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

Stimuli-sensitive polymer prodrug nanocarriers by reversible-deactivation radical polymerization

Polymer prodrugs are based on the covalent linkage of therapeutic molecules to a polymer structure which avoids the problems and limitations commonly encountered with traditional drug-loaded nanocarriers in which drugs are just physically entrapped (e.g., burst release, poor drug loadings). In the past few years, reversible-deactivation radical polymerization (RDRP) techniques have been extensively used to design tailor-made polymer prodrug nanocarriers. This synthesis strategy has received a lot of attention due to the possibility of fine tuning their structural parameters (e.g., polymer nature and macromolecular characteristics, linker nature, physico-chemical properties, functionalization, etc.), to achieve optimized drug delivery and therapeutic efficacy. In particular, adjusting the nature of the drug-polymer linker has enabled the easy synthesis of stimuli-responsive polymer prodrugs for efficient spatiotemporal drug release. In this context, this review article will give an overview of the different stimuli-sensitive polymer prodrug structures designed by RDRP techniques, with a strong focus on the synthesis strategies, the macromolecular architectures and in particular the drug-polymer linker, which governs the drug release kinetics and eventually the therapeutic effect. Their biological evaluations will also be discussed.

Self-Assembled Multilayer-Modified Needles Simulate Acupuncture and Diclofenac Sodium Delivery for Rheumatoid Arthritis

A novel therapeutic approach combining acupuncture and diclofenac sodium (DS) administration was established for the potential treatment for rheumatoid arthritis (RA). DS is a commonly used anti-inflammatory and analgesic drug but has short duration and adverse effects. Acupoints are critical linkages in the meridian system and are potential candidates for drug delivery. Herein, we fabricated a DS-loaded multilayer-modified acupuncture needle (DS-MMAN) and investigated its capacity for inhibiting RA. This DS-MMAN possesses sustained release properties and in vitro anti-inflammatory effects. Experimental results showed that the DS-MMAN with microdoses can enhance analgesia and efficiently relieve joint swelling compared to the oral or intra-articular administration of DS with gram-level doses. Moreover, the combination of acupoint and DS exerts a synergistic improvement in inflammation and joint damage. Cytokine and T cell analyses in the serum indicated that the application of DS-MMAN suppressed the levels of pro-inflammatory factors and increased the levels of anti-inflammatory factors. Furthermore, the acupoint administration via DS-MMAN could decrease the accumulation of DS in the liver and kidneys, which may express better therapeutic efficiency and low toxicity. The present study demonstrated that the acupuncture needle has the potential to build a bridge between acupuncture and medication, which would be a promising alternative to the combination of traditional and modern medicine.

Dexamethasone nanomedicines with optimized drug release kinetics tailored for treatment of site-specific rheumatic musculoskeletal diseases

The application of polymer-based drug delivery systems is advantageous for improved pharmacokinetics, controlled drug release, and decreased side effects of therapeutics for inflammatory disease. Herein, we describe the synthesis and characterization of linear N-(2-hydroxypropyl)methacrylamide-based polymer conjugates designed for controlled release of the anti-inflammatory drug dexamethasone through pH-sensitive bonds. The tailored release rates were achieved by modifying DEX with four oxo-acids introducing reactive oxo groups to the DEX derivatives. Refinement of reaction conditions yielded four well-defined polymer conjugates with varied release profiles which were more pronounced at the lower pH in cell lysosomes. In vitro evaluations in murine peritoneal macrophages, human synovial fibroblasts, and human peripheral blood mononuclear cells demonstrated that neither drug derivatization nor polymer conjugation affected cytotoxicity or anti-inflammatory properties. Subsequent in vivo tests using a murine arthritis model validated the superior anti-inflammatory efficacy of the prepared DEX-bearing conjugates with lower release rates. These nanomedicines showed much higher therapeutic activity compared to the faster release systems or DEX itself.

Single dose thermoresponsive dexamethasone prodrug completely mitigates joint pain for 15 weeks in a murine model of osteoarthritis

In this study, we aimed to assess the analgesic efficacy of a thermoresponsive polymeric dexamethasone (Dex) prodrug (ProGel-Dex) in a mouse model of osteoarthritis (OA). At 12 weeks post model establishment, the OA mice received a single intra-articular (IA) injection of ProGel-Dex, dose-equivalent Dex, or Saline. Comparing to Saline and Dex controls, ProGel-Dex provided complete and sustained pain relief for >15 weeks according to incapacitance tests. In vivo optical imaging confirmed the continuous presence of ProGel-Dex in joints for 15 weeks post-injection. According to micro-CT analysis, ProGel-Dex treated mice had significantly lower subchondral bone thickness and medial meniscus bone volume than Dex and Saline controls. Except for a transient delay of body weight increase and slightly lower endpoint liver and spleen weights, no other adverse effect was observed after ProGel-Dex treatment. These findings support ProGel-Dex's potential as a potent and safe analgesic candidate for management of OA pain.

Thermoresponsive Polymeric Hydromorphone Prodrug Provides Sustained Local Analgesia without Apparent Adverse Effects

The extensive use of opioids for chronic pain management has contributed significantly to the current opioid epidemic. While many alternative nonopioid analgesics are available, opioids remain the most potent analgesics for moderate to severe pain management. In addition to the implementation of multimodal analgesia, there is a pressing need for the development of more effective and safer opioids. In this study, we developed a thermoresponsive N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-based hydromorphone (HMP) prodrug (ProGel-HMP, HMP content = 16.2 wt %, in base form). The aqueous solution of ProGel-HMP was free-flowing at 4 °C but became a hydrogel when the temperature was raised to ≥37 °C, allowing sustained local retention when administered in vivo. When tested in the destabilization of the medial meniscus (DMM) mouse model of osteoarthritis (OA), ProGel-HMP was retained after intra-articular injection in the OA knee joint for at least 2 weeks postinjection, with low extra-articular distribution. ProGel-HMP was not detected in the central nervous system (CNS). A single dose of ProGel-HMP produced rapid and sustained joint pain resolution for greater than 14 days when compared to saline and dose-equivalent HMP controls, likely mediated through peripheral μ-opioid receptors in the knee joint. Systemic analgesia effect was absent in the DMM mice treated with ProGel-HMP, as evident in the lack of difference in tail flick response between the ProGel-HMP-treated mice and the controls (i.e., Healthy, Saline, and Sham). Repeated dosing of ProGel-HMP did not induce tolerance. Collectively, these data support the further development of ProGel-HMP as a potent, safe, long-acting and nonaddictive analgesic for better clinical pain management.

Context is key: glucocorticoid receptor and corticosteroid therapeutics in outcomes after traumatic brain injury

Traumatic brain injury (TBI) is a global health burden, and survivors suffer functional and psychiatric consequences that can persist long after injury. TBI induces a physiological stress response by activating the hypothalamic-pituitary-adrenal (HPA) axis, but the effects of injury on the stress response become more complex in the long term. Clinical and experimental evidence suggests long lasting dysfunction of the stress response after TBI. Additionally, pre- and post-injury stress both have negative impacts on outcome following TBI. This bidirectional relationship between stress and injury impedes recovery and exacerbates TBI-induced psychiatric and cognitive dysfunction. Previous clinical and experimental studies have explored the use of synthetic glucocorticoids as a therapeutic for stress-related TBI outcomes, but these have yielded mixed results. Furthermore, long-term steroid treatment is associated with multiple negative side effects. There is a pressing need for alternative approaches that improve stress functionality after TBI. Glucocorticoid receptor (GR) has been identified as a fundamental link between stress and immune responses, and preclinical evidence suggests GR plays an important role in microglia-mediated outcomes after TBI and other neuroinflammatory conditions. In this review, we will summarize GR-mediated stress dysfunction after TBI, highlighting the role of microglia. We will discuss recent studies which target microglial GR in the context of stress and injury, and we suggest that cell-specific GR interventions may be a promising strategy for long-term TBI pathophysiology.

Nanotechnology's frontier in combatting infectious and inflammatory diseases: prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases, which continuously pose one of the most serious threats to human health, attributed to factors such as the emergence of new pathogens, increasing drug resistance, changes in living environments and lifestyles, and the aging population. Despite rapid advancements in mechanistic research and drug development for these diseases, current treatments often have limited efficacy and notable side effects, necessitating the development of more effective and targeted anti-inflammatory therapies. In recent years, the rapid development of nanotechnology has provided crucial technological support for the prevention, treatment, and detection of inflammation-associated diseases. Various types of nanoparticles (NPs) play significant roles, serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability. NPs can also directly combat pathogens and inflammation. In addition, nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases. This review categorizes and characterizes different types of NPs, summarizes their applications in the prevention, treatment, and detection of infectious and inflammatory diseases. It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects. In conclusion, nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.

Cysteine-modified PEGylated nanoparticles for targeted delivery of methylprednisolone to pancreatitis

The timely suppression of inflammatory mediator production and mitigation of their effects on pancreatic acinar cells are crucial for the successful management of acute pancreatitis. To achieve effective treatment, we present a novel approach utilizing cysteine modified PEG nanoparticles for both precise accumulation at the site of pancreatitis and specific targeting of acinar cells. Methylprednisolone, a nonsteroidal anti-inflammatory drug, was tailored to enhance its circulation time in the bloodstream, preferentially accumulate in the pancreas and enhance cell uptake efficiency by acinar cells through specifically targeting L-Type amino acid transporter 1. The nanosystem significantly downregulated pro-inflammatory cytokines in plasma, resulting in the effective suppression of inflammation in acinar cells within an acute pancreatitis rat model. The utilization of the dual targeted therapy strategy holds considerable potential for the clinical management of pancreatitis.

Prodrug-based nanomedicines for rheumatoid arthritis

Most antirheumatic drugs with high toxicity exhibit a narrow therapeutic window due to their nonspecific distribution in the body, leading to undesirable side effects and reduced patient compliance. To in response to these challenges, prodrug-based nanoparticulate drug delivery systems (PNDDS), which combines prodrug strategy and nanotechnology into a single system, resulting their many advantages, including stability for prodrug structure, the higher drug loading capacity of the system, improving the target activity and bioavailability, and reducing their untoward effects. PNDDS have gained attention as a method for relieving arthralgia syndrome of rheumatoid arthritis in recent years. This article systematically reviews prodrug-based nanocarriers for rheumatism treatment, including Nano systems based on prodrug-encapsulated nanomedicines and conjugate-based nanomedicines. It provides a new direction for the clinical treatment of rheumatoid arthritis.

Synthetic peptides of IL-1Ra and HSP70 have anti-inflammatory activity on human primary monocytes and macrophages: Potential treatments for inflammatory diseases

Chronic inflammatory diseases are increasing in developed societies, thus new anti-inflammatory approaches are needed in the clinic. Synthetic peptides complexes can be designed to mimic the activity of anti-inflammatory mediators, in order to alleviate inflammation. Here, we evaluated the anti-inflammatory efficacy of tethered peptides mimicking the interleukin-1 receptor antagonist (IL-1Ra) and the heat-shock protein 70 (HSP70). We tested their biocompatibility and anti-inflammatory activity in vitro in primary human monocytes and differentiated macrophages activated with two different stimuli: the TLR agonists (LPS + IFN-γ) or Pam3CSK4. Our results demonstrate that IL-1Ra and HSP70 synthetic peptides present a satisfactory biocompatible profile and significantly inhibit the secretion of several pro-inflammatory cytokines (IL-6, IL-8, IL-1β and TNFα). We further confirmed their anti-inflammatory activity when peptides were coated on a biocompatible material commonly employed in surgical implants. Overall, our findings support the potential use of IL-1Ra and HSP70 synthetic peptides for the treatment of inflammatory conditions.

Therapeutic activity and biodistribution of a nano-sized polymer-dexamethasone conjugate intended for the targeted treatment of rheumatoid arthritis

Rheumatoid arthritis is a chronic inflammatory autoimmune disease caused by alteration of the immune system. Current therapies have several limitations and the use of nanomedicines represents a promising strategy to overcome them. By employing a mouse model of adjuvant induced arthritis, we aimed to evaluate the biodistribution and therapeutic effects of glucocorticoid dexamethasone conjugated to a nanocarrier based on biocompatible N-(2-hydroxypropyl) methacrylamide copolymers. We observed an increased accumulation of dexamethasone polymer nanomedicines in the arthritic mouse paw using non-invasive fluorescent in vivo imaging and confirmed it by the analysis of tissue homogenates. The dexamethasone conjugate exhibited a dose-dependent healing effect on arthritis and an improved therapeutic outcome compared to free dexamethasone. Particularly, significant reduction of accumulation of RA mediator RANKL was observed. Overall, our data suggest that the conjugation of dexamethasone to a polymer nanocarrier by means of stimuli-sensitive spacer is suitable strategy for improving rheumatoid arthritis therapy.

A comprehensive review of advanced drug delivery systems for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA), a chronic autoimmune disease, is characterized by articular pain and swelling, synovial hyperplasia, and cartilage and bone destruction. Conventional treatment strategies for RA involve the use of anti-rheumatic drugs, which warrant high-dose, frequent, and long-term administration, resulting in serious adverse effects and poor patient compliance. To overcome these problems and improve clinical efficacy, drug delivery systems (DDS) have been designed for RA treatment. These systems have shown success in animal models of RA. In this review, representative DDS that target RA through passive or active effects on inflammatory cells are discussed and highlighted using examples. In particular, DDS allowing controlled and targeted drug release based on a variety of stimuli, intra-articular DDS, and transdermal DDS for RA treatment are described. Thus, this review provides an improved understanding of these DDS and paves the way for the development of novel DDS for efficient RA treatment.

Macromolecular Dexamethasone Prodrug Ameliorates Neuroinflammation and Prevents Bone Loss Associated with Traumatic Brain Injury

Traumatic brain injury (TBI) is one of the leading causes of death and disability among children and young adults in the United States. In this manuscript, we assessed the utility of an N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-based dexamethasone (Dex) prodrug (P-Dex) in the treatment of TBI. Using a controlled cortical impact TBI mouse model, P-Dex was found to passively target and sustain at the traumatic/inflammatory brain tissue for over 14 days after systemic administration. The histological evidence supports P-Dex's therapeutic potential in ameliorating neuroinflammation and mitigating neurodegeneration. Behaviorally, the P-Dex-treated animals showed statistically significant improvement in balance recovery. A trend of neurological severity score improvement at the early time point post-TBI was also noted but did not achieve statistical significance. While probing the potential glucocorticoid side effects that may associate with P-Dex treatment, we discovered that the TBI mice develop osteopenia. Interestingly, the P-Dex-treated TBI mice demonstrated higher bone mineral density and better bone microarchitecture parameters when compared to free Dex and the saline control, revealing the osteoprotective effect of P-Dex in addition to its neuronal protection benefits post-TBI.

Inflammation-targeted sialic acid-dexamethasone conjugates for reducing the side effects of glucocorticoids

As a potent glucocorticoid drug (GCs), Dexamethasone (Dex) is widely used clinically for the treatment of inflammatory diseases. However, such side effects as Cushing's syndrome and osteoporosis caused severe distress to patients. Herein, a sialic acid (SA)-modified dexamethasone conjugate (Dex-SA) was synthesized successfully to reduce side effects by targeting inflammatory diseases. The solubility of Dex-SA in water reached 58 times that of Dex, which meets the need for intravenous administration. The excellent stability of Dex-SA in plasma also laid a foundation for targeting disease sites. According to cellular uptake and biodistribution experiments, Dex-SA was more readily to be taken up by inflammatory cells and accumulated in diseased kidneys compared to Dex, which is attributed to the interaction of SA with E-selectin receptors overexpressed on the surface of inflammatory vascular endothelial cells. Besides, the pharmacodynamics studies of acute kidney injury showed that Dex-SA and Dex could produce comparable therapeutic effects. More importantly, Dex-SA was found to significantly reduce Dex-related side effects, as measured by blood glucose, red blood cells and immune cells, etc. At last, molecular docking results were obtained to confirm that Dex-SA could enter the cells by binding specifically with the E-selectin receptor, for combination with glucocorticoid receptors in the cytoplasm to exert pharmacological effects. Our study is expected to contribute a new strategy to the safe and effective targeting treatment of inflammatory diseases.

Activatable Near-Infrared Fluorescent Organic Nanoprobe for Hypochlorous Acid Detection in the Early Diagnosis of Rheumatoid Arthritis

Early diagnosis of rheumatoid arthritis (RA) is crucial to prevent deterioration and improve the prognosis of disease outcome. However, current clinical diagnostic methods are unable to achieve accurate and early detection of RA. In this work, we designed an activatable organic nanoprobe (ONP-CySe) capable of specific and real-time imaging of ClO^- in early RA. ONP-CySe comprises a near-infrared fluorescent selenomorpholine-caged cyanine dye as the sensing component and an amphiphilic triblock copolymer triphenyl phosphine derivative for mitochondria targeting. Our results showed that ONP-CySe successfully detected elevated levels of ClO^- in the mitochondria of macrophages with high selectivity, low limit of detection (31.5 nM), excellent photostability, and good biocompatibility. Furthermore, ONP-CySe can also be used to monitor anti-inflammatory responses and efficacies of RA therapeutics, such as selenocysteine and methotrexate, in BALB/c mouse models. Therefore, our research proposes a universal molecular design strategy for the detection of ClO^-, which holds potential for early diagnosis and drug screening for RA.

Advancement of nanomedicines in chronic inflammatory disorders

Chronic diseases, as stated by the WHO, are a threat to human health which kill 3 out of every 5 people worldwide. Therapeutics for such illnesses can be developed using traditional medicine. However, it is not an easy path from natural products to Western pharmacological and pharmaceutical methods. For several decades, chronic inflammatory disorders, especially in Westernized countries, have increased incidence and prevalence. Several NSAIDs are used to decrease inflammation and pain; however, there are numerous negative consequences of these anti-inflammatory medications, whereas plant-based natural products have anti-inflammatory therapeutic benefits that have little or no adverse effects. Nanoparticles are a new type of drug delivery device that may be designed to provide excellent target selectivity for certain cells and tissues while also having a high drug loading capacity, resulting in better pharmacokinetics, pharmacodynamics (PKPD), and therapeutic bioavailability. The size and polarity of phytochemical compounds make it hard to pass the blood–brain barrier (BBB), blood-vessel endothelial lining, gastrointestinal tract and mucosa. In addition, the gastrointestinal system is enzymatically destroyed. Therefore, nanoparticles or nanocrystals might also be used for encapsulation or conjugation of these chemicals as a method to improve their organic effectiveness through their gastrointestinal stability, absorption rate and dispersion. The therapy of numerous inflammatory illnesses, including arthritis, gastritis, Nephritis, Hepatitis (Type A, B &C), ulcerative colitis, Alzheimer's disease, atherosclerosis, allergic responses (asthma, eczema) or autoimmune disorders, is characterised by nanoparticles. This review paper provides information on the numerous nanosystem described with their probable mechanism to treat chronic inflammatory diseases.

The mode of dexamethasone decoration influences avidin-nucleic-acid-nano-assembly organ biodistribution and in vivo drug persistence

Avidin-Nucleic-Acid-NanoASsemblies (ANANAS) possess natural tropism for the liver and, when loaded with dexamethasone, reduce clinical progression in an autoimmune hepatitis murine model. Here, we investigated the linker chemistry (hydrazide-hydrazone, Hz-Hz, or carbamate hydrazide-hydrazone, Cb-Hz bond) and length (long, 5 kDa PEG, or short, 5-6 carbons) in biotin-dexamethasone conjugates used for nanoparticle decoration through in vitro and in vivo studies. All four newly synthesized conjugates released the drug at acidic pH only. In vitro, the Hz-Hz and the PEG derivatives were less stable than the Cb-Hz and the short chain ones, respectively. Once injected in healthy mice, dexamethasone location in the PEGylated ANANAS outer layer favors liver penetration and resident macrophages uptake, while drug Hz-Hz, but not Cb-Hz, short spacing prolongs drug availability. In conclusion, the tight modulation of ANANAS decoration can significantly influence the host interaction, paving the way for the development of steroid nanoformulations suitable for different pharmacokinetic profiles.

Acupoint nanocomposite hydrogel for simulation of acupuncture and targeted delivery of triptolide against rheumatoid arthritis

Background

Attenuating inflammatory response and relieving pain are two therapeutic therapeutical goals for rheumatoid arthritis (RA). Anti-inflammatory and analgesic drugs are often associated with many adverse effects due to nonspecific distribution. New drug delivery systems with practical targeting ability and other complementary strategies urgently need to be explored. To achieve this goal, an acupoint drug delivery system that can target deliver anti-inflammatory drugs and simulate acupuncture in relieving pain was constructed, which can co-deliver triptolide (TP) and 2-chloro-N (6)-cyclopentyl adenosine (CCPA).

Results

We have successfully demonstrated that acupoint nanocomposite hydrogel composed of TP-Human serum album nanoparticles (TP@HSA NPs) and CCPA could effectively treat RA. The result shows that CCPA-Gel can enhance analgesic effects specifically at the acupoint, while the mechanical and thermal pain threshold was 4.9 and 1.6 times compared with non-acupoint, respectively, and the nanocomposite gel further enhanced. Otherwise, the combination of acupoint and nanocomposite hydrogel exerted synergetic improvement of inflammation, bone erosion, and reduction of systemic toxicity. Furthermore, it could regulate inflammatory factors and restore the balance of Th17/Treg cells, which provided a novel and effective treatment strategy for RA. Interestingly, acupoint administration could improve the accumulation of the designed nanomedicine in arthritic paws (13.5% higher than those in non-acupoint at 48 h), which may explain the better therapeutic efficiency and low toxicity.

Conclusion

This novel therapeutic approach-acupoint nanocomposite hydrogel, builds a bridge between acupuncture and drugs which sheds light on the combination of traditional and modern medicine.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-01157-z.

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.

Development and evaluation of a novel biodegradable implants with excellent inflammatory response suppression effect by hot-melt extrusion

PURPOSE

Dexamethasone (Dex) is a widely used drug for the treatment of inflammatory and autoimmune conditions, however, long-term systemic use of Dex is associated with serious adverse effects. The objective of the present study was to develop an implantable device to avoid side effects and realize a controlled release of Dex at the implant site.

METHODS

Hydrophobic Dex was incorporated into biodegradable polyesters derived from PCL and Pluronic® L64 (PCL-Pluronic L64-PCL, PCLC) by hot-melt extrusion (HME) method to prepare Dex/PCLC implantable devices. Drug loading and encapsulation efficiency, a series of physicochemical properties, and in vivo features of the implants were studied.

RESULTS

The maximum value of the drug loading and encapsulation efficiency for the Dex/PCLC implants were up to 47% and 94%, respectively. Incorporation of Dex resulted in accelerated crystallization of PCLC, decreased the wettability, increased contact angles and viscosity, and accelerated Dex release rate and degradation rate from the implants in vivo. Moreover, Dex/PCLC implants showed excellent biocompatibility. Furthermore, the inflammatory response to the Dex/PCLC implants was less severe than that to the positive control group.

CONCLUSION

All these results suggested that Dex/PCLC implants might be a safe and controlled local drug delivery system with excellent inflammatory response suppression effect.

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.

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.