chitosan (CH) modified with DEAE, folic acid (FA) and polyethylene glycol (PEG) was used to complex small interfering RNA (siRNA) and form nanoparticles (DEAE12-CH-PEG-FA2/siRNA). Based on the guidelines from the International Organization for Standardization (ISO), the American Society for Testing and Materials (ASTM), and the Nanotechnology Characterization Laboratory (NCL), we evaluated the effects of the interaction between these nanoparticles and blood components. In vitro screening assays such as hemolysis, hemagglutination, complement activation, platelet aggregation, coagulation times, cytokine production, and reactive species, such as nitric oxide (NO) and reactive oxygen species (ROS), were performed on erythrocytes, plasma, platelets, peripheral blood mononuclear cells (PBMC) and Raw 264.7 macrophages. Moreover, MTS and LDH assays on Raw 264.7 macrophages, PBMC and MG-63 cells were performed.

RESULTS

Our results show that a targeted theoretical plasma concentration (TPC) of DEAE12-CH-PEG-FA2/siRNA nanoparticles falls within the guidelines' thresholds: <1% hemolysis, 2.9% platelet aggregation, no complement activation, and no effect on coagulation times. ROS and NO production levels were comparable to controls. Cytokine secretion (TNF-α, IL-6, IL-4, and IL-10) was not affected by nanoparticles except for IL-1β and IL-8. Nanoparticles showed a slight agglutination. Cell viability was >70% for TPC in all cell types, although LDH levels were statistically significant in Raw 264.7 macrophages and PBMC after 24 and 48 h of incubation.

CONCLUSION

These DEAE12-CH-PEG-FA2/siRNA nanoparticles fulfill the existing ISO, ASTM and NCL guidelines' threshold criteria, and their low toxicity and blood biocompatibility warrant further investigation for potential clinical applications.

Risperidone accelerates bone loss in rats with autistic-like deficits induced by maternal lipopolysaccharides exposure

AIMS

Patients with neurodevelopmental disorders, usually suffer from bone diseases. Many studies have revealed a higher risk of fracture after atypical antipsychotic drug Risperidone (RIS) treatment, which is usually used to treat such disorders. It remains debatable whether neurodevelopmental disorders by itself are the cause of bone diseases or pharmacotherapy may be the reason.

MATERIALS AND METHODS

This study attempts to evaluate the biomechanical, histological, stereological, and molecular properties of bones in the offspring of Lipopolysaccharide (LPS) and saline-treated mothers that received saline, drug vehicle or the atypical antipsychotic drug risperidone (RIS) at different days of postnatal development. After postnatal drug treatment, animals were assessed for autistic-like behaviors. Then their bones were taken for evaluations.

RESULTS

Maternal LPS exposure resulted in deficits in all behavioral tests and RIS ameliorated these behaviors (p < 0.01& p < 0.05). The administration of LPS and RIS individually led to a significant decrease in the biomechanical parameters such as bone stiffness, strength and the energy used to fracture of bone. The numerical density of osteocalcin-positive cells were significantly decreased in these groups. These rats also had decreased RUNX2 and osteocalcin gene expression. When LPS rats were treated with RIS, these conditions were accelerated (p < 0.001).

DISCUSSIONS

The results of our preclinical study, consistent with previous studies in animals, explore that autistic-like deficits induced by prenatal exposure to LPS, can reduce bone stability and bone mass similar to those observed in neurodevelopmental disorders, and, for the first time, reveal that this condition worsened when these animals were treated with RIS.

Prospects for the potential of RNA interference in the treatment of autoimmune diseases: Small interfering RNAs in the spotlight

The identification of RNA interference (RNAi) has caused a growing interest in harnessing its potential in the treatment of different diseases. Modulation of dysregulated genes through targeting by RNAi represents a potential approach with which to alter the biological pathways at a post-transcriptional level, especially as it pertains to autoimmunity and malignancy. Short hairpin RNAs (shRNA), short interfering RNAs (siRNA), and microRNAs (miRNA) are mainly involved as effector mechanisms in the targeting of RNAi biological pathways. The manipulation and delivery of these molecules in an efficient way promotes the specificity and stability of RNAi-based systems, while minimizing the unwanted adverse reactions by the immune system and reducing cytotoxicity and off-target effects. Advances made to date in identifying the etiopathogenesis of autoimmune diseases has prompted the utilization of RNAi-based systems in vitro and in vivo. Future investigations aimed at deciphering the molecular basis of RNAi and optimizing the delivery of RNAi-based targeting systems will hopefully promote the applicability of such regulatory mechanisms and, ultimately, transfer the acquired knowledge from bench-to-bedside to ameliorate human diseases. In this review, we seek to clarify the potential of RNAi, with a focus on siRNAs, in designing therapeutics for potential treatment of human autoimmune disorders.

Advanced nanomedicines for the treatment of inflammatory diseases

Inflammation, a common feature of many diseases, is an essential immune response that enables survival and maintains tissue homeostasis. However, in some conditions, the inflammatory process becomes detrimental, contributing to the pathogenesis of a disease. Targeting inflammation by using nanomedicines (i.e. nanoparticles loaded with a therapeutic active principle), either through the recognition of molecules overexpressed onto the surface of activated macrophages or endothelial cells, or through enhanced vasculature permeability, or even through biomimicry, offers a promising solution for the treatment of inflammatory diseases. After providing a brief insight on the pathophysiology of inflammation and current therapeutic strategies, the review will discuss, at a pre-clinical stage, the main innovative nanomedicine approaches that have been proposed in the past five years for the resolution of inflammatory disorders, finally focusing on those currently in clinical trials.

The non-viral vectors and main methods of loading siRNA onto the titanium implants and their application

Surface modification of titanium implants by siRNA is quite efficient for improving implant osseointegration. Loading siRNA onto their surface is a crucial factor for siRNA-functionalized implants to realize their biological function. Direct binding of siRNA to implants has low siRNA binding and releasing rate, so usually it needs to be mediated by vectors. Polymeric, nonmaterial-mediated and lipid-based vectors are types of non-viral vectors which are commonly used for delivering siRNA. Three major methods of loading process, namely simple physical adsorption, layer-by-layer assembly and electrodeposition, are also summarized. A brief introduction, the basic principle and the general procedure of each method are included. The loading efficiency, which can be measured both qualitatively and quantitatively, together with gene knockdown efficiency, cytotoxicity assay and osteogenesis of the three methods are compared. A good many applications in osteogenesis have also been described in this review.

Nanoparticle-siRNA: A potential strategy for rheumatoid arthritis therapy?

Rheumatoid arthritis (RA) is a common clinical inflammatory disease of the autoimmune system manifested by persistent synovitis, cartilage damage and even deformities. Despite significant progress in the clinical treatment of RA, long-term administration of anti-rheumatic drugs can cause a series of problems, including infections, gastrointestinal reactions, and abnormal liver and kidney functions. The emergence of RNA interference (RNAi) drugs has brought new hope for the treatment of RA. Designing a reasonable vector for RNAi drugs will greatly expand the application prospects of RNAi. Nanoparticles as a promising drug carrier provide reliable support for RNAi drugs. The review summarizes the pathogenesis of RA as a possible target for small interference RNA (siRNA) design. At the same time, the review also analyzes the nanoparticles used in siRNA carriers in recent years, laying the foundation and prospect for the next step in the development of intelligent nanocarriers.

Nanomedicines for the delivery of glucocorticoids and nucleic acids as potential alternatives in the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects 0.5-1% of the world population. Current treatments include on one hand non-steroidal anti-inflammatory drugs and glucocorticoids (GCs) for treating pain and on the other hand disease-modifying anti-rheumatic drugs such as methotrexate, Janus kinase inhibitors or biologics such as antibodies targeting mainly cytokine expression. More recently, nucleic acids such as siRNA, miRNA, or anti-miRNA have shown strong potentialities for the treatment of RA. This review discusses the way nanomedicines can target GCs and nucleic acids to inflammatory sites, increase drug penetration within inflammatory cells, achieve better subcellular distribution and finally protect drugs against degradation. For GCs such a targeting effect would allow the treatment to be more effective at lower doses and to reduce the administration frequency as well as to induce much fewer side-effects. In the case of nucleic acids, particularly siRNA, knocking down proteins involved in RA, could importantly be facilitated using nanomedicines. Finally, the combination of both siRNA and GCs in the same carrier allowed for the same cell to target both the GCs receptor as well as any other signaling pathway involved in RA. Nanomedicines appear to be very promising for the delivery of conventional and novel drugs in RA therapeutics. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures.

Recent Advances in Nanotheranostics for Treat-to-Target of Rheumatoid Arthritis

Early diagnosis, standardized treatment, and regular monitoring are the clinical treatment principle of rheumatoid arthritis (RA). The overarching principles and recommendations of treat-to-target (T2T) in RA advocate remission as the optimum aim, especially for patients with very early disease who are initiating therapy with anti-RA medications. However, traditional anti-RA drugs cannot selectively target the inflammatory areas and may cause serious side effects due to its short biological half-life and poor bioavailability. These limitations have significantly driven the research and application of nanomaterial-based drugs in theranostics of RA. Nanomedicines have appropriate sizes and easily modified surfaces which can enhance their biological compatibility and prolong circulation time of drug-loading systems in vivo. Traditional T2T regimens cannot evaluate the efficacy of drugs in real time, while clinical drug nanosizing can realize the integration of diagnosis and treatment of RA. This review bridges clinically proposed T2T concepts and nanomedicine in an integrated system for RA early-stage diagnosis and treatment. The most advanced progress in various nanodrug delivery systems for theranostics of RA is summarized, establishing a clear path and a new perspective for further optimization of T2T. Finally, the key facing challenges are discussed and prospects are addressed.

siRNA release kinetics from polymeric nanoparticles correlate with RNAi efficiency and inflammation therapy via oral delivery

Despite many efforts in the rational design of nanoparticles (NPs) to overcome the biological barriers to small interfering RNA (siRNA) delivery for improving gene silencing efficiency, little is known about the correlations between siRNA release kinetics and RNA interference (RNAi) efficiency and inflammation therapy via oral delivery. On the basis of mannose-modified trimethyl chitosan-cysteine (MTC) polymers, seven types of MTC NPs containing tumor necrosis factor (TNF)-α siRNA were prepared through ionic gelation. The siRNA release kinetics from MTC NPs were finely tuned by adjusting the kinds and amounts of the crosslinkers involved. These MTC NPs exhibited no disparities in siRNA protection against enzymatic degradation in physiological fluids and cellular uptake in macrophages; however, they showed distinct in vitro siRNA release profiles and intracellular unpacking kinetics. MTC NPs with relatively rapid and sustained siRNA release were responsible for efficient, prompt, and prolonged RNAi, contributing to desired therapeutic efficacy in acute and chronic inflammatory murine models following oral delivery. However, MTC NPs insufficiently releasing siRNA could not elicit effective RNAi. Collectively, the present investigation might provide broad insights into the optimization of siRNA nanocarriers with respect to their release kinetics for improving RNAi efficacies aiming at different types of inflammatory diseases. STATEMENT OF SIGNIFICANCE: siRNA release kinetics in the cytoplasm and pathological characteristics of diseases themselves determine the therapeutic efficacy of siRNA delivery. Herein, by adjusting the kinds and amounts of the crosslinkers involved, we developed seven types of MTC NPs containing TNF-α siRNA with distinct siRNA release kinetics. MTC NPs with relatively rapid and sustained siRNA release were responsible for prompt and prolonged RNAi, respectively, contributing to desired therapeutic efficacy in acute and chronic inflammation following oral delivery. These results might provide broad insights into the optimization of siRNA nanocarriers in respect to their release kinetics for improving therapeutic outcomes toward different clinical requirements.

Applications of RNA interference in the treatment of arthritis

RNA interference (RNAi) is a cellular mechanism for post-transcriptional gene regulation mediated by small interfering RNA (siRNA) and microRNA. siRNA-based therapy holds significant promise for the treatment of a wide-range of arthritic diseases. siRNA selectively suppresses the expression of a gene product and can thus achieve the specificity that is lacking in small molecule inhibitors. The potential use of siRNA-based therapy in arthritis, however, has not progressed to clinical trials despite ample evidence for efficacy in preclinical studies. One of the main challenges to clinical translation is the lack of a suitable delivery vehicle to efficiently and safely access diverse pathologies. Moreover, the ideal targets in treatment of arthritides remain elusive given the complexity and heterogeneity of these disease pathogeneses. Herein, we review recent preclinical studies that use RNAi-based drug delivery systems to mitigate inflammation in models of rheumatoid arthritis and osteoarthritis. We discuss a self-assembling peptide-based nanostructure that demonstrates the potential of overcoming many of the critical barriers preventing the translation of this technology to the clinic.

Protective effects of Clematichinenoside AR against inflammation and cytotoxicity induced by human tumor necrosis factor-α

Clematichinenoside AR (AR), a major active ingredient extracted from traditional Chinese herb Clematis chinensis Osbeck, has been demonstrated to possess anti-inflammatory and immune-modulatory activities in the treatment of experimental rheumatoid arthritis (RA). The therapeutic potential of AR was supposed to be closely correlated to its ability against tumor necrosis factor-α (TNF-α). Therefore, we aimed to explore the protective effects of Clematichinenoside AR against inflammation and cytotoxicity induced by human TNF-α. AR treatment significantly decreased IL-6 and IL-8 secretion, and attenuated MMP-1 production in human RA-derived fibroblast-like synoviocyte MH7A cells stimulated by recombinant human TNF-α (rhTNF-α). AR might antagonize rhTNF-α-induced responses in MH7A cells through inhibiting p38 and ERK MAPKs signal activation. In TNF-α-sensitive murine fibroblast L929 cells, AR treatment attenuated the proliferation inhibition ratio induced by rhTNF-α/ActD and antagonized rhTNF-α-induced cytotoxicity. The cellular and nuclear morphological alterations in apoptotic characteristics induced by rhTNF-α/ActD in L929 cells were observed to be attenuated by the pretreatment with AR under a phase-contrast and fluorescence microscopy, respectively. The Annexin V-FITC/PI double-staining assay was performed to confirm that AR pretreatment obviously decreased the cell death. The antagonistic effects of AR against rhTNF-α-induced cytotoxicity might be potentially attributed to the degeneration of reactive oxygen species and the increasing of mitochondrial membrane potential, along with the suppression of durative phosphorylation of c-Jun N-terminal kinase (JNK). Collectively, our results indicated that AR antagonizes the inflammatory and cytotoxic activities induced by human TNF-α effectively in vitro, which provided further evidence for a novel mechanism underlying AR for treating RA correlating with excessive TNF-α production.

Natural Polysaccharides for siRNA Delivery: Nanocarriers Based on Chitosan, Hyaluronic Acid, and Their Derivatives

Natural polysaccharides are frequently used in the design of drug delivery systems due to their biocompatibility, biodegradability, and low toxicity. Moreover, they are diverse in structure, size, and charge, and their chemical functional groups can be easily modified to match the needs of the final application and mode of administration. This review focuses on polysaccharidic nanocarriers based on chitosan and hyaluronic acid for small interfering RNA (siRNA) delivery, which are highly positively and negatively charged, respectively. The key properties, strengths, and drawbacks of each polysaccharide are discussed. In addition, their use as efficient nanodelivery systems for gene silencing applications is put into context using the most recent examples from the literature. The latest advances in this field illustrate effectively how chitosan and hyaluronic acid can be modified or associated with other molecules in order to overcome their limitations to produce optimized siRNA delivery systems with promising in vitro and in vivo results.

Ligand decorated chitosan as an advanced nanocarrier for targeted delivery: a critical review

Nontargeted delivery systems present nonspecific delivery, low transfection efficiency and high toxicity. Ligand-conjugated chitosan (CS) nanocarriers have emerged as an outstanding option for achieving active delivery specifically and preferentially to the target sites by exploiting receptors mediated endocytosis. Mannosylated CS nanocarriers have brought tremendous breakthrough in gene therapy and have proven to be an excellent choice for treatment of infectious and inflammatory diseases. Similarly, folate and antibodies-conjugated CS play a significant role in diagnosis and treatment of various cancers. Current evidences obviously propose ligand-decorated CS as an attractive option for diagnosis and treatment of dreadful conditions. In order to bring huge revolution in the field of targeted delivery, challenges associated with these nanocarriers needs to be addressed.

In vitro and in vivo assessment of the proresolutive and antiresorptive actions of resolvin D1: relevance to arthritis

BACKGROUND

Resolvin D1 (RvD1), an important member of resolvins, exerts a wide spectrum of biological effects, including resolution of inflammation, tissue repair, and preservation of cell viability. The aim of the present study is to investigate the anti-arthritic potential and clarify the bone protective actions of RvD1 in vitro and in vivo.

METHODS

RAW264.7 cells were treated with 50 ng/ml LPS for 72 h in the presence or absence of RvD1 (0-500 nM). Primary human monocytes were treated with M-CSF + RANKL for 14 days ± RvD1 (0-500 nM) with or without siRNA against RvD1 receptor FPR2. Expressions of inflammatory mediators, degrading enzymes, osteoclasts (OC) formation, and bone resorption were analyzed. The therapeutic effect of RvD1 (0-1000 ng) was carried out in murine collagen antibody-induced arthritis. Arthritis scoring, joint histology, and inflammatory and bone turnover markers were measured.

RESULTS

RvD1 is not toxic and inhibits OC differentiation and activation. It decreases bone resorption, as assessed by the inhibition of TRAP and cathepsin K expression, hydroxyapatite matrix resorption, and bone loss. In addition, RvD1 reduces TNF-α, IL-1β, IFN-γ, PGE₂, and RANK and concurrently enhances IL-10 in OC. Moreover, in arthritic mice, RvD1 alleviates clinical score, paw inflammation, and bone and joint destructions. Besides, RvD1 reduces inflammatory mediators and markedly decreases serum markers of bone and cartilage turnover.

CONCLUSION

Our results provide additional evidence that RvD1 plays a key role in preventing bone resorption and other pathophysiological changes associated with arthritis. The study highlights the clinical relevance of RvD1 as a potential compound for the treatment of inflammatory arthritis and related bone disorders.

The Role of Gene Therapy in Cartilage Repair

The key principle of gene delivery to articulations by direct intra-articular injection is to release complementary DNA (cDNA)-encoding medical products that will lead to maintained, endogenous production of the gene products within the articulation. In fact, this has been accomplished for both in vivo and ex vivo gene delivery, using several vectors, genes, and cells in some animal models. Some clinical trials for rheumatoid arthritis and osteoarthritis (OA) using retrovirus vectors for ex vivo gene delivery and adeno-associated virus (AAV) for in vivo delivery have been reported. AAV is of special attention because, contrary to other viral vectors, it can enter deep within joint cartilage and transduce chondrocytes in situ. This quality is of special significance in OA, in which modifications in chondrocyte metabolism are believed to be crucial to the pathophysiology of the disease. The clinical effectiveness of TissueGene-C (TG-C), a cell and gene therapy for OA consisting of nontransformed and transduced chondrocytes (3:1) retrovirally transduced to overexpress TGF-β1 has been reported in patients with knee OA. The most common complications of TG-C were peripheral edema (9%), arthralgia (8%), articular swelling (6%), and injection site pain (5%). TG-C was associated with relevant ameliorations in function and pain. Gene therapy appears to be a viable method for the management of articular cartilage defects and OA.

Preparation and biological characterization of the mixture of poly(lactic-co-glycolic acid)/chitosan/Ag nanoparticles for periodontal tissue engineering

Objective

This study aims to produce nanoparticles of chitosan (CS), poly(lactic-co-glycolic acid) (PLGA), and silver and investigate the optimal composite ratio of these three materials for periodontal tissue regeneration.

Methods

PLGA nanoparticles (nPLGA), CS nanoparticles (nCS), and silver nanoparticles (nAg) were prepared. The antibacterial properties of single nanoparticles and their effects on the proliferation and mineralization of periodontal membrane cells were investigated. Different ratios of nPLGA and nCS were combined, the proliferation and mineralization of periodontal membrane cells were investigated, and based on the results, the optimal ratio was determined. Finally, nPLGA and nCS in optimal ratio were combined with nAg, and the effects of the complex of these three materials on the proliferation and mineralization of periodontal membrane cells were investigated and tested in animals.

Results

The single nanoparticles were found to have no cytotoxicity and were able to promote cell mineralization. nCS and nAg in low concentrations showed antibacterial activity; however, nAg inhibited cell proliferation. The nPLGA and nCS complex in 3:7 ratio contributed to cell mineralization and had no cytotoxicity. nPLGA/nCS/nAg complex, which had the optimal proportion of the three materials, showed no cytotoxicity and contributed to cell mineralization.

Conclusion

nPLGA/nCS/nAg complex had no cytotoxicity and contributed to cell mineralization. The 3:7 ratio of nPLGA/nCS and 50 µg/mL nAg were found as the optimal proportion of the three materials.

Lipid nanoparticles silence tumor necrosis factor α to improve wound healing in diabetic mice

Diabetes mellitus is a mounting concern in the United States, as are the mortality and morbidity that result from its complications. Of particular concern, diabetes patients frequently suffer from impaired wound healing and resultant nonhealing diabetic foot ulcers. These ulcers overproduce tumor necrosis factor α (TNFα), which reduces wound bed cell migration and proliferation while encouraging apoptosis. Herein, we describe the use of siRNA-loaded lipid nanoparticles (LNPs) as a potential wound treatment to combat an overzealous immune response and facilitate wound closure. LNPs were formulated with an ionizable, degradable lipidoid and siRNA specific for TNFα. Topical application of nanoparticles reduced TNFα mRNA expression in the wound by 40-55% in diabetic and nondiabetic mice. In diabetic mice, this TNFα knockdown accelerated wound healing compared to untreated controls. Together, these results serve as proof-of-concept that RNA interference therapy using LNPs can reduce the severity and duration of chronic diabetic wounds.