Thermoresponsive properties of polyacrylamides in physiological solutions

0545564 - ÚMCH 2022 RIV GB eng J - Journal Article
Kolouchová, Kristýna - Lobaz, Volodymyr - Beneš, Hynek - de la Rosa, V. R. - Babuka, David - Švec, Pavel - Černoch, Peter - Hrubý, Martin - Hoogenboom, R. - Štěpánek, Petr - Groborz, Ondřej
Thermoresponsive properties of polyacrylamides in physiological solutions.
Polymer Chemistry. Roč. 12, č. 35 (2021), s. 5077-5084. ISSN 1759-9954. E-ISSN 1759-9962
R&D Projects: GA ČR(CZ) GA19-01602S; GA TA ČR(CZ) TO01000074
Grant - others:AV ČR(CZ) FWO-19-03
Program: Bilaterální spolupráce
Institutional support: RVO:61389013
Keywords : lower critical solution temperature * LCST * cloud point temperature
OECD category: Polymer science
Impact factor: 5.364, year: 2021
Method of publishing: Open access
https://pubs.rsc.org/en/content/articlelanding/2021/PY/D1PY00843A

Polymer solutions with a lower critical solution temperature (LCST) undergo reversible phase separation when heated above their cloud point temperature (TCP or CPT). As such, they have been proposed for a wide range of biomedical applications, from injectable drug depots to switchable coatings for cell adhesion. However, in systematic studies, the TCP of these thermoresponsive polymers has been mostly measured in non-physiological solutions, thereby hindering the development of their medicinal applications. Here, we analysed the thermoresponsive properties of four acrylamide-based polymers with LCST, namely poly[(N-2,2-difluoroethyl)acrylamide] (pDFEA), poly[(N-isopropyl)acrylamide] (pNIPAM), poly[(N,N-diethyl)acrylamide] (pDEA), and poly[(N-acryloyl)pyrrolidine] (pAP). As shown by turbidimetry, their TCP in phosphate saline buffer (PBS) and foetal bovine serum (FBS) were consistently lower than those reported in the literature, typically assessed in pure water, even when using the same setup. In addition, these physiological solutions affected the variation of TCP as a function of polymer concentration (1.25 to 10.0 mg mL−1) and molar mass (20 to 50 kg mol−1). As shown by isothermal calorimetry, interactions between proteins in FBS and polymer aggregates were predominantly exothermic, which indicates that protein–polymer complexes are formed through enthalpically driven processes. In conclusion, the TCP of thermoresponsive polymers strongly depends on solvent composition and therefore should be measured under physiological conditions for future medicinal applications.

Permanent Link: http://hdl.handle.net/11104/0322759