ABSTRACT
Targeted drug delivery is constantly updated with a better understanding of the physiological and pathological features of various diseases. Depending on high safety, good compliance and many other undeniable advantages, attempts have been undertaken to complete an intravenous-to-oral conversion of targeted drug delivery. However, oral delivery of particulates to systemic circulation is highly challenging due to the biochemical aggressivity and immune exclusion in the gut that restrain absorption and access to the bloodstream. Little is known about the feasibility of targeted drug delivery via oral administration (oral targeting) to a remote site beyond the gastrointestinal tract. To this end, this review proactively contributes to a special dissection on the feasibility of oral targeting. We discussed the theoretical basis of oral targeting, the biological barriers of absorption, the in vivo fate and transport mechanisms of drug vehicles, and the effect of structural evolution of vehicles on oral targeting as well. At last, a feasibility analysis on oral targeting was performed based on the integration of currently available information. The innate defense of intestinal epithelium does not allow influx of more particulates into the peripheral blood through enterocytes. Therefore, limited evidence and lacking exact quantification of systemically exposed particles fail to support much success with oral targeting. Nevertheless, the lymphatic pathway may serve as a potentially alternative portal of peroral particles into the remote target sites via M-cell uptake.
ABSTRACT
In this review, the ability of borneol and menthol as the common penetration enhancers in traditional Chinese medicines was summarized, and the effect of borneol and menthol on the ability of nanopreparations across the main physiological barriers of the human body promoting drug absorption or increasing the distribution of drugs was also reviewed, which aims to provide reference for promoting the treatment effect of nanopreparations through the combination of traditional Chinese medicine and modern preparation technology.
ABSTRACT
High-density lipoproteins (HDL) are naturally-occurring nanoparticles that are biocompatible, non-immunogenic and completely biodegradable. These endogenous particles can circulate for an extended period of time and transport lipids, proteins and microRNA from donor cells to recipient cells. Based on their intrinsic targeting properties, HDL are regarded as promising drug delivery systems. In order to produce on a large scale and to avoid blood borne pollution, reconstituted high-density lipoproteins (rHDL) possessing the biological properties of HDL have been developed. This review summarizes the biological properties and biomedical applications of rHDL as drug delivery platforms. It focuses on the emerging approaches that have been developed for the generation of biomimetic nanoparticles rHDL to overcome the biological barriers to drug delivery, aiming to provide an alternative, promising avenue for efficient targeting transport of nanomedicine.