Fabrication of triblock ABA type peptide dendrimer based on glutamic acid dimethyl ester and PEG as a potential nano drug delivery agent

Peptide dendrimers build up from amino acids and they simulate to artificial proteins with globular architecture. These characteristics furnish dendrimers with best biodegradability and biocompatibility in drug delivery systems. A barbell-like dendrimer from glutamic acid dimethyl ester-poly (ethylene glycol)-glutamic acid dimethyl ester as ABA-type triblock copolymer PG-PEG-PG) was prepared with liquid-phase peptide synthesis via a divergent approach. PEG 600 diacid (PEG-A) and glutamic acid dimethyl ester were as the core and the monomeric building blocks, respectively. Linear-dendritic copolymer was prepared in the presence of DCC in pyridine. Transmission electron microscope (TEM) was used for measuring the size of first generation (G1-COOH) and second generation (G2-COOH) of dendrimer compounds. Thermal behavior of the synthesized dendrimers was investigated using DSC. The desired generations G1-COOH, G2-COOH and G3-COOH were prepared by divergent method using PEG diacid 600 as a core compound. The size range of the resulted particles was found to be 20-100 nm for various generations. The isolated dendrimer was examined as the drug-delivery agent and the controlled release was carried out for drug molecule in pH 7.4. Based on the obtained results, the synthesized biocompatible dendrimers could potentially be utilized as a drug carrier agent.