Wrapping of gold nanoparticles (AuNPs) with a biocompatible
matrix,
to gain AuNP colloids, is a general strategy to synthesize the AuNPs
for biomedical purposes. This work reports the synthesis of AuNP colloids
in the aqueous solution of several natural matrices using a liquid-phase
plasma process. Two classes of natural substances used are sugars
(including: glucose, fructose, and sucrose) and biopolymers (including:
carboxymethyl cellulose, sodium alginate, and gelatin). All are negatively
charged water-soluble substances that are claimed to be sources of
energy for cells to grow and have a high potential to be compatible
with them. The study has emerged since one question arises: “Do these matrices also promote the growth of cancer cells?” The synthesis is performed by generating plasma across
a pair of electrodes immersed in an aqueous solution of a natural
matrix containing a gold precursor (HAuCl4·3H2O). Two concentrations of the matrices (0.5 and 1.0% w/v)
are used, and the plasma treatment times are varied (0, 10, and 30
min). The effect of the type and concentration of natural matrices
as well as the plasma treatment time on the formation of AuNPs, along
with their physical and chemical properties, including morphology,
size, hydrodynamic diameter (d
h), colloidal
stability, and charge on the AuNP surface, is evaluated. We find that
the charge of the AuNP surfaces could be altered by the plasma treatment.
Eventually, cytotoxicity test results against normal (MRC-5) and cancer
(H460 and HeLa) cell lines could not only answer our opening question
but also suggest a rather complex response. Our findings indicate
the great potential of the obtained AuNP colloids as a part of cancer
therapy.