In the last few decades great efforts have been placed in studying carbon
nanomaterials. Nowadays the nanocarbon family spans from fullerene, the first
member, to Carbon Dots (C-Dots), the last to join. C-Dots have attracted considerable
attention for a wide range of applications, especially bioapplications, because of their
properties: emission, small sizes, aqueous solubility, biocompatibility and chemical
stability.
The aim of this doctoral thesis was to synthesize Carbon nanodots (CNDs), in
particular nitrogen-doped CNDs, and functionalize their surface with properly
designed molecules/biomolecules for bioapplications.
In the first chapter, an introduction on the different types of C-Dots is provided, with
a particular emphasis on CNDs. An overview of their most common production
methods, characterization techniques and properties is given. A brief discussion on
their applications, especially bioapplications, is reported.
In chapter 2, highly fluorescent and water-soluble nitrogen-doped CNDs were
prepared. A simple bottom approach by employing low-cost carbon and nitrogen
sources (arginine and ethylenediamine) was used. The as-prepared CNDs were
purified and characterized. They showed an excitation wavelength dependent
emission, several functional groups on their surface such as amines and a narrow size
distribution.
Chapter 3 reported the covalent and non-covalent modification of CNDs in preparing
hybrid materials for diverse bioapplications. The covalent modification of the CNDs
surface with iron nanoparticles or drugs, such as paclitaxel and chlorambucil, was
described. Moreover, it was studied the attachment of human serum albumin via noncovalent
approaches.
The Chapter 4 focused on the in vitro bioapplications of the materials described in
chapter 3 as drug delivery systems, bioimaging agents and nanocarriers. Moreover,
the effect of a protein corona around CNDs on their cellular uptake it was studied,
since it is a prerequisite for their successful use for such applications. The CNDs and
related materials presented non-toxicity, biocompatibility and good cellular imaging
capability. They were tested through the IC50 and a high pharmacological activity in
solid tumors was observed. Finally, their in vitro permeability was evaluated through
an inverted BBB using a real-time cell response and observing that they are able to
cross the BBB model.
