Preclinical Development of a Novel, Orally-Administered Anti-Tumour Necrosis Factor Domain Antibody for the Treatment of Inflammatory Bowel Disease. Sci Rep. 2018;8:4941. [PMID: 29563546 PMCID: PMC5862986 DOI: 10.1038/s41598-018-23277-7]

Lipid- and polymer-based formulations containing TNF-α inhibitors for the treatment of inflammatory bowel diseases

Monoclonal antibodies inhibiting tumor necrosis factor-alpha (iTNF-α) have revolutionized the therapeutic regimen of inflammatory bowel disease, but their main drawback is the parenteral route of administration they require. An alternative approach lies in the delivery of these molecules to the area involved in the inflammatory process by means of innovative formulations able to promote their localization in affected tissues while also decreasing the number of administrations required. This review describes the advantages deriving from the use of lipid- and polymer-based systems containing iTNF-α, focusing on their physicochemical and technological properties and discussing the preclinical results obtained in vivo using rodent models of colitis.

Preclinical proof of principle for orally delivered Th17 antagonist miniproteins

Interleukin (IL)-23 and IL-17 are well-validated therapeutic targets in autoinflammatory diseases. Antibodies targeting IL-23 and IL-17 have shown clinical efficacy but are limited by high costs, safety risks, lack of sustained efficacy, and poor patient convenience as they require parenteral administration. Here, we present designed miniproteins inhibiting IL-23R and IL-17 with antibody-like, low picomolar affinities at a fraction of the molecular size. The minibinders potently block cell signaling in vitro and are extremely stable, enabling oral administration and low-cost manufacturing. The orally administered IL-23R minibinder shows efficacy better than a clinical anti-IL-23 antibody in mouse colitis and has a favorable pharmacokinetics (PK) and biodistribution profile in rats. This work demonstrates that orally administered de novo-designed minibinders can reach a therapeutic target past the gut epithelial barrier. With high potency, gut stability, and straightforward manufacturability, de novo-designed minibinders are a promising modality for oral biologics.

Predictive biomarkers for anti-TNF alpha therapy in IBD patients

Inflammatory bowel disease (IBD) is a chronic gastrointestinal condition characterized by severe gut inflammation, commonly presenting as Crohn's disease, ulcerative colitis or categorized as IBD- unclassified. While various treatments have demonstrated efficacy in adult IBD patients, the advent of anti-TNF therapies has significantly revolutionized treatment outcomes and clinical management. These therapies have played a pivotal role in achieving clinical and endoscopic remission, promoting mucosal healing, averting disease progression, and diminishing the necessity for surgery. Nevertheless, not all patients exhibit positive responses to these therapies, and some may experience a loss of responsiveness over time. This review aims to present a comprehensive examination of predictive biomarkers for monitoring the therapeutic response to anti-TNF therapy in IBD patients. It will explore their limitations and clinical utilities, paving the way for a more personalized and effective therapeutic approach.

Microgels as Platforms for Antibody-Mediated Cytokine Scavenging

Therapeutic antibodies are the key treatment option for various cytokine-mediated diseases, such as rheumatoid arthritis, psoriasis, and inflammatory bowel disease. However, systemic injection of these antibodies can cause side effects and suppress the immune system. Moreover, clearance of therapeutic antibodies from the blood is limiting their efficacy. Here, water-swollen microgels are produced with a size of 25 µm using droplet-based microfluidics. The microgels are functionalized with TNFα antibodies to locally scavenge the pro-inflammatory cytokine TNFα. Homogeneous distribution of TNFα-antibodies is shown throughout the microgel network and demonstrates specific antibody-antigen binding using confocal microscopy and FLIM-FRET measurements. Due to the large internal accessibility of the microgel network, its capacity to bind TNFα is extremely high. At a TNFα concentration of 2.5 µg mL-1 , the microgels are able to scavenge 88% of the cytokine. Cell culture experiments reveal the therapeutic potential of these microgels by protecting HT29 colorectal adenocarcinoma cells from TNFα toxicity and resulting in a significant reduction of COX II and IL8 production of the cells. When the microgels are incubated with stimulated human macrophages, to mimic the in vivo situation of inflammatory bowel disease, the microgels scavenge almost all TNFα that is produced by the cells.

Colon-Targeted Trans-Cinnamic Acid Ameliorates Rat Colitis by Activating GPR109A

We designed colon-targeted trans-cinnamic acid (tCA) and synthesized its conjugates with glutamic acid (tCA-GA) and aspartic acid (tCA-AA). We evaluated the anti-colitic activity of colon-targeted tCA using a dinitrobenzenesulfonic acid-induced rat colitis model. The conjugates lowered the distribution coefficient and Caco-2 cell permeability of tCA and converted to tCA in the cecum, with higher rates and percentages with tCA-GA than with tCA-AA. Following oral gavage, tCA-GA delivered a higher amount of tCA to the cecum and exhibited better anti-colitic effects than tCA and sulfasalazine (SSZ), which is the current treatment for inflammatory bowel disease. In the cellular assay, tCA acted as a full agonist of GPR109A (EC50: 530 µM). The anti-colitic effects of tCA-GA were significantly compromised by the co-administration of the GPR109A antagonist, mepenzolate. Collectively, colon-targeted tCA potentiated the anti-colitic activity of tCA by effectively activating GPR109A in the inflamed colon, enabling tCA to elicit therapeutic superiority over SSZ.

Microbiome engineering: engineered live biotherapeutic products for treating human disease

The human microbiota is implicated in many disease states, including neurological disorders, cancer, and inflammatory diseases. This potentially huge impact on human health has prompted the development of microbiome engineering methods, which attempt to adapt the composition and function of the human host-microbiota system for a therapeutic purpose. One promising method is the use of engineered microorganisms that have been modified to perform a therapeutic function. The majority of these products have only been demonstrated in laboratory models; however, in recent years more concepts have reached the translational stage. This has led to an increase in the number of clinical trials, which are designed to assess the safety and efficacy of these treatments in humans. Within this review, we highlight the progress of some of these microbiome engineering clinical studies, with a focus on engineered live biotherapeutic products.

Nanobodies: from structure to applications in non-injectable and bispecific biotherapeutic development

The increasing demand for convenient, miniaturized and multifunctional antibodies necessitates the development of novel antigen-recognition molecules for biological and medical studies. Nanobodies, the functional variable regions of camelid heavy-chain-only antibodies, as a new tool, complement the conventional antibodies and are in the stage of rapid development. The outstanding advantages of nanobodies include a stable structure, easy production, excellent water solubility, high affinity toward antigens and low immunogenicity. With promising application potential, nanobodies are now increasingly applied to various studies, including protein structure analysis, microscopic imaging, medical diagnosis, and drug development. The approval of the first nanobody drug Caplacizumab by the FDA disclosed the therapeutic potential of nanobodies. The outbreak of COVID-19 accelerated the development of nanobody drugs in non-injectable and bispecific biotherapeutic applications. Herein, we reviewed recent studies on the nanobody structure, screening and their applications in protein structure analysis and nanobody drugs, especially on non-injectable nanobody and bispecific nanobody development.

How could nanobiotechnology improve treatment outcomes of anti-TNF-α therapy in inflammatory bowel disease? Current knowledge, future directions

Despite significant advances in therapeutic possibilities for the treatment of inflammatory bowel disease (IBD) in recent years, there is still a big room for improvement. In particular, biological treatment can induce not only clinical remission but also mucosal healing of the gastrointestinal tract. Among these therapeutic molecules, anti-tumor necrosis factor-alpha (anti-TNF-α) antibodies were the first to revolutionize treatment algorithms in IBD. However, due to the parenteral route of administration and systemic mode of action, TNF-α blockers are characterised by high rates of immunogenicity-related loss of response and serious adverse events. Moreover, intravenous or subcutaneous therapy is not considered patient-friendly and requires occasional, direct contact with healthcare centres. To overcome these limitations, several attempts have been made to design oral pharmaceutical formulations of these molecules. It is hypothesized that oral anti-TNF-α antibodies therapy can directly provide a targeted and potent anti-inflammatory effect in the inflamed gastrointestinal tissues without significant systemic exposure, improving long-term treatment outcomes and safety. In this review, we discuss the current knowledge and future perspectives regarding different approaches made towards entering a new era of oral anti-TNF-α therapy, namely, the tailoring of biocompatible nanoparticles with anti-TNF-α antibodies for site-specific targeting to IBD. In particular, we discuss the latest concepts applying the achievements of nanotechnology-based drug design in this area.

Preclinical development of a bispecific TNFα/IL-23 neutralising domain antibody as a novel oral treatment for inflammatory bowel disease

Anti-TNFα and anti-IL-23 antibodies are highly effective therapies for Crohn’s disease or ulcerative colitis in a proportion of patients. V56B2 is a novel bispecific domain antibody in which a llama-derived IL-23p19-specific domain antibody, humanised and engineered for intestinal protease resistance, V900, was combined with a previously-described TNFα-specific domain antibody, V565. V56B2 contains a central protease-labile linker to create a single molecule for oral administration. Incubation of V56B2 with trypsin or human faecal supernatant resulted in a complete separation of the V565 and V900 monomers without loss of neutralising potency. Following oral administration of V900 and V565 in mice, high levels of each domain antibody were detected in the faeces, demonstrating stability in the intestinal milieu. In ex vivo cultures of colonic biopsies from IBD patients, treatment with V565 or V900 inhibited tissue phosphoprotein levels and with a combination of the two, inhibition was even greater. These results support further development of V56B2 as an oral therapy for IBD with improved safety and efficacy in a greater proportion of patients as well as greater convenience for patients compared with traditional monoclonal antibody therapies.

Label-free methods for optical in vitro characterization of protein-protein interactions

Protein-protein interactions are involved in the regulation and function of the majority of cellular processes. As a result, much effort has been aimed at the development of methodologies capable of quantifying protein-protein interactions, with label-free methods being of particular interest due to the associated simplified workflows and minimisation of label-induced perturbations. Here, we review recent advances in optical technologies providing label-free in vitro measurements of affinities and kinetics. We provide an overview and comparison of existing techniques and their principles, discussing advantages, limitations, and recent applications.

Re-Assessing PK/PD Issues for Oral Protein and Peptide Delivery

Due to a lack of safe and effective oral delivery strategies for most protein and peptide therapeutics, pharmaceutical drug developers have focused on parenteral routes to administer these agents. Recent advances in delivery technologies have now shown clinical validation for a few of these biopharmaceuticals following oral administration. While these initial opportunities have provided more than just a glimmer of hope within the industry, there are important aspects of oral biopharmaceutical delivery that do not completely align with pharmacokinetic (PK) parameters and pharmacodynamics (PD) outcomes that have been learned from parenteral administrations. This commentary examines some of these issues with the goal of presenting a rationale for re-assessing methods, models, and success criteria to better measure oral protein or peptide delivery outcomes related to PK/PD events.

Oral Delivery of Biologics in Inflammatory Bowel Disease Treatment

Inflammatory bowel disease (IBD) has been posed as a great worldwide health threat. Having an onset during early adulthood, IBD is a chronic inflammatory disease characterized by remission and relapse. Due to its enigmatic etiology, no cure has been developed at the moment. Conventionally, steroids, 5-aminosalicylic acid, and immunosuppressants have been applied clinically to relieve patients’ syndrome which, unfavorably, causes severe adverse drug reactions including diarrhea, anemia, and glaucoma. Insufficient therapeutic effects also loom, and surgical resection is mandatory in half of the patients within 10 years after diagnosis. Biologics demonstrated unique and differentiative therapeutic mechanism which can alleviate the inflammation more effectively. However, their application in IBD has been hindered considering their stability and toxicity. Scientists have brought up with the concept of nanomedicine to achieve the targeted drug delivery of biologics for IBD. Here, we provide an overview of biologics for IBD treatment and we review existing formulation strategies for different biological categories including antibodies, gene therapy, and peptides. This review highlights the current trends in oral delivery of biologics with an emphasis on the important role of nanomedicine in the development of reliable methods for biologic delivery in IBD treatment.

Effects of compaction and storage conditions on stability of intravenous immunoglobulin - Implication on developing oral tablets of biologics

Biological products, such as therapeutic proteins, vaccines and cell - based therapeutics have a rapidly growing global market. Monoclonal antibody represents a major portion of the biologics market. For biologics that target gastrointestinal tract, the oral delivery route offers many advantages, such as better patient compliance, easy administration and increased stability, over the parental route of administration. To lay the ground work for the oral delivery of biologics, we studied the solid state properties and effects of compaction pressure, particle size, and storage relative humidity on the stability of immunoglobulin G (IVIG). We employed complementary analytical and biophysical techniques, such as size exclusion chromatography and Dynamic light scattering to characterize the aggregates, circular dichroism and solid state Fourier-transform infrared spectroscopy to evaluate protein secondary structure and nano-DSC to probe thermal stability of protein conformations. Our results showed storage relative humidity could induce conformational changes and aggregation of IVIG. However, the IVIG binding activity did not significantly change with relative humidity. The commonly used compaction pressures did not promote protein aggregation, but noticeably reduced binding activity.

Novel polyurethane based particulate formulations of infliximab reduce inflammation in DSS induced murine model of colitis - A preliminary study

Our recent study showed that novel infliximab (INF) loaded polyesterurethane (INF-PU) and INF-PU-PEG particulate formulations reduced inflammation in an in-vitro epithelial inflammation model. In this study we investigated therapeutic potential of novel INF-PU and INF-PU-PEG particulate formulations to reduce inflammation in a dextran sodium sulfate (DSS) induced murine model of colitis. Severity of colitis was assessed by measurement of disease activity index (DAI) score, inflammatory markers (neutrophil infiltration, TNFα) and histological score. Treatment groups orally administered with INF-PU and INF-PU-PEG particulate formulations showed improvement in the clinical signs of colitis, similar to that observed with intraperitoneally administered INF, in both, moderate and severe DSS induced colitis model. This was related to a significant reduction in inflammatory cytokines, resulting in a significant reduction in histological score (ANOVA; p < 0.05), indicative of mucosal healing, a key goal of IBD therapy. This could be attributed to its targeted delivery to the inflamed colon and higher permeation of these particulate formulations across the inflamed colonic mucosa, as observed by the confocal images, resulting in local inhibition of TNFα at its site of production. These promising preliminary results warrant further investigation of orally administered INF and its novel particulate formulations in a wider preclinical study.

Delivery of Orally Administered Digestible Antibodies Using Nanoparticles

Oral administration of medications is highly preferred in healthcare owing to its simplicity and convenience; however, problems of drug membrane permeability can arise with any administration method in drug discovery and development. In particular, commonly used monoclonal antibody (mAb) drugs are directly injected through intravenous or subcutaneous routes across physical barriers such as the cell membrane, including the epithelium and endothelium. However, intravenous administration has disadvantages such as pain, discomfort, and stress. Oral administration is an ideal route for mAbs. Nonetheless, proteolysis and denaturation, in addition to membrane impermeability, pose serious challenges in delivering peroral mAbs to the systemic circulation, biologically, through enzymatic and acidic blocks and, physically, through the small intestinal epithelium barrier. A number of clinical trials have been performed using oral mAbs for the local treatment of gastrointestinal diseases, some of which have adopted capsules or tablets as formulations. Surprisingly, no oral mAbs have been approved clinically. An enteric nanodelivery system can protect cargos from proteolysis and denaturation. Moreover, mAb cargos released in the small intestine may be delivered to the systemic circulation across the intestinal epithelium through receptor-mediated transcytosis. Oral Abs in milk are transported by neonatal Fc receptors to the systemic circulation in neonates. Thus, well-designed approaches can establish oral mAb delivery. In this review, I will introduce the implementation and possibility of delivering orally administered mAbs with or without nanoparticles not only to the local gastrointestinal tract but also to the systemic circulation.

Nanobody: A Small Antibody with Big Implications for Tumor Therapeutic Strategy

The development of monoclonal antibody treatments for successful tumor-targeted therapies took several decades. However, the efficacy of antibody-based therapy is still confined and desperately needs further improvement. Nanobodies are the recombinant variable domains of heavy-chain-only antibodies, with many unique properties such as small size (~15kDa), excellent solubility, superior stability, ease of manufacture, quick clearance from blood, and deep tissue penetration, which gain increasing acceptance as therapeutical tools and are considered also as building blocks for chimeric antigen receptors as well as for targeted drug delivery. Thus, one of the promising novel developments that may address the deficiency of monoclonal antibody-based therapies is the utilization of nanobodies. This article provides readers the significant factors that the structural and biochemical properties of nanobodies and the research progress on nanobodies in the fields of tumor treatment, as well as their application prospect.

Protease-stable DARPins as promising oral therapeutics

Clostridioides difficile is an enteric bacterium whose exotoxins, TcdA and TcdB, inactivate small GTPases within the host cells, leading to bloody diarrhea. In prior work, our group engineered a panel of potent TcdB-neutralizing designed ankyrin repeat proteins (DARPin) as oral therapeutics against C. difficile infection. However, all these DARPins are highly susceptible to digestion by gut-resident proteases, i.e. trypsin and chymotrypsin. Close evaluation of the protein sequence revealed a large abundance of positively charged and aromatic residues in the DARPin scaffold. In this study, we significantly improved the protease stability of one of the DARPins, 1.4E, via protein engineering. Unlike 1.4E, whose anti-TcdB EC50 increased >83-fold after 1-hour incubation with trypsin (1 mg/ml) or chymotrypsin (0.5 mg/ml), the best progenies-T10-2 and T10b-exhibit similar anti-TcdB potency as their parent in PBS regardless of protease treatment. The superior protease stability of T10-2 and T10b is attributed to the removal of nearly all positively charged and aromatic residues except those directly engaged in target binding. Furthermore, T10-2 was found to retain significant toxin-neutralization ability in ex vivo cecum fluid and can be easily detected in mouse fecal samples upon oral administration. Both T10-2 and T10b enjoy a high thermo- and chemo-stability and can be expressed very efficiently in Escherichia coli (>100 mg/l in shaker flasks). We believe that, in additional to their potential as oral therapeutics against C. difficile infection, T10-2 and T10b can also serve as a new generation DARPin scaffold with superior protease stability.

Colon tissue-accumulating mesoporous carbon nanoparticles loaded with Musca domestica cecropin for ulcerative colitis therapy

Ulcerative colitis (UC) is a modern refractory disease with steadily increasing incidence worldwide that urgently requires effective and safe therapies. Therapeutic peptides delivered using nanocarriers have shown promising developments for the treatment of UC. We developed a novel colon-accumulating oral drug delivery nanoplatform consisting of Musca domestica cecropin (MDC) and mesoporous carbon nanoparticles (MCNs) and investigated its effects and mechanism of action for the treatment of UC. Methods: An optimized one-step soft templating method was developed to synthesize MCNs, into which MDC was loaded to fabricate MDC@MCNs. MCNs and MDC@MCNs were characterized by BET, XRD, and TEM. MDC and MDC@MCNs resistance to trypsin degradation was measured through Oxford cup antibacterial experiments using Salmonella typhimurium as the indicator. Uptake of MDC and MDC@MCNs by NCM460 cells was observed by fluorescence microscopy. The biocompatibility of MDC, MCNs, and MDC@MCNs was evaluated in three cell lines (NCM460, L02, and NIH3T3) and C57BL/6 mice. Dextran sulphate sodium was used to establish models of NCM460 cell injury and UC in mice. MTT assay, flow cytometry, and mitochondrial membrane potential assay were applied to determine the effects of MDC@MCNs on NCM460 cells injury. Additionally, a variety of biological methods such as H&E staining, TEM, ELISA, qPCR, Western blotting, and 16s rDNA sequencing were performed to explore the effects and underlying mechanism of MDC@MCN on UC in vivo. Colonic adhesion of MCNs was compared in normal and UC mice. The oral biodistributions of MDC and MDC@MCNs in the gastrointestinal tract of mice were also determined. Results: MDC@MCNs were successfully developed and exhibited excellent ability to resist destruction by trypsin and were taken up by NCM460 cells more readily than MDC. In vitro studies showed that MDC@MCNs better inhibited DSS-induced NCM460 cells damage with lower toxicity to L02 and NIH3T3 cells compared with MDC. In vivo results indicated that MDC@MCNs have good biocompatibility and significantly improved colonic injury in UC mice by effectively inhibiting inflammation and oxidative stress, maintaining colonic tight junctions, and regulating intestinal flora. Moreover, MDC@MCNs were strongly retained in the intestines, which was attributed to intestinal adhesion and aggregation of MCNs, serving as one of the important reasons for its enhanced efficacy after oral administration compared with MDC. Conclusion: MDC@MCNs alleviated DSS-induced UC by ameliorating colonic epithelial cells damage, inhibiting inflammation and oxidative stress, enhancing colonic tight junctions, and regulating intestinal flora. This colon-accumulating oral drug delivery nanoplatform may provide a novel and precise therapeutic strategy for UC.

Nutritional Interventions Using Functional Foods and Nutraceuticals to Improve Inflammatory Bowel Disease

The gastrointestinal tract, the second largest organ in the body, plays an important role in nutrient and mineral intake through the intestinal barrier. Dysfunction of intestinal permeability and related disorders commonly occur in patients with inflammatory bowel disease (IBD), one of the health problems in the Western societies that are considered to be mainly due to the Western diet. Although the exact etiology of IBD has not been elucidated, environmental and genetic factors may be involved in its pathogenesis. Many synthetic or biological drugs, such as 5-aminosalicylic acid corticosteroids as anti-inflammatory drugs, have been used clinically to treat IBD. However, their long-term use exhibits some adverse health consequences. Therefore, many researchers have devised alternative therapies to overcome this problem. Many studies have revealed that some functional nutrients in nature can relieve gastrointestinal inflammation by controlling proinflammatory cytokines. In this study, we review the ability of functional nutraceuticals such as phytochemicals, fatty acids, and bioactive peptides in improving IBD by regulating its underlying pathogenic mechanisms.

A Novel, Orally Delivered Antibody Therapy and Its Potential to Prevent Clostridioides difficile Infection in Pre-clinical Models

Clostridioides difficile infection (CDI) is a toxin-mediated infection in the gut and a major burden on healthcare facilities worldwide. We rationalized that it would be beneficial to design an antibody therapy that is delivered to, and is active at the site of toxin production, rather than neutralizing the circulating and luminal toxins after significant damage of the layers of the intestines has occurred. Here we describe a highly potent therapeutic, OraCAb, with high antibody titers and a formulation that protects the antibodies from digestion/inactivation in the gastrointestinal tract. The potential of OraCAb to prevent CDI in an in vivo hamster model and an in vitro human colon model was assessed. In the hamster model we optimized the ratio of the antibodies against each of the toxins produced by C. difficile (Toxins A and B). The concentration of immunoglobulins that is effective in a hamster model of CDI was determined. A highly significant difference in animal survival for those given an optimized OraCAb formulation versus an untreated control group was observed. This is the first study testing the effect of oral antibodies for treatment of CDI in an in vitro gut model seeded with a human fecal inoculum. Treatment with OraCAb successfully neutralized toxin production and did not interfere with the colonic microbiota in this model. Also, treatment with a combination of vancomycin and OraCAb prevented simulated CDI recurrence, unlike vancomycin therapy alone. These data demonstrate the efficacy of OraCAb formulation for the treatment of CDI in pre-clinical models.

Soluble ligands as drug targets

Historically, the main classes of drug targets have been receptors, enzymes, ion channels and transporters. However, owing largely to the rise of antibody-based therapies in the past two decades, soluble protein ligands such as inflammatory cytokines have become an increasingly important class of drug targets. In this Review, we analyse drugs targeting ligands that have reached clinical development at some point since 1992. We identify 291 drugs that target 99 unique ligands, and we discuss trends in the characteristics of the ligands, drugs and indications for which they have been tested. In the last 5 years, the number of ligand-targeting drugs approved by the FDA has doubled to 34, while the number of clinically validated ligand targets has doubled to 22. Cytokines and growth factors are the predominant types of targeted ligands (70%), and inflammation and autoimmune disorders, cancer and ophthalmological diseases are the top therapeutic areas for both approved agents and agents in clinical studies, reflecting the central role of cytokine and/or growth factor pathways in such diseases.

Review: Local Tumor Necrosis Factor-α Inhibition in Inflammatory Bowel Disease

Crohn’s disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBD) characterized by intestinal inflammation. Increased intestinal levels of the proinflammatory cytokine tumor necrosis factor-α (TNF-α) are associated with disease activity and severity. Anti-TNF-α therapy is administered systemically and efficacious in the treatment of IBD. However, systemic exposure is associated with adverse events that may impede therapeutic treatment. Clinical studies show that the efficacy correlates with immunological effects localized in the gastrointestinal tract (GIT) as opposed to systemic effects. These data suggest that site-specific TNF-α inhibition in IBD may be efficacious with fewer expected side effects related to systemic exposure. We therefore reviewed the available literature that investigated the efficacy or feasibility of local TNF-α inhibition in IBD. A literature search was performed on PubMed with given search terms and strategy. Of 8739 hits, 48 citations were included in this review. These studies ranged from animal studies to randomized placebo-controlled clinical trials. In these studies, local anti-TNF-α therapy was achieved with antibodies, antisense oligonucleotides (ASO), small interfering RNA (siRNA), microRNA (miRNA) and genetically modified organisms. This narrative review summarizes and discusses these approaches in view of the clinical relevance of local TNF-α inhibition in IBD.

Short note: Infliximab recovery in a simulated intestinal fluid of the upper intestine tract

BACKGROUND

The oral administration of Infliximab (IFX) antibody would ensure a direct action on inflamed intestinal tissues without side effects. Thus, investigations about its resilience within the intestinal environment are required.

OBJECTIVE

Quantify the IFX recovery in a simulated upper intestinal environment.

METHODS

IFX was incubated for different times until 120 min in simulated intestinal fluid (SIF) which differed (i) for pH (7.2 vs 6.8, Exp 1), (ii) for addition or not with pancreatin (Exp 2) and (iii) for addition or not with bovine serum albumin in presence of pancreatin (BSA, Exp 3).

RESULTS

In Exp 1 the IFX incubated without pancreatin was degraded by about 15% by SIF pH change from 7.2 to 6.8 and after 120 min it was reduced by about 20%. In Exp 2 the presence of pancreatin determined an intense and rapid IFX degradation (recovery < 33%, within 30 min), but when BSA was added to simulate the presence of food protein (Exp 3) the IFX half-life ranged between 59 and 70 min.

CONCLUSIONS

A discrete in vitro stability of IFX in the upper intestine environment was demonstrated, if food protein is available and competes with pancreatin proteases.

Oral Delivery of Biologics for Precision Medicine

The emerging field of precision medicine is rapidly growing, fostered by the advances in genome mapping and molecular diagnosis. In general, the translation of these advances into precision treatments relies on the use of biological macromolecules, whose structure offers a high specificity and potency. Unfortunately, due to their complex structure and limited ability to overcome biological barriers, these macromolecules need to be administered via injection. The scientific community has devoted significant effort to making the oral administration of macromolecules plausible thanks to the implementation of drug delivery technologies. Here, an overview of the current situation and future prospects in the field of oral delivery of biologics is provided. Technologies in clinical trials, as well as recent and disruptive delivery systems proposed in the literature for local and systemic delivery of biologics including peptides, antibodies, and nucleic acids, are described. Strategies for the specific targeting of gastrointestinal regions-stomach, small bowel, and colon-cell populations, and internalization pathways, are analyzed. Finally, challenges associated with the clinical translation, future prospects, and identified opportunities for advancement in this field are also discussed.

Small molecules under development for psoriasis: on the road to the individualized therapies

Psoriasis is an incurable cutaneous illness characterized by the presence of well-delimited reddish plaques and silvery-white dry scales. So far, there is a limited understanding of its pathogenesis, though recent discoveries on the immunological, genetic and molecular aspects of this disease have significantly contributed to the identification of new targets and the development of novel drugs. Despite these advances, many patients are still dissatisfied, so to improve patient satisfaction, reliability, and clinical outcomes, the individualization of the treatments for this disease becomes a necessity. This review summarizes recent findings related to psoriasis pathogenesis and describes new small molecules and targets recently identified as promising for treatments. Additionally, the current status, challenges and the future directions for achieving individualized therapy for this disease and the need for more collaborative studies are discussed. The individualization of treatments for psoriasis, rather than a goal, is analyzed as a process where a dynamic integration between the needs and characteristics of the patients, the pharmacological progress, and the clinical decisions takes place.

Protein-protein interactions: a structural view of inhibition strategies and the IL-23/IL-17 axis

Protein-protein interactions are central to biology and provide opportunities to modulate disease with small-molecule or protein therapeutics. Recent developments in the understanding of the tractability of protein-protein interactions are discussed with a focus on the ligandable nature of protein-protein interaction surfaces. General principles of inhibiting protein-protein interactions are illustrated with structural biology examples from six members of the IL-23/IL-17 signaling family (IL-1, IL-6, IL-17, IL-23 RORγT and TNFα). These examples illustrate the different approaches to discover protein-protein interaction inhibitors on a target-specific basis that has proven fruitful in terms of discovering both small molecule and biologic based protein-protein interaction inhibitors.

Inflammatory bowel disease and targeted oral anti-TNFα therapy

Antibodies have provided invaluable treatment options for many diseases, with immunotherapy revolutionising the treatment of several inflammatory disorders including inflammatory bowel disease (IBD). Accumulating evidence suggests that IBD results from an inappropriate response to intestinal microbes and environmental factors in genetically susceptible individuals, with overactivity of the pro-inflammatory pathways. On a pathophysiological level, IBD is a complex disease with intestinal fibrosis, stenosis and an increased incidence of cancer observed in those whose disease is inadequately controlled over time. Regulating the actions of the pro-inflammatory cytokine human tumor necrosis factor-alpha (hTNFα) through the use of anti-TNFα monoclonal antibodies (e.g. infliximab, certolizumab, adalimumab and golimumab) has proven an effective intervention for IBD with their increased use a testament of their effectiveness. These agents are administered systemically thereby causing their distribution throughout the body in a condition that is localised to the gastrointestinal (GI) tract. Immunogenicity, the induction of anti-drug antibodies (ADAs), serum sickness and other undesirable side effects limit their use, whilst up to 50% of patients do not respond to initial therapy. Diseases confined to the GI tract are ideal for targeting by oral therapy which mitigates side effects and allows for lower doses to be administered. Several oral anti-TNFα agents have been investigated with success but are not yet in general clinical use. This partially reflects the fact that the oral administration of antibodies has many barriers including the harsh environment of the GI tract and the presence of enzymes including pepsin, trypsin and chymotrypsin in the intestine which provide significant challenges to targeted oral therapy.

Structure and development of single domain antibodies as modules for therapeutics and diagnostics

Since their discovery just over 25 years ago, the single variable domain from heavy-chain-only antibodies plays a role in an increasing number of antibody-based applications. Structural and biophysical studies have revealed that the small, ∼15 kDa, single variable domain found in camelids displays versatility in target recognition. Such insight has served as the foundation to develop and engineer VHH domains with enhanced properties capable of targeting a range of therapeutically relevant protein antigens or low-molecular weight haptens. Furthermore, the modular nature of VHH domains allows them to be introduced into constructs that are simply not possible with conventional antibodies. Here, we review the structural and biophysical properties of VHH domains, highlight recent VHH-based therapeutics and diagnostics, and provide insight into VHH engineering that may pave the way to next-generation single domain antibody applications.

Oral Anti-Tumour Necrosis Factor Domain Antibody V565 Provides High Intestinal Concentrations, and Reduces Markers of Inflammation in Ulcerative Colitis Patients

V565 is an engineered TNFα-neutralising single domain antibody formulated into enteric coated mini-tablets to enable release in the intestine after oral administration as a possible oral treatment for inflammatory bowel disease (IBD). Following oral administration, ileal recovery of V565 was investigated in four patients with terminal ileostomy. Intestinal and systemic pharmacokinetics were measured in six patients with Crohn's disease and evidence of target engagement assessed in five patients with ulcerative colitis. Following oral administration, V565 was detected at micromolar concentrations in ileal fluid from the ileostomy patients and in stools of the Crohn's patients. In four of the five ulcerative colitis patients, biopsies taken after 7d dosing demonstrated V565 in the lamina propria with co-immunostaining on CD3⁺ T-lymphocytes and CD14⁺ macrophages. Phosphorylation of signalling proteins in biopsies taken after 7d oral dosing was decreased by approximately 50%. In conclusion, enteric coating of V565 mini-tablets provided protection in the stomach with gradual release in intestinal regions affected by IBD. Immunostaining revealed V565 tissue penetration and association with inflammatory cells, while decreased phosphoproteins after 7d oral dosing was consistent with V565-TNFα engagement and neutralising activity. Overall these results are encouraging for the clinical utility of V565 in the treatment of IBD.

Mucosal delivery of Lactococcus lactis carrying an anti-TNF scFv expression vector ameliorates experimental colitis in mice

Background

Anti-Tumor Necrosis Factor-alpha therapy has become clinically important for treating inflammatory bowel disease. However, the use of conventional immunotherapy requires a systemic exposure of patients and collateral side effects. Lactic acid bacteria have been shown to be effective as mucosal delivering system for cytokine and single domain antibodies, and it is amenable to clinical purposes. Therefore, lactic acid bacteria may function as vehicles for delivery of therapeutic antibodies molecules to the gastrointestinal tract restricting the pharmacological effect towards the gut. Here, we use the mucosal delivery of Lactococcus lactis carrying an anti-TNFα scFv expression plasmid on a DSS-induced colitis model in mice.

Results

Experimental colitis was induced with DSS administered in drinking water. L. lactis carrying the scFv expression vector was introduced by gavage. After four days of treatment, animals showed a significant improvement in histological score and disease activity index compared to those of untreated animals. Moreover, treated mice display IL-6, IL17A, IL1β, IL10 and FOXP3 mRNA levels similar to health control mice. Therefore, morphological and molecular markers suggest amelioration of the experimentally induced colitis.

Conclusion

These results provide evidence for the use of this alternative system for delivering therapeutic biopharmaceuticals in loco for treating inflammatory bowel disease, paving the way for a novel low-cost and site-specific biotechnological route for the treatment of inflammatory disorders.

Electronic supplementary material

The online version of this article (10.1186/s12896-019-0518-6) contains supplementary material, which is available to authorized users.

Microglia-derived TNF-α mediates endothelial necroptosis aggravating blood brain-barrier disruption after ischemic stroke

Endothelium (EC) is a key component of blood–brain barrier (BBB), and has an important position in the neurovascular unit. Its dysfunction and death after cerebral ischemic/reperfusion (I/R) injury not only promote evolution of neuroinflammation and brain edema, but also increase the risk of intracerebral hemorrhage of thrombolytic therapies. However, the mechanism and specific interventions of EC death after I/R injury are poorly understood. Here we showed that necroptosis was a mechanism underlying EC death, which promoted BBB breakdown after I/R injury. Treatment of rats with receptor interacting protein kinase 1 (RIPK1)-inhibitor, necrostatin-1 reduced endothelial necroptosis and BBB leakage. We furthermore showed that perivascular M1-like microglia-induced endothelial necroptosis leading to BBB disruption requires tumor necrosis factor-α (TNF-α) secreted by M1 type microglia and its receptor, TNF receptor 1 (TNFR1), on endothelium as the primary mediators of these effects. More importantly, anti-TNFα (infliximab, a potent clinically used drug) treatment significantly ameliorate endothelial necroptosis, BBB destruction and improve stroke outcomes. Our data identify a previously unexplored role for endothelial necroptosis in BBB disruption and suggest infliximab might serve as a potential drug for stroke therapy.

Orally Delivered Antisense Oligodeoxyribonucleotides of TNF-α via Polysaccharide-Based Nanocomposites Targeting Intestinal Inflammation

Tumor necrosis factor alpha (TNF-α) is usually regarded as a potential target for inflammatory bowel disease therapy. Herein, a promising strategy for effective delivery of phosphorothioated antisense oligodeoxyribonucleotide of TNF-α (PS-ATNF-α), targeting the intestinal inflammation based on the interaction of the single chain of triple helical β-glucan (s-LNT) with poly-deoxyadenylic acid [poly(dA)], and the colon-specific degradation of chitosan-alginate (CA) hydrogel, is reported. The target gene of PS-ATNF-α, with a poly(dA) tail through a disulfide bond (-SS-), interacts with s-LNT to form a rod-like nanocomposite of s-LNT/poly(dA)-SS-PS-ATNF-α, which significantly inhibits lipopolysaccharide (LPS)-induced TNF-α at the protein level by 38.2% and mRNA level by 48.9% in RAW264.7 macrophages. The nanocomposites carried by the CA hydrogel with the loading amount of 83.5% are then orally administered and specifically released to the inflamed intestine, followed by internalization into intestinal cells such as macrophages, to reduce TNF-α production by 36.4% and dextran sulfate sodium-induced inflammation by decreasing myeloperoxidase and malondialdehyde. This study defines a new strategy for the oral delivery of antisense oligonucleotides to attenuate inflammatory response, demonstrating a notable potential for clinical applications in intestine-inflammation-targeted therapy.

Local delivery of macromolecules to treat diseases associated with the colon

Current treatments for intestinal diseases including inflammatory bowel diseases, irritable bowel syndrome, and colonic bacterial infections are typically small molecule oral dosage forms designed for systemic delivery. The intestinal permeability hurdle to achieve systemic delivery from oral formulations of macromolecules is challenging, but this drawback can be advantageous if an intestinal region is associated with the disease. There are some promising formulation approaches to release peptides, proteins, antibodies, antisense oligonucleotides, RNA, and probiotics in the colon to enable local delivery and efficacy. We briefly review colonic physiology in relation to the main colon-associated diseases (inflammatory bowel disease, irritable bowel syndrome, infection, and colorectal cancer), along with the impact of colon physiology on dosage form design of macromolecules. We then assess formulation strategies designed to achieve colonic delivery of small molecules and concluded that they can also be applied some extent to macromolecules. We describe examples of formulation strategies in preclinical research aimed at colonic delivery of macromolecules to achieve high local concentration in the lumen, epithelial-, or sub-epithelial tissue, depending on the target, but with the benefit of reduced systemic exposure and toxicity. Finally, the industrial challenges in developing macromolecule formulations for colon-associated diseases are presented, along with a framework for selecting appropriate delivery technologies.

Diets, functional foods, and nutraceuticals as alternative therapies for inflammatory bowel disease: Present status and future trends

Inflammatory bowel disease (IBD) is a serious health concern among western societies. The disease is also on the rise in some East Asian countries and in Australia. Health professionals and dietitians around the world are facing an unprecedented challenge to prevent and control the increasing prevalence of IBD. The current therapeutic strategy that includes drugs and biological treatments is inefficient and are associated with adverse health consequences. In this context, the use of natural products is gaining worldwide attention. In vivo studies and clinical evidence suggest that well-planned dietary regimens with specific nutrients can alleviate gastrointestinal inflammation by modulating inflammatory cytokines, such as tumor necrosis factor α (TNF-α), interleukin 1 (IL-1), IL-6, IL-1β, and IL-10. Alternatively, the avoidance of high-fat and high-carbohydrate diets is regarded as an effective tool to eliminate the causes of IBD. Many functional foods and bioactive components have received attention for showing strong therapeutic effects against IBD. Both animal and human studies suggest that bioactive functional foods can ameliorate IBD by downregulating the pro-inflammatory signaling pathways, such as nuclear factor κB, STAT1, STAT6, and pro-inflammatory cytokines, including IL-1β, IL-4, IL-6, COX-2, TNF-α, and interferon γ. Therefore, functional foods and diets have the potential to alleviate IBD by modulating the underlying pathogenic mechanisms. Future comprehensive studies are needed to corroborate the potential roles of functional foods and diets in the prevention and control of IBD.