Potential prospects of nanomedicine for targeted therapeutics in inflammatory bowel diseases

Orally available dextran-aspirin nanomedicine modulates gut inflammation and microbiota homeostasis for primary colorectal cancer therapy

Reversing the aggravated immunosuppression hence overgrowth of colorectal cancer (CRC) caused by the gut inflammation and microbiota dysbiosis is pivotal for effective CRC therapy and metastasis inhibition. However, the low delivery efficiency and severe dose-limiting off-target toxicities caused by unsatisfied drug delivery systems remain the major obstacles in precisely modulating gut inflammation and microbiota in CRC therapy. Herein, a multifunctional oral dextran-aspirin nanomedicine (P3C-Asp) was utilized for oral treatment of primary CRC, as it could release salicylic acid (SA) while scavenging reactive oxygen species (ROS) and held great potential in modulating gut microbiota with prebiotic (dextran). Oral P3C-Asp retained in CRC tissues for over 12 h and significantly increased SA accumulation in CRC tissues over free aspirin (10.8-fold at 24 h). The enhanced SA accumulation and ROS scavenging of P3C-Asp cooperatively induced more potent inflammation relief over free aspirin, characterized as lower level of cyclooxygenase-2 and immunosuppressive cytokines. Remarkably, P3C-Asp promoted the microbiota homeostasis and notably increased the relative abundance of strengthening systemic anti-cancer immune response associated microbiota, especially lactobacillus and Akkermansia to 6.66- and 103- fold over the control group. Additionally, a demonstrable reduction in pathogens associated microbiota (among 96% to 79%) including Bacteroides could be detected. In line with our findings, inflammation relief along with enhanced abundance of lactobacillus was positively correlated with CRC inhibition. In primary CRC model, P3C-Asp achieved 2.1-fold tumor suppression rate over free aspirin, with an overall tumor suppression rate of 85%. Moreover, P3C-Asp cooperated with αPD-L1 further reduced the tumor weight of each mouse and extended the median survival of mice by 29 days over αPD-L1 alone. This study unravels the synergistic effect of gut inflammation and microbiota modulation in primary CRC treatment, and unlocks an unconventional route for immune regulation in TME with oral nanomedicine.

Circular and Circulating DNA in Inflammatory Bowel Disease: From Pathogenesis to Potential Molecular Therapies

Inflammatory bowel diseases (IBD), including Crohn's Disease (CD) and Ulcerative Colitis (UC) are chronic multifactorial disorders which affect the gastrointestinal tract with variable extent. Despite extensive research, their etiology and exact pathogenesis are still unknown. Cell-free DNAs (cfDNAs) are defined as any DNA fragments which are free from the origin cell and able to circulate into the bloodstream with or without microvescicles. CfDNAs are now being increasingly studied in different human diseases, like cancer or inflammatory diseases. However, to date it is unclear how IBD etiology is linked to cfDNAs in plasma. Extrachromosomal circular DNA (eccDNA) are non-plasmidic, nuclear, circular and closed DNA molecules found in all eukaryotes tested. CfDNAs appear to play an important role in autoimmune diseases, inflammatory processes, and cancer; recently, interest has also grown in IBD, and their role in the pathogenesis of IBD has been suggested. We now suggest that eccDNAs also play a role in IBD. In this review, we have comprehensively collected available knowledge in literature regarding cfDNA, eccDNA, and structures involving them such as neutrophil extracellular traps and exosomes, and their role in IBD. Finally, we focused on old and novel potential molecular therapies and drug delivery systems, such as nanoparticles, for IBD treatment.

UBE2W Improves the Experimental Colitis by Inhibiting the NF-κB Signaling Pathway

BACKGROUND

The NF-κB signaling cascade regulates immune response and is often dysregulated in tumor development. UBE2W is a novel type I ubiquitin-conjugating enzyme (E2) whose biological function is still unclear.

AIMS

This study was designed to investigate whether UBE2W regulates NF-κB signaling pathway and is involved in the progression of experimental colitis.

METHODS

At the cellular level, the effect of UBE2W on NF-κB transcriptional activity was measured using a dual-luciferase reporter assay. The influence of UBE2W on NF-κB pathway activation and the entry of p65 into the nucleus were determined by Western blot and immunofluorescence analyses, respectively. Moreover, the colitis model was established by administering 2.5% dextran sulfate sodium (DSS)/water to UBE2W overexpression, UBE2W-knockdown and control mice. Body weight, stool consistency, colon length and clinical severity were examined. Expression of pro-inflammatory cytokines and phosphorylation of p65 and IκB in the colon tissue were measured by qRT-PCR and Western blot, respectively.

RESULTS

UBE2W inhibited TNFα-induced NF-κB transcription activity, attenuated IκB and p65 phosphorylation, downregulated TNFα and IL-8 expression and blocked the entry of p65 into the nucleus. In the DSS-induced colitis model, UBE2W-knockdown mice had increased weight loss, more serious diarrhea and mucosal injures compared with the control mice. Moreover, phosphorylation of IκB and p65 and the expression of pro-inflammatory mediators such as TNFα, IL-6 were significantly increased in UBE2W knockdown mice. However, these changes were completely reversed in UBE2W overexpression mice.

CONCLUSIONS

The overexpression of UBE2W ameliorates the severity of DSS-induced colitis, which may be mediated by inhibiting the expression of pro-inflammatory mediators and activation of the NF-κB signaling pathway. These findings provide evidence that UBE2W might have potential therapeutic implications in IBD.

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.

Protection against ulcerative colitis and colorectal cancer by evodiamine via anti‑inflammatory effects

Evodiamine (Evo) is an alkaloid that can be extracted from the berry fruit Evodia rutaecarpa and has been reported to exert various pharmacological effects, such as antidiarrheal, antiemetic and antiulcer effects. In vivo, the potential effects of Evo were investigated in a mouse model of dextran sodium sulfate (DSS)‑induced ulcerative colitis (UC) and in adenomatous polyposis coli (Apc)MinC/Gpt C57BL/6 mice with colorectal cancer (CRC), where the latter harbours a point‑mutation in the Apc gene. Evo suppressed the degree of weight loss and colon shortening induced by DSS, decreased the disease activity index value and ameliorated the pathological alterations in the colon of mice with UC as examined via H&E staining of colon tissues. In addition, Evo decreased the number and size of colonic tumors in ApcMinC/Gpt mice. Proteomics (colon tissues), ELISA (colon tissues and serum) and western blotting (colon tissues) results revealed that Evo inhibited NF‑κB to mediate the levels of various cytokines, including, in the DSS‑induced UC model, IL‑1β, IL‑2, IL‑6, IL‑8, TNF‑α, IFN‑γ (ELISA of colon tissues and serum), NF‑κB, IKKα+β, IκBα, S100a9, TLR4 and MyD88 (western blotting of colon tissues), and, in the colorectal cancer model, IL‑1β, IL‑2, IL‑6, IL‑15, IL‑17, IL‑22, TNF‑α (ELISA of colon tissues and serum), NF‑κB, IKKα+β, IκBα and S100a9 (western blotting of colon tissues), to achieve its anti‑inflammatory and antitumor effects. In vitro, Evo also reduced the viability of the colon cancer cell line SW480, inhibited mitochondrial membrane potential (MMP detection), caused G2/M‑phase arrest (cell cycle detection) and suppressed the translocation of phosphorylated‑NF‑κB from the cytoplasm into the nucleus (immunofluorescence of p‑NF‑κB). Theoretical evidence (MD simulations) suggest that Evo may bind to the ordered domain (α‑helix) of NF‑κB to influence this protein. The protein secondary structure changes were analyzed by the cpptraj module in Amber. In addition, these data provide experimental evidence that Evo may be an effective agent for treating UC and CRC.

Advances in the treatment of inflammatory bowel disease: Focus on polysaccharide nanoparticulate drug delivery systems

The complex pathogenesis of inflammatory bowel disease (IBD) explains the several hurdles for finding an efficient approach to cure it. Nowadays, therapeutic protocols aim to reduce inflammation during the hot phase or maintain remission during the cold phase. Nonetheless, these drugs suffer from severe side effects or poor efficacy due to low bioavailability in the inflamed region of the intestinal tract. New protocols based on antibodies that target proinflammatory cytokines are clinically relevant. However, besides being expensive, their use is associated with a primary nonresponse or a loss of response following a long administration period. Accordingly, many researchers exploited the physiological changes of the mucosal barrier for designing nanoparticulate drug delivery systems to target inflamed tissues. Others exploited biocompatibility and relative affordability of polysaccharides to test their intrinsic anti-inflammatory and healing properties in IBD models. This critical review updates state of the art on advances in IBD treatment. Data on using polysaccharide nanoparticulate drug delivery systems for IBD treatment are reviewed and discussed.

Current Strategies and Potential Prospects of Nanomedicine-Mediated Therapy in Inflammatory Bowel Disease

Inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis are highly debilitating. IBDs are associated with the imbalance of inflammatory mediators within the inflamed bowel. Conventional drugs for IBD treatment include anti-inflammatory medications and immune suppressants. However, they suffer from a lack of bioavailability and high dose-induced systemic side effects. Nanoparticle (NP)-derived therapy improves therapeutic efficacy and increases targeting specificity. Recent studies have shown that nanomedicines, based on bowel disease's pathophysiology, are a fast-growing field. NPs can prolong the circulation period and reduce side effects by improving drug encapsulation and targeted delivery. Here, this review summarizes various IBD therapies with a focus on NP-derived applications, whereas their challenges and future perspectives have also been discussed.

Inflammatory Bowel Disease: The Emergence of New Trends in Lifestyle and Nanomedicine as the Modern Tool for Pharmacotherapy

The human intestine, which harbors trillions of symbiotic microorganisms, may enter into dysbiosis when exposed to a genetic defect or environmental stress. The naissance of chronic inflammation due to the battle of the immune system with the trespassing gut bacteria leads to the rise of inflammatory bowel disease (IBD). Though the genes behind the scenes and their link to the disease are still unclear, the onset of IBD occurs in young adults and has expanded from the Western world into the newly industrialized countries. Conventional drug deliveries depend on a daily heavy dosage of immune suppressants or anti-inflammatory drugs targeted for the treatment of two types of IBD, ulcerative colitis (UC) and Crohn's disease (CD), which are often associated with systemic side effects and adverse toxicities. Advances in oral delivery through nanotechnology seek remedies to overcome the drawbacks of these conventional drug delivery systems through improved drug encapsulation and targeted delivery. In this review, we discuss the association of genetic factors, the immune system, the gut microbiome, and environmental factors like diet in the pathogenesis of IBD. We also review the various physiological concerns required for oral delivery to the gastrointestinal tract (GIT) and new strategies in nanotechnology-derived, colon-targeting drug delivery systems.

Carboxymethyl chitosan microspheres loaded hyaluronic acid/gelatin hydrogels for controlled drug delivery and the treatment of inflammatory bowel disease

A major drawback of oral treatment of inflammatory bowel disease (IBD) is the non-specific distribution of drugs during long-term treatment. Despite its effectiveness as an anti-inflammatory drug, curcumin (CUR) is limited by its low bioavailability in IBD treatment. Herein, a pH-sensitive composite hyaluronic acid/gelatin (HA/GE) hydrogel drug delivery system containing carboxymethyl chitosan (CC) microspheres loaded with CUR was fabricated for IBD treatment. The composition and structure of the composite system were optimized and the physicochemical properties were characterized using infrared spectroscopy, X-ray diffraction, swelling, and release behavior studies. In vitro, the formulation exhibited good sustained release property and the drug release rate was 65% for 50 h. In vivo pharmacokinetic experiments indicated that high level of CUR was maintained in the colon tissue for more than 24 h; it also played an anti-inflammatory role by evaluating the histopathological changes through hematoxylin and eosin (H&E), myeloperoxidase (MPO), and immunofluorescent staining. Additionally, the formulation substantially inhibited the level of the main pro-inflammatory cytokines of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) secreted by macrophages, compared to the control group. The pharmacodynamic experiment showed that the formulation group of CUR@gels had the best therapeutic effect on colitis in mice. The composite gel delivery system has potential for the effective delivery of CUR in the treatment of colitis. This study also provides a reference for the design and preparation of a new oral drug delivery system with controlled release behavior.

Role of nanostructures in improvising oral medicine

The most preferable mode of drugs administration is via the oral route but physiological barriers such as pH, enzymatic degradation etc. limit the absolute use of this route. Herein lies the importance of nanotechnology having a wide range of applications in the field of nano-medicine, particularly in drug delivery systems. The exclusive properties particularly small size and high surface area (which can be modified as required), exhibited by these nanoparticlesrender these structures more suitable for the purpose of drug delivery. Various nanostructures, like liposomes, dendrimers, mesoporous silica nanoparticles, etc. have been designed for the said purpose. These nanostructures have several advantages over traditional administration of medicine. Apart from overcoming the pharmacokinetic and pharmacodynamics limitations of many potential therapeutic molecules, they may also be useful for advanced drug delivery purposes like targeted drug delivery, controlled release, enhanced permeability and retention (EPR) effect. In this review, we attempt to describe an up-to-date knowledge on various strategically devised nanostructures to overcome the problems related to oral drug administration.

Oral Drug Delivery Systems for Ulcerative Colitis Therapy: A Comparative Study with Microparticles and Nanoparticles

Background:

Oral administrations of microparticles (MPs) and nanoparticles (NPs) have been widely employed as therapeutic approaches for the treatment of ulcerative colitis (UC). However, no previous study has comparatively investigated the therapeutic efficacies of MPs and NPs.

Methods:

In this study, curcumin (CUR)-loaded MPs (CUR-MPs) and CUR-loaded NPs (CUR-NPs) were prepared using a single water-in-oil emulsion solvent evaporation technique. Their therapeutic outcomes against UC were further comparatively studied.

Results:

The resultant spherical MPs and NPs exhibited slightly negative zeta-potential with average particle diameters of approximately 1.7 µm and 270 nm, respectively. It was found that NPs exhibited a much higher CUR release rate than MPs within the same period of investigation. In vivo experiments demonstrated that oral administration of CUR-MPs and CUR-NPs reduced the symptoms of inflammation in a UC mouse model induced by dextran sulfate sodium. Importantly, CUR-NPs showed much better therapeutic outcomes in alleviating UC compared with CUR-MPs.

Conclusion:

NPs can improve the anti-inflammatory activity of CUR by enhancing the drug release and cellular uptake efficiency, in comparison with MPs. Thus, they could be exploited as a promising oral drug delivery system for effective UC treatment.

Formulation, stabilisation and encapsulation of bacteriophage for phage therapy

Against a backdrop of global antibiotic resistance and increasing awareness of the importance of the human microbiota, there has been resurgent interest in the potential use of bacteriophages for therapeutic purposes, known as phage therapy. A number of phage therapy phase I and II clinical trials have concluded, and shown phages don't present significant adverse safety concerns. These clinical trials used simple phage suspensions without any formulation and phage stability was of secondary concern. Phages have a limited stability in solution, and undergo a significant drop in phage titre during processing and storage which is unacceptable if phages are to become regulated pharmaceuticals, where stable dosage and well defined pharmacokinetics and pharmacodynamics are de rigueur. Animal studies have shown that the efficacy of phage therapy outcomes depend on the phage concentration (i.e. the dose) delivered at the site of infection, and their ability to target and kill bacteria, arresting bacterial growth and clearing the infection. In addition, in vitro and animal studies have shown the importance of using phage cocktails rather than single phage preparations to achieve better therapy outcomes. The in vivo reduction of phage concentration due to interactions with host antibodies or other clearance mechanisms may necessitate repeated dosing of phages, or sustained release approaches. Modelling of phage-bacterium population dynamics reinforces these points. Surprisingly little attention has been devoted to the effect of formulation on phage therapy outcomes, given the need for phage cocktails, where each phage within a cocktail may require significantly different formulation to retain a high enough infective dose. This review firstly looks at the clinical needs and challenges (informed through a review of key animal studies evaluating phage therapy) associated with treatment of acute and chronic infections and the drivers for phage encapsulation. An important driver for formulation and encapsulation is shelf life and storage of phage to ensure reproducible dosages. Other drivers include formulation of phage for encapsulation in micro- and nanoparticles for effective delivery, encapsulation in stimuli responsive systems for triggered controlled or sustained release at the targeted site of infection. Encapsulation of phage (e.g. in liposomes) may also be used to increase the circulation time of phage for treating systemic infections, for prophylactic treatment or to treat intracellular infections. We then proceed to document approaches used in the published literature on the formulation and stabilisation of phage for storage and encapsulation of bacteriophage in micro- and nanostructured materials using freeze drying (lyophilization), spray drying, in emulsions e.g. ointments, polymeric microparticles, nanoparticles and liposomes. As phage therapy moves forward towards Phase III clinical trials, the review concludes by looking at promising new approaches for micro- and nanoencapsulation of phages and how these may address gaps in the field.

Caffeic acid phenethyl ester is protective in experimental ulcerative colitis via reduction in levels of pro-inflammatory mediators and enhancement of epithelial barrier function

Background

Inhibition of the nuclear factor kappa beta (NF-κβ) pathway has been proposed as a therapeutic target due to its key role in the expression of pro-inflammatory genes, including pro-inflammatory cytokines, chemokines, and adhesion molecules. Caffeic acid phenethyl ester (CAPE) is a naturally occurring anti-inflammatory agent, found in propolis, and has been reported as a specific inhibitor of NF-κβ. However, the impact of CAPE on levels of myeloperoxidases (MPO) and pro-inflammatory cytokines during inflammation is not clear. The aims of this study were to investigate the protective efficacy of CAPE in the mouse model of colitis and determine its effect on MPO activity, pro-inflammatory cytokines levels, and intestinal permeability.

Method

Dextran sulphate sodium was administered in drinking water to induce colitis in C57/BL6 mice before treatment with intraperitoneal administration of CAPE (30 mg kg⁻¹ day⁻¹). Disease activity index (DAI) score, colon length and tissue histology levels of MPO, pro-inflammatory cytokines, and intestinal permeability were observed.

Results

CAPE-treated mice had lower DAI and tissue inflammation scores, with improved epithelial barrier protection and significant reduction in the level of MPO and pro-inflammatory cytokines.

Conclusion

Our results show that CAPE is effective in suppressing inflammation-triggered MPO activity and pro-inflammatory cytokines production while enhancing epithelial barrier function in experimental colitis. Thus, we conclude that CAPE could be a potential therapeutic agent for further clinical investigations for treatment of inflammatory bowel diseases in humans.

Electronic supplementary material

The online version of this article (doi:10.1007/s10787-017-0364-x) contains supplementary material, which is available to authorized users.

GLP-1 nanomedicine alleviates gut inflammation

The gut hormone, glucagon like peptide-1 (GLP-1) exerts anti-inflammatory effects. However, its clinical use is limited by its short half-life. Previously, we have shown that GLP-1 as a nanomedicine (GLP-1 in sterically stabilized phospholipid micelles, GLP-1-SSM) has increased in vivo stability. The current study was aimed at testing the efficacy of this GLP-1 nanomedicine in alleviating colonic inflammation and associated diarrhea in dextran sodium sulfate (DSS) induced mouse colitis model. Our results show that GLP-1-SSM treatment markedly alleviated the colitis phenotype by reducing the expression of pro-inflammatory cytokine IL-1β, increasing goblet cells and preserving intestinal epithelial architecture in colitis model. Further, GLP-1-SSM alleviated diarrhea (as assessed by luminal fluid) by increasing protein expression of intestinal chloride transporter DRA (down regulated in adenoma). Our results indicate that GLP-1 nanomedicine may act as a novel therapeutic tool in alleviating gut inflammation and associated diarrhea in inflammatory bowel disease (IBD).

Clinical efficacy of micro-ecological agents in treatment of mild and moderate ulcerative colitis

AIM: To assess the clinical efficacy of micro-ecological agents in the treatment of mild and moderate ulcerative colitis.

METHODS: Ninety-six patients with mild and moderate ulcerative colitis who were treated at Department of Gastroenterology of Fengtai Hospital Affiliated to Capital Medical University from January 2012 to December 2015 were selected, and they were randomly divided into either an observation group or a control group according to the order of admission. Patients in the control group received treatment with mesalazine, while patients in the observation group were treated with mesalazine combined with micro-ecological agents Bifico. All patients were treated for 12 wk. Ulcerative colitis activity index (UCAI) score, serum level of C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and clinical efficacy were compared between the two groups after treatment.

RESULTS: Patients' age, gender, severity of disease, UCAI score, serum level of CRP, and ESR did not differ significantly between the two groups before treatment (P > 0.05). After treatment, UCAI score, serum level of CRP, and ESR were significantly lower than those before treatment in both groups (P < 0.05), and the decrease was more significant in the observation group than in the control group (P < 0.05). The total effective rate of the observation group was 95.8%, which was significantly higher than 79.2% of the control group (χ² = 4.667, P = 0.031).

CONCLUSION: In the treatment of mild and moderate ulcerative colitis, mesalazine combined with micro-ecological agents can not only correct intestinal microflora disorders and maintain the intestinal micro-environment, but also reduce serum levels of inflammatory cytokines.

CUEDC2 Protects Against Experimental Colitis and Suppresses Excessive Proliferation of Intestinal Mucosa

BACKGROUND

CUEDC2, a CUE domain-containing protein, is highly expressed in many tumors, which also may be associated with inflammation.

AIMS

In this study, we studied whether CUEDC2 plays a role in the progress of inflammatory bowel disease using CUEDC2 knockout (KO) mice and discussed the effects of CUEDC2 on cell proliferation in colonic mucosa.

METHODS

CUEDC2 KO mice were administered with drinking dextran sodium sulfate (DSS) to establish colitis mice model. At different time points after DSS administration, body weight and stool consistency of mice were graded. Cytokines in colon tissue such as IL-6 were measured by RT-PCR. NF-κB and STAT3 signaling pathways in colon tissue were assessed by western blotting. Besides, cell proliferation of intestinal mucosa was analyzed by immunohistochemical staining.

RESULTS

CUEDC2 alleviated the colonic inflammation, showing elevated body weight loss, worse diarrhea, and more severe colonic mucosal injury in CUEDC2 KO mice than WT mice. Moreover, pro-inflammatory cytokines such as IL-6, TNFα, COX2, and MIP2 were significantly elevated. In CUEDC2 KO mice, the NF-κB and STAT3 signaling pathways were increasingly activated in different stages of progression of the colonic inflammation, and the percentage of proliferating cells as indicated by Ki67, CyclinD1, and BrdU in the inflammatory tissues was significantly increased.

CONCLUSIONS

Our findings demonstrate that CUEDC2 plays an important role in protection from colonic inflammation, primarily by inhibiting the NF-κB and STAT3 signaling pathways and preventing excessive proliferation of the inflammatory epithelial cell.

Nanomedicines for Endothelial Disorders

The endothelium lines the internal surfaces of blood and lymphatic vessels and has a critical role in maintaining homeostasis. Endothelial dysfunction is involved in the pathology of many diseases and conditions, including disorders such as diabetes, cardiovascular diseases, and cancer. Given this common etiology in a range of diseases, medicines targeting an impaired endothelium can strengthen the arsenal of therapeutics. Nanomedicine - the application of nanotechnology to healthcare - presents novel opportunities and potential for the treatment of diseases associated with an impaired endothelium. This review discusses therapies currently available for the treatment of these disorders and highlights the application of nanomedicine for the therapy of these major disease complications.

Pharmacogenetics of inflammatory bowel disease

Pharmacogenetic studies have been performed for almost all classes of drugs that have been used in IBD but very few have generated consistent findings or have been replicated. The genetic test that has been approved for clinical practice is TPMT testing prior to starting treatment with thiopurine drugs. Research in IBD pharmacogenetics has focused on prediction of drug efficacy and toxicity by identifying polymorphisms in the genes encoding enzymes that are involved in metabolic pathways. Recent research has mainly focused on therapeutic agents such as azathioprine, methotrexate, aminosalicylates, corticosteroids, infliximab and adalimumab. Future pharmaceutical trials should include pharmacogenetic research to test appropriate candidate genes in a prospective manner and correlate genetic associations with trial outcomes and relevant functional data.

Epstein-Barr virus is related with 5-aminosalicylic acid, tonsillectomy, and CD19+ cells in Crohn’s disease

AIM: To study anti-Epstein-Barr virus (EBV) IgG antibodies in Crohn´s disease in relation to treatment, immune cells, and prior tonsillectomy/appendectomy.

METHODS: This study included 36 CD patients and 36 healthy individuals (controls), and evaluated different clinical scenarios (new patient, remission and active disease), previous mucosa-associated lymphoid tissue removal (tonsillectomy and appendectomy) and therapeutic regimens (5-aminosalicylic acid, azathioprine, anti-tumor necrosis factor, antibiotics, and corticosteroids). T and B cells subsets in peripheral blood were analyzed by flow cytometry (markers included: CD45, CD4, CD8, CD3, CD19, CD56, CD2, CD3, TCRαβ and TCRγδ) to relate with the levels of anti-EBV IgG antibodies, determined by enzyme-linked immunosorbent assay.

RESULTS: The lowest anti-EBV IgG levels were observed in the group of patients that were not in a specific treatment (95.4 ± 53.9 U/mL vs 131.5 ± 46.2 U/mL, P = 0.038). The patients that were treated with 5-aminosalicylic acid showed the highest anti-EBV IgG values (144.3 U/mL vs 102.6 U/mL, P = 0.045). CD19⁺ cells had the largest decrease in the group of CD patients that received treatment (138.6 vs 223.9, P = 0.022). The analysis of anti-EBV IgG with respect to the presence or absence of tonsillectomy showed the highest values in the tonsillectomy group of CD patients (169.2 ± 20.7 U/mL vs 106.1 ± 50.3 U/mL, P = 0.002). However, in the group of healthy controls, no differences were seen between those who had been tonsillectomized and subjects who had not been operated on (134.0 ± 52.5 U/mL vs 127.7 ± 48.1 U/mL, P = 0.523).

CONCLUSION: High anti-EBV IgG levels in CD are associated with 5-aminosalicylic acid treatment, tonsillectomy, and decrease of CD19⁺ cells.

Advances in oral nano-delivery systems for colon targeted drug delivery in inflammatory bowel disease: selective targeting to diseased versus healthy tissue

Colon targeted drug delivery is an active area of research for local diseases affecting the colon, as it improves the efficacy of therapeutics and enables localized treatment, which reduces systemic toxicity. Targeted delivery of therapeutics to the colon is particularly advantageous for the treatment of inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease. Advances in oral drug delivery design have significantly improved the bioavailability of drugs to the colon; however in order for a drug to have therapeutic efficacy during disease, considerations must be made for the altered physiology of the gastrointestinal (GI) tract that is associated with GI inflammation. Nanotechnology has been used in oral dosage formulation design as strategies to further enhance uptake into diseased tissue within the colon. This review will describe some of the physiological challenges faced by orally administered delivery systems in IBD, the important developments in orally administered nano-delivery systems for colon targeting, and the future advances of this research.

FROM THE CLINICAL EDITOR

Inflammatory Bowel Disease (IBD) poses a significant problem for a large number of patients worldwide. Current medical therapy mostly aims at suppressing the active inflammatory episodes. In this review article, the authors described and discussed the various approaches current nano-delivery systems can offer in overcoming the limitations of conventional drug formulations.

Nanotechnology in the treatment of inflammatory bowel diseases

BACKGROUND AND AIMS

Treatment of inflammatory bowel diseases (IBD) is only aimed to block or inhibit the pathogenetic steps of the inflammatory cascade. Side effects of systemic therapies, poor targeting of orally administered topical drug and low adherence to prescription represent frequent therapeutic challenges. Recent observations suggest that nanotechnology could provide amazing advantage in this field since particles having dimension in the nanometer scale (nanoparticles) can modify pharmacokinetic step of biologic and conventional therapeutic agents with a better delivery of drugs within the intestinal inflammatory cells. The aim of this review was to provide the clinician with an insight into the potential role of nanotechnology in the treatment of IBD.

METHODS

A systematic search (PubMed) for experimental studies on the treatment of intestinal inflammation using nanotechnology for the delivery of drugs.

RESULTS AND CONCLUSIONS

The size of the pharmaceutical formulation is inversely related to specificity for inflammation. Nanoparticles can penetrate epithelial and inflammatory cells resulting in much higher, effective and long-acting concentrations than can be obtained using conventional delivery systems. From a practical point of view, this should lead to improvements in both efficacy and adherence to treatment, providing patients with the prospect of stable and prolonged remissions with reduced drug loadings. Reduced systemic side effects could also be expected.

New strategies for treatment of inflammatory bowel disease

The etiology of inflammatory bowel disease (IBD), of which ulcerative colitis (UC) and Crohn’s disease (CD) are the two most prevailing entities, is unknown. However, IBD is characterized by an imbalanced synthesis of pro-inflammatory mediators of the inflamed intestine, and for more than a decade tumor necrosis factor-(TNF) α has been a major target for monoclonal antibody therapy. However, TNF inhibitors are not useful for one third of all patients (i.e. “primary failures”), and further one third lose effect over time (“secondary failures”). Therefore, other strategies have in later years been developed including monoclonal antibodies targeting the interleukin (IL)-6 family of receptors (the p40 subunit of IL-12/IL-23) as well as monoclonal antibodies inhibiting adhesion molecules (the α₄β₇ heterodimers), which direct leukocytes to the intestinal mucosa. Recently, small molecules, which are inhibitors of Janus kinases (JAKs), hold promise with a tolerable safety profile and efficacy in UC, and the field of nanomedicine is emerging with siRNAs loaded into polyactide nanoparticles that may silence gene transcripts at sites of intestinal inflammation. Thus, drug development for IBD holds great promise, and patients as well as their treating physicians can be hopeful for the future.

Blockade of CXCR2 signalling: A potential therapeutic target for preventing neutrophil-mediated inflammatory diseases

Polymorphonuclear neutrophils (PMN) play a key role in host innate immune responses by migrating to the sites of inflammation. Furthermore, PMN recruitment also plays a significant role in the pathophysiology of a plethora of inflammatory disorders such as chronic obstructive pulmonary disease (COPD), gram negative sepsis, inflammatory bowel disease (IBD), lung injury, and arthritis. Of note, chemokine-dependent signalling is implicated in the amplification of immune responses by virtue of its role in PMN chemotaxis in most of the inflammatory diseases. It has been clinically established that impediment of PMN recruitment ameliorates disease severity and provides relief in majority of other immune-associated disorders. This review focuses on different novel approaches clinically proven to be effective in blocking chemokine signalling associated with PMN recruitment that includes CXCR2 antagonists, chemokine analogs, anti-CXCR2 monoclonal antibodies, and CXCR2 knock-out models. It also highlights the significance of the utility of nanoparticles in drugs used for blocking migration of PMN to the sites of inflammation.

New therapeutic avenues in ulcerative colitis: thinking out of the box

Ulcerative colitis (UC) is a chronic idiopathic inflammatory disease of the gastrointestinal tract that affects the mucosal lining of the colon. Recent epidemiological data show that its incidence and prevalence are increasing in many parts of the world, in parallel with altered lifestyles, improved access to health, improved sanitation and industrialisation rates. Current therapeutic strategies for treating UC have only been moderately successful. Despite major recent advances in inflammatory bowel disease therapeutic resources, a considerable proportion of patients are still refractory to conventional treatment. Less than half of all patients achieve long-term remission, many require colectomy, and the disease still has a major impact on patients' lives. Moreover, recent data point to slightly raised mortality. While these outcomes could be partly improved by optimising current therapeutic strategies, they clearly highlight the need to develop new therapies. Currently, a number of promising and innovative therapeutic approaches are being explored, some of which will hopefully survive to reach the clinic. Until such a time arrives, it is important that a better understanding of the clinical particularities of the disease, an improved knowledge of the host-microbiome negative interactions and of the environmental factors beyond disease development is achieved to obtain the final and desired outcome: to provide better treatment and quality of life for patients with this disabling disease.