Tunable Layer-by-Layer Polyelectrolyte Platforms for Comparative Cell Assays

Abstract

We developed a cell-based assay based on the spin-assisted layer-by-layer (LbL) assembled polyelectrolyte matrix platforms. Three types of human breast epithelial cell lines including normal cells (184B5), noncancerous fibrocystic disease cells (MCF 10F), and metastatic cancerous cells (CAMA-1) were cultured, analyzed, and compared in parallel on various LbL-assembled polymer films. Poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) electrolyte polymers were used as the basic building units to form various LbL polyelectrolyte matrices. The mechanical rigidity, surface charge, and biorecognition property of the LbL platforms were controlled by tailoring the LbL surface, thermal cross-linking, and protein modification. Cellular phenotypic changes in adhesion, proliferation, and morphology on these LbL films were characterized and analyzed for the three different cell types. Our analysis results indicate that the cellular phenotype can be controlled by taking advantage of different surface charge, mechanical property, and biological modification (i.e., fibronectin in this case) of the LbL multilayer platforms. Importantly, cell phenotypical quantification results show that the cell spreading area per cell and optical density are useful parameters in distinguishing metastatic cancer cells from normal or fibrocystic disease cells on these LbL films. These LbL-based cell assay platforms have a potential for the development of various disease diagnostic cell assays.

Biomimetic Nanopatterns as Enabling Tools for Analysis and Control of Live Cells

“…Synthetic Polymer Nanofi brous Scaffold -Electrospinning [ 64,65,109] -Polymer Crosslinking [61] ECM Protein-Containing Nanofi ber…”

“…[59][60][61] These could be used for the development of various cell assays including cell phenotypic changebased disease diagnostic assay. [ 61 ] In addition to synthetic and natural homo polymers, copolymers and synthetic-synthetic or synthetic-natural polymer blends have been employed to render artifi cial cellular microenvironment suitable for maintaining and inducing certain cell fates and functions. [ 62 , 63 ] Surface modifi cation of electrospun fi bers with ligands for specifi c cell…”

Polyelectrolyte Multilayer Nanofilms Used as Thin Materials for Cell Mechano‐Sensitivity Studies

“…[24][25][26] In the absence of adhesion peptides, cells interact with materials by means of non specific interactions (electrostatic, hydrophobic, van der Waals) via their pericellular coat. [27] To date, three strategies have been developed for designing PEM films of controlled and tunable stiffness.…”

“…The first strategy relies on varying the degree of ionic cross-linking between the polyanion and polycation (poly(allylamine hydrochloride)/polyacrylic) as the pH of the polyelectrolyte solutions is increased. [28,29] The second Collagen [12,[14][15][16] Poly-D-lysine [60] Fibronectin [16,50,61] PDMS Tensile tests 5 Á 10 4 -2 Á 10 6 Collagen [17] PEM layer [51] Fibronectin [18] vmIPN Shear rheometry 10 1 -10 4 RGD or RGE peptides [62] Biopolymeric gels Alginate Compression rheometry 10 1 -3 Á 10 3 RGD or RGE peptides [63] Oligopeptide [64] Agarose Shear rheometry 10 3 -4 Á 10 6 No coating [65] Collagen Tensile tests 5Á10 2 -2 Á 10 3 No coating [66] Chitosan gels Compression rheometry 10 3 -2 Á 10 4 No coating [67] Laminin [68] PEM films PLL/HA capped with PAH/PSS AFM indentations 10 3 -5 Á 10 5 No coating [30] PAH/PAA AFM indentations 2 Á 10 5 -10 10 Fibronectin [26] No coating or collagen [29] PLL/HA AFM indentations 10 3 -4 Á 10 5 No coating [40] relies on depositing an increasing number of stiff layers onto a soft base. [30] The third makes use of post-diffusion on the film of a cross-linker, converting ammonium and carboxylic groups into covalent amide bonds.…”

Functionalization of polymer multilayer thin films for novel biomedical applications

“…It has been well documented that mechanical properties of polymeric multilayer films play an important role in controlling the interactions between a surface and cells [17] because cells prefer to adhere on hard surfaces, in general [18]. Here, diverse methods to finely tune the properties of multilayer thin films will be reviewed with a particular emphasis on the effect of thin film properties for biological functions.…”