Protein adsorption on poly(N-isopropylacrylamide)-modified silicon surfaces: Effects of grafted layer thickness and protein size

Yu, Qian; Zhang, Yanxia; Chen, Hong; Wu, Zhaoqiang; Huang, He; Cheng, David C.

doi:10.1016/j.colsurfb.2009.12.006

Cited by 93 publications

(96 citation statements)

References 72 publications

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“…As contact angle showed hydrophobic surfaces (higher than traditional anti-fouling polymer), the authors deduced that the anti-fouling properties of low PNIPAM thickness were not due to the hydrophilicity of the PNIPAM surface, but to the interactions between PNIPAM and the substrate. Indeed, short PNIPAM brush end chains can also interact with the substrate and reduce the freedom of conformation changes, reducing the temperature effect [132]. This study also showed the importance of the protein size on adsorption.…”

Section: Smart Bio-surfaces: Example Of Poly(n-isopropylacrylamide) Tsupporting

confidence: 54%

“…Comparing these two last results, it appears that in the case of polyurethane substrate the hydrophilicity tends to increase with the thickness, leading to a decrease of protein adsorption [131], whereas the Si substrate graft led to an increase of protein adsorption, as the hydrophobicity increased [132]. Thus, we see the importance of the substrate, and the resulting surface properties will depend on the ability of its substrate to allow primary binding and on the hydrophilicity/hydrophobicity balance of the resulting surface.…”

Section: Smart Bio-surfaces: Example Of Poly(n-isopropylacrylamide) Tmentioning

confidence: 87%

“…As a consequence, cells do not adhere to thick brushes and thus anti-adhesion surfaces can be produced by the use of PNIPAM. Yu et al showed thickness dependent thermo-sensitivity of PNIPAM grafted Si (surface initiated ATRP) surfaces and managed to produce HSA repellent, even with thin PNIPAM layers (< 15 nm) [132]. The variation of contact angle and HSA adsorption between 27 and 37 • C is not so notable at low PNIPAM thickness.…”

Section: Smart Bio-surfaces: Example Of Poly(n-isopropylacrylamide) Tmentioning

confidence: 99%

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PNIPAM grafted surfaces through ATRP and RAFT polymerization: Chemistry and bioadhesion

Conzatti

Cavalié

Combes

et al. 2017

Colloids and Surfaces B: Biointerfaces

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a b s t r a c tBiomaterials surface design is critical for the control of materials and biological system interactions. Being regulated by a layer of molecular dimensions, bioadhesion could be effectively tailored by polymer surface grafting. Basically, this surface modification can be controlled by radical polymerization, which is a useful tool for this purpose. The aim of this review is to provide a comprehensive overview of the role of surface characteristics on bioadhesion properties. We place a particular focus on biomaterials functionalized with a brush surface, on presentation of grafting techniques for "grafting to" and "grafting from" strategies and on brush characterization methods. Since atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization are the most frequently used grafting techniques, their main characteristics will be explained. Through the example of poly(N-isopropylacrylamide) (PNIPAM) which is a widely used polymer allowing tuneable cell adhesion, smart surfaces involving PNIPAM will be presented with their main modern applications.

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Section: Smart Bio-surfaces: Example Of Poly(n-isopropylacrylamide) Tsupporting

confidence: 54%

Section: Smart Bio-surfaces: Example Of Poly(n-isopropylacrylamide) Tmentioning

confidence: 87%

Section: Smart Bio-surfaces: Example Of Poly(n-isopropylacrylamide) Tmentioning

confidence: 99%

See 1 more Smart Citation

PNIPAM grafted surfaces through ATRP and RAFT polymerization: Chemistry and bioadhesion

Conzatti

Cavalié

Combes

et al. 2017

Colloids and Surfaces B: Biointerfaces

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“…The scan of pNIPAAm (14-15 nm) retained on the noncured APTES (c-2) was similar to that of an un-rinsed pNIPAAm film ($30 nm, c-1) with the atomic % ratios [ Table II] of C:O:N close to theoretical values (75:12.5:12.5) and observed by others for pNIPAAm brushes and films. 1,25,26 The scan of pNIPAAm retained on the 2 h (or longer) cured APTES layer (i.e., c-3) had a small Si2p peak (atomic % of 5.3) and a higher O content (14.3 atomic %) than c-1, but the spectrum still had the general shape as that of c-1, suggesting that the film was basically pNIPAAm. The high-resolution C1s peaks of these three samples were also similar in shape (Fig.…”

Section: Potential Mechanism Of Retaining Pnipaam On Aptesmentioning

confidence: 99%

“…For the cases of pNIPAAm, the peak at $285 eV could be further fitted into two bands, one at 284.9 eV for the two -CH 3 groups and the other at 285.3 eV for the -CH 2 -in the pNIPAAm backbone, but for a better comparison to the reported results, 1,25,26 we decided to combine these two (C-H/C-C) peaks as normally adopted by others. 1,25,26 The peak resolution was performed first using a Shirley background subtraction, followed by a seven point Savitzky-Golay smoothing operation, and then by applying a mixed Gaussian-Lorentzian peak. After roughly determining the location and the height of each band, the fullwidth at half maximum (FWHM) values were set to values that gave the best fits and made the most physical sense of the data.…”

Section: Characterizations Of Silane Layers and Polymer Filmsmentioning

confidence: 99%

Retention of poly(N-isopropylacrylamide) on 3-aminopropyltriethoxysilane

et al. 2017

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Silane coupling agents are commonly employed to link an organic polymer to an inorganic substrate. One of the widely utilized coupling agents is 3-aminopropyltriethoxy silane (APTES). In this study, the authors investigated the ability of APTES to retain thermo-responsive poly(N-isopropylacrylamide) (pNIPAAm) on hydroxylated surfaces such as glass. For comparison purposes, the authors also evaluated the retention behaviors of (1) polystyrene, which likely has weaker van der Waals interactions and acid-base interactions (contributed by hydrogen-bonding) with APTES, on APTES as well as (2) pNIPAAm on two other silane coupling agents, which have similar structures to APTES, but exhibit less interaction with pNIPAAm. Under our processing conditions, the stronger interactions, particularly hydrogen bonding, between pNIPAAm and APTES were found to contribute substantially to the retention of pNIPAAm on the APTES modified surface, especially on the cured APTES layer when the interpenetration was minimal or nonexistent. On the noncured APTES layer, the formation of an APTES-pNIPAAm interpenetrating network resulted in the retention of thicker pNIPAAm films. As demonstrated by water contact angles [i.e., 7 -15 higher at 40 C, the temperature above the lower critical solution temperature (LCST) of 32 C for pNIPAAm, as compared to those at 25 C] and cell attachment and detachment behaviors (i.e., attached/spread at 37 C, above LCST; detached at 20 C, below LCST), the retained pNIPAAm layer (6-15 nm), on both noncured and cured APTES, exhibited thermo-responsive behavior. The results in this study illustrate the simplicity of using the coupling/adhesion promoting ability of APTES to retain pNIPAAm films on hydroxylated substrates, which exhibit faster cell sheet detachment ( 30 min) as compared to pNIPAAm brushes (in hours) prepared using tedious and costly grafting approaches. The use of adhesion promoters to retain pNIPAAm provides an affordable alternative to current thermo-responsive supports for cell sheet engineering and stem cell therapy applications.

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Nanopatterned Polymer Brushes for Triggered Detachment of Anchorage‐Dependent Cells

Johnson

López

2014

Adv Funct Materials

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Surfaces modifi ed with thermoresponsive poly( N -isopropylacrylamide) (PNI-PAAm) support mild and effi cient harvesting of anchorage-dependent cells. To enable cellular detachment, however, the surfaces must exhibit a narrow range of PNIPAAm thicknesses. In this work, this limitation is circumvented by introducing nanopatterns to grafted PNIPAAm brushes, eliminating the critical thickness requirement for cell-culturing applications. Nanopatterned PNIPAAm surfaces are prepared using a combination of interferometric lithography (IL) and surface-initiated polymerization. Above the lower critical solution temperature (LCST) of PNIPAAm (∼32 °C), these surfaces support the attachment and proliferation of mammalian cells (e.g., fi broblasts and endothelial cells). Below the LCST of PNIPAAm, cells readily detach from the nanopatterned PNIPAAm surfaces without infl uence from the period of nanopatterns, which vary between 157 ± 9 nm to 1021 ± 17 nm. Cells selectively attach and proliferate on PNIPAAm nanopatterns as compared to thick unpatterned PNIPAAm, which is further exploited to spatially direct cellular growth to generate cellular micropatterns. Nanopatterned PNIPAAm surfaces provide a unique solution to the critical thickness issue for cell harvesting and facilitate spatial control of cellular growth on surfaces.

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Protein adsorption on poly(N-isopropylacrylamide)-modified silicon surfaces: Effects of grafted layer thickness and protein size

Cited by 93 publications

References 72 publications

PNIPAM grafted surfaces through ATRP and RAFT polymerization: Chemistry and bioadhesion

PNIPAM grafted surfaces through ATRP and RAFT polymerization: Chemistry and bioadhesion

Retention of poly(N-isopropylacrylamide) on 3-aminopropyltriethoxysilane

Nanopatterned Polymer Brushes for Triggered Detachment of Anchorage‐Dependent Cells

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