ABSTRACT
Activatable cell-penetrating peptides (ACPPs) is a new-type targeted delivery system, composed of cell-penetrating peptides, environmentally-sensitive (or stimuli-responsive) linker and shielding peptides, allowing cell-penetrating peptides high membrane permeability in specific environment or to specific stimulus, reducing systemic toxicity resulting from non-specific cellular uptake. To enhance the tumor selectivity of carriers, investigators combine ACPPs and nanocarriers in researches on cancer detection and treatment by delivering molecular probes and therapeutic agents (anticancer drugs and genes), and so on. This paper makes an overview about the reported ACPPs-modified nanocarrier systems in the recent decade.
ABSTRACT
AIM: To explore the transport and delivery of active drug from dexamethasone-angelica sinensis polysaccharides prodrug in the gastrointestinal tract of rats. METHODS: Dexamethasone and the prodrug were orally administered to rats at the dose of 1.96 mg?kg~ -1 (calculated by carried dexamethasone). The drugs in the plasma and contents of different parts of the rats' gastrointestinal tract were determined by high performance liquid chromatography (HPLC). RESULTS: Dexamethasone carried by the prodrug was mainly released in the contents and mucosa of cecum and colon after oral administration of the prodrug. The absorption of released dexamethasone was reduced significantly. The peak time, peak concentration and AUC were 7.2 h , 42 ?g?L~ -1 and 334 ?g?h?L~ -1 , respectively. However, free dexamethasone was found mainly in the contents and mucosa of the stomach, proximal and distal small intestine after oral administration. The peak time, peak concentration and AUC were 2.2 h, 2 120 ?g?L~ -1 and 11 875 ?g?h?L~ -1 , respectively. CONCLUSION: Dexamethasone can be specifically delivered to the cecum and colon by using dexamethasone- angelica sinensis polysaccharides prodrug. The absorption of dexamethasone was reduced significantly and the drug concentration in colon was increased significantly. The prodrug has a potential in the treatment of colitis.