Engineered Nanoparticles inside a Microparticle Oral System for Enhanced Mucosal and Systemic Immunity

Abstract

Antigen delivery through an oral route requires overcoming multiple challenges, including gastrointestinal enzymes, mucus, and epithelial tight junctions. Although each barrier has a crucial role in determining the final efficiency of the oral vaccination, transcytosis of antigens through follicle-associated epithelium (FAE) represents a major challenge. Most of the research is focused on delivering an antigen to the M-cell for FAE transcytosis because M-cells can easily transport the antigen from the luminal site. However, the fact is that the M-cell population is less than 1% of the total gastrointestinal cells, and most of the oral vaccines have failed to show any effect in clinical trials. To challenge the current dogma of M-cell targeting, in this study, we designed a novel tandem peptide with a FAE-targeting peptide at the front position and a cell-penetrating peptide at the back position. The tandem peptide was attached to a smart delivery system, which overcomes the enzymatic barrier and the mucosal barrier. The result showed that the engineered system could target the FAE (enterocytes and M-cells) and successfully penetrate the enterocytes to reach the dendritic cells located at the subepithelium dome. There was successful maturation and activation of dendritic cells in vitro confirmed by a significant increase in maturation markers such as CD40, CD86, presentation marker MHC I, and proinflammatory cytokines (TNF-α, IL-6, and IL-10). The in vivo results showed a high production of CD4+ T-lymphocytes (helper T-cell) and a significantly higher production of CD8+ T-lymphocytes (killer T-cell). Finally, the production of mucosal immunity (IgA) in the trachea, intestine, and fecal extracts and systemic immunity (IgG, IgG1, and IgG2a) was successfully confirmed. To the best of our knowledge, this is the first study that designed a novel tandem peptide to target the FAE, which includes M-cells and enterocytes rather than M-cell targeting and showed that a significant induction of both the mucosal and systemic immune response was achieved compared to M-cell targeting.

PA28γ induces dendritic cell maturation and activates T‐cell immune responses in oral lichen planus

“…Furthermore, mature DCs release various cytokines, including TNF‐α and IL‐6, 27 which not only promote T‐cell proliferation and differentiation but also enhance T‐cell adherence by upregulating the expression of adhesion molecules, facilitating T‐lymphocyte infiltration. 28 TNF‐α stimulation induces the production of chemokines and adhesion molecules, promoting lymphocyte recruitment 1 , 29 , 30 , 31 , 32 and leading to breaks in the epithelial basement membrane.…”

Bioinspired oral delivery devices

“…In addition, viruses have specific surface proteins that enable membrane fusion or membrane perforation to facilitate entry into host cells. Virus-mimetic oral delivery devices can be designed by decorating devices with inert material shields (for example, polyethylene glycol) 141,144 and cell-penetrating peptides (for example, cationic octa-arginine peptides (R8), polyarginines) 27,145 . Such devices can be further modified with functional molecules to enable intracellular trafficking; for example, nanoparticles modified with R8 and l-cysteine (a Golgi position-related amino acid) showed a 4.75-fold increase in cellular internalization in Caco-2 cells compared with unmodified nanoparticles.…”

“…Bioinspired oral delivery devices can be fabricated into various types of formulations and dosage forms, including capsules 148 , tablets 149 , nanoparticles 145 , microspheres 5 , bubbles 133 , films 1 , coatings 138 and sprays 39 , depending on their composition, structure and application. Tablets are typically formed by compressing or moulding 8,149 , and capsules are prepared by filling drug substances into a hard gelatin shell followed by sealing and polishing 8,149 (Box 1).…”

“…Devices also need to adapt to the peristaltic movement and the curved, tubular structures of the intestine. Biological materials (for example, pH-responsive DNA hydrogels 34 , silk sericin 121 , alginate 103 and lipids 104 ), modification techniques (for example, surface coating 74 and microfluidics-based encapsulation 76 ), bioinspired strategies of adhesion (for example, ivy-mimicking shape) 26 , penetration (for example, parasite-mimicking structures) 24 and permeation (for example, cell-penetrating peptide modification) 145,178 can be applied to design vehicles for intestinal delivery.…”

Recent advances in selective and targeted drug/gene delivery systems using cell-penetrating peptides

“…Despite the convenience of oral administration, several obstacles, which include low absorption rate and specificity, limit the number of developed oral vaccines for human use. Surwase et al ( 2022 ) synthesized a chitosan-based tandem polymer conjugated with a mucus-penetrating polymer (low-molecular polyethylene glycol), CPPs, and integrin receptor targeting moieties (cyclic RGDfK peptide) for M-cell-specific delivery. They prepared vaccine microparticles (termed NiMOS) composed of alginic acids, ovalbumin (OVA), and cationic chitosan-based tandem polymers via emulsification and ionic gelation.…”