Self Assembley Of Carbon Nanotubes On Polymer Nanofibrers And In Vitro Biocompatibility Evalution

Despite the long history and some preliminary works done in tissue engineering for more than 30 years, electrospinning has not gained widespread interest as a potential polymer processing technique for the biomedical applications in tissue engineering and drug delivery until the last 5-10 years. This renewed interest can be attributed to electrospinning's easy fabrication, applicability in many fields, and tunable fiber size on the nanometer scale. Furthermore, the micro to nanoscale topography and high porosity of the fibers can mimic the natural extracellular matrix (ECM), enabling the possibility to be used as scaffold in tissue engineering; various materials including biodegradable and non-degradable synthetic materials, as well as natural materials can be electrospun; Electrospun fibers can be oriented in designed direction or arranged randomly to tune the mechanical properties and the biological response of the formed nanofibers.In this present study, we report the fabrication of a novel carbon nanotube-containing nanofibrous polysaccharide scaffolding material via the combination of electrospinning and layer-by-layer (LbL) self-assembly techniques for tissue engineering applications. First, cellulose acetate (CA) was electrospun to form uniform nanofibers. Then the positively charged chitosan (CS) and negatively charged multiwalled carbon nanotubes (MWCNTs) were alternatively assembled on the fiber surfaces with designed cycles. For comparison, bilayers of CS and negatively charged sodium alginate (ALG) with the same cycles were also assembled onto the CA nanofiber surfaces. At last, the formed CA composite nanofibers were characterized by SEM, FTIR, TGA, mechanical testing, protein adsorption, cell attachment, cell proliferation, cell morphology and hemocompatibility testing. Our data show that the bilayers of both CS/MWCNTs and CS/ALG are successfully assembled on CA nanofibers via electrostatic LbL self assembly technique. The composite CA nanofibers assembled by CS/MWCNTs bilayers have much rougher surface than that assembled by CS/ALG bilayers with similar bilayer number, while the 3D porous structures of both two kinds of composite CA nanofibers were well maintained. Used as scaffolds, the composite CA fibers with the assembly of CS/MWCNTs tends to enhance the attachment, spread and proliferation of mouse fibroblast cells when comparing with those assembled by CS/ALG bilayers. With the improved protein adsorption capacity, mechanical properties, cellular attachment and proliferation, and hemocompatibility, the MWCNTs-containing composite fibrous scaffolding materials via LBL self assembly technique should find applications in the field of tissue engineering and regenerative medicine. The facile LbL self-assembly approach to modifying the nanofibrous scaffolds may be extended for immobilization of other functional bioactive materials for a range of biomedical applications.