In the past 5 years,, Prof Alan MacDiarmid developed a profound interest in the implementation of two of his major research areas, conductive polymers and electrospinning, for biotechnological applications. In this talk we will report on some of our collaborative efforts in this area, by outlining how Prof MacDiarmid inspired novel approaches towards generating �intelligent� scaffolds for neuronal and cardiac tissue engineering.

Conductive polymers have been considered for diverse biomedical applications. Electrospinning is an increasingly popular platform technology for generating nanofibrous scaffold for tissue engineering purposes. Co-electrospun PANi�gelatin fibers were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), electrical conductivity measurement, Differential Scanning Calorimetry (DSC), and mechanical tensile testing. For blends containing less than 5 % PANi in total weight, uniform nanofibrous scaffolds were obtained with no evidence for phase segregation. All PANi�gelatin blend fibers supported H9c2 cardiac myoblast attachment and proliferation to a similar degree as the control tissue culture-treated plastic (TCP). Depending on the concentrations of PANi (fiber sizes), the cells initially displayed different morphologies substrates, but after 1 week all cultures reached confluence of similar densities and morphology.

Importantly, electroactive surfaces made of/or containing conductive polymers were found to be �smart� venues, which promote the spontaneous differentiation of progenitor/stem cells growing on them. For example, conductive surfaces containing polyaniline or aniline-oligomers enhanced neuronal differentiation of PC12 pheochromocytoma cells. Similarly, electrical stimulation of murine embryonic stem cells towards the cardiac lineage was significantly enhanced when culturing these cells on conductive surfaces made of graphite nanoparticles or TiO

Taken together, these experiments, which largely grew out of our interactions with Prof. MacDiarmid, have opened a new field in basic and applied biomaterials and tissue engineering research.

We gratefully acknowledge support by the Nanotechnology Institute of Southeastern Pennsylvania (PIL, YW, AGM)