Folate-Targeted Dendrimers Selectively Accumulate at Sites of Inflammation in Mouse Models of Ulcerative Colitis and Atherosclerosis

Gut microbiota and blood biomarkers in IBD-Related arthritis: insights from mendelian randomization

With the ongoing rise in the incidence of inflammatory bowel disease (IBD), its extraintestinal manifestations have garnered significant attention. IBD-related arthritis is notable for its insidious onset and unpredictability, presenting considerable challenges for clinical diagnosis and management. Factors such as gut microbiota, plasma proteins, inflammatory proteins, and biomarkers found in blood and urine may be closely associated with IBD-related arthritis. However, the mechanisms by which these factors influence this condition remain poorly understood and require urgent investigation. We employed the method of linkage disequilibrium and the two-sample Mendelian randomization (MR) approach, utilizing single nucleotide polymorphisms (SNPs) identified from large-scale genome-wide association studies as instrumental variables. In this scientifically rigorous manner, we explored the potential causal relationship between gut microbiota, plasma proteins, inflammatory proteins, and blood and urine biomarkers in relation to arthritis resulting from inflammatory bowel disease (IBD). This method aids in elucidating the potential roles of these biomarkers in the development of arthritis following IBD, while minimizing the confounding factors and reverse causality commonly encountered in observational studies. To further verify and strengthen our findings, we conducted subsequent sensitivity analyses. These analyses will evaluate the strength of the association between SNPs and the studied biomarkers, as well as post-IBD arthritis, while accounting for variations in SNP distribution among populations and other potential genetic influencing factors. Through these rigorous analytical steps, our objective is to enhance the robustness and credibility of the research findings and provide more reliable scientific evidence regarding the pathogenesis of post-IBD arthritis. MR analysis provides evidence for the association between genetically predicted gut microbiota, plasma proteins, inflammatory proteins, and blood and urine biomarkers with the risk of IBD-related arthritis. This analysis investigates the characteristics of the associations between specific gut microbiota, plasma proteins, inflammatory proteins, and blood and urine biomarkers in relation to IBD-related arthritis. Among the plasma proteins, pterin-4-alpha-carbinolamine dehydratase, aldo-keto reductase family 1 member C4, cathepsin L2, angiostatin, hepatocyte growth factor-like protein, hepatitis A virus cellular receptor 2, protein O-linked mannose beta-1,4-N-acetylglucosaminyltransferase 2, epididymal-specific alpha-mannosidase, and platelet-derived growth factor receptor-like protein are associated with Crohn's disease-related arthritis. In contrast, agrin, methylenetetrahydrofolate synthetase domain-containing protein, neurotrophin-3 (NT-3) growth factor receptor, and neuropilin-1 are associated with ulcerative colitis-related arthritis. Furthermore, regarding gut bacterial pathway abundance, adenosylcobalamin, N-acetylglucosamine, N-acetylmannosamine, and N-acetylneuraminic acid degradation, as well as glycolysis metabolism and degradation pathways, are associated with Crohn's disease-related arthritis. Meanwhile, gut bacterial pathway abundance (pentose phosphate pathway) and gut microbiota abundance (Bacteroidetes, Bacteroidia, Bacteroidales, Porphyromonadaceae, Faecalibacterium, Eubacterium eligens) are linked to ulcerative colitis-related arthritis. Notably, we did not identify any connections between inflammatory protein factors, blood and urine biomarkers, and IBD-related arthritis. Lastly, in the reverse MR study, the insufficient number of SNPs available for analysis precluded the detection of a reverse causal relationship. This study employs the MR method to elucidate the potential causal relationships among gut microbiota, plasma proteins, inflammatory proteins, and blood and urine biomarkers in relation to the occurrence and progression of IBD-related arthritis. This research offers a novel perspective for a deeper understanding of the pathogenesis of IBD-related arthritis and highlights future directions for the diagnosis and treatment strategies of this condition.

Bioinspired and biomimetic strategies for inflammatory bowel disease therapy

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease with high morbidity and an increased risk of cancer or death, resulting in a heavy societal medical burden. While current treatment modalities have been successful in achieving long-term remission and reducing the risk of complications, IBD remains incurable. Nanomedicine has the potential to address the high toxic side effects and low efficacy in IBD treatment. However, synthesized nanomedicines typically exhibit some degree of immune rejection, off-target effects, and a poor ability to cross biological barriers, limiting the development of clinical applications. The emergence of bionic materials and bionic technologies has reshaped the landscape in novel pharmaceutical fields. Biomimetic drug-delivery systems can effectively improve biocompatibility and reduce immunogenicity. Some bioinspired strategies can mimic specific components, targets or immune mechanisms in pathological processes to produce targeting effects for precise disease control. This article highlights recent research on bioinspired and biomimetic strategies for the treatment of IBD and discusses the challenges and future directions in the field to advance the treatment of IBD.

Folate-conjugated organic CO prodrugs: Synthesis and CO release kinetic studies

Carbon monoxide (CO) is an endogenous produced molecule and has shown efficacy in animal models of inflammation, organ injury, colitis and cancer metastasis. Because of its gaseous nature, there is a need for developing efficient CO delivery approaches, especially those capable of targeted delivery. In this study, we aim to take advantage of a previously reported approach of enrichment-triggered prodrug activation to achieve targeted delivery by targeting the folate receptor. The general idea is to exploit folate receptor-mediated enrichment as a way to accelerate a biomolecular Diels-Alder reaction for prodrug activation. In doing so, we first need to find ways to tune the reaction kinetics in order to ensure minimal rection without enrichment and optimal activation upon enrichment. In this feasibility study, we synthesized two diene-dienophile pairs and studied their reaction kinetics and ability to target the folate receptor. We found that folate conjugation significantly affects the reaction kinetics of the original diene-dienophile pairs. Such information will be very useful in future designs of similar targeted approaches of CO delivery.

Cationic nanoparticles-based approaches for immune tolerance induction in vivo

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

In Vitro Targeted Delivery of Simvastatin and Niacin to Macrophages Using Mannan-Grafted Magnetite Nanoparticles

Atherosclerosis, a leading cause of mortality worldwide, involves various subsets of macrophages that contribute to its initiation and progression. Current treatment approaches focus on systemic, long-term administration of cholesterol-lowering antioxidants such as statins and certain vitamins, which unfortunately come with prolonged side effects. To overcome these drawbacks, a mannose-containing magnetic nanoparticle (NP) is introduced as a drug delivery system to specifically target macrophages in vitro using simvastatin or niacin and a combinational therapy approach that reduces local inflammation while avoiding unwanted side effects. The synthesized NPs exhibited superparamagnetic behavior, neutrally charged thin coating with a hydrodynamic size of 77.23 ± 13.90 nm, and a metallic core ranging from 15 to 25 nm. Efficient loading of niacin (87.21%) and simvastatin (75.36%) on the NPs was achieved at respective weights of 20.13 and 5.03 (w/w). In the presence of a mannan hydrolyzing enzyme, 79.51% of simvastatin and 67.23% of niacin were released from the NPs within 90 min, with a leakage rate below 19.22%. Additionally, the coated NPs showed no destructive effect on J774A macrophages up to a concentration of 200 μg/mL. Simvastatin-loaded NPs exhibited a minimal increase in IL-6 expression. The low dosage of simvastatin decreased both IL-6 and ARG1 expressions, while niacin and combined simvastatin/niacin increased the level of ARG1 expression significantly. Toxicity evaluations on human umbilical vein endothelial cells and murine liver cells revealed that free simvastatin administration caused significant toxicity, whereas the encapsulated forms of simvastatin, niacin, and a combination of simvastatin/niacin at equivalent concentrations exhibited no significant toxicity. Hence, the controlled release of the encapsulated form of simvastatin and niacin resulted in the effective modulation of macrophage polarization. The delivery system showed suitability for targeting macrophages to atherosclerotic plaque.

Advancements in Macrophage-Targeted Drug Delivery for Effective Disease Management

Macrophages play a crucial role in tissue homeostasis and the innate immune system. They perform essential functions such as presenting antigens, regulating cytokines, and responding to inflammation. However, in diseases like cancer, cardiovascular disorders, and autoimmune conditions, macrophages undergo aberrant polarization, which disrupts tissue regulation and impairs their normal behavior. To address these challenges, there has been growing interest in developing customized targeted drug delivery systems specifically designed for macrophage-related functions in different anatomical locations. Nanomedicine, utilizing nanoscale drug systems, offers numerous advantages including improved stability, enhanced pharmacokinetics, controlled release kinetics, and precise temporal drug delivery. These advantages hold significant promise in achieving heightened therapeutic efficacy, specificity, and reduced side effects in drug delivery and treatment approaches. This review aims to explore the roles of macrophages in major diseases and present an overview of current strategies employed in targeted drug delivery to macrophages. Additionally, this article critically evaluates the design of macrophage-targeted delivery systems, highlighting limitations and discussing prospects in this rapidly evolving field. By assessing the strengths and weaknesses of existing approaches, we can identify areas for improvement and refinement in macrophage-targeted drug delivery.

A Polarity-Sensitive Far-Red Fluorescent Probe for Glucose Sensing through Skin

The field of glucose biosensors for diabetes management has been of great interest over the past 60 years. Continuous glucose monitoring (CGM) is important to continuously track the glucose level to provide better management of the disease. Concanavalin A (ConA) can reversibly bind to glucose and mannose molecules and form a glucose biosensor via competitive binding. Here, we developed a glucose biosensor using ConA and a fluorescent probe, which generated a fluorescent intensity change based on solvatochromism, the reversible change in the emission spectrum dependent on the polarity of the solvent. The direction in which the wavelength shifts as the solvent polarity increases can be defined as positive (red-shift), negative (blue-shift), or a combination of the two, referred to as reverse. To translate this biosensor to a subcutaneously implanted format, Cyanine 5.5 (Cy5.5)-labeled small mannose molecules were used, which allows for the far-red excitation wavelength range to increase the skin penetration depth of the light source and returned emission. Three Cy5.5-labeled small mannose molecules were synthesized and compared when used as the competing ligand in the competitive binding biosensor. We explored the polarity-sensitive nature of the competing ligands and examined the biosensor's glucose response. Cy5.5-mannotetraose performed best as a biosensor, allowing for the detection of glucose from 25 to 400 mg/dL. Thus, this assay is responsive to glucose within the physiologic range when its concentration is increased to levels needed for an implantable design. The biosensor response is not statistically different when placed under different skin pigmentations when comparing the percent increase in fluorescence intensity. This shows the ability of the biosensor to produce a repeatable signal across the physiologic range for subcutaneous glucose monitoring under various skin tones.

The Role of Macrophages in Atherosclerosis: Pathophysiologic Mechanisms and Treatment Considerations

Atherosclerotic diseases are a leading cause of morbidity and mortality worldwide, despite the recent diagnostic and therapeutic advances. A thorough understanding of the pathophysiologic mechanisms is thus essential to improve the care of affected individuals. Macrophages are crucial mediators of the atherosclerotic cascade, but their role has not been fully elucidated. The two main subtypes, tissue-resident and monocyte-derived macrophages, have distinct functions that contribute to atherosclerosis development or regression. Since polarization of macrophages to an M2 phenotype and induction of macrophage autophagy have been demonstrated to be atheroprotective, targeting these pathways could represent an appealing approach. Interestingly, macrophage receptors could act as drug targets, as seen in recent experimental studies. Last but not least, macrophage-membrane-coated carriers have been investigated with encouraging results.

Orally Administrated Olsalazine-Loaded Multilayer Pectin/Chitosan/Alginate Composite Microspheres for Ulcerative Colitis Treatment

The pathogenesis of inflammatory bowel diseases (IBDs) including ulcerative colitis (UC) and Crohn's disease is extremely cloudy. Maintaining the level of remission lesions in colitis is the default treatment attitude at present. Epithelial barrier restoration is considered as the same important strategy as colonic targeted drug delivery in UC treatment. In this paper, we developed a multilayer natural polysaccharide microsphere (pectin/chitosan/alginate) with pH and enzyme dual sensitivity to reduce the loss of medication in the upper digestive tract and preferentially adhere to exposed epithelial cells in colonic tissues by electrostatic forces for efficiently targeted UC treatment. Olsalazine as an inflammatory drug was efficiently loaded in the chitosan layer and realized a colonic pH-responsive drug release. Furthermore, the multilayer microspheres exhibited excellent capability in suppressing harmful flora and a bio-adhesion effect to extend the duration of local medicine. In the in vivo anti-colitis study, the downregulated levels of pro-inflammatory factors and the increase of tight junction protein indicated the excellent anti-inflammation effect of the olsalazine-loaded microspheres. In summary, these results showed that the multilayer natural polysaccharide microspheres could be a powerful candidate in the targeted drug delivery system for UC therapy.

Harnessing polymer-derived drug delivery systems for combating inflammatory bowel disease

The inflammatory bowel disease (IBD) is incurable, chronic, recrudescent disorders in the inflamed intestines. Current clinic treatments are challenged by systemic exposure-induced severe side effects, inefficiency after long-term treatment, and increased risks of infection and malignancy due to immunosuppression. Fortunately, naturally bioactive small molecules, reactive oxygen species scavengers (or antioxidants), and gut microbiota modulators have emerged as promising candidates for the IBD treatment. Polymeric systems have been engineered as a delivery vehicle to improve the bioavailability and efficacy of these therapeutic agents through targeting the mucosa and enhancing intestinal adhesion and retention, and reduce their systemic toxicity. Herein we survey polymer-derived drug delivery systems for combating the IBD. Advanced delivery technologies, therapeutic intervention strategies, and the principles for the construction of hierarchical, mucosa-targeting, and bioresponsive systems are elaborated, providing insights into design and development of from-bench-to-bedside drug delivery polymeric systems for the IBD treatment.

Tuning macrophages for atherosclerosis treatment

Atherosclerosis is a chronic inflammatory vascular disease and a leading cause of death worldwide. Macrophages play an important role in inflammatory responses, cell-cell communications, plaque growth and plaque rupture in atherosclerotic lesions. Here, we review the sources, functions and complex phenotypes of macrophages in the progression of atherosclerosis, and discuss the recent approaches in modulating macrophage phenotype and autophagy for atherosclerosis treatment. We then focus on the drug delivery strategies that target macrophages or use macrophage membrane-coated particles to deliver therapeutics to the lesion sites. These biomaterial-based approaches that target, modulate or engineer macrophages have broad applications for disease therapies and tissue regeneration.

Targeting pathophysiological changes using biomaterials-based drug delivery systems: A key to managing inflammatory bowel disease

Inflammatory bowel disease (IBD) is a gastrointestinal disorder, affecting about several million people worldwide. Current treatments fail to adequately control some clinical symptoms in IBD patients, which can adversely impact the patient's quality of life. Hence, the development of new treatments for IBD is needed. Due to their unique properties such as biocompatibility and sustained release of a drug, biomaterials-based drug delivery systems can be regarded as promising candidates for IBD treatment. It is noteworthy that considering the pathophysiological changes occurred in the gastrointestinal tract of IBD patients, especially changes in pH, surface charge, the concentration of reactive oxygen species, and the expression of some biomolecules at the inflamed colon, can help in the rational design of biomaterials-based drug delivery systems for efficient management of IBD. Here, we discuss about targeting these pathophysiological changes using biomaterials-based drug delivery systems, which can provide important clues to establish a strategic roadmap for future studies.

Pathological features-based targeted delivery strategies in IBD therapy: A mini review

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is characterized by a complex and dysfunctional immune response. Currently, IBD is incurable, and patients with IBD often need to take drugs for life. However, as the traditional systemic treatment strategies for IBD do not target the site of inflammation, only limited efficacy can be obtained from them. Moreover, the possibility of serious side effects stemming from the systemic administration or redistribution of drugs in the body is high when conventional drug formulations are used. Therefore, a targeted drug-delivery system for IBD should be considered. Based on the pathological features related to IBD, the new targeted drug-delivery strategy can directly transfer the drug to the inflammatory site, thus enhancing the accumulation of the drugs and reducing side effects. This article reviews the pathological features of IBD and the application of the IBD-targeted delivery system based on different pathological features, and discusses the challenges and new prospects in this field.

Dendrimers as Antiamyloid Agents

Dendrimer-protein conjugates have significant prospects for biological applications. The complexation changes the biophysical behavior of both proteins and dendrimers. The dendrimers could influence the secondary structure of proteins, zeta-potential, distribution of charged regions on the surface, the protein-protein interactions, etc. These changes offer significant possibilities for the application of these features in nanotheranostics and biomedicine. Based on the dendrimer-protein interactions, several therapeutic applications of dendrimers have emerged. Thus, the formation of stable complexes retains the disordered proteins on the aggregation, which is especially important in neurodegenerative diseases. To clarify the origin of these properties and assess the efficiency of action, the mechanism of protein-dendrimer interaction and the nature and driving force of binding are considered in this review. The review outlines the antiamyloid activity of dendrimers and discusses the effect of dendrimer structures and external factors on their antiamyloid properties.

Immune cell targeting nanoparticles: a review

Immune cells are attractive targets for therapy as they are direct participants in a variety of diseases. Delivering a therapeutic agent only to cells that act on a disease by distinguishing them from other cells has the advantage of concentrating the therapeutic effect and lowering systemic side effects. Distinguishing each immune cell from other immune cells to deliver substances, including drugs and genes, can be achieved using nanotechnology. And also nanoparticles can ensure in vivo stability and sustained drug release. In addition, there is an ease of surface modification, which is an important characteristic that can be utilized in targeted drug delivery systems. This characteristic allows us to utilize various properties that are specifically expressed in each immune cell. A number of studies have delivered various substances specifically to immune cells through surface engineering with active target ligands that can target each immune cell and enzyme-responsive coating, and demonstrated high therapeutic effects compared to conventional treatments. Progress in research on target delivery has been suggested to be a breakthrough for the treatments of various diseases, including cancer treatment.

Preparation of Oral Core-Shell Zein Nanoparticles to Improve the Bioavailability of Glycyrrhizic Acid for the Treatment of Ulcerative Colitis

In this study, oral colon-targeted adhesion core-shell nanoparticles were designed by applying FA-Zein as the core and using pectin as the shell to enhance the low bioavailability exhibited by glycyrrhizic acid (GA) and the anti-inflammatory effect in specific parts of the intestine. As indicated by the results, the nanoparticles (NPs) remained stable in the stomach and small intestine, while pectins began to degrade and release GA in considerable amounts in the colon with the abundant flora. Subsequently, folate-acid targeting was further assessed with Raw 264.7 and NCM 460 cells. Lastly, NPs were reported to exhibit high adhesion on the colon by using the DSS-induced ulcerative colitis mouse model. Moreover, as indicated by in vitro and in vivo studies, nanoparticles could decrease the levels of MPO and TNF-α by reducing macrophages and neutrophils. In brief, this study provides an ideal loaded natural anti-inflammatory drug delivery system to treat ulcerative colitis.

Antioxidant Enzymes Sequestered within Lipid-Polymer Hybrid Nanoparticles for the Local Treatment of Inflammatory Bowel Disease

The local treatment of inflammatory bowel disease (IBD) by enzyme therapeutics is challenging owing to hostile environments in the gastrointestinal tract, leading to the hydrolysis and enzymatic degradation of labile proteins. In this study, safe and efficient local drug delivery systems were developed by antioxidant superoxide dismutase (SOD) sequestered within lipid-polymer hybrid nanoparticles through sequential self-assembly processes. Interestingly, we found that the sequestered SOD exhibited long-term enzymatic stability and comparable biological activity to the enzymes in the native form, probably owing to particle encapsulation providing a physical barrier to prevent the enzymolysis of proteins. We demonstrated that nanoparticle-based local drug delivery systems showed excellent mucus-penetrating ability and inflammation-targeting properties, owing to the particle surface with a poly(ethylene glycol) (PEG) coating and folate functionalization, thus improving mucosal retention time and drug delivery efficiency within the colorectal region. Furthermore, SOD-containing lipid-polymer hybrid nanoparticles could effectively mitigate inflammatory responses by regulating the secretion of inflammation-associated cytokines, thus increasing therapeutic outcomes in colitis mice through intrarectal administration. The findings indicated that antioxidant enzymes sequestered within lipid-polymer hybrid nanoparticles might be potential enzyme therapeutics for the local treatment of some inflammatory diseases in the near future.

Oral delivery of natural active small molecules by polymeric nanoparticles for the treatment of inflammatory bowel diseases

The incidence of inflammatory bowel disease (IBD) is rapidly rising throughout the world. Although tremendous efforts have been made, limited therapeutics are available for IBD management. Natural active small molecules (NASMs), which are a gift of nature to humanity, have been widely used in the prevention and alleviation of IBD; they have numerous advantageous features, including excellent biocompatibility, pharmacological activity, and mass production potential. Oral route is the most common and acceptable approach for drug administration, but the clinical application of NASMs in IBD treatment via oral route has been seriously restricted by their inherent limitations such as high hydrophobicity, instability, and poor bioavailability. With the development of nanotechnology, polymeric nanoparticles (NPs) have provided a promising platform that can efficiently encapsulate versatile NASMs, overcome multiple drug delivery barriers, and orally deliver the loaded NASMs to targeted tissues or cells while enhancing their stability and bioavailability. Thus, NPs can enhance the preventive and therapeutic effects of NASMs against IBD. Herein, we summarize the recent knowledge about polymeric matrix-based carriers, targeting ligands for drug delivery, and NASMs. We also discuss the current challenges and future developmental directions.

Receptor-mediated targeted drug delivery systems for treatment of inflammatory bowel disease: Opportunities and emerging strategies

Inflammatory bowel disease (IBD) is a chronic intestinal disease with painful clinical manifestations and high risks of cancerization. With no curative therapy for IBD at present, the development of effective therapeutics is highly advocated. Drug delivery systems have been extensively studied to transmit therapeutics to inflamed colon sites through the enhanced permeability and retention (EPR) effect caused by the inflammation. However, the drug still could not achieve effective concentration value that merely utilized on EPR effect and display better therapeutic efficacy in the inflamed region because of nontargeted drug release. Substantial researches have shown that some specific receptors and cell adhesion molecules highly expresses on the surface of colonic endothelial and/or immune cells when IBD occurs, ligand-modified drug delivery systems targeting such receptors and cell adhesion molecules can specifically deliver drug into inflamed sites and obtain great curative effects. This review introduces the overexpressed receptors and cell adhesion molecules in inflamed colon sites and retrospects the drug delivery systems functionalized by related ligands. Finally, challenges and future directions in this field are presented to advance the development of the receptor-mediated targeted drug delivery systems for the therapy of IBD.

What We Know So Far about the Metabolite-Mediated Microbiota-Intestinal Immunity Dialogue and How to Hear the Sound of This Crosstalk

Trillions of microorganisms, termed the "microbiota", reside in the mammalian gastrointestinal tract, and collectively participate in regulating the host phenotype. It is now clear that the gut microbiota, metabolites, and intestinal immune function are correlated, and that alterations of the complex and dynamic host-microbiota interactions can have deep consequences for host health. However, the mechanisms by which the immune system regulates the microbiota and by which the microbiota shapes host immunity are still not fully understood. This article discusses the contribution of metabolites in the crosstalk between gut microbiota and immune cells. The identification of key metabolites having a causal effect on immune responses and of the mechanisms involved can contribute to a deeper insight into host-microorganism relationships. This will allow a better understanding of the correlation between dysbiosis, microbial-based dysmetabolism, and pathogenesis, thus creating opportunities to develop microbiota-based therapeutics to improve human health. In particular, we systematically review the role of soluble and membrane-bound microbial metabolites in modulating host immunity in the gut, and of immune cells-derived metabolites affecting the microbiota, while discussing evidence of the bidirectional impact of this crosstalk. Furthermore, we discuss the potential strategies to hear the sound of such metabolite-mediated crosstalk.

Targeting macrophages using nanoparticles: a potential therapeutic strategy for atherosclerosis

Atherosclerosis is one of the leading causes of vascular diseases, with high morbidity and mortality worldwide. Macrophages play a critical role in the development and local inflammatory responses of atherosclerosis, contributing to plaque rupture and thrombosis. Considering their central roles, macrophages have gained considerable attention as a therapeutic target to attenuate atherosclerotic progression and stabilize existing plaques. Nanoparticle-based delivery systems further provide possibilities to selectively and effectively deliver therapeutic agents into intraplaque macrophages. Although challenges are numerous and clinical application is still distant, the design and development of macrophage-targeting nanoparticles will generate new knowledge and experiences to improve therapeutic outcomes and minimize toxicity. Hence, the review aims to discuss various strategies for macrophage modulation and the development and evaluation of macrophage targeting nanomedicines for anti-atherosclerosis.

Recent advances in nanomaterials for therapy and diagnosis for atherosclerosis

Atherosclerosis is a chronic inflammatory disease driven by lipid accumulation in arteries, leading to narrowing and thrombosis. It affects the heart, brain, and peripheral vessels and is the leading cause of mortality in the United States. Researchers have strived to design nanomaterials of various functions, ranging from non-invasive imaging contrast agents, targeted therapeutic delivery systems to multifunctional nanoagents able to target, diagnose, and treat atherosclerosis. Therefore, this review aims to summarize recent progress (2017-now) in the development of nanomaterials and their applications to improve atherosclerosis diagnosis and therapy during the preclinical and clinical stages of the disease.

Oral delivery of folate-targeted resveratrol-loaded nanoparticles for inflammatory bowel disease therapy in rats

AIMS

In the current study, resveratrol-loaded PLGA nanoparticles targeted with folate were developed in order to protect resveratrol from fast degradation, modify its pharmacokinetics and increase its intestinal permeation. Then, the therapeutic efficacy of the prepared system was evaluated in suppression of colon inflammation on TNBS-induced colitis model.

MAIN METHODS

In this regard, resveratrol was encapsulated in PLGA and FA-conjugated PLGA in order to prepare non-targeted (PLGA-RSV) and targeted (PLGA-FA-RSV) platforms, respectively.

KEY FINDINGS

Obtained results demonstrated that the prepared formulations encapsulated the resveratrol with high encapsulation efficiency of 90.7% ± 5.1% for PLGA-RSV and 59.1% ± 3.3% for PLGA-FA-RSV. In vitro release experiment showed that the prepared formulations were capable of retaining good amount of resveratrol under the simulated gastric condition (HCl 0.1 N, pH 1.2), while significant amount of resveratrol was released under simulated intestinal condition (PBS, pH 7.4). The trans-well permeability rates through Caco-2 monolayer during 180 min, was determined to be 4.5%, 61% and 99% for resveratrol, PLGA-RSV and PLGA-FA-RSV respectively. The pathological analysis of the rat intestinal sections (hematoxylin & eosin staining) at 7th day post-TNBS colonic inflammation induction illustrated that the oral administrations of FA-PLGA-RSV and PLGA-RSV were able to significantly inhibit the inflammation and reduce neutrophil and lymphocytes accumulation. It is worth noting that the folate-targeted system demonstrated highest efficacy in suppressing colon inflammation.

SIGNIFICANCE

It could be concluded that the encapsulation of resveratrol into biodegradable folate-targeted PLGA nanoparticles could introduce a potent platform in suppressing colonic inflammation thus offering a great capability for clinical translation.

Dendrimers as Modulators of Brain Cells

Nanostructured hyperbranched macromolecules have been extensively studied at the chemical, physical and morphological levels. The cellular structural and functional complexity of neural cells and their cross-talk have made it rather difficult to evaluate dendrimer effects in a mixed population of glial cells and neurons. Thus, we are at a relatively early stage of bench-to-bedside translation, and this is due mainly to the lack of data valuable for clinical investigations. It is only recently that techniques have become available that allow for analyses of biological processes inside the living cells, at the nanoscale, in real time. This review summarizes the essential properties of neural cells and dendrimers, and provides a cross-section of biological, pre-clinical and early clinical studies, where dendrimers were used as nanocarriers. It also highlights some examples of biological studies employing dendritic polyglycerol sulfates and their effects on glia and neurons. It is the aim of this review to encourage young scientists to advance mechanistic and technological approaches in dendrimer research so that these extremely versatile and attractive nanostructures gain even greater recognition in translational medicine.

Dextran-Coated Cerium Oxide Nanoparticles: A Computed Tomography Contrast Agent for Imaging the Gastrointestinal Tract and Inflammatory Bowel Disease

Computed tomography (CT) is an X-ray-based medical imaging technique commonly used for noninvasive gastrointestinal tract (GIT) imaging. Iodine- and barium-based CT contrast agents are used in the clinic for GIT imaging; however, inflammatory bowel disease (IBD) imaging is challenging since iodinated and barium-based CT agents are not specific for sites of inflammation. Cerium oxide nanoparticles (CeNP) can produce strong X-ray attenuation due to cerium's k-edge at 40.4 keV but have not yet been explored for CT imaging. In addition, we hypothesized that the use of dextran as a coating material on cerium oxide nanoparticles would encourage accumulation in IBD inflammation sites in a similar fashion to other inflammatory diseases. In this study, therefore, we sought to develop a CT contrast agent, i.e., dextran-coated cerium oxide nanoparticles (Dex-CeNP) for GIT imaging with IBD. We synthesized Dex-CeNP, characterized them using various analytical tools, and examined their in vitro biocompatibility, CT contrast generation, and protective effect against oxidative stress. In vivo CT imaging was done with both healthy mice and a dextran sodium sulfate induced colitis mouse model. Dex-CeNP's CT contrast generation and accumulation in inflammation sites were compared with iopamidol, an FDA approved CT contrast agent. Dex-CeNP was found to be protective against oxidative damage. Dex-CeNP produced strong CT contrast and accumulated in the colitis area of large intestines. In addition, >97% of oral doses were cleared from the body within 24 h. Therefore, Dex-CeNP can be used as a potential CT contrast agent for imaging GIT with IBD while protecting against oxidative damage.

X-ray recharged long afterglow luminescent nanoparticles MgGeO3:Mn2+,Yb3+,Li+ in the first and second biological windows for long-term bioimaging

In this paper, we have designed long afterglow luminescent MgGeO₃:Mn²⁺,Yb³⁺,Li⁺ (MGO) nanoparticles in the first (NIR-I) and second (NIR-II) biological windows. Yb³⁺ ions served not only as the trap center to enhance the NIR-I long afterglow emission of Mn²⁺ at 680 nm, but also as an emitting center to produce a NIR-II long afterglow emission at ∼1000 nm. Furthermore, we have found the addition of Li⁺ can greatly increase the NIR-II afterglow emission of Yb³⁺ and the optimal amount of Mn²⁺, Yb³⁺ and Li⁺ was found to be 0.1, 0.5 and 0.5 mol%, respectively. The MGO nanoparticles synthesized using sol-gel methods showed a uniform morphology with a diameter of 50-100 nm, which were suitable for applications in bioimaging. More importantly, we have found MGO nanoparticles can be effectively excited to produce long persistent NIR-I and II luminescence using soft X-rays, suggesting that low dosage soft X-rays can also serve as a more powerful and deep tissue excitation source to recharge MGO nanoparticles. Furthermore, the MGO nanoparticles can also be re-excited to produce photo-stimulated emission under the irradiation of 650 and 808 nm NIR lasers. The in vivo imaging results have shown that MGO nanoparticles modified with folic acid (FA) can effectively realize super long-term targeted in vivo imaging of inflammation with a high sensitivity via recharging using soft X-rays and NIR lasers, which can provide not only an accurate diagnosis of inflammation, but also long-term monitoring of possible changes in the focus of inflammation in real time.

Site-specific targeted drug delivery systems for the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) includes Crohn's disease and ulcerative colitis and manifests as a complex and dysregulated immune response. To date, there is no cure for IBD; thus, lifelong administration of maintenance drugs is often necessary. Since conventional IBD treatment strategies do not target the sites of inflammation, only limited efficacy is observed with their use. Moreover, the possibility of severe side effects resulting from systemic drug redistribution is high when conventional drug treatments are used. Therefore, a straightforward disease-targeted drug delivery system is desirable. Based on the pathophysiological changes associated with IBD, novel site-specific targeted drug delivery strategies that deliver drugs directly to the inflammation sites can enhance drug accumulation and decrease side effects. This review summarizes novel inflammation targeted delivery systems in the management of IBD. It also discusses the challenges and new perspectives in this field.

Macrophage-Based Therapies for Atherosclerosis Management

Atherosclerosis (AS), a typical chronic inflammatory vascular disease, is the main pathological basis of ischemic cardio/cerebrovascular disease (CVD). Long-term administration was characterized with low efficacy and serious side effects, while the macrophages with attractive intrinsic homing target have great potential in the efficient and safe management of AS. In this review, we focused on the systematical summary of the macrophage-based therapies in AS management, including macrophage autophagy, polarization, targeted delivery, microenvironment-triggered drug release, and macrophage- or macrophage membrane-based drug carrier. In conclusion, macrophage-based therapies have great promise to effectively manage AS in future research and clinic translation.

Drug delivery to macrophages: A review of targeting drugs and drug carriers to macrophages for inflammatory diseases

Macrophages play a key role in defending against foreign pathogens, healing wounds, and regulating tissue homeostasis. Driving this versatility is their phenotypic plasticity, which enables macrophages to respond to subtle cues in tightly coordinated ways. However, when this coordination is disrupted, macrophages can aid the progression of numerous diseases, including cancer, cardiovascular disease, and autoimmune disease. The central link between these disorders is aberrant macrophage polarization, which misguides their functional programs, secretory products, and regulation of the surrounding tissue microenvironment. As a result of their important and deterministic roles in both health and disease, macrophages have gained considerable attention as targets for drug delivery. Here, we discuss the role of macrophages in the initiation and progression of various inflammatory diseases, summarize the leading drugs used to regulate macrophages, and review drug delivery systems designed to target macrophages. We emphasize strategies that are approved for clinical use or are poised for clinical investigation. Finally, we provide a prospectus of the future of macrophage-targeted drug delivery systems.

Liposomes in Active, Passive and Acoustically-Triggered Drug Delivery

Cancer has become one of the most deadly noncommunicable diseases globally. Several modalities used to treat cancer patients exist today yet many have failed to prove high efficacy with low side effects. The most common example of such modalities is the use of chemotherapeutic drugs to treat cancerous cells and deter their uncontrolled proliferation. In addition to the destruction of cancerous tissues, chemotherapy destroys healthy tissues as it lacks the specificity to annihilate cancerous cells only and preferentially, which result in adverse side effects including nausea, hair fall and myocardial infarction. To prevent the side effects of non-selective chemotherapy, cancer therapy research has been focused on the implementation of nanocarrier systems that act as vehicles to encapsulate drugs and selectively transport their agent to the tumor site. In this paper, we shed light on liposomes along with three anticancer drug delivery approaches: passive, active and ultrasound-triggered drug delivery.

Rhesus Brain Transcriptomic Landscape in an ex vivo Model of the Interaction of Live Borrelia Burgdorferi With Frontal Cortex Tissue Explants

Lyme neuroborreliosis (LNB) is the most dangerous manifestation of Lyme disease caused by the spirochete Borrelia burgdorferi which can reach the central nervous system most commonly presenting with lymphocytic meningitis; however, the molecular basis for neuroborreliosis is still poorly understood. We incubated explants from the frontal cortex of three rhesus brains with medium alone or medium with added live Borrelia burgdorferi for 6, 12, and 24 h and isolated RNA from each group was used for RNA sequencing with further bioinformatic analysis. Transcriptomic differences between the ex vivo model of live Borrelia burgdorferi with rhesus frontal cortex tissue explants and the controls during the progression of the infection were identified. A total of 2249, 1064, and 420 genes were significantly altered, of which 80.7, 52.9, and 19.8% were upregulated and 19.3, 47.1, 80.2% were downregulated at 6, 12, and 24 h, respectively. Gene ontology and KEGG pathway analyses revealed various pathways related to immune and inflammatory responses during the spirochete infection were enriched which is suggested to have a causal role in the pathogenesis of neurological Lyme disease. Moreover, we propose that the overexpressed FOLR2 which was demonstrated by the real-time PCR and western blotting could play a key role in neuroinflammation of the neuroborreliosis based on PPI analysis for the first time. To our knowledge, this is the first study to provide comprehensive information regarding the transcriptomic signatures that occur in the frontal cortex of the brain upon exposure to Borrelia burgdorferi, and suggest that FOLR2 is a promising target that is associated with neuroinflammation and may represent a new diagnostic or therapeutic marker in LNB.

Depletion of activated macrophages with a folate receptor-beta-specific antibody improves symptoms in mouse models of rheumatoid arthritis

Objectives

Most therapies for autoimmune and inflammatory diseases either neutralize or suppress production of inflammatory cytokines produced by activated macrophages (e.g., TNFα, IL-1, IL-6, IL-17, GM-CSF). However, no approved therapies directly target this activated subset of macrophages.

Methods

First, we undertook to examine whether the folate receptor beta (FR-β) positive subpopulation of macrophages, which marks the inflammatory subset in animal models of rheumatoid arthritis, might constitute the prominent population of macrophages in inflamed lesions in humans. Next, we utilized anti-FR-β monoclonal antibodies capable of mediating antibody-dependent cell cytotoxicity (ADCC) to treat animal models of rheumatoid arthritis and peritonitis.

Results

Human tissue samples of rheumatoid arthritis, Crohn’s disease, ulcerative colitis, idiopathic pulmonary fibrosis, nonspecific interstitial pneumonia, chronic obstructive pulmonary disease, systemic lupus erythematosus, psoriasis, and scleroderma are all characterized by dramatic accumulation of macrophages that express FR-β, a protein not expressed on resting macrophages or any other healthy tissues. A monoclonal antibody to FR-β accumulates specifically in inflamed lesions of murine inflammatory disease models and successfully treats such models of rheumatoid arthritis and peritonitis. More importantly, elimination of FR-β-positive macrophages upon treatment with an anti-FR-β monoclonal antibody promotes the departure of other immune cells, including T cells, B cells, neutrophils, and dendritic cells from the inflamed lesions.

Conclusions

These data suggest that specific elimination of FR-β-expressing macrophages may constitute a highly specific therapy for multiple autoimmune and inflammatory diseases and that a recently developed human anti-human FR-β monoclonal antibody (m909) might contribute to suppression of this subpopulation of macrophages.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1912-0) contains supplementary material, which is available to authorized users.

Modular synthesis and modification of novel bifunctional dendrons

The modular synthesis of two generations of highly branched bifunctional dendrons is reported. The first generation dendron–antibody conjugate is shown to selectively detect CD4⁺ T cells in the PBMC culture.

Tissue Engineering Therapies Based on Folic Acid and Other Vitamin B Derivatives. Functional Mechanisms and Current Applications in Regenerative Medicine

B-vitamins are a group of soluble vitamins which are cofactors of some of the enzymes involved in the metabolic pathways of carbohydrates, fats and proteins. These compounds participate in a number of functions as cardiovascular, brain or nervous systems. Folic acid is described as an accessible and multifunctional niche component that can be used safely, even combined with other compounds, which gives it high versatility. Also, due to its non-toxicity and great stability, folic acid has attracted much attention from researchers in the biomedical and bioengineering area, with an increasing number of works directed at using folic acid and its derivatives in tissue engineering therapies as well as regenerative medicine. Thus, this review provides an updated discussion about the most relevant advances achieved during the last five years, where folic acid and other vitamins B have been used as key bioactive compounds for enhancing the effectiveness of biomaterials' performance and biological functions for the regeneration of tissues and organs.

Efficient Cholera Toxin B Subunit-Based Nanoparticles with MRI Capability for Drug Delivery to the Brain Following Intranasal Administration

Alzheimer's disease (AD) is an incurable neurodegenerative brain disorder that exhibits clear pathologic changes in the hippocampus. Traditional drug delivery systems are ineffective due to the existence of the blood-brain barrier (BBB). In this study, an efficient, stable, and easily constructed nanosystem (CB-Gd-Cy5.5) based on the cholera toxin B subunit (CB) is designed to improve the efficiency of drug delivery to the brain, especially the hippocampus. Through intranasal administration, CB-Gd-Cy5.5 is easily delivered to the brain without intervention by the BBB. The CB in CB-Gd-Cy5.5 is used for specifically combining with the monosialoganglioside GM1, which is widely found in the hippocampus. This nanosystem exhibits impressive performance in accumulating in the hippocampus. In addition, the good magnetic resonance imaging (MRI) capability of CB-Gd-Cy5.5 can satisfy the monitoring of AD in the different stages.

Biotin-Tagged Polysaccharide Vesicular Nanocarriers for Receptor-Mediated Anticancer Drug Delivery in Cancer Cells

Biotin-conjugated multistimuli-responsive polysaccharide vesicular nanocarriers are designed and developed, for the first time, to accomplish receptor-mediated endocytosis in cancer cells and to deliver anticancer drugs to intracellular compartments. For this purpose, a new renewable hydrophobic unit was custom designed with redox-degradable disulfide and enzyme-biodegradable aliphatic ester chemical linkages, and it was conjugated along with biotin on the dextran backbone. The dextran derivative self-assembled into nanovesicles of <200 nm in size, which were characterized by dynamic and static light scattering, electron, and atomic force microscopes. Avidin-HABA assay established the high affinity of biotin-tagged dextran vesicles toward membrane-receptors up to 25 nM concentration. Doxorubicin-hydrochloride (DOX.HCl)-loaded dextran vesicles exhibited stable formulation in phosphate-buffered saline (PBS) and fetal bovine serum (FBS). Redox-degradation by glutathione (GSH) showed 60% drug release, whereas lysosomal esterase enzyme enabled >98% drug release in 12 h. Confocal microscope and flow cytometry-assisted time-dependent cellular uptake studies revealed that the biotin-receptors overexpressed in cervical cancer cells (HeLa) exhibited larger drug accumulation through the receptor-assisted endocytosis process. This process enabled the delivery of higher amount of DOX and significantly enhanced the killing in cancer cells (HeLa) compared to wild-type mouse embryonic fibroblast cells (WT-MEF, normal cells). Control experiments such as biotin pretreatment in cancer cells and energy-suppressed cellular uptake at 4 °C further supported the occurrence of receptor-mediated endocytosis by the biotin-tagged polymer vesicles. This report provides first insights into the targeted polysaccharide vesicle platform, and the proof-of-concept is successfully demonstrated in biotin receptor-overexpressed cervical cancer cells.