Effects of Methacrylate-Based Thermoresponsive Polymer Brush Composition on Fibroblast Adhesion and Morphology

Abstract

Thermoresponsive polymers are being used increasingly in cell culture applications due to their temperature dependent surface properties. Poly(MEO2MA-co-OEGMA) (PMO) brushes offer tunable physical properties via variation in the copolymer ratio, but the effects of composition on cell-substrate interactions is unclear. To this end, a series of PMO brushes (0â8% OEGMA) was fabricated and L-929 fibroblast adhesion and morphology was quantified in the presence of serum (FBS) or after functionalization via the adsorption of fibronectin (FN) and vitronectin (VN). Quantification of the adsorption of model proteins, bovine serum albumin and FN, revealed that the extent of adsorption was correlated to the amount MEO2MA content, which represents the more hydrophobic component in PMO brushes. Cells exhibited delayed attachment and spreading on all PMO substrates in the presence of FBS. After 24 h, cell attachment was comparable; however, increased spreading was correlated with increased MEO2MA content

Modulation of cell responses to Ag‐(MeO2MA‐co‐OEGMA): Effects of nanoparticle surface hydrophobicity and serum proteins on cellular uptake and toxicity

“…The ( x:y ) ratio can be tuned during polymer synthesis to manipulate the LCST, which, in turn, impacts hydrophobicity and other physico‐chemical properties that impact interactions with biological systems. For example, studies with poly(MeO 2 MA x ‐ co ‐OEGMA y ) based cell culture substrates comprised of 0–8% OEGMA have shown that cell adhesion and spreading are enhanced on more hydrophobic surfaces with increased ( x:y ) ratio . Here, we utilize similar copolymer ratios (5–10% OEGMA) to elicit distinct AgNP surface hydrophobicity at a physiological temperature of 37°C.…”

“…In the presence of serum proteins, it is well established that NP are rapidly coated with a protein corona, and the molecular identity and function of adsorbed proteins are important mediators of cellular interactions . For poly(MeO 2 MA x ‐ co ‐OEGMA y ) immobilized on polyelectrolyte substrates, the adsorption capacity for model proteins, albumin and fibronectin, is correlated to the ratio of the hydrophobic MeO 2 MA unit in the copolymer composition . Thus, it is likely that the differential cytotoxicity observed in response to Ag‐poly(MeO 2 MA x ‐ co ‐OEGMA y ) is, in part, attributed to differences in the extent of protein corona formation.…”

“…For example, studies with poly(MeO 2 MA x -co-OEGMA y ) based cell culture substrates comprised of 0-8% OEGMA have shown that cell adhesion and spreading are enhanced on more hydrophobic surfaces with increased (x:y) ratio. 38,41 Here, we utilize similar copolymer ratios (5-10% OEGMA) to elicit distinct AgNP surface hydrophobicity at a physiological temperature of 378C. The OEGMA unit is less hydrophobic than MeO 2 MA; 36 therefore, both increasing LCST and hydrophilicity are correlated to increased OEGMA content in the copolymer composition.…”

“…We hypothesized that composition dependent changes in Ag‐(MeO 2 MA x ‐ co ‐OEGMA y ) surface hydrophobicity at a physiological temperature (37°C) would modulate cytotoxicity due to differential cell uptake in the presence of serum proteins. We have previously shown that protein adsorption to planar poly(MeO 2 MA x ‐ co ‐OEGMA y ) cell culture substrates at 37°C is correlated to the amount of hydrophobic (MeO 2 MA) units in the copolymer composition for 100:0 ≤ x:y ≤ 92:8 . Thus, we aimed to study the role of both copolymer composition and the presence of serum proteins in governing Ag‐(MeO 2 MA x ‐ co ‐OEGMA y ) induced cytotoxicity.…”

“…We have previously shown that protein adsorption to planar poly(MeO 2 MA x -co-OEGMA y ) cell culture substrates at 378C is correlated to the amount of hydrophobic (MeO 2 MA) units in the copolymer composition for 100:0 x:y 92:8. 38 Thus, we aimed to study the role of both copolymer composition and the presence of serum proteins in governing Ag-(MeO 2-MA x -co-OEGMA y ) induced cytotoxicity. Here, we utilize a substrate of 10 nm AgNP grafted with poly(MeO 2 MA x -co-OEGMA y ) by a ligand exchange reaction.…”