Dextrin vesicles and their encapsulation abilities for drug delivery applications

Abstract

This thesis emphasizes a facile method of preparing dextrin (starch derivative) amphiphiles using renewable hydrophobic units such as 3-pentadecylphenol as the hydrophobic moiety. Dextrin amphiphiles with different degree of substitutions were synthesized and their structures were characterized by NMR and FTIR techniques. The self assembly of the newly synthesized amphiphiles were investigated using dynamic light scattering, electron microscope (SEM and TEM) and atomic force microscopic techniques. The critical vesicular concentrations (CVCs) were determined using pyrene as fluorophore. Further, the encapsulation capabilities of the dextrin scaffolds were investigated using hydrophobic and hydrophilic dye molecules. The results proved that dextrin with 7 % hydrophobic substitution stabilizes the Rhodamine-B (Rh-B) in the vesicular scaffold. On the other hand, higher incorporation of hydrophobic content fails to show any encapsulation. The invitro release characteristics of Rhodamine-B loaded dextrin vesicles were studied under physiological conditions. Esterase enzyme was employed as stimuli to breakdown he vesicular scaffolds and delivers the encapsulated cargo at much faster rate. The study gives an insight into role of the hydrophobic unit in the self assembly and the forces that are responsible for giving rise to these structures at the molecular level. The scaffolds, thus synthesized could be used for the loading and delivery of hydrophobic as well as hydrophilic anticancer drugs which are currently investigated in detail.