Effect of Polymer Deposition Method on Thermoresponsive Polymer Films and Resulting Cellular Behavior

Abstract

Poly(N-isopropyl acrylamide) or pNIPAM is a thermoresponsive polymer that is widely studied for use in bioengineering applications. The interest in this polymer lies in the polymer’s unique capability to undergo a sharp property change near physiological temperatures, which aids in the spontaneous release of biological cells from substrates. Currently, there are many methods to deposit pNIPAM onto substrates, including atom transfer radical polymerization (ATRP) and electron beam ionization. Each method yields pNIPAM coated substrates with different surface characteristics which can influence cell behavior. In this work, we compare two methods of pNIPAM deposition: plasma deposition and co-deposition with a sol gel. The resulting pNIPAM films were analyzed for use as substrates for mammalian cell culture based on surface characterization (XPS, ToF-SIMS, AFM, contact angles), cell attachment/detachment studies, and an analysis of exocytosis function using carbon-fiber microelectrode amperometry (CFMA). We find that, although both methods are useful for the deposition of functional pNIPAM films, plasma deposition is much preferred for cell-sheet engineering applications due to the films’ thermoresponse, minimal change in cell density, and maintenance of supported cell exocytosis function.

Transcatheter intra-arterial infusion of doxorubicin loaded porous magnetic nano-clusters with iodinated oil for the treatment of liver cancer

“…[15–19] Their magnetic susceptibility enables MRI monitoring, tracking and quantification of delivery of these chemo-drug-loaded pMNCs to targeted tissues. [20–22] In the present study, we synthesized Dox loaded pMNCs (Dox-pMNCs) and characterized Dox drug release kinetics and MR contrast effects. Then, Dox-pMNCs were combined with iodinated oil as a possible translational form to mirror routine clinical practice (Dox-pMNCs combined with iodized oil) and delivered to liver tumors via hepatic artery in the rabbit liver tumor model.…”

PNIPAM grafted surfaces through ATRP and RAFT polymerization: Chemistry and bioadhesion

“…A perturbation in the exocytosis response of cells is revelatory of this perturbation in ways that can, for instance, be measured by histological studies or carbon-fibre microelectrode amperometry (CFMA), as observed by Reed et al [10]. In this study, the introduction of PNIPAM (through plasma deposition or spin coating) on surfaces have shown to slow down the cell exchange between vesicles and extracellular space.…”

“…In addition, it was shown that plasma-deposited PNI-PAM shows greater cell adhesion than e-beam coated PNIPAM [10]. These results emphasized the importance of the method used for surface modification.…”

“…For biological applications, covalent grafting seems to be the best choice compared to physically grafted systems, due to risks of desorption with this latter method. Polymer brushes, which consist on a thin film of self-assembled polymers, are of interest [10,45]. Wettability, but also the variety of possible end-group functions, the substrate and the chemistry are the main points that make these systems attractive.…”

“…Finally, carbon fibre microelectrode amperometry (CMFA) can give information about biochemical exocytosis of cells (kinetics and amount of release) and thus evaluate how the substrate impacts the excretion activity of cells [10].…”