Chemical Sciences

Chemically modified nanocomposite materials for Biomedical applications

Research Activity

Carbon nanostructures (CNSs), which are made up of extended sp2-hybridized carbon networks, are largely employed as nanofillers for polymer phases to obtain polymer-based nanocomposites (PNCs). Following their inclusion, the polymer matrices are often improved in many ways, such as enhanced electrical and thermal conductivity, increased stability, and mechanical robustness. The chemical functionalization of the external CNS surfaces with organic substituents is often a key tool for their effective and homogeneous incorporation within a polymer phase, avoiding the formation of aggregates, which can lower the performance of the the final material. These CNS-based PNCs can be used as organic functional materials in different applications that range from clean energy harvesting and storage to sensing and biomedicine. This research is focused on the design, preparation and characterization of novel polymer nanocomposite (PNC) materials for biomedical applications, based on carbon nanostructures (CNSs) such as carbon nanotubes (CNTs), Graphene and Carbon Nanohorns as nanofillers and biocompatible polymers as a matrix. We recently demonstrated the possibility of boosting human neuronal cells growth/differentiation on a nanocomposite free-standing scaffold obtained by efficiently dispersing soluble organic derivatives of CNTs in a poly-L-lactic acid (PLLA) matrix. The electrical resistance of the nanocomposite scaffold resulted more than one order of magnitude lower than that of a pure PLLA scaffold. Cells showed better adhesion to the MWCNT-PLLA scaffold in comparison with pure PLLA and, in addition, they presented a higher total neurite length. Scanning electron microscopy (SEM) images of cells cultured onto the PNC scaffold show an evidently healthy morphology and the outgrowth of neurites attaching to the scaffold surface, with intimate contact between this last one and the neuronal membrane. As a rational extension of this concept, we obtained a nanofibrous matrix, via electrospinning a CNT-PLLA nanocomposite solution, as a biocompatible scaffold for neuronal growth, aimed at better mimicking the extracellular matrix. Indeed, by using this scaffold as support for cells growth, the extension of neurites along the direction of the nanofibers was evidenced.

Expertise

Organic functionalization of carbon nanotubes and graphene through different approaches, including covalent linking, endohedral encapsulation for nanotubes (peapods) and supramolecular (non covalent) exohedral interactions. Characterization through Raman and IR spectroscopy, UV-vis-NIR adsorption spectroscopy, fluorescence spectorscopy, dynamic light scattering (DLS), thermal gravimetric analysis (TGA)

Publications

Nanomed.-Nanotechnol. Biol. Med. 2015, 11, 621-632.
Carbon 2015, 95, 725-730.
Nanomedicine 2016, 11, 1929-1946.
Eur. J. Org. Chem. 2016, 1071-1090.
Mater. Chem. Phys., 2018, 214, 265-276.

A PNC based on chemically modified graphene materials

Scanning electron microscopy (a, b) and optical microscopy (c) images of cells cultured onto the PNC scaffold