Nano‐spaced Gold on Glassy Carbon Substrate for Controlling Cell Behavior

Chauhan, Gaurav; Ángeles, Alejandro Lujambio; Gonzalez‐González, Everardo; Kulkarni, Mukund G.; Cardenas‐Benitez, Braulio; Jiménez, Martín Francisco; Santiago, Grissel Trujillo‐de; Álvarez, Mario Moisés; Madou, Marc; Martínez-Chapa, Sergio O.

doi:10.1002/admi.202000238

Cited by 12 publications

(14 citation statements)

References 89 publications

(96 reference statements)

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“…The generated photoacid (H + ) is consumed in the tautomeric conversion of cyclopentanone into enolic intermediates [(CH₂)₄CO (CH₂)₄COH − ]. [ 56 ] This enolic (–OH − ) intermediate activates the reduction of NaAuCl 4 , followed by an equilibrium disproportionation reaction to generate zerovalent gold ions (Au 0 ). [ 56,58,59 ] The hard baking temperature delivers a sufficient concentration of zerovalent gold ions causing nucleation into GNPs.…”

Section: Resultsmentioning

confidence: 99%

“…[56,58,59] The hard baking temperature delivers a sufficient concentration of zerovalent gold ions causing nucleation into GNPs. [56,60,61] The color of the wrinkled film changes from transparent yellow to light purple instantaneously when the temperature reaches 180-200 °C. This marks the nucleation of GNPs inside the wrinkled photoresist thin films (wSU8-GNPs).…”

Section: Fabrication Of Carbon-nanogold Micro/nano Topographiesmentioning

confidence: 99%

“…The diffusion of zerovalent gold and the nanometal surface reaction rates are the key factors governing the GNPs growth. [56] Higher temperatures encourage the diffusion of monomeric gold, on the contrary, the carbonizing photoresist matrix opposes the diffusion process. A unique balance achieved during this process determines the final presentation of GNPs in the carbonized wrinkles.…”

Section: Pyrolysis (Wsu8-gnps To Wgc-gnps)mentioning

confidence: 99%

“…Understanding of the nucleation and growth mechanisms involved in the nanoscale organization of GNPs in the carbonizing matrix becomes the basis of this work. [ 56 ] Fabrication of this dual‐structured hierarchical topography involved three steps: a) gradient photopolymerization of SU8 photoresist with added gold precursor, b) wrinkle generation and GNPs nucleation during hard bake stabilization (wSU8‐GNPs), and c) pyrolysis up to 900 °C, resulting in the carbonization of the polymeric wrinkles along with the growth of GNPs (wGC‐GNPs). [ 56 ] The crosslinking gradient and thus the wrinkle morphology are dependent on the gold precursor concentration, exposure dose and thickness of the photoresist film.…”

Section: Introductionmentioning

confidence: 99%

“…[ 56 ] Fabrication of this dual‐structured hierarchical topography involved three steps: a) gradient photopolymerization of SU8 photoresist with added gold precursor, b) wrinkle generation and GNPs nucleation during hard bake stabilization (wSU8‐GNPs), and c) pyrolysis up to 900 °C, resulting in the carbonization of the polymeric wrinkles along with the growth of GNPs (wGC‐GNPs). [ 56 ] The crosslinking gradient and thus the wrinkle morphology are dependent on the gold precursor concentration, exposure dose and thickness of the photoresist film. A physical‐mathematical framework based on Lambert–Beer's law of light absorption and experimental observations are used to explain this gradient photocrosslinking and wrinkling mechanism.…”

Section: Introductionmentioning

confidence: 99%

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Carbon‐Nanogold Hierarchical Micro/Nano Topographies for Cell Guidance

Chauhan

Ángeles

Gonzalez‐González

et al. 2020

Adv Materials Inter

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characteristics of a material surface determine its biological interaction and cellular fate. [1-4] Hierarchical 3D surfaces for that reason are of significant interest in biomaterial and nanosciences. [5] These topological cues are reported to have a strong influence on the cell activity, adhesion, alignment, migration, and differentiation (with specific responses depending on the cell type). [4,6-9] Microscopic guidance and capillary effects between nanoscale patterns are the basic mechanisms defining the cellular interactions with these types of 3D surfaces. [10-12] The influence of anisotropic topographies on cell function underlies the growing application of these hierarchical surfaces in the field of biomedical engineering, designing next-generation biomaterials, medical implants, and controlled drug delivery technology. [13-16] Natural and synthetic polymers [17,18] are used to fabricate micro/ nano features applying techniques such as lithography (photo, soft, electron beam, and colloidal), [19-23] self-assembly, [24,25] dry etching, [26] and electrospinning. [27,28] With special importance in biomaterial science, plasmonics, and sensing, hierarchical topographies of gold have attracted Here it is reported on the fabrication of a carbon-gold micro/nano hierarchical platform using a stimuli-responsive wrinkling technology. The approach exploits the generation of depth wise photo-crosslinking gradient in SU8 thin films doped with a UV light absorbing gold precursor. Wrinkled films are then pyrolyzed at 900 °C, resulting in well preserved carbonized wrinkle patterns along with the growth of GNPs. The wrinkling phenomenon is explained using a theoretical model that includes the influence of the film thickness, the gold precursor concentration, and the exposure gradient that sets the theoretical intermolecular distance of free monomers along the film's depth direction. The predicted evolution of the wrinkle patterns is supported by experimental results. Surface roughness and wetting properties of the resulting topographies are studied in detail. GNPs act as potential anchor points for cell adhesion whereas mechanical topographies controls the cellular alignment as a result of contact guidance. Fibronectin functionalization significantly improves cell attachment, biocompatibility, and provides highly aligned cell cultures. This whole strategy of fabricating non-planar carbon/ gold-based cell culture platform has great potential for their use in lab on a chip and tissue engineering based applications.

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Section: Resultsmentioning

confidence: 99%