Development of macromolecular prodrug for rheumatoid arthritis

Development of pH-sensitive dextran-based methotrexate nanodrug for rheumatoid arthritis therapy through inhibition of JAK-STAT pathways

Rheumatoid arthritis (RA) is a chronic and symmetrical autoimmune disease that primarily characterized with articular synovial hyperplasia, joint swelling, cartilage and bone destruction. The in-depth understanding of the role of immune signaling pathway inhibitors provides inspiration for the construction of new and more effective strategy for RA therapy. In this study, by loading methotrexate (MTX) into an acetalated dextran biopolymer, AcDEX, we developed a pH-sensitive, MTX-loaded and molecularly targeted nanodrug MTX@pH-AcDEX NPs) to decrease the toxicity of MTX and simultaneously enhance its therapeutic effect. The resultant MTX@pH-AcDEX NPs showed the spherical morphology and notable pH-responsiveness with high drug loading of 88.32%. As demonstrated in vitro and in vivo, the reduced cytotoxicity of both RAW264.7 cells and LPS-activated RAW264.7 cells treated with MTX@pH-AcDEX NPs was found compared to free MTX. Upon intravenous administration into adjuvant-induced arthritis (AIA) rat model, the nanodrug had potent pharmacokinetic and pharmacodynamic profiles, which can accumulate in RA lesions and release MTX inhibitors for regulating the JAK-STAT pathways. As a result, the MTX@pH-AcDEX NPs achieved the cartilage and bone protective and a better anti-inflammatory effect with negligible systemic toxicity, suggesting the strong potential of safe and effective nanodrug for RA therapy as well as other autoimmune diseases.

Synergistic and receptor-mediated targeting of arthritic joints via intra-articular injectable smart hydrogels containing leflunomide-loaded lipid nanocarriers

Intra-articular drug delivery represents a tempting strategy for local treatment of rheumatoid arthritis. Targeting drugs to inflamed joints bypasses systemic-related side effects. Albeit, rapid drug clearance and short joint residence limit intra-articular administration. Herein, injectable smart hydrogels comprising free/nanoencapsulated leflunomide (LEF) were developed. Nanostructured lipid carriers (NLCs), 200-300 nm, were coated with either chondroitin sulfate (CHS), hyaluronic acid (HA), or chitosan (CS) to provide joint targetability. Coated NLCs were incorporated in either hyaluronic/pluronic (HP) or chitosan/β-glycerophosphate (CS/βGP) hydrogels. Optimized systems ensured convenient gelation time (14-100 s), injectability (5-15 s), formulation-dependent mechanical strength, and extended LEF release up to 51 days. In vivo intra-articular injection in induced arthritis rat model revealed that rats treated with HA-coated NLCs showed the fastest recovery. Histopathological examination demonstrated perfect joint healing in case of HA-coated LEF-NLCs in CS/βGP thermogel manifested as minor erosion of subchondral bone, improved intensity of extracellular matrix, cartilage thickness, and chondrocyte number. Both HA- and CHS-coated NLCs reduced TNF-α level 4-5-fold relative to positive control. The feat would be achieved via active targeting to CD44 receptors overexpressed in the articular tissue, limiting chondrocyte apoptosis together with innate synergistic targetability by promoting chondrocyte proliferation and neovascularization, inhibiting the production of pro-inflammatory cytokines, thus enhancing cartilaginous tissue repair.

Nanomedicine-based combination of dexamethasone palmitate and MCL-1 siRNA for synergistic therapeutic efficacy against rheumatoid arthritis

The main aim of this research was to design a MCL-1 siRNA and dexamethasone (DEX)-loaded folate modified poly(lactide-co-glycolide) (PLGA)-based polymeric micelles with an eventual goal to improve the therapeutic outcome in the rheumatoid arthritis (RA). Polymeric micelles encapsulating the MCL-1 siRNA and DEX was successfully developed and observed to be stable. Physicochemical characteristics such as particle size and particle morphology were ideal for the systemic administration. Folate-conjugated DEX/siRNA-loaded polymeric micelles (DS-FPM) significantly lowered the MCL-1 mRNA expression compared to either DEX/siRNA-loaded polymeric micelles (DS-PM) or free siRNA in Raw264.7 cells and macrophage cells suggesting the importance of targeted nanocarriers. Most importantly, DS-FPM exhibited a greatest decrease in the hind paw volume with lowest clinical score compared to any other treated group indicating a superior anti-inflammatory activity. DS-FPM showed significantly lower levels of the TNF-α and IL-1β compared to AIA model and free groups. The folate receptor (FR)-targeting property of DS-FPM has been demonstrated to be a promising delivery platform for the effective delivery of combination therapeutics (siRNA and DEX) toward the treatment of rheumatoid arthritis.

Targeted therapy of rheumatoid arthritis via macrophage repolarization

The polarization of macrophages plays a critical role in the physiological and pathological progression of rheumatoid arthritis (RA). Activated M1 macrophages overexpress folate receptors in arthritic joints. Hence, we developed folic acid (FA)-modified liposomes (FA-Lips) to encapsulate triptolide (TP) (FA-Lips/TP) for the targeted therapy of RA. FA-Lips exhibited significantly higher internalization efficiency in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells than liposomes (Lips) in the absence of folate. Next, an adjuvant-induced arthritis (AIA) rat model was established to explore the biodistribution profiles of FA-Lips which showed markedly selective accumulation in inflammatory paws. Moreover, FA-Lips/TP exhibited greatly improved therapeutic efficacy and low toxicity in AIA rats by targeting M1 macrophages and repolarizing macrophages from M1 to M2 subtypes. Overall, a safe FA-modified liposomal delivery system encapsulating TP was shown to achieve inflammation-targeted therapy against RA via macrophage repolarization.

Thermoresponsive polymeric dexamethasone prodrug for arthritis pain

Intra-articular (IA) glucocorticoids (GC) are commonly used for clinical management of both osteoarthritis and rheumatoid arthritis, but their efficacy is limited by the relatively short duration of action and associated side effects. To provide sustained efficacy and to improve the safety of GCs, we previously developed a N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-based dexamethasone (Dex) prodrug. Serendipitously, we discovered that, by increasing the Dex content of the prodrug to unusually high levels, the aqueous solution of the polymeric prodrug becomes thermoresponsive, transitioning from a free-flowing liquid at 4 °C to a hydrogel at 30 °C or greater. Upon IA injection, the prodrug solution forms a hydrogel (ProGel-Dex) that is retained in the joint for more than 1 month, where it undergoes gradual dissolution, releasing the water-soluble polymeric prodrug. The released prodrug is swiftly internalized and intracellularly processed by phagocytic synoviocytes to release free Dex, resulting in sustained amelioration of joint inflammation and pain in rodent models of inflammatory arthritis and osteoarthritis. The low molecular weight (6.8 kDa) of the ProGel-Dex ensures rapid renal clearance once it escapes the joint, limiting systemic GC exposure and risk of potential off-target side effects. The present study illustrates the translational potential of ProGel-Dex as a potent opioid-sparing, locally delivered adjuvant analgesic for sustained clinical management of arthritis pain and inflammation. Importantly, the observed thermoresponsive properties of the prodrug establishes ProGel as a platform technology for the local delivery of a broad spectrum of therapeutic agents to treat a diverse array of pathological conditions.

Nanomedicine for acute respiratory distress syndrome: The latest application, targeting strategy, and rational design

Acute respiratory distress syndrome (ARDS) is characterized by the severe inflammation and destruction of the lung air-blood barrier, leading to irreversible and substantial respiratory function damage. Patients with coronavirus disease 2019 (COVID-19) have been encountered with a high risk of ARDS, underscoring the urgency for exploiting effective therapy. However, proper medications for ARDS are still lacking due to poor pharmacokinetics, non-specific side effects, inability to surmount pulmonary barrier, and inadequate management of heterogeneity. The increased lung permeability in the pathological environment of ARDS may contribute to nanoparticle-mediated passive targeting delivery. Nanomedicine has demonstrated unique advantages in solving the dilemma of ARDS drug therapy, which can address the shortcomings and limitations of traditional anti-inflammatory or antioxidant drug treatment. Through passive, active, or physicochemical targeting, nanocarriers can interact with lung epithelium/endothelium and inflammatory cells to reverse abnormal changes and restore homeostasis of the pulmonary environment, thereby showing good therapeutic activity and reduced toxicity. This article reviews the latest applications of nanomedicine in pre-clinical ARDS therapy, highlights the strategies for targeted treatment of lung inflammation, presents the innovative drug delivery systems, and provides inspiration for strengthening the therapeutic effect of nanomedicine-based treatment.

A Novel Nanomedicine Ameliorates Acute Inflammatory Bowel Disease by Regulating Macrophages and T-Cells

Ramulus mori polysaccharide (RMP), one of the most important active components of R. mori, has been attracting increasing interest because of its potent bioactive properties, including anti-inflammatory, antitumor, and antidiabetic effects. Despite the great therapeutic potential of RMP, its inherent properties of low bioavailability and brief biological half-life have limited its applications to the clinic. Thus, RMP was packaged by poly(lactic-co-glycolic acid) (PLGA) nanoparticles to develop a novel anti-inflammatory nanomedicine (PLGA-RMP) in this study. The nanoparticles were synthesized via a double-emulsion solvent evaporation technique, and the average diameter of PLGA-RMP was about 202 nm. PLGA-RMP nanoparticles reduced the expression of inflammatory cytokines while promoting the production of IL-10, and boosted the phenotypic shift in macrophages in vitro. Furthermore, lipopolysaccharide (LPS)-induced inflammatory bowel disease (IBD) in mouse was used to examine the anti-inflammatory effect of PLGA-RMP in vivo. Oral administration of PLGA-RMP in LPS-induced IBD mice substantially mitigated the intestinal inflammation compared to treatment with LPS alone, as evidenced by attenuation of disease activity index scores and inflammatory damage in the intestine. Meanwhile, PLGA-RMP suppressed the expression and secretion of specific inflammatory cytokines including TNF-α, IL-6, IL-1β, and PGE2 in the inflamed intestine while inhibiting the activation of CD3⁺CD8⁺ T-cells and increasing the number of activated T_regs in the intestine. These results indicated that PLGA-RMP deserves further consideration as a potential therapeutic nanomedicine to treat various inflammatory diseases, including IBD.

Folate receptor-targeting semiconducting polymer dots hybrid mesoporous silica nanoparticles against rheumatoid arthritis through synergistic photothermal therapy, photodynamic therapy, and chemotherapy

With ideal optical properties, semiconducting polymer quantum dots (SPs) have become a research focus in recent years; a considerable number of studies have been devoted to the application of SPs in non-invasive and biosafety phototherapy with near-infrared (NIR) lasers. Nevertheless, the relatively poor stability of SPs in vitro and in vivo remains problematic. PCPDTBT was chosen to synthesize photothermal therapy (PTT) and photodynamic therapy (PDT) dual-model SPs, considering its low band gap and desirable absorption in the NIR window. For the first time, cetrimonium bromide was used as a stabilizer to guarantee the in vitro stability of SPs, and as a template to prepare SP hybrid mesoporous silica nanoparticles (SMs) to achieve long-term stability in vivo. The mesoporous structure of SMs was used as a reservoir for the hypoxia-activated prodrug Tirapazamine (TPZ). SMs were decorated with polyethylene glycol-folic acid (SMPFs) to specifically target activated macrophages in rheumatoid arthritis (RA). Upon an 808 nm NIR irradiation, the SMPFs generate intracellular hyperthermia and excessive singlet oxygen. Local hypoxia caused by molecular oxygen consumption simultaneously activates the cytotoxicity of TPZ, which effectively kills activated macrophages and inhibits the progression of arthritis. This triple PTT-PDT-chemo synergistic treatment suggests that SMPFs realize the in vivo application of SPs and may be a potential nano-vehicle for RA therapy with negligible side-toxicity.

Topical nanocarriers for management of Rheumatoid Arthritis: A review

Rheumatoid arthritis (RA) is a systemic autoimmune disease manifested by chronic joint inflammation leading to severe disability and premature mortality. With a global prevalence of about 0.3%-1% RA is 3-5 times more prevalent in women than in men. There is no known cure for RA; the ultimate goal for treatment of RA is to provide symptomatic relief. The treatment regimen for RA involves frequent drug administration and high doses of NSAIDs such as indomethacin, diclofenac, ibuprofen, celecoxib, etorcoxib. These potent drugs often have off target effects which drastically decreases patient compliance. Moreover, conventional non-steroidal anti-inflammatory have many formulation challenges like low solubility and permeability, poor bioavailability, degradation by gastrointestinal enzymes, food interactions and toxicity. To overcome these barriers, researchers have turned to topical route of drug administration, which has superior patience compliance and they also bypass the first past effect experienced with conventional oral administration. Furthermore, to enhance the permeation of drug through the layers of the skin and reach the site of inflammation, nanosized carriers have been designed such as liposomes, nanoemulsions, niosomes, ethosomes, solid lipid nanoparticles and transferosomes. These drug delivery systems are non-toxic and have high drug encapsulation efficiency and they also provide sustained release of drug. This review discusses the effect of formulation composition on the physiochemical properties of these nanocarriers in terms of particle size, surface charge, drug entrapment and also drug release profile thus providing a landscape of topically used nanoformulations for symptomatic treatment of RA.

Targeted-lung delivery of dexamethasone using gated mesoporous silica nanoparticles. A new therapeutic approach for acute lung injury treatment

Acute lung injury (ALI) is a critical inflammatory syndrome, characterized by increased diffuse inflammation and severe lung damage, which represents a clinical concern due to the high morbidity and mortality in critical patients. In last years, there has been a need to develop more effective treatments for ALI, and targeted drug delivery to inflamed lungs has become an attractive research field. Here, we present a nanodevice based on mesoporous silica nanoparticles loaded with dexamethasone (a glucocorticoid extensively used for ALI treatment) and capped with a peptide that targets the TNFR1 receptor expressed in pro-inflammatory macrophages (TNFR-Dex-MSNs) and avoids cargo leakage. TNFR-Dex-MSNs nanoparticles are preferentially internalized by pro-inflammatory macrophages, which overexpressed the TNFR1 receptor, with the subsequent cargo release upon the enzymatic hydrolysis of the capping peptide in lysosomes. Moreover, TNFR-Dex-MSNs are able to reduce the levels of TNF-α and IL-1β cytokines in activated pro-inflammatory M1 macrophages. The anti-inflammatory effect of TNFR-Dex-MSNs is also tested in an in vivo ALI mice model. The administered nanodevice (intravenously by tail vein injection) accumulated in the injured lungs and the controlled dexamethasone release reduces markedly the inflammatory response (TNF-α IL-6 and IL-1β levels). The attenuation in lung damage, after treatment with TNFR-Dex-MSNs, is also confirmed by histopathological studies. Besides, the targeted-lung dexamethasone delivery results in a decrease of dexamethasone derived side-effects, suggesting that targeted nanoparticles can be used for therapy in ALI and could help to overcome the clinical limitations of current treatments.

Ramulus mori polysaccharide-loaded PLGA nanoparticles and their anti-inflammatory effects in vivo

In this study, ramulus mori polysaccharide (RMP) was encapsulated into Poly (lactic-co-glycolicacid) (PLGA) to form PLGA-RMP (PR). The aim of study is to investigate anti-inflammatory effects of PR. The particle size of PR nanoparticles was approximately 205.6 ± 1.86 nm. PR nanoparticles showed significant therapeutic effects on colitis mice model, evidenced by attenuation of the loss of body weight, reduction of the DAI score, and restoration of the colon length. From the histopathological analysis, alleviation of the histopathological damage, less production of IFN-γ and IL-6, and improvement of IL-10 were observed with the treatment of PR. Meanwhile, the treatment of PR not only promoted the expression of ZO-1 and occludin, but also improved the contents of acetate, propionate, and butyrate in the colitis colon. Furthermore, PR extenuated the reduction of the diversity and richness of gut microbiota induced by DSS, and decreased the ratio of Firmicutes to Bacteroidetes while increasing the proportion of Clostridium XIVa, Mucispirillum, and Paraprevotella in the gut microbiota. What's more, PR nanoparticles attenuated the metabolic disorders in the colitis colon induced by DSS. These results indicated that PR nanoparticles could serve as a potent nanomedicine to treat IBD and be used as potential prebiotics.

Nanomedicine Strategies for Anti-Inflammatory Treatment of Noninfectious Arthritis

Noninfectious arthritis (NIA) comprises a class of chronic and progressive inflammatory disorders that require early-stage management to prevent disease progression. The most common forms include osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, and gouty arthritis. Current treatments involve nonsteroidal anti-inflammatory drugs, disease-modifying antirheumatic drugs and glucocorticoids to alleviate clinical symptoms, although regular use of these can result in a high risk of chronic kidney disease and heart failure, as well as severe adverse gastrointestinal effects. Nanomedicine offers unique opportunities to address these challenges and improve therapeutic efficacy due to its ability to deliver therapeutics locally in a sustained manner, thus extending the half-life, improving bioavailability, and reducing the side effects of these agents. This review includes a comprehensive analysis of the mechanisms of various treatment options for NIA and highlights recent progress and emerging strategies in treating NIA with nanomedicine platforms, particularly related to long-term biosafety and nonspecific targeting in designing nanomedicine delivery systems.

Optimizing an Antioxidant TEMPO Copolymer for Reactive Oxygen Species Scavenging and Anti-Inflammatory Effects in Vivo

Oxidative stress is broadly implicated in chronic, inflammatory diseases because it causes protein and lipid damage, cell death, and stimulation of inflammatory signaling. Supplementation of innate antioxidant mechanisms with drugs such as the superoxide dismutase (SOD) mimetic compound 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) is a promising strategy for reducing oxidative stress-driven pathologies. TEMPO is inexpensive to produce and has strong antioxidant activity, but it is limited as a drug due to rapid clearance from the body. It is also challenging to encapsulate into micellar nanoparticles or polymer microparticles, because it is a small, water soluble molecule that does not efficiently load into hydrophobic carrier systems. In this work, we pursued a polymeric form of TEMPO [poly(TEMPO)] to increase its molecular weight with the goal of improving in vivo bioavailability. High density of TEMPO on the poly(TEMPO) backbone limited water solubility and bioactivity of the product, a challenge that was overcome by tuning the density of TEMPO in the polymer by copolymerization with the hydrophilic monomer dimethylacrylamide (DMA). Using this strategy, we formed a series of poly(DMA-co-TEMPO) random copolymers. An optimal composition of 40 mol % TEMPO/60 mol % DMA was identified for water solubility and O2•- scavenging in vitro. In an air pouch model of acute local inflammation, the optimized copolymer outperformed both the free drug and a 100% poly(TEMPO) formulation in O2•- scavenging, retention, and reduction of TNFα levels. Additionally, the optimized copolymer reduced ROS levels after systemic injection in a footpad model of inflammation. These results demonstrate the benefit of polymerizing TEMPO for in vivo efficacy and could lead to a useful antioxidant polymer formulation for next-generation anti-inflammatory treatments.

Dual-Stimuli Responsive Polymeric Micelles for the Effective Treatment of Rheumatoid Arthritis

The nontargeted distribution and uncontrolled in vivo release of drugs impede their efficacy in the treatment of rheumatoid arthritis (RA). Delivering drugs to arthritic joints and releasing drugs on demand are a feasible solution to achieve the effective treatment of RA. In this paper, we report a facile method to assemble dual-stimuli responsive polymeric micelles from polyethylene glycol-phenylboric acid-triglycerol monostearate (PEG-PBA-TGMS, PPT) conjugates with the aim of delivering dexamethasone (Dex) to arthritic joints and controlling the release of Dex by inflammatory stimuli. We show that the release of Dex from the PPT micelles is accelerated in response to acidic pH and overexpressed matrix metalloproteinases. In an adjuvant-induced arthritis model, the PPT micelles preferentially accumulate in arthritic joints and show an excellent therapeutic efficacy after being intravenously administrated. Our results highlight the potential of the dual stimuli-responsive micelles as a promising therapeutic option for the effective treatment of inflammatory diseases.

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.

Hyaluronic acid-green tea catechin conjugates as a potential therapeutic agent for rheumatoid arthritis

Fibroblast-like synoviocytes are a key effector cell type involved in the pathogenesis of rheumatoid arthritis. The major green tea catechin, epigallocatechin-3-O-gallate (EGCG), has attracted significant interest for rheumatoid arthritis therapy because of its ability to suppress the proliferation and interleukin-6 secretion of synoviocytes. However, therapeutic efficacy of EGCG has been limited by a lack of target cell specificity. Herein we report hyaluronic acid-EGCG (HA-EGCG) conjugates as an anti-arthritic agent that is capable of targeting fibroblast-like synoviocytes via HA-CD44 interactions. These conjugates exhibited superior anti-proliferative and anti-inflammatory activities compared with EGCG under simulated physiological conditions. Near-infrared fluorescence imaging revealed preferential accumulation of the conjugates at inflamed joints in a collagen-induced arthritis rat model, and their anti-arthritic efficacy was investigated by measuring a change in the edema and histopathological scores. Our findings suggest the potential of HA-EGCG conjugates as an anti-arthritic agent for the treatment of rheumatoid arthritis.

Folic acid decorated chitosan-coated solid lipid nanoparticles for the oral treatment of rheumatoid arthritis

Background: Systemic treatment of rheumatoid arthritis has been accompanied with several side effects. This study attempts to reduce leflunomide systemic side effects besides increasing its joint healing outcomes via formulation of layer-by-layer coated, leflunomide-loaded solid lipid nanoparticles (SLNs). Methods: SLNs were coated with chitosan (CS) followed by folic acid (FA). FA-CS-SLNs were about 284.9 nm and carried negative surface charge. Results & conclusion: FA-CS-SLNs showed sustained release profile for 168 h. Results of oral administration of FA-CS-SLNs in rats with adjuvant-induced arthritis revealed improved joint healing and reduced hepatotoxicity compared with leflunomide suspension. This may be attributed to the ability of FA-CS-SLNs to actively target FA receptors that are overexpressed in inflamed rheumatic joints in addition to innate joint healing properties of CS.

A Review on Rheumatoid Arthritis Interventions and Current Developments

Rheumatoid arthritis is a chronic autoimmune disorder characterized by inflammation, swelling, and joint destruction primarily affecting the peripheral joints. In recent years, RA has become an alarming concern affecting more than 1.5% of the population worldwide. The majority of the drugs in clinical trials for rheumatoid arthritis are immunomodulatory. The development of novel drugs for RA is impending and scientists are exploring new strategies through various innovative approaches for RA drug development. Treat-to-target and window of opportunity hypothesis are the new approaches that are used to treat, improve outcomes, and prevent long-term use of ineffective therapy, respectively. Novel therapeutic agents (e.g. GM-CSF inhibitors, Matrix metalloproteinase inhibitors) and delivery systems (e.g., Liposomes, Superparamagnetic iron oxide nano particles (SPIONs)) are under investigation for more target based therapy with reduced side effects and toxicity. The new drug discovery and repositioning of previously FDA-approved drugs are also being considered for chronic inflammatory disorder. The review encompasses a vast array of information, including genetics, etiology, clinical symptoms, current treatment, and newer therapeutics approaches, focused on the development of RA interventions. The introduction of the bioinformatics-based approach in RA has also been significantly discussed in the review. This review provides a general understanding of the challenges and uncertainties in the treatment of RA and summarizes the evolving scenario as well as innovative approaches taken into consideration for drug development in rheumatoid arthritis.

Platelet membrane camouflaged nanoparticles: Biomimetic architecture for targeted therapy

Cell membrane coating strategy is one of the promising techniques for biomimetic functionalization of nanoparticle. The biomimetic nanoparticles camouflage themselves utilizing the fundamental properties of native cells. Cell membranes are extracted from various cells to cloak the nanoparticles for targeted drug delivery. Platelet membrane is one such cell membrane proposing itself as a potential camouflager to escape the immune surveillance and aid prolonged blood circulation with minimum systemic cytotoxicity. Platelets play a very important role in the physiological functions of the body and also feature in few pathological disorders like cancer, atherosclerosis and rheumatoid arthritis. This review comprises of preparation and characterization of platelet membrane camouflaged nanoparticles and also focuses on their recent developments towards targeted therapy in cancer, immune diseases, atherosclerosis and phototherapy. Although platelet membrane camouflaged nanoparticles are currently in the preliminary stage of development, there is huge potential to explore this biodegradable and biocompatible delivery system.

Meta-analysis of global and high throughput public gene array data for robust vascular gene expression discovery in chronic rhinosinusitis: Implications in controlled release

BACKGROUND

Chronic inflammation is known to cause alterations in vascular homeostasis that directly affects blood vessel morphogenesis, angiogenesis, and tissue permeability. These phenomena have been investigated and exploited for targeted drug delivery applications in the context of cancers and other disease processes. Vascular pathophysiology and its associated genes and signaling pathways, however, have not been systematically investigated in patients with chronic rhinosinusitis (CRS). Understanding the interplay between key vascular signaling pathways and top biomarkers associated with CRS may facilitate the development of new targeted delivery strategies and treatment paradigms. Herein, we report findings from a gene meta-analysis to identify key vascular pathways and top genes involved in CRS.

METHODS

Proprietary software (Illumina BaseSpace Correlation Engine) and open-access data sets were used to perform a gene meta-analysis to systematically determine significant differences between key vascular biomarkers and vascular signaling pathways expressed in sinonasal tissue biopsies of controls and patients with CRS.

RESULTS

Thirteen studies were initially identified, and then reduced to five after applying exclusion principle algorithms. Genes associated with vasculature development and blood vessel morphogenesis signaling pathways were identified to be overexpressed among the top 15 signaling pathways. Out of many significantly upregulated genes, the levels of pro angiogenic genes such as early growth response (EGR3), platelet endothelial cell adhesion molecule (PECAM1) and L-selectin (SELL) were particularly significant in patients with CRS compared to controls.

DISCUSSION

Key vascular biomarkers and signaling pathways were significantly overexpressed in patients with CRS compared to controls, suggesting a contribution of vascular dysfunction in CRS pathophysiology. Vascular dysregulation and permeability may afford opportunities to develop drug delivery systems to improve efficacy and reduce toxicity of CRS treatment.

Construction of a pH-responsive, ultralow-dose triptolide nanomedicine for safe rheumatoid arthritis therapy

Rheumatoid arthritis (RA) is a chronicautoimmune disease, marked by joint swelling and pain, articular synovial hyperplasia, as well as cartilage and bone destruction. Triptolide (TP) is an anti-inflammatory molecule but its use to treat RA is limited due to poor solubility and extremely high toxicity. In this study, by encapsulating TP into a star-shaped amphiphilic block copolymer, POSS-PCL-b-PDMAEMA, we engineered a pH-sensitive TP-loaded nanomedicine (TP@NPs) to simultaneously reduce the toxicity of TP and improve its therapeutic efficacy. TP@NPs shows a uniform spherical structure with a hydrodynamic diameter of ~92 nm and notable pH-responsiveness. In vitro TP@NPs showed reduced cytotoxicity and cell apoptosis of treated RAW264.7 cells compared to free TP. And in vivo intravenous injection of indocyanine green-labeled NPs into a collagen-induced arthritis model in mice showed that the engineered compound had potent pharmacokinetic and pharmacodynamic profiles, while exhibiting significant cartilage-protective and anti-inflammatory effects with a better efficacy and neglible systemic toxicity even at an ultralow dose compared to free TP. These results suggest that TP@NPs may be a safe and effective therapy for RA and other autoimmune diseases.

Treatment of Rheumatoid Arthritis by Serum Albumin Nanoparticles Coated with Mannose to Target Neutrophils

Rheumatoid arthritis (RA) is an angiogenic and chronic inflammatory disease. One of the most extensively used first-line drugs against RA is methotrexate (MTX), but it shows poor solubility, short in vivo circulation, and off-target binding, leading to strong toxicity. To overcome these shortcomings, the present study loaded MTX into nanoparticles of human serum albumin modified with mannose (MTX-M-NPs) to target the drug to neutrophils. MTX-M-NPs were prepared, and their uptake by neutrophils was studied using laser confocal microscopy and flow cytometry. A chick chorioallantoic membrane assay was used to assess their ability to inhibit angiogenesis. The pharmacokinetics and tissue distribution of MTX-M-NPs were investigated using fluorescence microscopy and high-performance liquid chromatography. Their pharmacodynamics was evaluated in a rat model with arthritis induced by collagen. Neutrophils took up MTX-M-NPs significantly better than the same nanoparticles (NPs) without mannose. MTX-M-NPs markedly suppressed angiogenesis in chick embryos, and the MTX circulation was significantly longer when it was delivered as MTX-M-NPs than as a free drug. MTX-M-NPs accumulated mainly in arthritic joints. The retention of NPs was promoted by mannose-derived coating in arthritic joints. Serum levels of inflammatory cytokines, joint swelling, and bone erosion were significantly decreased by MTX-M-NPs. In conclusion, these NPs can prolong the in vivo circulation of MTX and target it to the sites of inflammation in RA, reducing drug toxicity. MTX-M-NPs allow the drug to exert its intrinsic anti-inflammatory, antiangiogenic, and analgesic properties, making it a useful drug delivery system in RA.

Targeting Strategies for Tissue-Specific Drug Delivery

Off-target effects of systemically administered drugs have been a major hurdle in designing therapies with desired efficacy and acceptable toxicity. Developing targeting strategies to enable site-specific drug delivery holds promise in reducing off-target effects, decreasing unwanted toxicities, and thereby enhancing a drug's therapeutic efficacy. Over the past three decades, a large body of literature has focused on understanding the biological barriers that hinder tissue-specific drug delivery and strategies to overcome them. These efforts have led to several targeting strategies that modulate drug delivery in both the preclinical and clinical settings, including small molecule-, nucleic acid-, peptide-, antibody-, and cell-based strategies. Here, we discuss key advances and emerging concepts for tissue-specific drug delivery approaches and their clinical translation.

Dexamethasone prodrug nanomedicine (ZSJ-0228) treatment significantly reduces lupus nephritis in mice without measurable side effects - A 5-month study

Lupus nephritis (LN) is a major cause of morbidity and mortality among systemic lupus erythematosus patients. Glucocorticoids (GCs) are uniformly used in clinical LN management. Their notorious toxicities, however, have hampered the long-term clinical application. To circumvent GC side effects while maintaining their potent therapeutic efficacy, we have developed a macromolecular prodrug nanomedicine based on dexamethasone (ZSJ-0228). The focus of this study was to investigate its long-term efficacy and, most importantly, safety in the lupus-prone NZB/W F1 mouse. Monthly ZSJ-0228 treatment for five months significantly reduced the incidence of nephritis in NZB/W F1 mice with an improved survival rate. In contrast to treatment with dose equivalent daily free dexamethasone, long-term monthly ZSJ-0228 did not result in any measurable GC-associated side effects. With its outstanding efficacy and exceptional safety, it is anticipated that ZSJ-0228 may be a novel therapy for long-term clinical management of LN.

Recent Advances in Smart Biomaterials for the Detection and Treatment of Autoimmune Diseases

Autoimmune diseases are a group of debilitating illnesses that are often idiopathic in nature. The steady rise in the prevalence of these conditions warrants new approaches for diagnosis and treatment. Stimuli-responsive biomaterials also known as "smart", "intelligent" or "recognitive" biomaterials are widely studied for their applications in drug delivery, biosensing and tissue engineering due to their ability to produce thermal, optical, chemical, or structural changes upon interacting with the biological environment. This critical analysis highlights studies within the last decade that harness the recognitive capabilities of these biomaterials towards the development of novel detection and treatment options for autoimmune diseases.

Polymer nanomedicines

Polymer nanomedicines (macromolecular therapeutics, polymer-drug conjugates, drug-free macromolecular therapeutics) are a group of biologically active compounds that are characterized by their large molecular weight. This review focuses on bioconjugates of water-soluble macromolecules with low molecular weight drugs and selected proteins. After analyzing the design principles, different structures of polymer carriers are discussed followed by the examination of the efficacy of the conjugates in animal models and challenges for their translation into the clinic. Two innovative directions in macromolecular therapeutics that depend on receptor crosslinking are highlighted: a) Combination chemotherapy of backbone degradable polymer-drug conjugates with immune checkpoint blockade by multivalent polymer peptide antagonists; and b) Drug-free macromolecular therapeutics, a new paradigm in drug delivery.

Polymer Nanomedicines with Ph-Sensitive Release of Dexamethasone for the Localized Treatment of Inflammation

Polymer-drug conjugates have several advantages in controlled drug delivery to inflammation as they can accumulate and release the drug in inflamed tissues or cells, which could circumvent the shortcomings of current therapy. To improve the therapeutic potential of polymer-drug conjugates in joint inflammation, we synthesized polymer conjugates based on N-(2-hydroxypropyl) methacrylamide) copolymers labeled with a near-infrared fluorescent dye and covalently linked to the anti-inflammatory drug dexamethasone (DEX). The drug was bound to the polymer via a spacer enabling pH-sensitive drug release in conditions mimicking the environment inside inflammation-related cells. An in vivo murine model of adjuvant-induced arthritis was used to confirm the accumulation of polymer conjugates in arthritic joints, which occurred rapidly after conjugate application and remained until the end of the experiment. Several tested dosage schemes of polymer DEX-OPB conjugate showed superior anti-inflammatory efficacy. The highest therapeutic effect was obtained by repeated i.p. application of polymer conjugate (3 × 1 mg/kg of DEX eq.), which led to a reduction in the severity of inflammation in the ankle by more than 90%, compared to 40% in mice treated with free DEX.

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.

Head-to-head comparative pharmacokinetic and biodistribution (PK/BD) study of two dexamethasone prodrug nanomedicines on lupus-prone NZB/WF1 mice

HPMA copolymer-based dexamethasone prodrug (P-Dex) and PEG-based dexamethasone prodrug (PEG-Dex, ZSJ-0228) were previously found to passively target the inflamed kidney and provide potent and sustained resolution of nephritis in NZB/WF1 lupus-prone mice. While both prodrug nanomedicines effectively ameliorate lupus nephritis, they have demonstrated distinctively different safety profiles. To explore the underlining mechanisms of these differences, we conducted a head-to-head comparative PK/BD study of P-Dex and PEG-Dex on NZB/WF1 mice. Overall, the systemic organ/tissue exposures to P-Dex and Dex released from P-Dex were found to be significantly higher than those of PEG-Dex. The high prodrug concentrations were sustained in kidney for only 24 h, which cannot explain their lasting therapeutic efficacy (>1 month). P-Dex showed sustained presence in liver, spleen and adrenal gland, while the presence of PEG-Dex in these organs was transient. This difference in PK/BD profiles may explain PEG-Dex' superior safety than P-Dex.

Nanomedicine for the Treatment of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that results in severe inflammatory microenvironments in the joint tissues. In clinics, disease-modifying antirheumatic drugs (DMARDs) are generally prescribed to patients with RA, but their long-term use often shows toxicity in some organs such as the gastrointestinal system, skin, and kidneys and immunosuppression-mediated infection. Nanomedicine has emerged as a new therapeutic strategy to efficiently localize the drugs in inflamed joints for the treatment of RA. In this Review, we introduce recent research in the area of nanomedicine for the treatment of RA and discuss how the nanomedicine can be used to deliver therapeutic agents to the inflamed joints and manage the progression of RA, particularly focusing on targeted delivery, controlled drug release, and immune modulation.

Sialic acid-modified dexamethasone lipid calcium phosphate gel core nanoparticles for target treatment of kidney injury

Acute kidney injury (AKI) is a common clinical disease with high morbidity and mortality. Glucocorticoids are drugs that effectively relieve AKI, but the systemic side effects of long-term use limit their use. Herein, we constructed sialic acid-modified dexamethasone sodium phosphate (Dsp)-loaded lipid calcium phosphate gel core nanoparticles (SA-NPs) for the targeted treatment of ischemia-reperfusion (I/R)-induced AKI to improve efficacy and reduce side effects. The obtained nanoparticles could effectively encapsulate Dsp with 66.8% encapsulation efficiency and 4.56% (w/w) drug content. In vitro release indicates that the nanoparticles have a certain sustained release effect and have the characteristics of acid-sensitive release. And SA-NPs significantly increased the cellular uptake and kidney accumulation respectively through the combination of SA and E-selectin receptors overexpressed in inflamed vascular endothelial cells. Besides, the in vivo pharmacokinetic studies showed that Dsp-loaded SA-NPs significantly increased the residence time in the body and their plasma half-life was 1.7 times that of free Dsp. SA-NPs significantly improved the renal function, decreased the level of pro-inflammatory factors, and adjusted the oxidative stress factors and apoptotic proteins compared to free Dsp solution in pharmacodynamic studies. Moreover, little negative effects on blood glucose and bone mineral density were observed. Our study might provide a new strategy for the safe and effective targeting treatment of AKI or other related inflammatory diseases.

Reactive Oxygen Species Responsive Theranostic Nanoplatform for Two-Photon Aggregation-Induced Emission Imaging and Therapy of Acute and Chronic Inflammation

Inflammation is a protective response to stimuli trauma, which can also lead to severe tissue injury. The existing anti-inflammatory drugs, such as corticosteroids and glucocorticoids, generally exhibit side effects and poor accumulation in inflammatory tissue. Hence, a theranostic nanoplatform with serial reactive oxygen species (ROS) responsiveness and two-photon AIE bioimaging has been constructed for dimensional diagnosis and accurate therapy of inflammation. Prednisolone (Pred) is bridged to a two-photon fluorophore (TP) developed by us via a ROS sensitive bond to form a diagnosis-therapy compound TPP, which is then loaded by the amphipathic polymer PMPC-PMEMA (PMM) through self-assembling into the core-shell structured micelles (TPP@PMM). With a particle size of 57.5 nm, TPP@PMM can realize the accumulation in the inflammatory site via the oedematous tissue and the accurate release of anti-inflammatory drug Pred through the serial response to the local overexpressed ROS. The micellar structure is first interrupted by the ROS triggered hydrophobic-to-hydrophilic conversion of PMEMA, which allows the release of TPP. Then the ROS responsive bond in TPP is subsequently broken, resulting in the accurate delivery of Pred and the inflammation therapy. Furthermore, TPP@PMM can be traced in vivo with a distinct two-photon imaging due to the AIE active fluorophore TP. The theranostic TPP@PMM reveals high-resolution inflammation diagnosis and efficient anti-inflammatory activity owing to the two-photon fluorophore and the serial ROS responsiveness and has been proven to achieve the efficient treatment of acute lung injury, arthritis, and atherosclerosis. Therefore, TPP@PMM holds considerable promise as a potential strategy for acute and chronic inflammation theranostics.

Structural optimization of HPMA copolymer-based dexamethasone prodrug for improved treatment of inflammatory arthritis

Despite their notorious adverse effects, glucocorticoids (GC, potent anti-inflammatory drugs) are used extensively in clinical management of rheumatoid arthritis (RA) and other chronic inflammatory diseases. To achieve a sustained therapeutic efficacy and reduced toxicities, macromolecular GC prodrugs have been developed with promising outcomes for the treatment of RA. Fine-tuning the activation kinetics of these prodrugs may further improve their therapeutic efficacy and minimize the off-target adverse effects. To assess the feasibility of this strategy, five different dexamethasone (Dex, a potent GC)-containing monomers with distinctively different linker chemistries were designed, synthesized, and copolymerized with N-(2-hydroxypropyl) methacrylamide (HPMA) to obtain 5 macromolecular Dex prodrugs. Their Dex releasing rates were analyzed in vitro and shown to display a wide spectrum of activation kinetics. Their therapeutic efficacy and preliminary toxicology profiles were assessed and compared in vivo in an adjuvant-induced arthritis (AA) rat model in order to identify the ideal prodrug design for the most effective and safe treatment of inflammatory arthritis. The in vivo data demonstrated that the C3 hydrazone linker-containing prodrug design was the most effective in preserving joint structural integrity. The results from this study suggest that the design and screening of different activation mechanisms may help to identify macromolecular prodrugs with the most potent therapeutic efficacy and safety for the management of inflammatory arthritis.

Sialic acid-modified chitosan oligosaccharide-based biphasic calcium phosphate promote synergetic bone formation in rheumatoid arthritis therapy

Therapeutic goals for rheumatoid arthritis (RA) consist of inhibiting the inflammatory response and repairing the damaged bone/cartilage. Tissue engineering could achieve both goals, however, it was hindered due to the lack of biologically relevant tissue complexity, limitation in covering the entire polyarthritis lesions and requirement of extra surgical implantation. Integrating nanotechnologies into clinically sized implants represents a major opportunity to overcome these problems. Herein, we designed a sialic acid (SA)-modified chitosan oligosaccharide-based biphasic calcium phosphate (BCP), a biomimetic nanoplatform that could load with methotrexate. We found that SA modification could not only improve the accumulation of the designed organic-inorganic nanoplatform in arthritic paws (34.38% higher than those without SA modification at 48 h), but also cooperate with BCP to exert synergetic mineralization of calcium phosphate, allowing more osteoblasts to attach, proliferate and differentiate. The more differentiated osteoblasts produced 4.46-fold type I collagen and 2.60-fold osteoprotegerin compared to the control group. Besides, the disassembled nanorods released chitosan oligosaccharide-based micelles, revealing a cartilage-protective effect by reducing the loss of glycosaminoglycan. All these improvements contributed to the light inflammatory response and reduced destruction on cartilage/bone. The findings provide a novel strategy for RA therapy via nanometer-scale dimension mimicking the natural tissues.

Modulating inflammatory macrophages with an apoptotic body-inspired nanoparticle

Macrophages play a critical role in the initiation, maintenance, and resolution of inflammation because of their diverse and plastic phenotypic responses to extracellular stimuli. Inflammatory stimuli drive the recruitment and activation of inflammatory (M1) macrophages, capable of significant cytokine production that potentiates inflammation. Local environmental signals including apoptotic cell efferocytosis drive a phenotypic transition toward pro-reparative (M2) macrophages to facilitate the resolution of inflammation. However, prolonged or dysregulated inflammatory macrophage response contributes to many disease states and tissue damage. We have developed a nanoparticle to help resolve macrophage-mediated inflammation by mimicking the anti-inflammatory effect of apoptotic cell engulfment. The nanoparticle, comprised of a poly(lactide-co-glycolide) core, is coated in phosphatidylserine (PS)-supplemented cell plasma membrane to emulate key characteristics of the apoptotic cell surface. These apoptotic body-inspired PS/membrane-coated nanoparticles (PS-MNPs) reduce inflammatory cytokine expression to promote an anti-inflammatory, phenotypic shift in macrophages in vitro, without the use of small molecule inhibitors or other drugs. Specifically, PS-MNP treatment before lipopolysaccharide (LPS)-induced inflammatory challenge resulted in a 2.5-fold reduction in secreted tumor necrosis factor α (TNFα) at 24 h, with co-treatment of PS-MNPs and LPS demonstrating a 5-fold TNFα reduction compared to LPS alone. Reduced TNFα production, as well as gene expression of several pro-inflammatory cytokines, correlated with a reduction in NFκB activation from PS-MNP treatment. The development of a nanoparticle to reduce the production of multiple inflammatory cytokines and transition away from an inflammatory macrophage phenotype, through the use of a physiologic anti-inflammatory pathway, illustrates a new potential strategy in creating anti-inflammatory therapeutics. STATEMENT OF SIGNIFICANCE: Macrophages propagate inflammation as the major source of cytokine production in the body. In inflammatory diseases, pro-inflammatory macrophages persist in the site of inflammation and exacerbate tissue destruction. Current anti-inflammatory drugs have significant drawbacks, including variable response rates and off-target effects. Here, we have developed an apoptotic-body inspired nanoparticle to modulate inflammatory macrophage phenotype. This polymeric nanoparticle is coated with phosphatidylserine-supplemented cell plasma membrane to mimic the anti-inflammatory effect of apoptotic cell engulfment. Nanoparticle delivery reduces inflammatory cytokine production and promotes an anti-inflammatory phenotypic macrophage shift. The capacity of these nanoparticles to help resolve macrophage-mediated inflammation may be a useful tool to study macrophage-apoptotic cell interactions, the role of macrophages in inflammatory diseases, and in the design of anti-inflammatory therapeutics.

Exploration and Evaluation of Therapeutic Efficacy of Drug-Free Macromolecular Therapeutics in Collagen-Induced Rheumatoid Arthritis Mouse Model

Monoclonal antibodies (mAbs) against B cell antigens are extensively used in the treatment of rheumatoid arthritis (RA). The B cell depletion therapy prevents RA symptoms and/or alleviates existing inflammation. The previously established two-step drug-free macromolecular therapeutics (DFMT) is applied in the treatment of collagen-induced rheumatoid arthritis in a collagen-induced rheumatoid arthritis mouse model. DFMT is a B cell depletion strategy utilizing Fab' fragment of anti-CD20 mAb for biorecognition and receptor crosslinking to induce B cell apoptosis. DFMT is composed from two nanoconjugates: 1) bispecific engager, Fab'-MORF1 (anti-CD20 Fab' fragment conjugated with morpholino oligonucleotide MORF1), and 2) a crosslinking (effector) component P-(MORF2)X (N-(2-hydroxypropyl)methacrylamide copolymer grafted with multiple copies of complementary morpholino oligonucleotide MORF2). The absence of Fc fragment has the potential to avoid development of resistance and infusion-related reactions. DFMT produces B cell depletion, keeps the RA score low for more than 100 days, and shows minimal cartilage and bone erosion and inflammatory cell infiltration. Further improvements will be explored to optimize DFMT strategy in autoimmune disease treatment.

MicroRNA-125a-Loaded Polymeric Nanoparticles Alleviate Systemic Lupus Erythematosus by Restoring Effector/Regulatory T Cells Balance

Systemic lupus erythematosus (SLE), a common lethal autoimmune disease, is characterized by effector/regulatory T cells imbalance. Current therapies are either inefficient or have severe side effects. MicroRNA-125a (miR-125a) can stabilize Treg-mediated self-tolerance by targeting effector programs, but it is significantly downregulated in peripheral T cells of patients with SLE. Therefore, overexpression of miR-125a may have therapeutic potential to treat SLE. Considering the stability and targeted delivery of miRNA remains a major challenge in vivo, we constructed a monomethoxy (polyethylene glycol)-poly(d,l-lactide-co-glycolide)-poly(l-lysine) (mPEG-PLGA-PLL) nanodelivery system to deliver miR-125a into splenic T cells. Results demonstrate that miR-125a-loaded mPEG-PLGA-PLL (PEAL_miR-125a) nanoparticles (NPs) exhibit good biocompatibility and protect miR-125a from degradation, thereby prolonging the circulatory time of miRNA in vivo. In addition, PEAL_miR-125a NPs are preferentially enriched in a pathological spleen and efficiently deliver miR-125a into the splenic T cells in SLE mice models. The PEAL_miR-125a NPs treatment significantly alleviates SLE disease progression by reversing the imbalance of effector/regulatory T cells. Collectively, the PEAL_miR-125a NPs show excellent therapeutic efficacy and safety, which may provide an effective treatment for SLE.

Modular Acid-Activatable Acetone-Based Ketal-Linked Nanomedicine by Dexamethasone Prodrugs for Enhanced Anti-Rheumatoid Arthritis with Low Side Effects

Given the physically encapsulated payloads with drug burst release and/or low drug loading, it is critical to initiate an innovative prodrug strategy to optimize the design of modular nanomedicines. Here, we designed modular pH-sensitive acetone-based ketal-linked prodrugs of dexamethasone (AKP-dexs) and formulated them as nanoparticles. We comprehensively studied the relationships between AKP-dex structure and properties, and we selected two types of AKP-dex-loaded nanoparticles for in vivo studies on the basis of their size, drug loading, and colloidal stability. In a collagen-induced arthritis rat model, these AKP-dex-loaded nanoparticles showed higher accumulation in inflamed joints and better therapeutic efficacy than free dexamethasone phosphate with less-severe side effects. AKP-dex-loaded nanoparticles may be useful for treating other inflammatory diseases and thus have great translational potential. Our findings represent an important step toward the development of practical applications for acetone-based ketal-linked prodrugs and are useful in the design of modular nanomedicines.

Nanomaterials for Nanotheranostics: Tuning Their Properties According to Disease Needs

Nanotheranostics is one of the biggest scientific breakthroughs in nanomedicine. Most of the currently available diagnosis and therapies are invasive, time-consuming, and associated with severe toxic side effects. Nanotheranostics, on the other hand, has the potential to bridge this gap by harnessing the capabilities of nanotechnology and nanomaterials for combined therapeutics and diagnostics with markedly enhanced efficacy. However, nanomaterial applications in nanotheranostics are still in its infancy. This is due to the fact that each disease has a particular microenvironment with well-defined characteristics, which promotes deeper selection criteria of nanomaterials to meet the disease needs. In this review, we have outlined how nanomaterials are designed and tailored for nanotheranostics of cancer and other diseases such as neurodegenerative, autoimmune (particularly on rheumatoid arthritis), and cardiovascular diseases. The penetrability and retention of a nanomaterial in the biological system, the therapeutic strategy used, and the imaging mode selected are some of the aspects discussed for each disease. The specific properties of the nanomaterials in terms of feasibility, physicochemical challenges, progress in clinical trials, its toxicity, and their future application on translational medicine are addressed. Our review meticulously and critically examines the applications of nanotheranostics with various nanomaterials, including graphene, across several diseases, offering a broader perspective of this emerging field.

Glucocorticoids delivered by inorganic-organic hybrid nanoparticles mitigate acute graft-versus-host disease and sustain graft-versus-leukemia activity

Glucocorticoids (GCs) are widely used to treat acute graft-versus-host disease (aGvHD) due to their immunosuppressive activity, but they also reduce the beneficial graft-versus-leukemia (GvL) effect of the allogeneic T cells contained in the graft. Here, we tested whether aGvHD therapy could be improved by delivering GCs with the help of inorganic-organic hybrid nanoparticles (IOH-NPs) that preferentially target myeloid cells. IOH-NPs containing the GC betamethasone (BMP-NPs) efficiently reduced morbidity, mortality, and tissue damage in a totally MHC mismatched mouse model of aGvHD. Therapeutic activity was lost in mice lacking the GC receptor (GR) in myeloid cells, confirming the cell type specificity of our approach. BMP-NPs had no relevant systemic activity but suppressed cytokine and chemokine gene expression locally in the small intestine, which presumably explains their mode of action. Most importantly, BMP-NPs delayed the development of an adoptively transferred B cell lymphoma better than the free drug, although the overall incidence was unaffected. Our findings thus suggest that employing IOH-NPs could diminish the risk of relapse associated with GC therapy of aGvHD patients while still allowing to efficiently ameliorate the disease.

PET Imaging of Liposomal Glucocorticoids using 89Zr-oxine: Theranostic Applications in Inflammatory Arthritis

The encapsulation of Glucocorticoids (GCs) into long-circulating liposomes (LCLs) is a proven strategy to reduce the side effects of glucocorticoids and improve the treatment of inflammatory diseases, such as rheumatoid arthritis (RA). With the aim of supporting the development of GC-loaded LCLs, and potentially predict patient response to therapy clinically, we evaluated a direct PET imaging radiolabelling approach for preformed GC-LCLs in an animal model of human inflammatory arthritis. Methods: A preformed PEGylated liposomal methylprednisolone hemisuccinate (NSSL-MPS) nanomedicine was radiolabelled using [89Zr]Zr(oxinate)4 (89Zr-oxine), characterised and tracked in vivo using PET imaging in a K/BxN serum-transfer arthritis (STA) mouse model of inflammatory arthritis and non-inflamed controls. Histology and joint size measurements were used to confirm inflammation. The biodistribution of 89Zr-NSSL-MPS was compared to that of free 89Zr in the same model. A therapeutic study using NSSL-MPS using the same time points as the PET/CT imaging was carried out. Results: The radiolabelling efficiency of NSSL-MPS with [89Zr]Zr(oxinate)4 was 69 ± 8 %. PET/CT imaging of 89Zr-NSSL-MPS showed high uptake (3.6 ± 1.5 % ID; 17.4 ± 9.3 % ID/mL) at inflamed joints, with low activity present in non-inflamed joints (0.5 ± 0.1 % ID; 2.7 ± 1.1 % ID/mL). Importantly, a clear correlation between joint swelling and high 89Zr-NSSL-MPS uptake was observed, which was not observed with free 89Zr. STA mice receiving a therapeutic dose of NSSL-MPS showed a reduction in inflammation at the time points used for the PET/CT imaging compared with the control group. Conclusions: PET imaging was used for the first time to track a liposomal glucocorticoid, showing high uptake at visible and occult inflamed sites and a good correlation with the degree of inflammation. A subsequent therapeutic response matching imaging time points in the same model demonstrated the potential of this radiolabeling method as a theranostic tool for the prediction of therapeutic response - with NSSL-MPS and similar nanomedicines - in the treatment of inflammatory diseases.

Stimuli-responsive Drug Delivery Systems as an Emerging Platform for Treatment of Rheumatoid Arthritis

Rheumatoid Arthritis (RA) is a systemic autoimmune disease accompanied by chronic inflammation. Due to the long-term infiltration in inflammatory sites, joints get steadily deteriorated, eventually resulting in functional incapacitation and disability. Despite the considerable effect, RA sufferers treated with current drug therapeutic efficacy are exposed to severe side effects. Application of Drug Delivery Systems (DDS) has improved these situations while the problem of limited drug exposure remains untackled. Stimuli-responsive DDS that are responsive to a variety of endogenous and exogenous stimuli, such as pH, redox status, and temperature, have emerged as a promising therapeutic strategy to optimize the drug release. Herein, we discussed the therapeutic regimes and serious side effects of current RA therapy, as well as focused on some of the potential stimuliresponsive DDS utilized in RA therapy. Besides, the prospective room in designing DDS for RA treatment has also been discussed.

Intra-articular injection of indomethacin-methotrexate in situ hydrogel for the synergistic treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic systemic autoimmune disease that causes joint swelling and cartilage damage. The objective of the present work was to develop a temperature-sensitive hydrogel (D-NGel) containing nanoparticles (D-NPs), which could simultaneously deliver combination indomethacin and methotrexate. D-NPs were formed by multiple non-covalent interactions between PEI-SS and the carboxyl-containing hydrophobic small molecule drugs IND and MTX, which were then loaded into a temperature-sensitive hydrogel matrix. The T_sol/gel of the temperature-sensitive hydrogel matrix composed of 27% F127 and 10% F68 was 33 °C and the gelation time was less than 15 s. The resultant D-NGel was injected into the articular cavity of collagen-induced arthritis rats and quickly transformed in situ into gels which slowly released drug in the joint fluid for up to 72 h. The D-NGel effectively reduced joint swelling, bone erosion and expression of inflammatory cytokines in the ankle fluid and knee joint fluid. In addition, liver and kidney function tests and histopathological examination indicated there was a good biological safety for D-NGel. In conclusion, this work has demonstrated the great potential of the D-NGel for sustained co-delivery of IND and MTX for the synergistic treatment of rheumatoid arthritis, treating both the symptoms and the root causes of rheumatoid arthritis.