Surface chemical immobilization of parylene C with thermosensitive block copolymer brushes based on N-isopropylacrylamide and N-tert-butylacrylamide: synthesis, characterization, and cell adhesion/detachment.

Poly(N-isopropylacrylamide) (pNIPAM), poly(N-tert-butylacrylamide) (pNTBAM), and their copolymer brushes were covalently immobilized onto parylene C (PC) surfaces via surface initiated atom transfer radical polymerization (ATRP). Contact angle measurement between 13 and 40°C showed that the hydrophobicity of the modified PC surfaces was thermally sensitive. Among these samples, PC grafted with pNIPAM (PC-NI), PC grafted with pNTBAM (PC-NT) and PC grafted with copolymer brushes containing pNTBAM and pNIPAM (PC-NT-NI) exhibited the lower critical solution temperature (LCST) at 29, 22, and 24°C, respectively. Cytocompatibility study for the modified surfaces was performed by 5 days human skin fibroblast culture at 37°C. Data showed that only a very small amount of cells adhered on the PC and PC-NI surfaces, while a significantly higher amount of cell adhesion and growth was observed on PC-NT and PC-NT-NI surfaces. Furthermore, cell detachment at the temperatures of 24 and 6°C were studied after the substrates were cultured with cells at 37°C for 24 h. The results showed that the cells on PC-NI formed the aggregations and loosely attached on the substrate after 30-min culture at 24°C, while no significant cell detachment was observed for PC-NT and PC-NT-NI samples at this temperature. By continuing the cell culture for additional 100 min at 6°C for PC-NT and PC-NT-NI, about 10 and 35% of the cells were found detached respectively, and the unattached cells aggregated on the substrate. In comparison, cells cultured on the tissue culture petri dish (TCP) exhibited no quantity and morphology changes at the culture temperatures of 37, 24, and 6°C. This study showed that: (1) immobilization of PC with nonthermal sensitive pNTBAM could provide PC surface thermal sensitive hydrophilicity; (2) the chlorines on the polymer brushes of PC-NT could be used to further initiate the ATRP pNIPAM and form block copolymer brushes; (3) the incorporation of pNTBAM into pNIPAM on PC-NT-NI could change the surface thermal hydrophilicity property, and be further applied to decrease the LCST of the modified PC surface; (4) grafted pNIPAM brushes on PC-NI by ATRP showed very low cell adhesion and proliferation in 5 days fibroblast culture at 37°C, and cell detached at 24°C; (5) the incorporation of pNTBAM into pNIPAM on PC-NT-NI decreased the thermal sensitivity of cell adhesion/detachment, cell detached at 6°C, but the cell adhesion and proliferation were significantly improved at a wide temperature range.

[1]  I Lundström,et al.  Protein adsorption studies on model organic surfaces: an ellipsometric and infrared spectroscopic approach. , 1998, Biomaterials.

[2]  Y. Ito,et al.  Surface micropatterning to regulate cell functions. , 1999, Biomaterials.

[3]  T. J. McCarthy,et al.  Chemical surface modification of poly(p-xylylene) thin films. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[4]  S. Ramakrishna,et al.  Biomedical applications of polymer-composite materials: a review , 2001 .

[5]  P. Tresco,et al.  Relative importance of surface wettability and charged functional groups on NIH 3T3 fibroblast attachment, spreading, and cytoskeletal organization. , 1998, Journal of biomedical materials research.

[6]  Masayuki Yamato,et al.  Preparation of thermoresponsive polymer brush surfaces and their interaction with cells. , 2008, Biomaterials.

[7]  Vikramaditya G. Yadav,et al.  Cell and protein compatibility of parylene-C surfaces. , 2007, Langmuir : the ACS journal of surfaces and colloids.

[8]  David Hui,et al.  A critical review on polymer-based bio-engineered materials for scaffold development , 2007 .

[9]  T. Okano,et al.  Release of adsorbed fibronectin from temperature-responsive culture surfaces requires cellular activity. , 2000, Biomaterials.

[10]  G. López,et al.  Lower critical solubility temperature materials as biofouling release agents , 1998, Journal of Industrial Microbiology and Biotechnology.

[11]  J. Breeze,et al.  Implants. , 2019, RDH.

[12]  M. Nowak-Wyrzykowska,et al.  Modulation of adhesion, spreading and cytoskeleton organization of 3T3 fibroblasts by sulfonic groups present on polymer surfaces , 2003, Cell biology international.

[13]  I. Mihailescu,et al.  Biocompatibility evaluation of a novel hydroxyapatite-polymer coating for medical implants (in vitro tests) , 2008, Journal of materials science. Materials in medicine.

[14]  R. Narain,et al.  Water-assisted atom transfer radical polymerization of N-isopropylacrylamide: nature of solvent and temperature. , 2009, The journal of physical chemistry. B.

[15]  I. Choi,et al.  The control of cell adhesion and detachment on thin films of thermoresponsive poly[(N-isopropylacrylamide)-r-((3-(methacryloylamino)propyl)-dimethyl(3-sulfopropyl)ammonium hydroxide)]. , 2009, Biomaterials.

[16]  T. Okano,et al.  Thermo-responsive culture dishes allow the intact harvest of multilayered keratinocyte sheets without dispase by reducing temperature. , 2001, Tissue engineering.

[17]  Y. Ito,et al.  Effect of protein and cell behavior on pattern-grafted thermoresponsive polymer. , 1998, Journal of biomedical materials research.

[18]  Jan Feijen,et al.  Effect of comonomer hydrophilicity and ionization on the lower critical solution temperature of N-isopropylacrylamide copolymers , 1993 .

[19]  A. Gorelov,et al.  Estimation of the strength of adhesion between a thermoresponsive polymer coating and nitinol wire , 2008, Journal of materials science. Materials in medicine.

[20]  A. Whitty,et al.  Effect of Divalent Cations on the Affinity and Selectivity of α4 Integrins Towards the Integrin Ligands Vascular Cell Adhesion Molecule-1 and Mucosal Addressin Cell Adhesion Molecule-1: Ca 2+ Activation of Integrin α4β1 Confers a Distinct Ligand Specificity , 2002, Cell communication & adhesion.

[21]  Yan Xia,et al.  Thermal Response of Narrow-Disperse Poly(N-isopropylacrylamide) Prepared by Atom Transfer Radical Polymerization , 2005 .

[22]  M. Humayun,et al.  REVERSIBLE THERMOSENSITIVE GLUE FOR RETINAL IMPLANTS , 2007, Retina.

[23]  J. Uhlemann,et al.  Influence of artificial body fluids and medical sterilization procedures on chemical stability of Parylene C , 2010, 2010 Proceedings 60th Electronic Components and Technology Conference (ECTC).

[24]  Buddy D. Ratner,et al.  Biomaterials Science: An Introduction to Materials in Medicine , 1996 .

[25]  Kerstin Länge,et al.  Chemical modification of parylene C coatings for SAW biosensors , 2007 .

[26]  T. Okano,et al.  Signal transduction and cytoskeletal reorganization are required for cell detachment from cell culture surfaces grafted with a temperature-responsive polymer. , 1999, Journal of biomedical materials research.

[27]  G. Guo,et al.  Cell adhesion and accelerated detachment on the surface of temperature-sensitive chitosan and poly(N-isopropylacrylamide) hydrogels , 2009, Journal of materials science. Materials in medicine.

[28]  K. Dawson,et al.  Surface modification for controlled cell growth on copolymers of N-isopropylacrylamide , 2001 .

[29]  K. Dawson,et al.  Interaction of soft condensed materials with living cells: Phenotype/transcriptome correlations for the hydrophobic effect , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[30]  K. Neoh,et al.  Surface-active and stimuli-responsive polymer--Si(100) hybrids from surface-initiated atom transfer radical polymerization for control of cell adhesion. , 2004, Biomacromolecules.

[31]  A. Gristina,et al.  Biomaterial-centered infection: microbial adhesion versus tissue integration. , 1987, Science.

[32]  Y. Tai,et al.  Improvement of metal and tissue adhesion on surface-modified parylene C. , 2008, Journal of biomedical materials research. Part A.

[33]  T. Okano,et al.  Intelligent thermoresponsive polymeric stationary phases for aqueous chromatography of biological compounds , 2002 .

[34]  T. Takezawa,et al.  A novel method to prepare multicellular spheroids from varied cell types , 1995, Biotechnology and bioengineering.

[35]  G. Demirel,et al.  Poly(N-isopropylacrylamide) layers on silicon wafers as smart DNA-sensor platforms. , 2009, Journal of nanoscience and nanotechnology.

[36]  Masayuki Yamato,et al.  Ultrathin poly(N-isopropylacrylamide) grafted layer on polystyrene surfaces for cell adhesion/detachment control. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[37]  J. Lwebuga-Mukasa,et al.  Divalent cation-dependent regulation of rat alveolar epithelial cell adhesion and spreading. , 1994, Experimental cell research.

[38]  Shin-ichi Nakao,et al.  Regulation of cell adhesion using a signal-responsive membrane substrate. , 2005, Biotechnology and bioengineering.

[39]  T. Okano,et al.  Decrease in culture temperature releases monolayer endothelial cell sheets together with deposited fibronectin matrix from temperature-responsive culture surfaces. , 1999, Journal of biomedical materials research.

[40]  S. Armes,et al.  Copper(I)‐mediated radical polymerization of methacrylates in aqueous solution , 2001 .

[41]  Garrett F. Farrell,et al.  Correlation of the adhesive properties of cells to N-isopropylacrylamide/N-tert-butylacrylamide copolymer surfaces with changes in surface structure using contact angle measurements, molecular simulations, and Raman spectroscopy , 2005 .

[42]  K. Ishihara,et al.  Prevention of biofilm formation with a coating of 2-methacryloyloxyethyl phosphorylcholine polymer. , 2008, The Journal of veterinary medical science.

[43]  Buddy D Ratner,et al.  Novel cell patterning using microheater-controlled thermoresponsive plasma films. , 2004, Journal of biomedical materials research. Part A.

[44]  K. Kubota,et al.  Single-chain transition of poly(N-isopropylacrylamide) in water , 1990 .

[45]  C. Werner,et al.  Thermo-responsive PNiPAAm-g-PEG films for controlled cell detachment. , 2003, Biomacromolecules.

[46]  Chi Wu,et al.  Globule-to-Coil Transition of a Single Homopolymer Chain in Solution , 1998 .

[47]  S. Beaudoin,et al.  Characterization of parylene‐N and parylene‐C photooxidation , 2003 .

[48]  Melik C. Demirel,et al.  Growth of nanostructured thin films of poly(p-xylylene) derivatives by vapor deposition , 2007 .

[49]  T. Okano,et al.  Growth factor release from thermally reversible tissue culture substrates. , 1998, Journal of controlled release : official journal of the Controlled Release Society.

[50]  A. Maeder,et al.  Medical device research , 2005, Expert review of medical devices.

[51]  G. Masci,et al.  Atom Transfer Radical Polymerization of N-Isopropylacrylamide , 2004 .

[52]  S. Naidu,et al.  Fibroblast cell attachment and growth on nanoengineered sculptured thin films. , 2007, Journal of biomedical materials research. Part B, Applied biomaterials.

[53]  K. L. Tan,et al.  Surface modification of plasma-pretreated poly(tetrafluoroethylene) films by graft copolymerization , 1993 .

[54]  Y. Nakayama,et al.  Thermoresponsive artificial extracellular matrix for tissue engineering: hyaluronic acid bioconjugated with poly(N-isopropylacrylamide) grafts. , 2001, Biomacromolecules.

[55]  J. Fawcett,et al.  Assessment of the biocompatibility of photosensitive polyimide for implantable medical device use. , 2009, Journal of biomedical materials research. Part A.

[56]  Mitsuo Umezu,et al.  Control of cell adhesion and detachment using temperature and thermoresponsive copolymer grafted culture surfaces. , 2004, Journal of biomedical materials research. Part A.

[57]  Mohd Zobir Hussein,et al.  Synthesis of organic-inorganic hybrid nanocomposite material: alizarin-3-sulfonate in the lamella of zinc-aluminium-layered double hydroxide , 2005, SPIE Micro + Nano Materials, Devices, and Applications.

[58]  K. Matyjaszewski.  Controlled/living radical polymerization : progress in ATRP, NMP, and RAFT , 2000 .

[59]  Thomas Boland,et al.  Synthesis and characterization of biodegradable elastomeric polyurethane scaffolds fabricated by the inkjet technique. , 2008, Biomaterials.

[60]  Buddy D Ratner,et al.  Surface characterization of the extracellular matrix remaining after cell detachment from a thermoresponsive polymer. , 2005, Langmuir : the ACS journal of surfaces and colloids.