An insight into gastrointestinal macromolecule delivery using physical oral devices

Oral delivery is preferred over other routes of drug administration by both patients and physicians. The bioavailability of some therapeutics that are delivered via the oral route is restricted due to the protease- and bacteria-rich environment in the gastrointestinal tract, and by the pH variability along the delivery route. Given these harsh environments, the oral delivery of therapeutic macromolecules is complicated and remains challenging. Various formulation approaches, including the use of permeation enhancers and nanosized carriers, as well as chemical alteration of the drug structure, have been studied as ways to improve the oral absorption of macromolecular drugs. Nevertheless, the bioavailability of marketed oral peptide medicines is often relatively poor. This review highlights the most recent and promising physical methods for improving the oral bioavailability of macromolecules such as peptides. These methods include microneedle injections, high-speed stream injectors, magnetic drug targeting, expandable hydrogels, and iontophoresis. We highlight the potential and challenges of these new technologies, which may impact the future approaches used by pharmaceutical companies to create more efficient and safer orally administered macromolecules

A Chimeric Vaccine Consisting of Highly Immunogenic Regions Form Escherichia coli Iron Regulated Outer-Membrane Proteins: An In Silico Approach

Background: Six pathogen-associated Outer Membrane Iron receptors (OMPs) reside in Uropathogenic strains of E. coli (UPEC): haem-utilization gene (ChuA), Heme acquisition protein (Hma), IrgA homologue adhesin (Iha), Iron-regulated virulence gene (IreA), IroN, and IutA. Cumulative concern over the prevalence of this bacteria in hospital environments, especially in Intensive Care Units (ICUs), highlights the significance of vaccination against this pathogen. In this study, we aimed to develop 3D models of ChuA, Hma, IutA, IreA, Iha, and IroN proteins by invoking various in silico methods and design a chimeric immunogen composed of highly immunogenic regions from these six Escherichia coli antigens as a chimeric vaccine. Materials and Methods: In the present study, homology modeling, fold recognition, Ab initio approaches, and their combination were invoked to determine the Three-Dimensional (3D) structures of ChuA, Hma, Iha, IreA, IroN, and IutA. Next, a set of biochemical, immunological, and functional properties were predicted using various bioinformatics tools. Results: The obtained results indicated that all six modeled proteins fold to a β-barrel structure. The results of biochemical, immunological, and functional analysis determined the regions of each antigen carrying the best immunogenic properties. These regions are employed to construct the final vaccine linked via flexible GGGGS linkers. Intriguingly, re-analyzing the properties of the final vaccine indicated its immunological advantage over individual proteins.  Conclusion: The strategy of this study to predict the protein 3D structure, followed by epitope prediction, could be adapted to design efficient vaccine candidates. Applying this approach, we designed a vaccine candidate harboring the most promising regions of six OMPs. This approach could lead to better functional, structural, and therapeutic outcomes in the context of vaccine design investigations