Controlling cell-material interactions using coatings with advanced polymer architectures

摘要

Polymeric coatings which allow the effective control of biointerfacial interactions and cellular responses are of increasing interest in a range of biomedical applications in vitro and in vivo such as cell culture tools, biosensors and implantable medical devices. A variety of coating strategies have been developed to gain control over cell-surface interactions but many of them are limited with respect to their function and transferability between different substrate materials. Here, our aim was to establish an easily transferable coating that reduces non-specific cell-surface interactions to a minimum while at the same time presenting functional groups which allow for the subsequent immobilisation of bioactive signals. To achieve this, we have applied an allylamine plasma polymer coating followed by the covalent immobilisation of a macro-initiator providing iniferter functional groups. Subsequent controlled free radical graft polymerisation using the monomers acrylamide and acrylic acid in different molar ratios resulted in highly uniform polymer coatings. Non-specific cell attachment was significantly reduced on coatings representing molar ratios of less than 10% acrylic acid. At the same time we have demonstrated the suitability of these coatings for the subsequent covalent binding of bioactive compounds carrying amine functional groups using the label 2,2,2-trifiuoroethylamine. Successful surface modifications were confirmed by X-ray photoelectron spectroscopy (XPS) and profilometry. The cellular response was evaluated using HeLa cell attachment experiments for up to 24 hours. We expect that the coating platform established in this study will be translated into a number of biomedical applications, including applications in implantable devices and regenerative medicine.