Polymer surface functionalities that control human embryoid body cell adhesion revealed by high throughput surface characterization of combinatorial material microarrays. Biomaterials

Laboratory of Biophysics and Surface and Analysis, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
Biomaterials (Impact Factor: 8.56). 12/2010; 31(34):8827-38. DOI: 10.1016/j.biomaterials.2010.08.028
Source: PubMed


High throughput materials discovery using combinatorial polymer microarrays to screen for new biomaterials with new and improved function is established as a powerful strategy. Here we combine this screening approach with high throughput surface characterization (HT-SC) to identify surface structure-function relationships. We explore how this combination can help to identify surface chemical moieties that control protein adsorption and subsequent cellular response. The adhesion of human embryoid body (hEB) cells to a large number (496) of different acrylate polymers synthesized in a microarray format is screened using a high throughput procedure. To determine the role of the polymer surface properties on hEB cell adhesion, detailed HT-SC of these acrylate polymers is carried out using time of flight secondary ion mass spectrometry (ToF SIMS), X-ray photoelectron spectroscopy (XPS), pico litre drop sessile water contact angle (WCA) measurement and atomic force microscopy (AFM). A structure-function relationship is identified between the ToF SIMS analysis of the surface chemistry after a fibronectin (Fn) pre-conditioning step and the cell adhesion to each spot using the multivariate analysis technique partial least squares (PLS) regression. Secondary ions indicative of the adsorbed Fn correlate with increased cell adhesion whereas glycol and other functionalities from the polymers are identified that reduce cell adhesion. Furthermore, a strong relationship between the ToF SIMS spectra of bare polymers and the cell adhesion to each spot is identified using PLS regression. This identifies a role for both the surface chemistry of the bare polymer and the pre-adsorbed Fn, as-represented in the ToF SIMS spectra, in controlling cellular adhesion. In contrast, no relationship is found between cell adhesion and wettability, surface roughness, elemental or functional surface composition. The correlation between ToF SIMS data of the surfaces and the cell adhesion demonstrates the ability to identify surface moieties that control protein adsorption and subsequent cell adhesion using ToF SIMS and multivariate analysis.

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    • "In addition to materials discovery, the large number of cell–material interactions observed on a microarray can be used to enhance the understanding of the underlying material properties that control the biological response. This knowledge can be subsequently used to develop future generations of materials [15] [17] [19]. High throughput surface analysis of the materials present on the array is required to provide the surface chemical and mechanical properties that the biological response can then be correlated with. "
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    • "Polymer microarrays are ideally suited to high throughput materials screening by presenting thousands of unique polymers on one glass microscope slide.1 Combinatorial microarrays have been used to screen for biomaterials that are capable of supporting the clonal expansion of stem cells, resist bacterial attachment, identify switchable materials and sort co-culture cell populations.2–6 Furthermore, high throughput surface characterisation of arrays has successfully been applied to determine the chemical and physical properties of the materials7–10 which can then be correlated with the biological performance of the materials to elucidate structure–function relationships.2,3 Progress in this field relies on the application of polymer microarrays, with an expansion of the combinatorial space that these explore, and increased throughput in processing tools to effectively analyse the plethora of data that high throughput studies produce. "
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