Development of Thermally Responsive PolyNIPAm Microcarrier for Application of Cell Culturing—Part I: A Feasibility Study

Chou, Pui May; Khiew, Poi Sim; Brown, Paul D; Hu, Binjie

Abstract

Poly(N-isopropylacrylamide) (polyNIPAm) microspheres were synthesized via the suspension polymerization technique. Thermal and redox initiators were compared for the polymerization, in order to study the effect of initiator type on the surface charge and particle size of polyNIPAm microspheres. The successful polymerization of NIPAm was confirmed by FTIR analysis. Microspheres of diameter >50 µm were synthesized when a pair of ammonium persulfate (APS) and N,N,N’,N’-tetramethylene-diamine (TEMED) redox initiators was used, whilst relatively small microspheres of ~1 µm diameter were produced using an Azobis-isobutyronitrile (AIBN) thermal initiator. Hence, suspension polymerization using a redox initiator pair was found to be more appropriate for the synthesis of polyNIPAm microspheres of a size suitable for human embryonic kidney (HEK) cell culturing. However, the zeta potential of polyNIPAm microspheres prepared using an APS/TEMED redox initiator was significantly more negative than AIBN thermal initiator prepared microspheres and acted to inhibit cell attachment. Conversely, strong cell attachment was observed in the case of polyNIPAm microspheres of diameter ~90 µm, prepared using an APS/TEMED redox initiator in the presence of a cetyl trimethyl ammonium bromide (CTAB) cationic surfactant; demonstrating that surface charge modified polyNIPAm microspheres have great potential for use in cell culturing.

Citation

Chou, P. M., Khiew, P. S., Brown, P. D., & Hu, B. (2021). Development of Thermally Responsive PolyNIPAm Microcarrier for Application of Cell Culturing—Part I: A Feasibility Study. Polymers, 13(16), Article 2629. https://doi.org/10.3390/polym13162629

• Journal Article Type: Article
• Acceptance Date: Aug 2, 2021
• Online Publication Date: Aug 7, 2021
• Publication Date: Aug 7, 2021
• Deposit Date: Sep 17, 2021
• Publicly Available Date: Sep 17, 2021
• Journal: Polymers
• Electronic ISSN: 2073-4360
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 16
• Article Number: 2629
• DOI: https://doi.org/10.3390/polym13162629
• Keywords: Polymers and Plastics; General Chemistry
• Public URL: https://nottingham-repository.worktribe.com/output/6244538
• Publisher URL: https://www.mdpi.com/2073-4360/13/16/2629