Synthesis and characterization of Poloxamer 188-grafted heparin copolymer.
BACKGROUND
Poloxamer 188 is a safe biocompatible polymer that can be used in protein drug delivery system.


OBJECTIVE
In this study, a new heparin-poloxamer 188 conjugate (HP) was synthesized and its physicochemical properties were investigated. HP structure was confirmed by Fourier transform infrared spectroscopy (FTIR) and Hydrogen-1 nuclear magnetic resonance spectroscopy ((1)H-NMR). Content of the conjugated heparin was analyzed using Toluidine Blue. The critical micelle concentration (CMC) of the copolymer was determined by a fluorescence probe technique. The effect of HP on the gelation of poloxamer 188 was characterized by the rheological properties of the HP-poloxamer hydrogels. Solubility and viscosity of HP were also evaluated compared with poloxamer 188.


RESULTS
From the results, the solubility of the conjugated heparin was increased compared with free heparin. The content of heparin in HP copolymer was 62.9%. The CMC of HP and poloxamer 188 were 0.483 and 0.743 mg/mL, respectively. The gelation temperature of 0.4 g/mL HP was 43.5 degrees C, whereas that of the same concentration of poloxamer 188 was 37.3 degrees C. With HP content in poloxamer 188 solution increasing, a V-shape change of gelation temperature was observed.


CONCLUSIONS
Considering the importance of poloxamer 188 in functional material, HP may prove to be a facile temperature-sensitive material for protein drug-targeted therapy.
Pharmacy School, Wenzhou Medical College, Wenzhou, Zhejiang Province, PR China.
Ji-Lai
JL
Tian
Ying-Zheng
YZ
Zhao
Zhuo
Z
Jin
Cui-Tao
CT
Lu
Qin-Qin
QQ
Tang
Qi
Q
Xiang
Chang-Zheng
CZ
Sun
Lu
L
Zhang
Yan-Yan
YY
Xu
Hui-Sheng
HS
Gao
Zhi-Cai
ZC
Zhou
Xiao-Kun
XK
Li
Ying
Y
Zhang
D004337:Drug Carriers; D004339:Drug Compounding; D016503:Drug Delivery Systems; D006493:Heparin / Q000737:chemistry*; D008823:Micelles; D020442:Poloxamer / Q000737:chemistry*; D012995:Solubility; D013678:Technology, Pharmaceutical; D014783:Viscosity
D004337:Drug Carriers; D008823:Micelles; D020442:Poloxamer; D006493:Heparin