Recent advances in oral drug delivery materials for targeted diagnosis or treatment of gastrointestinal diseases

Gastrointestinal diseases offer a serious potential hazard to people's health due to their high morbidity, mortality, and low early diagnosis rates. Due to its location within the body, the gastrointestinal tract is relatively difficult to observe and traditional endoscopy is primarily based on white light detection, resulting in a high rate of missed diagnosis. Therefore, some supplementary methods are needed to improve diagnostic accuracy. The development of probes has expanded new opportunities for the diagnosis or treatment of gastrointestinal diseases, which can deliver drugs to the lesion location through active or passive targeting. Among them, oral administration are the preferred method due to their simple administration and high patient compliance; however, they can be affected by the gastrointestinal environment, including changes in pH, obstacles of various mucus, and the effects of gastrointestinal enzymes, etc. These physiological traits also serve as the basis for designing an oral drug delivery system, which can perform precise drug delivery with these characteristics and the features of the lesion location. This review highlights the most recent developments in common oral drug delivery materials and discusses them according to material types, primarily polymeric particles, lipid particles, and inorganic particles.