Nano- and microparticulate drug carriers for targeting of the inflamed intestinal mucosa

Targeted and intelligent nano-drug delivery systems for colorectal cancer treatment

Colorectal cancer (CRC) remains a highly heterogeneous malignancy with significant morbidity and mortality worldwide. Despite advancements in surgery, chemotherapy, immunotherapy, and targeted therapy, treatment efficacy is often hampered by drug resistance and systemic toxicity. In recent years, nano-drug delivery systems (NDDS) have emerged as a promising strategy to enhance therapeutic precision, reduce adverse effects, and overcome resistance in CRC treatment. This review discusses the recent advancements in NDDS for CRC treatment, focusing on the optimization of oral drug delivery systems, the development of tumor-specific targeting strategies, and the design of intelligent delivery systems responsive to the tumor microenvironment (TME). Furthermore, we summarize current challenges in NDDS translation and explore future research directions for enhancing their clinical feasibility and therapeutic impact.

Silver Nanoparticles with Mebeverine in IBS Treatment: DFT Analysis, Spasmolytic, and Anti-Inflammatory Effects

Background/Objectives: Mebeverine hydrochloride (MBH) is an antispasmodic agent used to regulate bowel movements and relax intestinal smooth muscle, but its application is limited by specific side effects; therefore, this study investigates the effects of previously synthesized MBH-loaded silver nanoparticles (AgNPs) on smooth muscle contractile activity and their anti-inflammatory potential as an alternative delivery system. Methods: The interactions of AgNPs with cholinergic inhibitors, selective antagonists, Ca2+ blockers, and key neurotransmitters were analyzed. In vitro, albumin denaturation suppression and ex vivo assays evaluated the anti-inflammatory effects of AgNPs-MBH, validated using a DFT in silico approach. To comprehensively assess the systemic impact and IBS treatment potential of AgNPs-MBH, we also examined in vitro their antimicrobial activity and hepatic cell responses, as the liver is a key organ in evaluating the overall safety and efficacy of nanoparticles. Additionally, the drug-release capabilities of Ag NPs were established. Results: Our findings indicate that AgNPs with MBH do not affect blocked cholinergic receptors, but their effects are more pronounced and distinct in amplitude and character than MBH. MBH-loaded AgNPs showed a lower anti-inflammatory effect than MBH but were still better than diclofenac. They also affected hepatic cell morphology and proliferation, suggesting potential for enhanced therapeutic efficacy. Drug-loaded AgNPs are considered not bactericidal. Conclusions: Based on our results, drug-loaded AgNPs might be a promising medication delivery system for MBH and a useful treatment option for IBS. Future in vivo and preclinical experiments will contribute to the establishment of drug-loaded AgNPs in IBS treatment.

Advancing Inflammatory Bowel Disease Treatment by Targeting the Innate Immune System and Precision Drug Delivery

Inflammatory bowel disease (IBD), encompassing Crohn's disease and ulcerative colitis, involves chronic inflammation of the gastrointestinal tract. Current immune-modulating therapies are insufficient for 30-50% of patients or cause significant side effects, emphasizing the need for new treatments. Targeting the innate immune system and enhancing drug delivery to inflamed gut regions are promising strategies. Neutrophils play a central role in IBD by releasing reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) -DNA-based structures with cytotoxic proteins-that contribute to mucosal damage and inflammation. Recent studies linking ROS production, DNA repair, and NET formation have identified NETs as potential therapeutic targets, with preclinical models showing positive outcomes from NET inhibition. Innovative oral drug delivery systems designed to target gut inflammation directly-without systemic absorption-could improve treatment precision and reduce side effects. Advanced formulations utilize properties such as particle size, surface modifications, and ROS-triggered release to selectively target the distal ileum and colon. A dual strategy that combines a deeper understanding of IBD pathophysiology to identify inflammation-related therapeutic targets with advanced drug delivery systems may offer significant promise. For instance, pairing NET inhibition with ROS-responsive nanocarriers could enhance treatment efficacy, though further research is needed. This synergistic approach has the potential to greatly improve outcomes for IBD patients.

An enhanced bioactive chitosan-modified microemulsion for mucosal healing of ulcerative colitis

The intestinal mucus layer plays a crucial role in the systemic absorption of drugs. While penetration through this layer traditionally constitutes a pivotal phase in drug absorption, the approach for treating ulcerative colitis (UC) shifts towards facilitating the direct delivery of drugs to the colon. In this study, we engineered a chitosan-modified microemulsion encapsulated nobiletin (NOB-CS-ME) characterized by small particle dimensions and positive charge specifically, designed to enable targeted delivery. In vitro experiments demonstrated that this NOB-CS-ME effectively became less into the intestinal mucus layer, thus achieving successful escape of the intestinal mucus barrier absorption. After circumventing this barrier, NOB-CS-ME exhibited heightened cellular uptake by colonic epithelial cells, displaying an approximately 1.3-fold increase compared to the unmodified microemulsion. Collectively, these observations imply enhanced drug bioavailability, potentially resulting in more efficacious mucosal healing, providing a promising avenue for natural small-molecule drug delivery in UC treatment.

Oral Targeted Delivery of Codonopsis Radix Polysaccharide via Succinyl -DHA Functionalized Nanoparticles Efficiently Alleviates Ulcerative Colitis

Introduction

Ulcerative colitis (UC) is a chronic intestinal disease characterized by spleen-lung qi deficiency and dampness-pathogenic obstruction. Although there are various treatment options available, patients frequently encounter significant drug-related side effects. Previous studies have shown the potential of Codonopsis Radix polysaccharides A (CPA) in treating UC, but their limited bioavailability has restricted their clinical use. Therefore, the objective of this study was to develop a novel formulation that can address the aforementioned limitations and assess its potential advantages.

Methods and Results

We synthesized a negatively charged amphipathic prodrug called CPA-SA-DHA (CSD), which consists of CPA as the hydrophilic component, and succinic anhydride and docosahexaenoic acid as the hydrophobic segments. The CSD nanoparticles obtained had a particle size of 180.0 ± 3.2 nm, a negative zeta potential of -29.8 ± 5.3 mV, and a uniform shape with a PDI index of 0.230 ± 0.003. The interaction between positive and negative charges significantly increased the retention time of CSD nanoparticles in the colonic microenvironment. Furthermore, CSD nanoparticles demonstrated enhanced bioavailability in UC mice compared to CPA. Additionally, we observed that CSD nanoparticles exhibited therapeutic effects on DSS-induced UC mice by regulating the diversity and abundance of gut microbiota. This effect may be mediated by the inhibition of pro-inflammatory signaling pathways TLR4/NF-κB.

Conclusion

These findings confirm the potential of CSD nanoparticles as a promising treatment option for UC.

Development of Targeted Drug Delivery System for the Treatment of SARS-CoV-2 Using Aptamer-Conjugated Gold Nanoparticles

Background: The SARS-CoV-2 pandemic has highlighted niclosamide (NIC) as a promising treatment for COVID-19. However, its clinical application is limited due to its poor water solubility, resulting in low bioavailability. Methods: To address this issue, we developed a AuNP-HA-NIC system, which combines gold nanoparticles with hyaluronic acid to enhance drug delivery. Our comprehensive characterization of the system revealed that hyaluronic acid with specific molecular weights, particularly those exposed to electron-beam irradiation between 2 and 20 kGy, produced the most stable nanoparticles for efficient drug loading and delivery. Results: Additionally, the AuNP-HA-NIC system exhibits a significant sensitivity to pH changes, which is a critical feature for targeted drug release. Under acidic conditions mimicking the stomach and small intestine, minimal drug release was observed, indicating the effective prevention of premature drug release in the gastrointestinal tract. Furthermore, the integration of a targeting aptamer established specific binding abilities towards the SARS-CoV-2 spike protein, distinguishing it from other coronaviruses. Conclusions: As research progresses, and with further in vivo testing and optimization, the AuNP-HA-NIC-aptamer system holds great promise as a game-changer in the field of antiviral therapeutics, particularly in the battle against COVID-19.

Influence of natural polysaccharides on the morphology and properties of hybrid vaterite microcrystals

Co-precipitation of biopolymers into calcium carbonate crystals changes their physicochemical and biological properties. This work studies hybrid microcrystals of vaterite obtained in the presence of natural polysaccharides, as carriers for the delivery of proteins and enzymes. Hybrid microcrystals with dextran sulfate, chondroitin sulfate, heparin, fucoidan, and pectin were obtained and compared. The impact of polysaccharides on the morphology (particle diameter, surface area, nanocrystallite and pore size), polysaccharide content and surface charge of hybrid microcrystals was studied. Only microcrystals with fucoidan and heparin exhibited antioxidant activity against •ОН radical. The surface charge and pore size of the hybrid microcrystals affected the sorption of albumin, catalase, chymotrypsin, mucin. A decrease in the catalytic constant and Michaelis constant was observed for catalase sorbed on the hybrid crystals. The biocompatibility of microcrystals depended on the nature of the included polysaccharide: crystals with sulfated polysaccharides increased blood plasma coagulation but not platelet aggregation, and crystals with dextran sulfate had the greatest cytotoxicity against HT-29 cells but not erythrocytes. Hybrid microcrystals with all polysaccharides except chondroitin sulfate reduced erythrocyte lysis in vitro compared with vaterite crystals. The obtained results enable to create novel carriers based on hybrid vaterite crystals with polysaccharides, beneficial for the delivery of protein drugs.

Liposomes delivery systems of functional substances for precision nutrition

Natural bioactive compounds with antioxidant, antimicrobial, anticancer, and other biological activities are vital for maintaining the body's physiological functions and enhancing immunity. These compounds have great potential as nutritional therapeutic agents, but they can be limited due to their poor flavor, color, unstable nature, and poor water solubility, and degradation by gastrointestinal enzymes. Liposomes, as ideal carriers, can encapsulate both water-soluble and fat-soluble nutrients, enhance the bioavailability of functional substances, promote the biological activity of functional substances, and control the release of nutrients. Despite their potential, liposomes still face obstacles in nutrient delivery. Therefore, the design of liposomes for special needs, optimization of the liposome preparation process, enhancement of liposome encapsulation efficiency, and industrial production are key issues that must be addressed in order to develop food-grade liposomes. Moreover, the research on surface-targeted modification and surface functionalization of liposomes is valuable for expanding the scope of application of liposomes and achieving the release of functional substances from liposomes at the appropriate time and site. The establishment of in vivo and in vitro digestion models of nutrient-loaded liposomes, in-depth study of gastrointestinal digestive behavior after liposome ingestion, targeted nutrient release, and deciphering the nutritional intervention of human diseases and positive health promotion are promising fields with broad development prospects.

Bioinspired and bioderived nanomedicine for inflammatory bowel disease

Due to its chronic nature and complex pathophysiology, inflammatory bowel disease (IBD) poses significant challenges for treatment. The long-term therapies for patients, often diagnosed between the ages of 20 and 40, call for innovative strategies to target inflammation, minimize systemic drug exposure, and improve patients' therapeutic outcomes. Among the plethora of strategies currently pursued, bioinspired and bioderived nano-based formulations have garnered interest for their safety and versatility in the management of IBD. Bioinspired nanomedicine can host and deliver not only small drug molecules but also biotherapeutics, be made gastroresistant and mucoadhesive or mucopenetrating and, for these reasons, are largely investigated for oral administration, while surprisingly less for rectal delivery, recommended first-line treatment approach for several IBD patients. The use of bioderived nanocarriers, mostly extracellular vesicles (EVs), endowed with unique homing abilities, is still in its infancy with respect to the arsenal of nanomedicine under investigation for IBD treatment. An emerging source of EVs suited for oral administration is ingesta, that is, plants or milk, thanks to their remarkable ability to resist the harsh environment of the upper gastrointestinal tract. Inspired by the unparalleled properties of natural biomaterials, sophisticated avenues for enhancing therapeutic efficacy and advancing precision medicine approaches in IBD care are taking shape, although bottlenecks arising either from the complexity of the nanomedicine designed or from the lack of a clear regulatory pathway still hinder a smooth and efficient translation to the clinics. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Oral targeted drug delivery to post-gastrointestinal sites

As an essential branch of targeted drug delivery, oral targeted delivery is attracting growing attention in recent years. In addition to site-specific delivery for the treatment of locoregional diseases in the gastrointestinal tract (GIT), oral targeted delivery to remote sites beyond the GIT emerges as a cutting-edge research topic. This review aims to provide an overview of the fundamental concepts and most recent advances in this field. Owing to the physiological barriers existing in the GIT, carrier systems should be transported across the enteric epithelia to target remote sites. Recently, pioneer investigations have validated the transport of intact micro- or nanocarriers across gastrointestinal barriers and subsequently to various distal organs and tissues. The microfold (M) cell pathway is the leading mechanism underlying the oral absorption of particulates, but the contribution of the transcellular and paracellular pathways should not be neglected either. In addition to well-acknowledged physicochemical and biological factors, the formation of a protein corona may also influence the biological fate of carrier systems. Although in an early stage of conceptualization, oral targeted delivery to remote diseases has demonstrated promising potential for the treatment of inflammation, tumors, and diseases inflicting the lymphatic and mononuclear phagocytosis systems.

Recent progress on engineered micro/nanomaterials mediated modulation of gut microbiota for treating inflammatory bowel disease

Inflammatory bowel disease (IBD) is a type of chronic recurrent inflammation disease that mainly includes Crohn's disease and ulcerative colitis. Currently, the treatments for IBD remain highly challenging, with clinical treatment drugs showing limited efficacy and adverse side effects. Thus, developing drug candidates with comprehensive therapeutic effects, high efficiency, and low toxicity is urgently needed. Recently, micro/nanomaterials have attracted considerable interest because of their bioavailability, multitarget and efficient effects on IBD. In addition, gut modulation plays a substantial role in restoring intestinal homeostasis. Therefore, efficient microbiota-based strategies modulating gut microenvironment have great potential in remarkably treating IBD. With the development of micro- and nanomaterials for the treatment of IBD and more in-depth studies of their therapeutic mechanisms, it has been found that these treatments also have a tendency to positively regulate the intestinal flora, resulting in an increase in the beneficial flora and a decrease in the level of pathogenic bacteria, thus regulating the composition of the intestinal flora to a normal state. In this review, we first present the interactions among the immune system, intestinal barrier, and gut microbiome. In addition, recent advances in administration routes and methods that positively arouse the regulation of intestinal flora for IBD using probiotics, prebiotics, and redox-active micro/nanomaterials have been reviewed. Finally, the key challenges and critical perspectives of gut microbiota-based micro/nanomaterial treatment are also discussed.

Resveratrol-loaded pH-responsive Mesona chinensis polysaccharides-zein nanoparticles for effective treatment of ulcerative colitis

BACKGROUND

Resveratrol (Res) is promising food functional factor with favorable antioxidant and anti-inflammatory properties, although its poor water solubility and low bioavailability limit extensive application. Therefore, in combination with another promising polysaccharide (Mesona chinensis polysaccharides, MCP), Res-loaded food nanocarriers (ResNPs) were developed to increase its water solubility, bioactivity and targeting properties. ResNPs were then applied to alleviate dextran sulfate sodium (DSS)-induced ulcerative colitis.

RESULTS

Resveratrol can be well encapsulated in MCP-based nanoparticles in an amorphous state, improving its water solubility. ResNPs showed pH-response controlled release behavior in the gastrointestinal tract and increased the enrichment of Res in the colon. In vivo experiments of ResNPs against DSS-induced ulcerative colitis (UC) revealed that ResNPs significantly improved UC symptoms, modulated intestinal inflammation and down-regulated oxidative stress levels compared to free Res. ResNPs also play an positive role with respect to inhibiting the mitogen-activated protein kinase pathway and promoting the expression of tight junction proteins. In addition, ResNPs improved the species composition and relative abundance of intestinal flora in UC mice, which effectively regulated the balance of intestinal flora and promoted the production of short-chain fatty acids.

CONCLUSION

These results suggest that MCP-based nanoparticles can effectively improve the solubility of resveratrol and enhance its in vivo bioactivity. Moreover, the present study also provides a new strategy for the prevention and treatment of UC with food polyphenol. © 2024 Society of Chemical Industry.

Exploring the potential of pH-sensitive polymers in targeted drug delivery

The pH-sensitive polymers have attained significant attention in the arena of targeted drug delivery (TDD) because of their exceptional capability to respond to alteration in pH in various physiological environments. This attribute aids pH-sensitive polymers to act as smart carriers for therapeutic agents, transporting them precisely to target locations while curtailing the release of drugs in off-targeted sites, thereby diminishing side effects. Many pH-responsive polymers in TDD have revealed promising results, with increased therapeutic efficacy and decreased toxic effects. Several pH-sensitive polymers, including, hydroxy-propyl-methyl cellulose, poly (methacrylic acid) (Eudragit series), poly (acrylic acid), and chitosan, have been broadly studied for their myriad applications in the management of various types of diseases. Additionally, the amalgamation of pH-sensitive polymers with, additive manufacturing techniques like 3D printing, has resulted in the progression of novel drug delivery systems that regulate drug release in a controlled manner. Herein, types of pH-sensitive polymers in TDD are systemically reviewed. We have briefly discussed the nanocarriers employed for the delivery of various pH-sensitive polymers in TDD. Finally, miscellaneous applications of pH-sensitive polymers are discussed thoroughly with special attention to the implication of 3D printing in pH-sensitive polymers.

Recent advances in zwitterionic nanoscale drug delivery systems to overcome biological barriers

Nanoscale drug delivery systems (nDDS) have been employed widely in enhancing the therapeutic efficacy of drugs against diseases with reduced side effects. Although several nDDS have been successfully approved for clinical use up to now, biological barriers between the administration site and the target site hinder the wider clinical adoption of nDDS in disease treatment. Polyethylene glycol (PEG)-modification (or PEGylation) has been regarded as the gold standard for stabilising nDDS in complex biological environment. However, the accelerated blood clearance (ABC) of PEGylated nDDS after repeated injections becomes great challenges for their clinical applications. Zwitterionic polymer, a novel family of anti-fouling materials, have evolved as an alternative to PEG due to their super-hydrophilicity and biocompatibility. Zwitterionic nDDS could avoid the generation of ABC phenomenon and exhibit longer blood circulation time than the PEGylated analogues. More impressively, zwitterionic nDDS have recently been shown to overcome multiple biological barriers such as nonspecific organ distribution, pressure gradients, impermeable cell membranes and lysosomal degradation without the need of any complex chemical modifications. The realization of overcoming multiple biological barriers by zwitterionic nDDS may simplify the current overly complex design of nDDS, which could facilitate their better clinical translation. Herein, we summarise the recent progress of zwitterionic nDDS at overcoming various biological barriers and analyse their underlying mechanisms. Finally, prospects and challenges are introduced to guide the rational design of zwitterionic nDDS for disease treatment.

Bi-functional astaxanthin macromolecular nanocarriers to alleviate dextran sodium sulfate-induced inflammatory bowel disease

Dextran sulfate sodium is one of the important members in the field of polysaccharide biotechnology, which can induce inflammatory bowel disease (IBD) in the gastrointestinal tract. Nevertheless, the application of astaxanthin (AST) and epigallocatechin-3-gallate (EGCG), known for their pronounced antioxidant and anti-inflammatory properties, is encumbered by limited stability and bioavailability. To surmount this challenge, dual nutritional macromolecular nanoparticles were provided for alleviating IBD. The forementioned strategy entailed the utilization of EGCG as a wall material via the Mannich reaction, resulting in the creation of specialized nanocarriers capable of mitochondrial targeting and glutathione-responsive AST delivery. In vitro investigations, these nanocarriers demonstrated an enhanced propensity for mitochondrial accumulation, leading to proficient elimination of reactive oxygen species and preservation of optimal mitochondrial membrane potential about 1.5 times stronger than free AST and EGCG. Crucially, in vivo experiments showed that the colon length of IBD mice treated with these nanocarriers increased by 51.29 % and facilitated the polarization of M2 macrophages. Moreover, the assimilation of these nanocarriers exerted a favorable impact on the composition of gut microbiota. These findings underscore the immense potential of dual nutrition nanocarriers in contemporaneously delivering hydrophobic biological activators through oral absorption, thereby presenting a highly promising avenue for combating IBD.

Delivery Strategies of Probiotics from Nano- and Microparticles: Trends in the Treatment of Inflammatory Bowel Disease-An Overview

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder, most known as ulcerative colitis (UC) and Crohn's disease (CD), that affects the gastrointestinal tract (GIT), causing considerable symptoms to millions of people around the world. Conventional therapeutic strategies have limitations and side effects, prompting the exploration of innovative approaches. Probiotics, known for their potential to restore gut homeostasis, have emerged as promising candidates for IBD management. Probiotics have been shown to minimize disease symptoms, particularly in patients affected by UC, opening important opportunities to better treat this disease. However, they exhibit limitations in terms of stability and targeted delivery. As several studies demonstrate, the encapsulation of the probiotics, as well as the synthetic drug, into micro- and nanoparticles of organic materials offers great potential to solve this problem. They resist the harsh conditions of the upper GIT portions and, thus, protect the probiotic and drug inside, allowing for the delivery of adequate amounts directly into the colon. An overview of UC and CD, the benefits of the use of probiotics, and the potential of micro- and nanoencapsulation technologies to improve IBD treatment are presented. This review sheds light on the remarkable potential of nano- and microparticles loaded with probiotics as a novel and efficient strategy for managing IBD. Nonetheless, further investigations and clinical trials are warranted to validate their long-term safety and efficacy, paving the way for a new era in IBD therapeutics.

Targeted delivery of budesonide in acetic acid induced colitis: impact on miR-21 and E-cadherin expression

Inflammatory bowel disease (IBD) is characterized by chronic inflammation along the gastrointestinal tract. For IBD effective treatment, developing an orally administered stable drug delivery system capable of targeting inflammation sites is a key challenge. Herein, we report pH responsive hyaluronic (HA) coated Eudragit S100 (ES) nanoparticles (NPs) for the targeted delivery of budesonide (BUD) (HA-BUD-ES-NPs). HA-BUD-ES-NPs showed good colloidal properties (274.8 ± 2.9 nm and - 24.6 ± 2.8 mV) with high entrapment efficiency (98.3 ± 3.41%) and pH-dependent release profile. The negative potential following incubation in simulated gastrointestinal fluids reflected the stability of HA coat. In vitro studies on Caco-2 cells showed HA-BUD-ES-NPs biocompatibility and enhanced cellular uptake and anti-inflammatory effects as shown by the significant reduction in IL-8 and TNF-α. The oral administration of HA-BUD-ES-NPs in an acetic acid induced colitis rat model significantly mitigated the symptoms of IBD, and improved BUD therapeutic efficacy compared to drug suspension. This was proved via the improvement in disease activity index and ulcer score in addition to refined histopathological findings. Also, the assessment of inflammatory markers, epithelial cadherin, and mi-R21 all reflected the higher efficiency of HA-BUD-ES-NPs compared to free drug and uncoated formulation. We thus suggest that HA-BUD-ES-NPs provide a promising drug delivery platform for the management and site specific treatment of IBD.

Oral delivery of porous starch-loaded bilayer microgels for controlled drug delivery and treatment of ulcerative colitis

We prepared one type of bilayer microgels for oral administration with three effects: pH responsiveness, time lag, and colon enzyme degradation. Combined with the dual biological effects of curcumin (Cur) for reducing inflammation and promoting repair of colonic mucosal injury, targeted colonic localization and release of Cur according to the colonic microenvironment were enhanced. The inner core, derived from guar gum and low-methoxyl pectin, afforded colonic adhesion and degradation behavior; the outer layer, modified by alginate and chitosan via polyelectrolyte interaction, achieved colonic localization. The porous starch (PS)-mediated strong adsorption allowed Cur loading in inner core to achieve a multifunctional delivery system. In vitro, the formulations exhibited good bioresponses at different pH conditions, potentially delaying Cur release in the upper gastrointestinal tract. In vivo, dextran sulfate sodium-induced ulcerative colitis (UC) symptoms were significantly alleviated after oral administration, accompanied by reduced levels of inflammatory factors. The formulations facilitated colonic delivery, allowing Cur accumulation in colonic tissue. Moreover, the formulations could alter gut microbiota composition in mice. During Cur delivery, each formulation increased species richness, decreased pathogenic bacterial content, and afforded synergistic effects against UC. These PS-loaded bilayer microgels, exhibiting excellent biocompatibility, multi-bioresponsiveness, and colon targeting, could be beneficial in UC therapy, allowing development into a novel oral formulation.

Modulation of engineered nanomaterial interactions with organ barriers for enhanced drug transport

The biomedical use of nanoparticles (NPs) has been the focus of intense research for over a decade. As most NPs are explored as carriers to alter the biodistribution, pharmacokinetics and bioavailability of associated drugs, the delivery of these NPs to the tissues of interest remains an important topic. To date, the majority of NP delivery studies have used tumor models as their tool of interest, and the limitations concerning tumor targeting of systemically administered NPs have been well studied. In recent years, the focus has also shifted to other organs, each presenting their own unique delivery challenges to overcome. In this review, we discuss the recent advances in leveraging NPs to overcome four major biological barriers including the lung mucus, the gastrointestinal mucus, the placental barrier, and the blood-brain barrier. We define the specific properties of these biological barriers, discuss the challenges related to NP transport across them, and provide an overview of recent advances in the field. We discuss the strengths and shortcomings of different strategies to facilitate NP transport across the barriers and highlight some key findings that can stimulate further advances in this field.

Oral nanoparticulate drug delivery systems for the treatment of intestinal bowel disease and colorectal cancer

INTRODUCTION

The most popular method for delivering drugs locally and systemically is oral. However, the gastrointestinal tract's severe physiological (mucosal and enzymatic barrier) and physicochemical (pH) environment places restrictions on the oral drug delivery system's bioavailability and targeted design.

AREAS COVERED

Various nanoparticulate drug delivery systems (NPDDSs) based on lipids or polymers, such as liposomes, solid lipid nanoparticles, polymeric micelles, nanospheres, and nanocapsules and their application in successful treatment of serious diseases such as intestinal bowel disease and colorectal cancer (CRC). These systems can ensure advantages over conventional systems liked improved bioavailability, prolonged residence time, and enhanced solubility of poorly soluble drugs. Moreover, the nature of these NPDDSs led to numerous breakthroughs in bioavailability, active and passive targeting, controlled release, and cost-efficient production on an industrial scale in recent years.

EXPERT OPINION

An expert opinion on orally administrable lipid and polymer based NPDDS, the physiological barriers and their use in the treatment of intestinal bowel disease and CRC is provided within this review.

Poly-ɛ-caprolactone nanocapsules loaded with copaiba essential oil reduce inflammation and pain in mice

Diverse drugs have been used for the management of inflammation disorders and pain. However, they present many side effects and stimulate the search for new pharmacotherapeutic alternatives. Plant-derived products such as copaiba essential oil (CO) offer beneficial pharmacological effects. On the other hand, essential oil's low water solubility and physical instability hinder itsin vivoapplication. Thus, poly-ɛ-caprolactone (PCL)-based nanocarriers have been used to increase their stability and efficacy. This work aimed to encapsulate CO in PCL nanocapsules and evaluate their effect on inflammation models and pain. The polymeric nanocapsules loading CO (CO-NC) were prepared by nanoprecipitation technique, characterized, and analyzed for their anti-inflammatory effectin vitroandin vivo. The results showed that CO-NC presented a spherical shape, 229.3 ± 1.5 nm diameter, and a negative zeta potential (approximately -23 mV). CO and CO-NC presented anti-inflammatory and antioxidant effects by LPS-activated macrophages (J774 cells). In addition, CO-NC significantly reduced TNF-α secretion (3-fold) compared to CO.In vivo, pre-treatment with CO or CO-NC (50, 100, 200 mg/kg, intraperitoneal; i.p) reduced the mechanical allodynia, paw edema, and pro-inflammatory cytokines induced by intraplantar (i.pl) injection of carrageenan in mice. Specifically, CO-NC (200 mg/kg; i.p.) reduced the production of TNF-α similar to the control group. Our results support using polymeric nanocapsules for CO delivery in inflammatory conditions.

Drug-Loaded Silver Nanoparticles-A Tool for Delivery of a Mebeverine Precursor in Inflammatory Bowel Diseases Treatment

Chronic, multifactorial illnesses of the gastrointestinal tract include inflammatory bowel diseases. One of the greatest methods for regulated medicine administration in a particular region of inflammation is the nanoparticle system. Silver nanoparticles (Ag NPs) have been utilized as drug delivery systems in the pharmaceutical industry. The goal of the current study is to synthesize drug-loaded Ag NPs using a previously described 3-methyl-1-phenylbutan-2-amine, as a mebeverine precursor (MP). Methods: A green, galactose-assisted method for the rapid synthesis and stabilization of Ag NPs as a drug-delivery system is presented. Galactose was used as a reducing and capping agent forming a thin layer encasing the nanoparticles. Results: The structure, size distribution, zeta potential, surface charge, and the role of the capping agent of drug-loaded Ag NPs were discussed. The drug release of the MP-loaded Ag NPs was also investigated. The Ag NPs indicated a very good drug release between 80 and 85%. Based on the preliminary results, Ag NPs might be a promising medication delivery system for MP and a useful treatment option for inflammatory bowel disease. Therefore, future research into the potential medical applications of the produced Ag NPs is necessary.

Surface-anchored microbial enzyme-responsive solid lipid nanoparticles enabling colonic budesonide release for ulcerative colitis treatment

Colon-targeted oral drug delivery systems (CDDSs) are desirable for the treatment of ulcerative colitis (UC), which is a disease with high relapse and remission rates associated with immune system inflammation and dysregulation localized within the lining of the large bowel. However, the success of current available approaches used for colon-targeted therapy is limited. Budesonide (BUD) is a corticosteroid drug, and its rectal and oral formulations are used to treat UC, but the inconvenience of rectal administration and the systemic toxicity of oral administration restrict its long-term use. In this study, we designed and prepared colon-targeted solid lipid nanoparticles (SLNs) encapsulating BUD to treat UC by oral administration. A negatively charged surfactant (NaCS-C12) was synthesized to anchor cellulase-responsive layers consisting of polyelectrolyte complexes (PECs) formed by negatively charged NaCS and cationic chitosan onto the SLNs. The release rate and colon-specific release behavior of BUD could be easily modified by regulating the number of coated layers. We found that the two-layer BUD-loaded SLNs (SLN-BUD-2L) with a nanoscale particle size and negative zeta potential showed the designed colon-specific drug release profile in response to localized high cellulase activity. In addition, SLN-BUD-2L exhibited excellent anti-inflammatory activity in a dextran sulfate sodium (DSS)-induced colitis mouse model, suggesting its potential anti-UC applications.

Hyaluronic acid-coated gold nanoparticles as a controlled drug delivery system for poorly water-soluble drugs

Hyaluronic acid (HA) is a natural linear polysaccharide which has been widely used in cosmetics and pharmaceuticals including drug delivery systems because of its excellent biocompatibility. In this study, we investigated the one-pot synthesis of HA-coated gold nanoparticles (AuNP-HA) as a drug delivery carrier. The HAs with different molecular weights were produced by e-beam irradiation and employed as coating materials for AuNPs. Sulfasalazine (SSZ), a poorly water-soluble drug, was used to demonstrate the efficiency of drug delivery and the controlled release behaviour of the AuNP-HA. As the molecular weight of the HA decreased, the drug encapsulation efficiency of the SSZ increased up to 94%, while drug loading capacity of the SSZ was maintained at the level of about 70%. The prepared AuNP-HA-SSZ exhibited slow release of the SSZ over a short time and excellent sensitivity to different pHs and physiological conditions. The SSZ release rate was the lowest in simulated gastric conditions and the highest in simulated intestinal conditions. In this case, the AuNP-HA protects the SSZ from release under the acidic pH conditions in the stomach; on the other hand, the drug release was facilitated in the basic environment of the small intestine and colon. The SSZ was released under simulated intestinal conditions through anomalous drug transport and followed the Korsmeyer-Peppas model. Therefore, this study suggests that AuNP-HA is a promising orally-administered and intestine-targeted drug delivery system with controlled release characteristics.

pH-sensitive molybdenum (Mo)-based polyoxometalate nanoclusters have therapeutic efficacy in inflammatory bowel disease by counteracting ferroptosis

Current therapeutic drugs for ulcerative colitis (UC) remained inadequate due to drug dependence and unacceptable adverse events. Reactive oxygen species (ROS) played a critical role in the occurrence and development of UC, which most likely benefited from treatment in scavenging ROS. In this study, we developed a pH-sensitive molybdenum-based polyoxometalate (POM) nanocluster, which might contribute to site specific colonic delivery and enhance systemic efficacy of UC treatment. Our results demonstrated that POM displayed robust ROS scavenging ability in vitro. POM could significantly alleviate the enteric symptoms and inflammatory indicators in DSS-induced UC mouse models. Flow cytometry showed an effective diminishment of macrophages, neutrophils and T cells infiltration after POM administration in UC models. Also, for the first time, we demonstrated that POM interfered with metabolic pathway associated to oxidative stress and partially improved the abnormal production of intestinal metabolites in UC to some extent. Benefiting from the ROS scavenging ability, POM attenuated ferroptosis in DSS induced UC, as evidenced by increase of GSH, down-expression of GPX4 and improvement in mitochondrial morphological changes. Meanwhile, there were no side effects on normal tissues. Thus, our powerful therapeutic effects pioneered the application of POM for safer and more effective POM-based UC therapy.

Hyaluronic acid/serotonin-decorated cerium dioxide nanomedicine for targeted treatment of ulcerative colitis

Ulcerative colitis (UC) is a chronic nonspecific inflammatory bowel disease often characterized by rapid progression and frequent comorbidities that make its treatment challenging. In colonic ulcers of UC patients, myeloperoxidase (MPO) is highly expressed, which results in an abundance of macrophages and reactive oxygen species. This study developed an active MPO-targeting hyaluronic acid/serotonin ceria nanoenzyme (HA-5-HT@CeO₂) using the electrostatic interaction between CeO₂ nanoparticles, 5-hydroxyserotonin-cerium oxide and hyaluronic acid. Based on the dual targeting effects of MPO and the macrophage CD44+ receptor in locating the inflammatory site in conjunction with the inflammatory area of the colon through electrostatic action, CeO₂ nanoparticles along with multiple similar enzymes were used to eliminate O₂, H₂O₂ and ˙OH and other reactive oxygen species, achieving targeted repair of the intestinal epithelial barrier through the elimination of inflammatory factors. In studies involving pharmacodynamics in vitro and DSS-induced animal models of acute colitis in vivo, HA-5-HT@CeO₂ has been shown to reduce inflammation further and treat ulcerative colitis compared to traditional drugs. Additionally, active targeting of MPO inflammation can lead to accurate drug delivery to the site and can minimize the side effects associated with the drug. HA-5-HT@CeO₂ is a promising novel drug for the treatment of ulcerative colitis. In addition to illustrating the benefits of this novel nanodrug delivery in treating ulcerative colitis compared to traditional medications, this study provides theoretical and experimental support for its application to any targeted therapy for ulcerative colitis.

The application of natural product-delivering micro/nano systems in the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a type of recurrent intestinal diseases. Natural product molecules have been gradually developed into an important source of anti-inflammatory drugs for treating IBD owing to their high anti-inflammatory activity, well known safety, structural specificity and therapeutic mechanism diversity. However, most of the natural products are restricted by poor solubility in actual application. How to achieve satisfactory bioavailability during the treatment of IBD is one of the urgent problems to be solved in the current research. Micro/nano drug delivery systems could improve the solubility of drugs with targeted delivery of anti-inflammatory drugs to the colon with responsive release property. Therefore, using micro/nano drug delivery systems, the problems mentioned above involving natural product molecules in the treatment of IBD could be solved. According to the compositions of the intestinal tract and inflammatory characteristics of IBD, the strategies of using micro/nano drug delivery systems for natural products could be summarized in two steps: targeted delivery and responsive release. In this review, the targeted and responsive release strategies of the micro/nano drug delivery systems combined with their anti-inflammatory effects in IBD animal models to illustrate that the proposed strategies could be potential treatments for symptomatic IBD are described.

Impact of gastric and bowel surgery on gastrointestinal drug delivery

General surgical procedures on the gastrointestinal tract are commonly performed worldwide. Surgical resections of the stomach, small intestine, or large intestine can have a significant impact on the anatomy and physiological environment of the gastrointestinal tract. These physiological changes can affect the effectiveness of orally administered formulations and drug absorption and, therefore, should be considered in rational drug formulation design for specific pathological conditions that are commonly associated with surgical intervention. For optimal drug delivery, it is important to understand how different surgical procedures affect the short-term and long-term functionality of the gastrointestinal tract. The significance of the surgical intervention is dependent on factors such as the specific region of resection, the degree of the resection, the adaptive and absorptive capacity of the remaining tissue, and the nature of the underlying disease. This review will focus on the common pathological conditions affecting the gastric and bowel regions that may require surgical intervention and the physiological impact of the surgery on gastrointestinal drug delivery. The pharmaceutical considerations for conventional and novel oral drug delivery approaches that may be impacted by general surgical procedures of the gastrointestinal tract will also be addressed.

Hydrogel Derived from Glucomannan-Chitosan to Improve the Survival of Lactobacillus acidophilus FNCC 0051 in Simulated Gastrointestinal Fluid

The probiotic encapsulating hydrogel derived from porang (Amorphophallus oncophyllus) glucomannan and chitosan was investigated with regard to its encapsulation efficiency, physical properties, prebiotic activity, and survival under simulated gastrointestinal conditions. The hydrogel's encapsulation efficiency was improved by varying the number of the Lactobacillus acidophilus FNCC 0051, which also served to increase the diameter (2-3 mm), polydispersity index (1.23-1.65), positive zeta potential, whiteness, and brightness of the hydrogel. Moreover, the hydrogel's prebiotic activity score was higher than that of inulin after 24 h of incubation, reflecting its role as a cell encapsulant, particularly when it comes to maintaining cells during exposure to simulated gastrointestinal fluid. The cell viability increased from 86% to 100% when immersed in intestinal juice, which is comparable to the increase achieved using alginate and konjac glucomannan hydrogels. Future animal studies are required to determine the cell viability in actual gastrointestinal conditions and assess the health effects of the hydrogel.

Enteric Polymer-Coated Porous Silicon Nanoparticles for Site-Specific Oral Delivery of IgA Antibody

Porous silicon (pSi) nanoparticles are loaded with Immunoglobulin A-2 (IgA2) antibodies, and the assembly is coated with pH-responsive polymers on the basis of the Eudragit family of enteric polymers (L100, S100, and L30-D55). The temporal release of the protein from the nanocomposite formulations is quantified following an in vitro protocol simulating oral delivery: incubation in simulated gastric fluid (SGF; at pH 1.2) for 2 h, followed by a fasting state simulated intestinal fluid (FasSIF; at pH 6.8) or phosphate buffer solution (PBS; at pH 7.4). The nanocomposite formulations display a negligible release in SGF, while more than 50% of the loaded IgA2 is released in solutions at a pH of 6.8 (FasSIF) or 7.4 (PBS). Between 21 and 44% of the released IgA2 retains its functional activity. A capsule-based system is also evaluated, where the IgA2-loaded particles are packed into a gelatin capsule and the capsule is coated with either EudragitL100 or EudragitS100 polymer for a targeted release in the small intestine or the colon, respectively. The capsule-based formulations outperform polymer-coated nanoparticles in vitro, preserving 45-54% of the activity of the released protein.

Colonic Delivery of Nutrients for Sustained and Prolonged Release of Gut Peptides: A Novel Strategy for Appetite Management

Obesity is one of the major global threats to human health and risk factors for cardiometabolic diseases and certain cancers. Glucagon-like peptide-1 (GLP-1) plays a major role in appetite and glucose homeostasis and recently the USFDA approved GLP-1 agonists for the treatment of obesity and type 2 diabetes. GLP-1 is secreted from enteroendocrine L-cells in the distal part of the gastrointestinal (GI) tract in response to nutrient ingestion. Endogenously released GLP-1 has a very short half-life of <2 min and most of the nutrients are absorbed before reaching the distal GI tract and colon, which hinders the use of nutritional compounds for appetite regulation. The review article focuses on nutrients that endogenously stimulate GLP-1 and peptide YY (PYY) secretion via their receptors in order to decrease appetite as preventive action. In addition, various delivery technologies such as pH-sensitive, mucoadhesive, time-dependent, and enzyme-sensitive systems for colonic targeting of nutrients delivery are described. Sustained colonic delivery of nutritional compounds could be one of the most promising approaches to prevent obesity and associated metabolic diseases by, e.g., sustained GLP-1 release.

Microfluidized Dextran Microgels Loaded with Cisplatin/SPION Lipid Nanotherapeutics for Local Colon Cancer Treatment via Oral Administration

Multifunctional sequential targeted delivery system is developed as an efficient therapeutic strategy against malignant tumors with selective accumulation and minimal systemic drug absorption. The therapeutic system is comprised of microfluidized dextran microgels encapsulating cisplatin/superparamagnetic iron oxide nanoparticles (SPIONs)-loaded trilaurin-based lipid nanoparticles (LNPs). The microgel system is imparted hierarchically dual targeting via dextran and folic acid (FA) residues, leading to increases both in retention of the microgels in colon and in cellular uptake of the therapeutic LNPs by colon cancer cells while being used for oral therapeutic delivery. Encapsulation of the therapeutic LNPs into dextran microgels attained by microfluidized crosslinking reaction reduces gastrointestinal adhesion and prevents the FA-modified LNPs from cellular transport by proton-coupled FA transporters in small intestine during their oral delivery to colon. Upon enzymatic degradation of the dextran microgels by dextranase present exclusively in colon, LNPs thus released become more recognizable and readily internalized by FA receptor-overexpressing colon cancer cells. The combined chemo/magnetothermal therapeutic effect of dual targeted lipid nanoparticle-loaded microgels from entrapped lipidized cisplatin and alternating magnetic field-treated SPIONs significantly inhibits tumor growth and suppresses metastatic peritoneal carcinomatosis in orthotopic colon cancer-bearing mice.

Budesonide-Loaded Hyaluronic Acid Nanoparticles for Targeted Delivery to the Inflamed Intestinal Mucosa in a Rodent Model of Colitis

The aim of the present study was to investigate the therapeutic potential of budesonide- (BDS-) loaded hyaluronic acid nanoparticles (HANPs) for treatment of inflammatory bowel disease (IBD) using an acute model of colitis in rats. The therapeutic efficacy of BDS-loaded HANPs in comparison with an aqueous suspension of the drug with the same dose (30 μg/kg) was investigated 48 h following induction of colitis by intrarectal administration of acetic acid 4% in rats. Microscopic and histopathologic examinations were conducted in inflamed colonic tissue. Tissue concentration of tumor necrosis factor (TNF)-α was assessed by ELISA assay kit, while the activity of myeloperoxidase (MPO) was measured spectrophotometrically. Results from in vivo evaluations demonstrated that administrations of BDS-HANPs ameliorated the general endoscopic appearance, quite close to the healthy animals with no signs of inflammation and reduced the cellular infiltration, as well as the TNF-α level, and the MPO activity. It was found that delivery by BDS-loaded HANPSs alleviated the induced colitis significantly better than the same dose of the free drug. These data further suggest the potential of HANPs as a targeted drug delivery system to the inflamed colon mucosa.

Nanoparticles for oral delivery: targeted therapy for inflammatory bowel disease

As a group of chronic and idiopathic gastrointestinal (GI) disorders, inflammatory bowel disease (IBD) is characterized by recurrent intestinal mucosal inflammation. Oral administration is critical for the treatment of IBD. Unfortunately, it is difficult to target the bowel located in the GI tract due to multiple physical barriers. The unique physicochemical properties of nanoparticle-based drug delivery systems (DDSs) and their enhanced permeability and retention effects in the inflamed bowel, render nanomedicines to be used to implement precise drug delivery at diseased sites in IBD therapy. In this review, we described the pathophysiological features of IBD, and designed strategies to exploit these features for intestinal targeting. In addition, we introduced the types of currently developed nano-targeted carriers, including synthetic nanoparticle-based and emerging naturally derived nanoparticles (e.g., extracellular vesicles and plant-derived nanoparticles). Moreover, recent developments in targeted oral nanoparticles for IBD therapy were also highlighted. Finally, we presented challenges associated with nanotechnology and potential directions for future IBD treatment.

Apigenin-Mn(II) loaded hyaluronic acid nanoparticles for ulcerative colitis therapy in mice

Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disease characterized by rapid progression and frequent comorbidities that make its treatment challenging. Nanomaterial-based strategies have been extensively studied to target the GI mucosal immune system in recent years. Herein, we propose a novel apigenin-Mn(II) loaded sodium hyaluronate nanoparticles where apigenin (API) was incorporated in the Mn2+ ramework, coated with hyaluronic acid. The apigenin-Mn(II) loaded sodium hyaluronate nanoparticles (API-Mn(II)@HA NPs) exhibited a diameter of 200 nm and were effective against UC. The preparation of the API-Mn(II) complex was relatively simple, and the mechanism underlying its therapeutic effect on UC induced by sodium dextran sulfate (DSS) was studied in detail. We found that API-Mn(II)@HA nanoparticles could effectively repair the intestinal barrier and significantly improve the damaged colon tissue by mediating inflammatory factors. This study provides novel insights on a new kind of active targeted nanoparticle for improving the efficacy of drugs for UC treatment.

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.

Novel drug delivery systems for inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic illness characterized by relapsing inflammation of the intestines. The disorder is stratified according to the severity and is marked by its two main phenotypical representations: Ulcerative colitis and Crohn's disease. Pathogenesis of the disease is ambiguous and is expected to have interactivity between genetic disposition, environmental factors such as bacterial agents, and dysregulated immune response. Treatment for IBD aims to reduce symptom extent and severity and halt disease progression. The mainstay drugs have been 5-aminosalicylates (5-ASAs), corticosteroids, and immunosuppressive agents. Parenteral, oral and rectal routes are the conventional methods of drug delivery, and among all, oral administration is most widely adopted. However, problems of systematic drug reactions and low specificity in delivering drugs to the inflamed sites have emerged with these regular routes of delivery. Novel drug delivery systems have been introduced to overcome several therapeutic obstacles and for localized drug delivery to target tissues. Enteric-coated microneedle pills, various nano-drug delivery techniques, prodrug systems, lipid-based vesicular systems, hybrid drug delivery systems, and biologic drug delivery systems constitute some of these novel methods. Microneedles are painless, they dislodge their content at the affected site, and their release can be prolonged. Recombinant bacteria such as genetically engineered Lactococcus Lactis and eukaryotic cells, including GM immune cells and red blood cells as nanoparticle carriers, can be plausible delivery methods when evaluating biologic systems. Nano-particle drug delivery systems consisting of various techniques are also employed as nanoparticles can penetrate through inflamed regions and adhere to the thick mucus of the diseased site. Prodrug systems such as 5-ASAs formulations or their derivatives are effective in reducing colonic damage. Liposomes can be modified with both hydrophilic and lipophilic particles and act as lipid-based vesicular systems, while hybrid drug delivery systems containing an internal nanoparticle section for loading drugs are potential routes too. Leukosomes are also considered as possible carrier systems, and results from mouse models have revealed that they control anti- and pro-inflammatory molecules.

Untangling Mucosal Drug Delivery: Engineering, Designing, and Testing Nanoparticles to Overcome the Mucus Barrier

Mucus is a complex viscoelastic gel and acts as a barrier covering much of the soft tissue in the human body. High vascularization and accessibility have motivated drug delivery to various mucosal surfaces; however, these benefits are hindered by the mucus layer. To overcome the mucus barrier, many nanomedicines have been developed, with the goal of improving the efficacy and bioavailability of drug payloads. Two major nanoparticle-based strategies have emerged to facilitate mucosal drug delivery, namely, mucoadhesion and mucopenetration. Generally, mucoadhesive nanoparticles promote interactions with mucus for immobilization and sustained drug release, whereas mucopenetrating nanoparticles diffuse through the mucus and enhance drug uptake. The choice of strategy depends on many factors pertaining to the structural and compositional characteristics of the target mucus and mucosa. While there have been promising results in preclinical studies, mucus-nanoparticle interactions remain poorly understood, thus limiting effective clinical translation. This article reviews nanomedicines designed with mucoadhesive or mucopenetrating properties for mucosal delivery, explores the influence of site-dependent physiological variation among mucosal surfaces on efficacy, transport, and bioavailability, and discusses the techniques and models used to investigate mucus-nanoparticle interactions. The effects of non-homeostatic perturbations on protein corona formation, mucus composition, and nanoparticle performance are discussed in the context of mucosal delivery. The complexity of the mucosal barrier necessitates consideration of the interplay between nanoparticle design, tissue-specific differences in mucus structure and composition, and homeostatic or disease-related changes to the mucus barrier to develop effective nanomedicines for mucosal delivery.

pH-Sensitive nanoparticles containing 5-fluorouracil and leucovorin as an improved anti-cancer option for colon cancer

Background: Parenteral administration of chemotherapeutic drugs, 5-fluorouracil (5-FU) and leucovorin (LV), is commonly used to treat large bowel carcinomas such as colon cancer (CC) and colorectal carcinoma (CRC). Aim: Our study aims to design a novel nanoparticulate drug-delivery vehicle for oral use capable of colon-specific release. Methods: A modified double-emulsion solvent evaporation method was used in the preparation of pH-responsive Eudargit^® S100 polymeric nanoparticles, loaded with 5-FU/LV combination (5-FU/LV-loaded Eudargit S100 NPs). Results: Our optimized drug-loaded NP showed a pH-responsive drug release and exhibited significantly more cytotoxic actions in cancer-cell lines than free drugs. Conclusion: These findings open the way for conducting clinical trials for colon malignancies treated with nanoparticles.

Hemoglobin bio-adhesive nanoparticles as a colon-specific delivery system for sustained release of 5-aminosalicylic acid in the effective treatment of inflammatory bowel disease

A colonic drug delivery system was developed to specifically deliver 5-aminosalicylic acid (5-ASA) to the inflamed site by conjugating with hemoglobin nanoparticles (HbNPs). The 5-ASA-HbNPs (eight 5-ASA molecules per Hb molecule) with the size of 220 nm and zeta potential of -14.6 mV is a tailored nanoparticle able to pass through the mucus layer. The 5-ASA-HbNPs do not undergo chemical and enzymatic hydrolysis in the simulated gastrointestinal fluids over 6 h. Significantly higher cellular uptakes and prolonged release was seen for the 5-ASA-HbNPs in Caco-2 cells, compared to free 5-ASA over 72 h. In addition, 5-ASA-HbNPs revealed similar therapeutic effectiveness with free 5-ASA against tumor necrosis factor and showed less inhibitory concentration (IC50) for myeloperoxidase enzyme activity. In vivo imaging of mouse demonstrated the localization of drug in the descending colon after oral administration and about 15% of the administered dose was recovered as 5-ASA from urine in 6 h. The use of these nanoparticles with the mucus adhesion properties and permeability to intestinal epithelial cells can be a good candidate with potential application in the colonic drug delivery field.

Preparation and in vitro/in vivo evaluation of a self-microemulsifying drug delivery system containing chrysin

OBJECTIVE

To prepare a self-microemulsifying drug delivery system (SMEDDS) to increase the solubility and oral bioavailability of chrysin.

METHODS

The preparation conditions were determined using factor analysis method. Preliminarily screening was conducted using compatibility tests and pseudo-ternary phase diagram studies. The central composite design-response surface methodology was used to determine the maximum drug loading and optimize SMEDDS formation, as characterized by surface morphology, pH, diameter, polydispersity index (PDI), zeta potential, and phase type. In vitro release of chrysin-suspension and chrysin-SMEDDS was investigated using the bulk-equilibrium reverse dialysis bag technique. Short-term stability of chrysin-SMEDDS at high and low temperatures was assessed. Pharmacokinetic behaviors were evaluated after intragastric and intravenous administration to rats.

RESULTS

The final optimal formulation was medium chain triglyceride:oleic acid:Cremophor RH40: Transcutol HP (w/w) (12%:12%:32%:44%), with a drug loading capacity of 5 mg/g. Diluted chrysin-SMEDDS was characterized as an oil-in-water type and spherical, with a diameter, pH, PDI, and zeta potential of 28.26 ± 0.83 nm, 5.60 ± 0.84, 0.18 ± 0.01, and -23.13 ± 0.95 mV, respectively. The release speed of chrysin-SMEDDS was significantly higher than that of chrysin-suspension, and the release process was not affected by the media pH. In vivo pharmacokinetic data revealed that the oral bioavailability of chrysin-SMEDDS was 2.7-fold higher than that of chrysin suspension, compared with the chrysin microemulsion.

CONCLUSION

The optimal SMEDDS formulation increased the dissolution and oral bioavailability of chrysin and may be useful for investigating chrysin efficacy in animal disease models and toxicokinetic studies.

pH-Responsive Alginate-Based Microparticles for Colon-Targeted Delivery of Pure Cyclosporine A Crystals to Treat Ulcerative Colitis

Cyclosporine A (CsA) is a potent immunosuppressant for treating ulcerative colitis (UC). However, owing to severe systemic side effects, CsA application in UC therapy remains limited. Herein, a colon-targeted drug delivery system consisting of CsA crystals (CsAc)-loaded, Eudragit S 100 (ES)-coated alginate microparticles (CsAc-EAMPs) was established to minimize systemic side effects and enhance the therapeutic efficacy of CsA. Homogeneously-sized CsAs (3.1 ± 0.9 μm) were prepared by anti-solvent precipitation, followed by the fabrication of 47.1 ± 6.5 μm-sized CsAc-EAMPs via ionic gelation and ES coating. CsAc-EAMPs exhibited a high drug loading capacity (48 ± 5%) and a CsA encapsulation efficacy of 77 ± 9%. The in vitro drug release study revealed that CsA release from CsAc-EAMPs was suppressed under conditions simulating the stomach and small intestine, resulting in minimized systemic absorption and side effects. Following exposure to the simulated colon conditions, along with ES dissolution and disintegration of alginate microparticles, CsA was released from CsAc-EAMPs, exhibiting a sustained-release profile for up to 24 h after administration. Given the effective colonic delivery of CsA molecules, CsAc-EAMPs conferred enhanced anti-inflammatory activity in mouse model of dextran sulfate sodium (DSS)-induced colitis. These findings suggest that CsAc-EAMPs is a promising drug delivery system for treating UC.

Evaluating the mucoprotective effects of glycyrrhizic acid-loaded polymeric nanoparticles in a murine model of 5-fluorouracil-induced intestinal mucositis via suppression of inflammatory mediators and oxidative stress

OBJECTIVES

5-Fluorouracil (5-FU), a chemotherapeutic drug, has severe deteriorating effects on the intestine, leading to mucositis. Glycyrrhizic acid is a compound derived from a common herbal plant Glycyrrhiza glabra, with mucoprotective, antioxidant and anti-inflammatory actions, however, associated with poor pharmacokinetics. Owing to the remarkable therapeutic action of glycyrrhizic acid-loaded polymeric nanocarriers in inflammatory bowel disease, we explored their activity against 5-FU-induced intestinal mucositis in mice. Polymeric nanocarriers have proven to be efficient drug delivery vehicles for the long-term treatment of inflammatory diseases, but have not yet been explored for 5-FU-induced mucositis. Therefore, this study aimed to produce glycyrrhizic acid-loaded polylactic-co-glycolic acid (GA-PLGA) nanoparticles to evaluate their protective and therapeutic effects in a 5-FU-induced mucositis model.

METHODS

GA-PLGA nanoparticles were prepared using a modified double emulsion method, physicochemically characterized, and tested for in vitro drug release. Thereafter, mucositis was induced by 5-FU (50 mg/kg; IP) administration to the mice for the first 3 days (day 0, 1, 2), and mice were treated orally with GA-PLGA nanoparticles for 7 days (day 0-6).

RESULTS

GA-PLGA nanoparticles significantly reduced mucositis severity measured by body weight, diarrhea score, distress, and anorexia. Further, 5-FU induced intestinal histopathological damage, altered villi-crypt length, reduced goblet cell count, elevated pro-inflammatory mediators, and suppressed antioxidant enzymes, all of which were reversed by GA-PLGA nanoparticles.

CONCLUSION

Morphological, behavioral, histological, and biochemical results suggested that GA-PLGA nanoparticles were efficient, biocompatible, targeted, and sustained release drug delivery nano-vehicle for enhanced mucoprotective, anti-inflammatory, and antioxidant effects in 5-FU-induced intestinal mucositis.