As an essential branch of targeted drug delivery, oral targeted delivery is attracting growing attention in recent years. In addition to site-specific delivery for the treatment of locoregional diseases in the gastrointestinal tract (GIT), oral targeted delivery to remote sites beyond the GIT emerges as a cutting-edge research topic. This review aims to provide an overview of the fundamental concepts and most recent advances in this field. Owing to the physiological barriers existing in the GIT, carrier systems should be transported across the enteric epithelia to target remote sites. Recently, pioneer investigations have validated the transport of intact micro- or nanocarriers across gastrointestinal barriers and subsequently to various distal organs and tissues. The microfold (M) cell pathway is the leading mechanism underlying the oral absorption of particulates, but the contribution of the transcellular and paracellular pathways should not be neglected either. In addition to well-acknowledged physicochemical and biological factors, the formation of a protein corona may also influence the biological fate of carrier systems. Although in an early stage of conceptualization, oral targeted delivery to remote diseases has demonstrated promising potential for the treatment of inflammation, tumors, and diseases inflicting the lymphatic and mononuclear phagocytosis systems.

中文翻译：

---

口服靶向药物递送至胃肠道后部位

作为靶向药物递送的一个重要分支，口服靶向递送近年来受到越来越多的关注。除了用于治疗胃肠道 (GIT) 局部疾病的定点递送外，向胃肠道以外的远程部位进行口服靶向递送也成为一个前沿研究课题。本综述旨在概述该领域的基本概念和最新进展。由于胃肠道中存在生理屏障，载体系统应穿过肠上皮细胞运输至远程部位。最近，先驱研究验证了完整的微米或纳米载体穿过胃肠道屏障并随后到达各种远端器官和组织的运输。微折叠（M）细胞途径是颗粒口服吸收的主要机制，但跨细胞和细胞旁途径的贡献也不应忽视。除了众所周知的物理化学和生物学因素外，蛋白冠的形成也可能影响载体系统的生物学命运。尽管处于概念化的早期阶段，口服靶向递送治疗远程疾病已显示出治疗炎症、肿瘤以及影响淋巴和单核吞噬系统的疾病的巨大潜力。