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. | Journal of Science and Technology 54 (5A) (2016) 142-150 pH/TEMPERATURE SENSITIVE PENTABLOCK BASED ON D,L-SERINE Dai Phu Huynh1, 2, *, Dang Nguyen Tri1 1 Faculty of Material Technology, Ho Chi Minh University of Technology, HCMUT–VNUHCM, 268 Ly Thuong Kiet Street, Ward 14, District 10, Ho Chi Minh City 2 National Key Laboratory of Polymer and Composite Materials, HCMUT–VNUHCM, 268 Ly Thuong Kiet Street, Ward 14, District 10, Ho Chi Minh City * Email: hdphu@ Received: 15 July 2016; Accepted for publication: 3 December 2016 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. Keywords: pH/temperature sensitive, D,L-Serine, benzenesulfonyl chloride, pentablock. 1. INTRODUCTION Smart hydrogels have been applied in wide range of scientific applications such as medicine, agriculture, and biotechnology because they are classified as one of smart polymers that not only can exist in both liquid form and solid form but also have many functional properties (. swelling, mechanical, permeation, surface and optical) [1 - 8]. Various stimulisensitive hydrogels that respond to pH [9], temperature [10, 11], electric fields [12, 13], .
