A series of dual stimuli-responsive poly(L–histidine)n–S–S–polyurethane–S–S–poly(L–histidine)n [p(His)n–SS–PU–SS–p(His)n; n = 25, 35, 50, and 75] triblock copolymers that bear two pH-responsive p(His)n end-blocks and PU middle-block tethered by a redox-responsive disulphide linker have been synthesized. The resulting triblock copolymers self-assemble to form micelles, nanodaisies (NDs), of uniform size (~100 nm) and efficiently encapsulate the anticancer drug doxorubicin (Dox) with a high drug loading content (~19%). The in vitro release profile shows an enhanced release of Dox at an acidic environment in the presence of 10 mM of glutathione. The in vitro cell viability assays performed in various cell lines show that the NDs have no acute or intrinsic toxicity. Confocal microscopy images and flow cytometry results show the pH-responsive cellular uptake of Dox-loaded NDs, accelerated at pH ≤ 5.0. The tumour accumulation and in vivo bio-distribution studies of near-infrared dye (IR-820)-labeled NDs show higher tumour accumulation in CT26 tumour-bearing mice within 72 h. Furthermore, the Dox-loaded NDs effectively inhibit the CT26 tumours, suggesting they are promising nanocarriers for cancer therapy.

Professor Il Kim, male, polymer chemist, graduated from chemical engineering department, Korea Advanced Institute of Science and Engineering in 1990. He worked for University of Ulsan 1990-2000, Pusan National University (PNU), 2000 to date. Since 2013, he became the director of the Brain Korea (BK) 21 PLUS Center for Advanced Chemical Technology supported by the Ministry of Education and the chair of the Department of Chemical Engineering・Polymer Science and Engineering in PNU. He has been a professor of Department of Medicine, PNU School of Medicine, from 2011. From 1994-1995 and 2004-2005, he worked in University of Iowa and Cornell University, respectively, as a visiting scholar. Now he has published more than 400 peer-reviewed SCI papers and got more than 20 items of awards for the science and technology success including the Catalyst Award (Korean Institute of Chemical Engineering, 2005), the Science and Technology Award (Pusan City. 2011), and the Industry-Academy Cooperation Award (Korea Polymer Society, 2012). He played important roles in organizing lots of international scientific meetings related with polymer science and advanced materials and has been editorial board members of 9 international journals. In recent year he focused on the designing synthetic polymer bioconjugate hybrid materials for tissue engineering applications, therapeutic delivery, surgical sealants, and antimicrobial polypeptides for treatment against infectious diseases.