pH/TEMPERATURE SENSITIVE PENTABLOCK BASED ON D,L-SERINE

Abstract

For recent decades, researchers have been increasing their attention to pH/temperaturesensitive polymers as drug/protein delivery systems. In this research, we aim to synthesize a new pH/temperature sensitive pentablock based on D,L-Serine. Amino groups of D,L-Serine were modified with benzenesulfonyl chloride in order to create sulfonamide groups as desired pHsensitive groups. Pentablocks were then synthesized by conjugation reaction between carboxylic, hydroxyl groups of D,L-Serine and hydroxyl-terminal groups of temperature sensitive triblock PCL-PEG-PCL. The synthesized products were analyzed by 1H-NMR and their molecular weights were measured by gel permeation chromatography (GPC). The sol-gel transition of pentablock was also investigated by the inverting test method. The pH dependent property of the pH sensitive moiety could be very useful for preparing drug carriers.