References of "Courtenay, James C."
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See detailModulating cell response on cellulose surfaces; tunable attachment and scaffold mechanics
Courtenay, James C.; Deneke, Christoph; Martin Lanzoni, Evandro UL et al

in Cellulose (2017)

Combining surface chemical modification of cellulose to introduce positively charged trimethylammonium groups by reaction with glycidyltrimethylammonium chloride (GTMAC) allowed for direct attachment of ... [more ▼]

Combining surface chemical modification of cellulose to introduce positively charged trimethylammonium groups by reaction with glycidyltrimethylammonium chloride (GTMAC) allowed for direct attachment of mammalian MG-63 cells, without addition of protein modifiers, or ligands. Very small increases in the surface charge resulted in significant increases in cell attachment: at a degree of substitution (DS) of only 1.4\%, MG-63 cell attachment was \textgreater 90 compared to tissue culture plastic, whereas minimal attachment occurred on unmodified cellulose. Cell attachment plateaued above DS of ca. 1.85 reflecting a similar trend in surface charge, as determined from ζ-potential measurements and capacitance coupling (electric force microscopy). Cellulose film stiffness was modulated by cross linking with glyoxal (0.3–2.6 degree of crosslinking) to produce a range of materials with surface shear moduli from 76 to 448 kPa (measured using atomic force microscopy). Cell morphology on these materials could be regulated by tuning the stiffness of the scaffolds. Thus, we report tailored functionalised biomaterials based on cationic cellulose that can be tuned through surface reaction and glyoxal crosslinkin+g, to influence the attachment and morphology of cells. These scaffolds are the first steps towards materials designed to support cells and to regulate cell morphology on implanted biomaterials using only scaffold and cells, i.e. without added adhesion promoters. [less ▲]

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See detailSurface modified cellulose scaffolds for tissue engineering
Courtenay, James C.; Johns, Marcus A.; Galembeck, Fernando et al

in Cellulose (2016)

We report the ability of cellulose to support cells without the use of matrix ligands on the surface of the material, thus creating a two-component system for tissue engineering of cells and materials ... [more ▼]

We report the ability of cellulose to support cells without the use of matrix ligands on the surface of the material, thus creating a two-component system for tissue engineering of cells and materials. Sheets of bacterial cellulose, grown from a culture medium containing Acetobacter organism were chemically modified with glycidyltrimethylammonium chloride or by oxidation with sodium hypochlorite in the presence of sodium bromide and 2,2,6,6-tetramethylpipiridine 1-oxyl radical to introduce a positive, or negative, charge, respectively. This modification process did not degrade the mechanical properties of the bulk material, but grafting of a positively charged moiety to the cellulose surface (cationic cellulose) increased cell attachment by 70 compared to unmodified cellulose, while negatively charged, oxidised cellulose films (anionic cellulose), showed low levels of cell attachment comparable to those seen for unmodified cellulose. Only a minimal level of cationic surface derivitisation (ca 3 degree of substitution) was required for increased cell attachment and no mediating proteins were required. Cell adhesion studies exhibited the same trends as the attachment studies, while the mean cell area and aspect ratio was highest on the cationic surfaces. Overall, we demonstrated the utility of positively charged bacterial cellulose in tissue engineering in the absence of proteins for cell attachment. [less ▲]

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