title: Engineering cell de-adhesion dynamics on thermoresponsive poly(N-isopropylacrylamide).
abstract: Poly(N-isopropylacrylamide) (PIPAAm) has been demonstrated as an effective thermoresponsive polymer for non-invasive cell regeneration/recovery. However, little is known about the intricate relationship between the biophysical response of cells and physiochemical properties of PIPAAm during cell recovery. In this study, the de-adhesion kinetics of smooth muscle cell (SMC) on PIPAAm surfaces is probed with unique biophysical techniques. Water-immersion atomic force microscope (AFM) first showed that the nanotopology of PIPAAm surfaces is dependent on the polymerization time and collagen coating. It is found that the initial rate of cell de-adhesion increases with the increase in polymerization time. Moreover, the degree of cell deformation (a/R) and average adhesion energy are reduced with the increase of grafted PIPAAm density during 40min of cell de-adhesion. It has been shown that collagen coating regulates cell adhesion on biomaterial surface. Interestingly, lower collagen density on PIPAAm leads to higher adhesion energy per cell during the initial 20min compared with as-prepared PIPAAm, while the initial rate of cell de-adhesion remains unchanged. In contrast, higher collagen density leads to 50% reduction in the initial rate of cell de-adhesion and higher adhesion energy per cell during the entire 90min. Furthermore, immunostaining of actin provides supporting evidence that the de-adhesion kinetics is correlated with the cytoskeleton transformation during cell de-adhesion below the lower solution critical temperature (LCST).
authors.affiliation: Center of Biotechnology, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 639798, Singapore.
authors.forename: Beiyi
authors.initials: B
authors.lastname: Chen
authors.forename: F J
authors.initials: FJ
authors.lastname: Xu
authors.forename: Ning
authors.initials: N
authors.lastname: Fang
authors.forename: K G
authors.initials: KG
authors.lastname: Neoh
authors.forename: E T
authors.initials: ET
authors.lastname: Kang
authors.forename: Wei Ning
authors.initials: WN
authors.lastname: Chen
authors.forename: Vincent
authors.initials: V
authors.lastname: Chan
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D000180:Acrylic Resins; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001698:Biomedical Engineering; D055592:Biophysical Phenomena; D001703:Biophysics; D002448:Cell Adhesion / Q000502:physiology*; D002460:Cell Line; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003094:Collagen / Q000737:chemistry; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000502:physiology; D011108:Polymers / Q000737:chemistry*; D051381:Rats; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D003094:Collagen