Epithelial heparin delivery via microspheres mitigates experimental colitis in mice

Adalimumab Decorated Nanoparticles Enhance Antibody Stability and Therapeutic Outcome in Epithelial Colitis Targeting

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract with increasing incidence worldwide. Although a deeper understanding of the underlying mechanisms of IBD has led to new therapeutic approaches, treatment options are still limited. Severe adverse events in conventional drug therapy and poor drug targeting are the main cause of early therapy failure. Nanoparticle-based targeting approaches can selectively deliver drugs to the site of inflammation and reduce the risk of side effects by decreasing systemic availability. Here, we developed a nanoparticulate platform for the delivery of the anti-TNF-α antibody adalimumab (ADA) by covalent crosslinking to the particle surface. ADA binding to nanoparticles improved the stability of ADA against proteolytic degradation in vitro and led to a significantly better therapeutic outcome in a murine colitis model. Moreover, immobilization of ADA reduced systemic exposure, which can lead to enhanced therapeutic safety. Thus, nanoparticle protein decoration constitutes a platform through which epithelial delivery of any biological of interest to the inflamed gut and hence a local treatment can be achieved.

pH-dependent ileocolonic drug delivery, part II: preclinical evaluation of novel drugs and novel excipients

Novel drugs and novel excipients in pH-dependent ileocolonic drug delivery systems have to be tested in animals. Which animal species are suitable and what in vivo methods are used to verify ileocolonic drug delivery?

Low-Molecular-Weight Heparins: Reduced Size Particulate Systems for Improved Therapeutic Outcomes

A wide range of diseases have been treated using low-molecular-weight heparins (LMWHs), the drug of choice for anticoagulation. Owing to their better pharmacokinetic features compared to those of unfractionated heparin (uFH), several systems incorporating LMWHs have been investigated to deliver and improve their therapeutic outcomes, especially through development of their micro- and nano-particles. This review article describes current perspectives on the fabrication, characterization, and application of LMWHs-loaded micro- and nano-particles to achieve ameliorated bioavailability. The valuable applications of LMWH will continue to encourage researchers to identify efficient delivery systems that have specific release characteristics and ameliorated bioavailability, overcoming the challenges presented by biological obstructions and the physicochemical properties of LMWHs.

More than an anticoagulant: Do heparins have direct anti-inflammatory effects?

The heparins, well-known for their anticoagulant properties, may also have anti-inflammatory effects that could contribute to their effectiveness in the treatment of venous thromboembolism and other vascular diseases. This review focuses on the inflammatory pathophysiology that underlies the development of thrombosis and the putative effects of heparin on these pathways. We present evidence supporting the use of heparin for other indications, including autoimmune disease, malignancy, and disseminated intravascular coagulation. These considerations highlight the need for further research to elucidate the mechanisms of the possible pleiotropic effects of the heparins, with a view to advancing treatments based upon heparin derivatives.

Nanoparticle-based delivery enhances anti-inflammatory effect of low molecular weight heparin in experimental ulcerative colitis

Epithelial administration of low molecular weight heparin (LMWH) has proven its therapeutic efficiency in ulcerative colitis (UC) but still lacks of a sufficiently selective drug delivery system. Polymeric nanoparticles were used here not only to protect LMWH from intestinal degradation but also to provide targeted delivery to inflamed tissue in experimental colitis mice. LMWH was associated with polymethacrylate nanoparticles (NP) type A (PEMT-A) or type B (PEMT-B) of a size: 150 nm resulting in a maximum drug loading: 0.1 mg/mg. In a lipopolysaccharide-stimulated macrophages both, free LMWH and LMWH-NP have significantly reduced the cytokines secretion independently from cellular uptake. The in-vivo therapeutic efficiency was dose dependent as at low doses (100 IU/kg) only minor differences between free LMWH and LMWH-NP were found and the superiority of LMWH-NP became prominent with dose increase (500 IU/kg). Administration of LMWH-NP at 500 IU/kg has markedly improved the clinical activity as compared to LMWH while similarly pathophysiological indicators revealed increased therapeutic outcome in presence of NP compared to LMWH alone: Myeloperoxidase (Colitis control: 10 480 ± 5335, LMWH-PEMT-A NP: 1507 ± 2165, LMWH-PEMT-B NP: 382 ± 143, LMWH: 8549 ± 5021 units/g) and tumor necrosis factor: (Colitis control: 1636 ± 544, LMWH-PEMT-A NP: 511 ± 506, LMWH-PEMT-B NP: 435 ± 473, LMWH: 1110 ± 309 pg/g). Associating LMWH with NP is improving the anti-inflammatory efficiency of LMWH in-vivo by its protection against degradation in luminal environment and selective drug delivery. Such a combination holds promise for a highly specific therapy by its double selectivity towards the inflamed intestinal tissue. LMWH-PEMT NP have significantly improved the clinical activity in-vivo in comparison to free LMWH.

Intestinal anti-inflammatory effects of RGD-functionalized silk fibroin nanoparticles in trinitrobenzenesulfonic acid-induced experimental colitis in rats

BACKGROUND

Current treatment of inflammatory bowel disease is based on the use of immunosuppressants or anti-inflammatory drugs, which are characterized by important side effects that can limit their use. Previous research has been performed by administering these drugs as nanoparticles that target the ulcerated intestinal regions and increase their bioavailability. It has been reported that silk fibroin can act as a drug carrier and shows anti-inflammatory properties.

PURPOSE

This study was designed to enhance the interaction of the silk fibroin nanoparticles (SFNs) with the injured intestinal tissue by functionalizing them with the peptide motif RGD (arginine-glycine-aspartic acid) and to evaluate the intestinal anti-inflammatory properties of these RGD-functionalized silk fibroin nanoparticles (RGD-SFNs) in the trinitrobenzenesulfonic acid (TNBS) model of rat colitis.

MATERIALS AND METHODS

SFNs were prepared by nanoprecipitation in methanol, and the linear RGD peptide was linked to SFNs using glutaraldehyde as the crosslinker. The SFNs (1 mg/rat) and RGD-SFNs (1 mg/rat) were administered intrarectally to TNBS-induced colitic rats for 7 days.

RESULTS

The SFN treatments ameliorated the colonic damage, reduced neutrophil infiltration, and improved the compromised oxidative status of the colon. However, only the rats treated with RGD-SFNs showed a significant reduction in the expression of different pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, and IL-12) and inducible nitric oxide synthase in comparison with the TNBS control group. Moreover, the expression of both cytokine-induced neutrophil chemoattractant-1 and monocyte chemotactic protein-1 was significantly diminished by the RGD-SFN treatment. However, both treatments improved the intestinal wall integrity by increasing the gene expression of some of its markers (trefoil factor-3 and mucins).

CONCLUSION

SFNs displayed intestinal anti-inflammatory properties in the TNBS model of colitis in rats, which were improved by functionalization with the RGD peptide.

Effect of aqueous and particulate silk fibroin in a rat model of experimental colitis

Silk fibroin (SF) has anti-inflammatory properties and promotes wound healing. Moreover, SF particles act as carriers of active drugs against intestinal inflammation due to their capacity to deliver the compound to the damaged colonic tissue. The present work assesses the effect of SF in the trinitrobenzenesulfonic acid model of rat colitis that resembles human intestinal inflammation. SF (8mg/kg) was administered in aqueous solution orally and in two particulate formats by intrarectal route, following two technologies: spray drying to make microparticles and desolvation in organic solvent to produce nanoparticles. SF treatments ameliorated the colonic damage, reduced neutrophil infiltration and improved the compromised oxidative status of the colon. They also reduced the gene expression of pro-inflammatory cytokines like IL-1β and the anti-inflammatory cytokine IL-10. Moreover, they improved the intestinal wall integrity by increasing the gene expression of some of its markers (villin, trefoil factor-3 and mucins), thus accelerating the healing. The immunomodulatory properties of SF particles were also tested in vitro in macrophages: they activated the immune response in basal conditions without increasing it after a pro-inflammatory insult. In conclusion, SF particles could be useful as carriers to deliver active drugs to the damaged intestinal colon with additional anti-inflammatory and healing properties.

Magnesium lithospermate B acts against dextran sodiumsulfate-induced ulcerative colitis by inhibiting activation of the NRLP3/ASC/Caspase-1 pathway

This study aimed to observe the therapeutic effects of magnesium lithospermate B on acute and chronic colitis induced by dextran sodiumsulfate (DSS) and the role of inflammasome complex (NOD-like receptor protein, NLRP; apoptosis-associated speck-like protein containing, ASC; caspase-1). Establishment of acute and chronic colitis models were by using 5% DSS oral administration in BALB/C male mice. Magnesium lithospermate B (240 mg/kg body weight) was given by subcutaneous injection. Samples were collected for biomarker assay, histological examination, immunohistochemical evaluation and western blot. There was obvious increase in TNF-α level and NLPR3, ASC, and caspase-1 expressions in acute and chronic colitis groups compared with the normal control. Significant decrease of the tumor necrosis factor-α level and the expressions of NLPR3, ASC, and caspase-1 were observed after treatment with magnesium lithospermate B. This study showed that magnesium lithospermate B could be used to treat acute and chronic colitis by inhibiting the activation of the NLRP3/ASC/Caspase-1 pathway.

Heparins in ulcerative colitis: proposed mechanisms of action and potential reasons for inconsistent clinical outcomes

Current drug therapies for ulcerative colitis (UC) are not completely effective in managing moderate-to-severe UC and approximately 20% of patients with severe UC require surgical interventions. Heparins, polydisperse mixtures of non-anticoagulant and anticoagulant oligosaccharides, are widely used as anticoagulants. However, heparins are also reported to have anti-inflammatory properties. Unfractionated heparin was initially used in patients with UC for the treatment of rectal microthrombi. Surprisingly, it was found to be effective in reducing UC-associated symptoms. Since then, several pre-clinical and clinical studies have reported promising outcomes of heparins in UC. In contrast, some controlled clinical trials demonstrated no or only limited benefits, thus the potential of heparins for the treatment of UC remains uncertain. This review discusses potential mechanisms of action of heparins, as well as proposed reasons for their contradictory clinical effectiveness in the treatment of UC.

Orally Administered Enoxaparin Ameliorates Acute Colitis by Reducing Macrophage-Associated Inflammatory Responses

Inflammatory bowel diseases, such as ulcerative colitis, cause significant morbidity and decreased quality of life. The currently available treatments are not effective in all patients, can be expensive and have potential to cause severe side effects. This prompts the need for new treatment modalities. Enoxaparin, a widely used antithrombotic agent, is reported to possess anti-inflammatory properties and therefore we evaluated its therapeutic potential in a mouse model of colitis. Acute colitis was induced in male C57BL/6 mice by administration of dextran sulfate sodium (DSS). Mice were treated once daily with enoxaparin via oral or intraperitoneal administration and monitored for colitis activities. On termination (day 8), colons were collected for macroscopic evaluation and cytokine measurement, and processed for histology and immunohistochemistry. Oral but not intraperitoneal administration of enoxaparin significantly ameliorated DSS-induced colitis. Oral enoxaparin-treated mice retained their body weight and displayed less diarrhea and fecal blood loss compared to the untreated colitis group. Colon weight in enoxaparin-treated mice was significantly lower, indicating reduced inflammation and edema. Histological examination of untreated colitis mice showed a massive loss of crypt architecture and goblet cells, infiltration of immune cells and the presence of edema, while all aspects of this pathology were alleviated by oral enoxaparin. Reduced number of macrophages in the colon of oral enoxaparin-treated mice was accompanied by decreased levels of pro-inflammatory cytokines. Oral enoxaparin significantly reduces the inflammatory pathology associated with DSS-induced colitis in mice and could therefore represent a novel therapeutic option for the management of ulcerative colitis.

Nanomedicines in gastroenterology and hepatology

Nanoscale systems are currently under investigation for multiple different diagnostic and therapeutic applications. These systems can be used to identify pathologically changed tissues or to selectively deliver drugs to these sites; both applications have an extremely high potential to ameliorate therapeutic outcomes for patients. Tissues as well as single cells can be targeted because of the small size of these systems, which enables enhanced diagnosis and increased specificity of therapy. Drug loads can be delivered directly to the site of action, which can result in a reduction in incidence and severity of adverse systemic effects. Several nano-based platform technologies are currently under investigation for use in therapeutic approaches, mainly for anti-inflammatory and anti-cancer therapies. Although many nanoscale systems show promising therapeutic outcomes in preclinical studies, only a limited number are ready for clinical use. This Review will discuss the diverse nanomaterials currently available and the first specific uses for select gastroenterological and hepatological pathologies. The discussion of diagnostic and therapeutic applications will consider realities of market introduction of these sometimes very complex systems in light of remaining regulatory challenges and hurdles for industrial production.

Central role of the gut epithelial barrier in the pathogenesis of chronic intestinal inflammation: lessons learned from animal models and human genetics

The gut mucosa is constantly challenged by a bombardment of foreign antigens and environmental microorganisms. As such, the precise regulation of the intestinal barrier allows the maintenance of mucosal immune homeostasis and prevents the onset of uncontrolled inflammation. In support of this concept, emerging evidence points to defects in components of the epithelial barrier as etiologic factors in the pathogenesis of inflammatory bowel diseases (IBDs). In fact, the integrity of the intestinal barrier relies on different elements, including robust innate immune responses, epithelial paracellular permeability, epithelial cell integrity, as well as the production of mucus. The purpose of this review is to systematically evaluate how alterations in the aforementioned epithelial components can lead to the disruption of intestinal immune homeostasis, and subsequent inflammation. In this regard, the wealth of data from mouse models of intestinal inflammation and human genetics are pivotal in understanding pathogenic pathways, for example, that are initiated from the specific loss of function of a single protein leading to the onset of intestinal disease. On the other hand, several recently proposed therapeutic approaches to treat human IBD are targeted at enhancing different elements of gut barrier function, further supporting a primary role of the epithelium in the pathogenesis of chronic intestinal inflammation and emphasizing the importance of maintaining a healthy and effective intestinal barrier.

Low molecular weight heparin relieves experimental colitis in mice by downregulating IL-1β and inhibiting syndecan-1 shedding in the intestinal mucosa

Low molecular weight heparin (LMWH) exhibits anti-inflammatory properties, but its effect on inflammation in colitis remains unclear. This study aimed to evaluate the therapeutic effects of LMWH on dextran sulfate sodium (DSS)-induced colitis in mice, in which acute colitis progresses to chronic colitis, and to explore the potential mechanism involved in this process. C57BL/6 mice were randomly divided into control, DSS, and DSS plus LMWH groups (n = 18). Disease activity was scored by a disease activity index (DAI). Histological changes were evaluated by hematoxylin and eosin (HE) staining. The mRNA levels of syndecan-1, interleukin (IL)-1β, and IL-10 were determined by quantitative reverse transcription polymerase chain reaction. Protein expression of syndecan-1 was detected by immunohistochemistry. The serum syndecan-1 level was examined by a dot immunobinding assay. LMWH ameliorated the disease activity of colitis induced by DSS administration in mice. Colon destruction with the appearance of crypt damage, goblet cell loss, and a larger ulcer was found on day 12 after DSS administration, which was greatly relieved by the treatment of LMWH. LMWH upregulated syndecan-1 expression in the intestinal mucosa and reduced the serum syndecan-1 level on days 12 and 20 after DSS administration (P<0.05 vs. DSS group). In addition, LMWH significantly decreased the expression of both IL-1β and IL-10 mRNA on days 12 and 20 (P<0.05 vs. DSS group). LMWH has therapeutic effects on colitis by downregulating inflammatory cytokines and inhibiting syndecan-1 shedding in the intestinal mucosa.

Protective effect of magnesium lithospermate B against dextran sodiumsulfate induced ulcerative colitis in mice

Anti-platelet drugs have been used to treat inflammatory bowel disease. In this study, we observed the therapeutic effects of magnesium lithospermate B, a main component of salvianolate, on colitis induced by dextran sodiumsulfate (DSS). Colitis was induced by 5% DSS oral administration in BALB/C male mice. Magnesium lithospermate B (60-240mg/kg) was given by subcutaneous injection for 2 weeks. Then, mice were sacrificed; serum and colon tissues were collected for biomarker assay, histological examination, immunohistochemical study and real-time quantitative polymerase chain reaction. DSS induced gross bleeding, inflammation, crypt damage and mucosal damage in colon. Treatment with magnesium lithospermate B could reduce colon inflammation induced by DSS. Magnesium lithospermate B could reverse the high CD40/CD40L expression and hypercoagulable state induced by DSS in colon. This study showed that magnesium lithospermate B could be used to treat colitis. The protective effects of magnesium lithospermate B may be due to its effects on CD40/CD40L expression and blood clotting status.

Exogenous alkaline phosphatase treatment complements endogenous enzyme protection in colonic inflammation and reduces bacterial translocation in rats

Alkaline phosphatase (AP) inactivates bacterial lipopolysaccharide and may therefore be protective. The small intestine and colon express intestinal (IAP) and tissue nonspecific enzyme (TNAP), respectively. The aim of this study was to assess the therapeutic potential of exogenous AP and its complementarity with endogenous enzyme protection in the intestine, as evidenced recently. IAP was given to rats by the oral or intrarectal route (700U/kgday). Oral budesonide (1mg/kgday) was used as a reference treatment. Treatment with intrarectal AP resulted in a 54.5% and 38.0% lower colonic weight and damage score, respectively, and an almost complete normalization of the expression of S100A8, LCN2 and IL-1β (p<0.05). Oral AP was less efficacious, while budesonide had a more pronounced effect on most parameters. Both oral and intrarectal AP counteracted bacterial translocation effectively (78 and 100%, respectively, p<0.05 for the latter), while budesonide failed to exert a positive effect. AP activity was increased in the feces of TNBS colitic animals, associated with augmented sensitivity to the inhibitor levamisole, suggesting enhanced luminal release of this enzyme. This was also observed in the mouse lymphocyte transfer model of chronic colitis. In a separate time course study, TNAP was shown to increase 2-3 days after colitis induction, while dextran sulfate sodium was a much weaker inducer of this isoform. We conclude that exogenous AP exerts beneficial effects on experimental colitis, which includes protection against bacterial translocation. AP of the tissue-nonspecific isoform is shed in higher amounts to the intestinal lumen in experimental colitis, possibly aiding in intestinal protection.

Efficacy of oral colon-specific delivery capsule of low-molecular-weight heparin on ulcerative colitis

Low-molecular-weight heparin has the potential for the treatment of ulcerative colitis, and targeted drug delivery to the colon is important for topical treatment of this disease, so low-molecular-weight heparin oral colon-specific delivery capsule was prepared, and the in vitro and in vivo drug release behavior was investigated. The macroscopical and histological scoring systems, wet colon mass index and myeloperoxidase activity were assessed to evaluate the efficacy of the capsule after administered orally to experimental colitis mice. Serum levels, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and a link factor of blood coagulation and inflammation factor Xa (FXa) were assayed by enzyme-linked immunosorbent assay. The expression of Musashi-1 (as an intestinal stem cell marker) in the colons was assessed by immunohistochemical analysis. The in vitro and in vivo drug release studies clearly indicated that the specific coated capsules were capable of protecting low-molecular-weight heparin from releasing in stomach and small intestine, while specifically delivering at colon. The oral colon-specific delivery capsule of low-molecular-weight heparin could attenuate macroscopic and histological features of colitis. The results showed that low-molecular-weight heparin oral colon-specific delivery capsule significantly decreased the serum levels of TNF-α, IL-6 as well as FXa, while increased the expression of Musashi-1 in colon compared with acetic acid-induced ulcerative colitis model group. The results showed that low-molecular-weight heparin oral colon-specific delivery capsule had the potential for treatment of inflammatory bowel disease.

Effect of low molecular weight heparin rectal suppository on experimental ulcerative colitis in mice

The objective of this study was to investigate the effect and possible mechanism of rectally administered low molecular weight heparin (LMWH) on experimental ulcerative colitis. LMWH rectal suppository was prepared and its efficacy was studied by macroscopical and histological scoring systems as well as myeloperoxidase activity. Serum levels, including tumor necrosis factor-α (TNFα), interleukin-6 (IL-6) and a link factor of blood coagulation and inflammation factor Xa (FXa) were assayed by enzyme-linked immunosorbent assay. The expression of Musashi-1 (as an intestinal stem cell marker) in the colons was assessed by immunohistochemical analysis. The results showed that LMWH rectal suppository significantly decreased serum levels of TNF-α, IL-6 as well as FXa, while increased the expression of Musashi-1 in colon compared with acetic acid induced ulcerative colitis model group. All these preliminary results indicate LMWH rectal suppository is promising for treatment of ulcerative colitis.

Pectin/Kollicoat SR30D isolated films for colonic delivery [I]: a comparison of normal and colitis-induced models to assess the efficiency of microbially triggered drug delivery

Objectives

The purpose of the study was to evaluate digestion of pectin/Kollicoat SR30D free films for colonic delivery in vitro and in vivo.

Methods

Free films containing different ratios of pectin to Kollicoat SR30D were prepared by casting/solvent evaporation method. An in-vitro comparison of swelling, degradation and permeability of the free films was carried out in simulated colon fluids containing caecal contents from normal rats with colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) or oxazolone. A comparative in-vivo evaluation of degradation was also conducted in normal and colitis-induced model rats.

Key findings

The pectin within the mixed films was susceptible to rat colonic bacterial enzymes. The extent of digestion correlated with the amount of pectin present within the film. In vitro, the swelling index, drug permeability and extent of film digestion in simulated colon fluids with caecal contents obtained from normal rats were higher than from TNBS- or oxazolone-induced model rats, whereas in-vivo degradation was similar in the three groups of rats. The pectin/Kollicoat SR30D free films were completely degraded in the colitis-induced rats.

Conclusions

Pectic/Kollicoat SR30D films may be useful as coatings to target delivery of drugs to the colon.

Enoxaparin improves the course of dextran sodium sulfate-induced colitis in syndecan-1-deficient mice

Syndecan-1 (Sdc1) plays a major role in wound healing and modulates inflammatory responses. Sdc1 expression is reduced in lesions of patients with ulcerative colitis. The aim of this study was to investigate the role of Sdc1 in murine dextran sodium sulfate (DSS)-induced colitis. DSS colitis was induced in Sdc1-deficient (knockout (KO)) and wild-type mice by oral administration of 3% DSS. KO mice exhibited a significantly increased lethality as compared with wild-type controls (61 versus 5%, P < 0.05). Impaired mucosal healing and prolonged recruitment of inflammatory cells in KO mice were accompanied by significant up-regulation of tumor necrosis factor-alpha, CC chemokine ligand 3/macrophage inflammatory protein-1alpha, and vascular cell adhesion molecule-1, as determined by histological correlation between 0 and 15 days after colitis induction, TaqMan low-density array analysis, and quantitative real-time PCR. Treatment from days 7 through 14 with enoxaparin, a functional analogue of the Sdc1 heparan sulfate chains, significantly reduced lethality of KO mice due to DSS-induced colitis, which was correlated with improved mucosal healing. In vitro, Sdc1-deficient polymorphonuclear cells displayed increased adhesion to endothelial cells and intercellular adhesion molecule-1, and enoxaparin reverted adhesion to wild-type levels. Small interfering RNA-mediated knockdown of Sdc1 expression resulted in reduced basic fibroblast growth factor-mediated mitogen-activated protein kinase signaling and reduced Caco-2 cell proliferation. We conclude that Sdc1 has a protective effect during experimental colitis. The modification of missing Sdc1 function by heparin analogues may emerge as a promising anti-inflammatory approach.

Efficacy of intracolonic administration of low-molecular-weight heparin CB-01-05, compared to other low-molecular-weight heparins and unfractionated heparin, in experimentally induced colitis in rat

PURPOSE

Parenteral administration of low-molecular-weight heparins (LMWHs) and unfractionated heparin (UFH) resulted effective in improving the symptoms of experimental colitis in rat. Today, there is little information about their activity by intracolonic instillation. The scope of this study was to evaluate the ability of CB-01-05 (a LMWH with a mean molecular weight of about 5,700), compared to a series of other LMWHs and to UFH, directly instilled into the distal colon of the rat, to ameliorate dinitrobenzene (DNB)-induced experimental colitis.

METHOD

Adult male Wistar rats underwent colitis induction by intracolonic instillation of DNB. Starting 24 h after colitis induction, CB-01-05 (0.005-0.9 mg), other LMWHs (0.3-0.6 mg), and UFH (0.6 mg) were instilled, by rectal route, into the distal colon once a day for three consecutive days. On the day following the last administration, the animals were sacrificed and the distal colon was isolated, weighed, macroscopically examined, and processed for histology. Additional experiments in rat splenocytes, performed in order to elucidate the anti-inflammatory mechanisms of CB-01-05, were performed.

RESULTS

Among the tested items, only CB-01-05 at doses ranging from 0.2 to 0.9 mg was significantly effective in reducing colon weight increase and in improving both the mucosal damaged area and the histological score. The other LMWHs resulted far less effective, showing decreasing activity closely related with the decrease of their molecular weight, thus demonstrating their biological nonequivalence. CB-01-05 resulted also more active than UFH. CB-01-05 was shown to interfere with cytokines production by rat splenocytes, mainly inhibiting interferon (IFN)-gamma expression.

CONCLUSIONS

CB-01-05 instilled into the colon is well tolerated, has strong anti-inflammatory effect on DNB-induced colitis in rat, and is the most effective agent among other LMWHs and UFH. These results suggest that the anti-inflammatory activity of CB-01-05, together with its topical administration, could represent a new approach in the management of ulcerative colitis.

Delivery strategies to target therapies to inflammatory tissue

BACKGROUND

Inflammation plays a key role in many chronic disease processes as well as an acute role in injury and wound healing. Various cell types are recruited from the bloodstream to the inflamed site through adhesion molecules, cytokines, chemokines and others.

OBJECTIVES

This review examines many drug-targeting strategies that make use of these molecules or signaling pathways, and seeks to describe certain commonalities irrespective of the disease process or agent to be delivered.

METHODS

A survey of the literature, primarily within the last year, was performed. Search words included 'drug targeting' and 'inflammation' and of those, the scope was refined to include those studies that specifically sought to modify or ameliorate an aspect of the inflammatory process in the treatment of a disease.

RESULTS/CONCLUSION

Inflammation plays a key role in many diseases, and many similar targets (such as adhesion molecules) are the focus of the treatment of those diseases.

Alternative drug delivery approaches for the therapy of inflammatory bowel disease

This article shall give an overview on drug delivery systems for new therapeutic strategies in the treatment of inflammatory bowel disease. The various features of the different approaches allowing locally restricted drug delivery to the inflamed colon are discussed including the main physiological and pathophysiological limitations for the different systems. Conventional drug delivery systems are tightly adapted from developments for colonic delivery by oral administration triggered by release mechanisms owing to the physiological environment that these systems encounter in the colonic region. The newer developments in this context aim for an increased selectivity of drug delivery by targeting mechanisms which have a closer relation to pathophysiological particularities of the disease. Therefore, we were focused especially on new strategies for such treatment including liposomal formulations, cyclodextrins, micro- or nanoparticles, viral gene therapy approaches, and others. Effective and selective delivery even of an otherwise nonspecifically acting drug could provide new therapeutic pathways in the treatment of inflammatory bowel disease.

The targeting of surface modified silica nanoparticles to inflamed tissue in experimental colitis

One aspect in the emerging field of nanomedicine is site specific drug delivery via nanoparticles. The use of nanoparticles allows for increased therapeutic efficiency with a lowered risk for and extent of adverse reactions resulting from systemic drug absorption. 5-Amino salicylic acid (5ASA) loaded silica nanoparticles (SiNP) are proposed here as drug delivery system for specific accumulation in inflamed colonic tissues allowing for selective medication delivery to such inflammation sites. The drug was covalently bound to SiNP by a four-step reaction process. In-vitro toxicity of modified SiNP was tested in appropriate cell culture systems, while targeting index and therapeutic efficiency were evaluated in a pre-existing colitis in mice. Particle diameter was around 140 nm after final surface modification. In-vitro drug release demonstrated significant drug retention inside the NP formulation. Toxicity of the different formulations was evaluated in-vitro cell culture exhibiting a lowered toxicity for 5ASA when bound to SiNP. In-vivo, oral SiNP were found to accumulate selectively in the inflamed tissues allowing for significant amounts of drug load. SiNP demonstrated their therapeutic potential by significantly lowering the therapeutically necessary drug dose when evaluating clinical activity score and myeloperoxidase activity (untreated control: 28.0+/-5.0 U/mg; 5ASA-solution (100mg/kg): 8.2+/-3.4 U/mg 5ASA-SiNP (25mg/kg): 5.2+/-2.4 U/mg). SiNP allow to combine advantages from selective drug targeting and prodrugs appearing to be a promising therapeutic approach for clinical testing in the therapy of inflammatory bowel disease.

Oral, colonic-release low-molecular-weight heparin: an initial open study of Parnaparin-MMX for the treatment of mild-to-moderate left-sided ulcerative colitis

BACKGROUND

Efficacy of heparin and low-molecular-weight heparins (LMWHs) in inflammatory bowel disease (IBD) treatment has been suggested. The multimatrix oral formulation MMX releases active drugs in the colon, avoiding systemic absorption. Parnaparin sodium is the LMWH chosen to be carried in the MMX formulation.

AIM

To assess the safety of three different oral dosages (70, 140 and 210 mg once daily) of Parnaparin-MMX (CB-01-05) in left-sided ulcerative colitis (UC).

METHODS

Left-sided UC patients, with a mild-to-moderate relapse were enrolled. All patients received Parnaparin-MMX for 8 weeks. Clinical Activity Index (CAI), Disease Activity Index (DAI), Endoscopic Activity Index and IBD-QoL were assessed throughout the study. A strict clinical and laboratory follow-up, including assessment of anti-factor Xa activity, was performed. Clinical remission was defined as CAI <4.

RESULTS

Ten UC patients were enrolled. One patient retired for clinical deterioration. No relevant side effects, including either interference with haemostasis parameters or increased bleeding, were observed. At the end of the treatment, seven patients (70%) were in clinical remission, only one achieving endoscopic healing. Mean final CAI, DAI and IBD-QoL scores were significantly improved from baseline.

CONCLUSIONS

Parnaparin-MMX appears to be a safe treatment option in mild-to-moderate UC. Controlled studies are warranted.

5-amino salicylic acid bound nanoparticles for the therapy of inflammatory bowel disease

Nanoparticles (NP) are known for their specific accumulation in the inflamed tissues in the colon and may therefore allow a selective delivery to the site of inflammation including a reduction of adverse effects. 5-amino salicylic acid (5ASA) loaded NP were designed in order to investigate their therapeutic potential in the treatment of inflammatory bowel disease. 5ASA was covalently bound to poly(caprolactone) prior to all formulation steps. Oil/water emulsification or nanoprecipitation methods were used for the NP formulation. Particle diameters were either 200 or 350 nm for emulsification or nanoprecipitation, respectively. In-vitro drug release demonstrated a significant drug retention inside the NP formulation. Toxicity of the different formulations was evaluated on Caco-2 and HEK cell culture which was slightly increased for 5ASA grafted NP in comparison to blank NP (Me5ASA-NP: 75 microg/l; blank NP: 210 microg/l). In-vivo, clinical activity score and myeloperoxidase activity decreased after administration of all 5ASA containing formulations (untreated control: 28.0+/-5.6 U/mg; 5ASA-NP (0.5 mg/kg): 15.2+/-5.6 U/mg; 5ASA solution (30 mg/kg): 16.2+/-3.6 U/mg). NP formulations allowed to lower significantly the dose of 5ASA. These oral NP formulations demonstrated their therapeutic potential and appear to be an interesting approach for the therapy of inflammatory bowel disease.