کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6674 511 2012 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Theoretical considerations on mechanisms of harvesting cells cultured on thermoresponsive polymer brushes
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Theoretical considerations on mechanisms of harvesting cells cultured on thermoresponsive polymer brushes
چکیده انگلیسی

Poly (N-isopropylacrylamide) (PNIPAM) brushes and hydrogels serve as temperature-responsive cell culture substrates. The cells adhere at 37 °C and are detached by cooling to below the lower critical solution temperature TLCST ≈ 32 °C, an effect hitherto attributed to change in PNIPAM hydration. The article proposes a mechanism coupling the change of hydration to integrin mediated environmental sensing for cell culture on brushes and hydrogels in serum containing medium. Hydration is associated with swelling and higher osmotic pressure leading to two effects: (i) The lower osmotic pressure in the collapsed brush/hydrogel favors the adsorption of serum borne extracellular matrix (ECM) proteins enabling cell adhesion; (ii) Brush/hydrogel swelling at T < TLCST gives rise to a disjoining force fcell due to confinement by the ventral membrane of a cell adhering via integrin-ECM bonds. fcell places the integrin–ECM bonds under tension thus accelerating their dissociation and promoting desorption of ECM proteins. Self consistent field theory of PNIPAM brushes quantifies the effect of the polymerization degree N, the area per chain Σ, and the temperature, T on ECM adsorption, fcell and the dissociation rate of integrin–ECM bonds. It suggests guidelines for tuning Σ and N to optimize adhesion at 37 °C and detachment at T < TLCST. The mechanism rationalizes existing experimental results on the influence of the dry thickness and the RGD fraction on adhesion and detachment.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biomaterials - Volume 33, Issue 20, July 2012, Pages 4975–4987
نویسندگان
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