Concentration Dependent Fabrication of Short Peptide Based Different Self-assembled Nanostructures with Various Morphologies and Intracellular Delivery Property
Fabrication of suparmolecular architectures with various morphologies by self assembly of appropriate molecular building block is a proficient and convenient approach. Moreover controlling the key parameters responsible for self-assembly process is vital in understanding the fundamental aspects of molecular self-assembly which provide insight into the fabrication of new assemblies with functional nano-architectures. To this end, in the present study, we report the synthesis of a simple tripeptide Boc-Phe-Phe-Glu-(OH)2 (PS1) and the mechanism of the concentration dependent self-assembly of this tripeptide building block. This peptide self-assembles into discrete spherical assemblies at a low concentration. An increase in concentration of monomeric building block during self assembly generates nanotubes by connecting the nanospheres through neck formation. At higher concentration and with a prolong incubation time of self-assembly fabricate necklace like supramolecular architectures comprise both linear and spherical unit together. Furthermore, spherical assemblies produced with lower concentration of monomeric building block were able to encapsulate small molecules as well as able to release inside the cells. Therefore, these spherical assemblies stand for a potential candidate for the delivery of exogenous entities directly into cells and may behave like the conventional hollow sphere-based drug delivery vehicles. To the best of our knowledge, this is the first report on the fabrication of biomolecular necklace like complex assembly with bi-component type of morphology from a single short peptide based molecular backbone.