In this study, hydrophilic magnetic nanoparticles were synthesized by green routes using
a methanolic extract of Rubus ulmifolius Schott flowers. The prepared magnetic nanoparticles were
coated with carbon-based shell for drug delivery application. The nanocomposites were further
chemically functionalized with nitric acid and, sequentially, with Pluronic® F68 (CMNPs-plur) to
enhance their colloidal stability. The resulting material was dispersed in phosphate buffer solution at
pH 7.4 to study the Doxorubicin loading. After shaking for 48 h, 99.13% of the drug was loaded by the
nanocomposites. Subsequently, the drug release was studied in different working phosphate buffer
solutions (i.e., PB pH 4.5, pH 6.0 and pH 7.4) to determine the efficiency of the synthesized material
for drug delivery as pH-dependent drug nanocarrier. The results have shown a drug release quantity
18% higher in mimicking tumor environment than in the physiological one. Therefore, this study
demonstrates the ability of CMNPs-plur to release a drug with pH dependence, which could be used
in the future for the treatment of cancer "in situ" by means of controlled drug release.
This research was funded by: Project POCI-01-0145-FEDER-006984 – Associate Laboratory LSRE-LCM
funded by FEDER through COMPETE2020 - POCI – and by national funds through FCT (Fundação para a Ciência e a Tecnologia); RTChip4Theranostics, supported by Programa Operacional Regional do Norte—Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and by FCT.
The authors are grateful to FCT, and FEDER under Programme PT2020 for financial
support to CIMO (UID/AGR/00690/2013) and L. Barros contract. R.O.R. acknowledges the Ph.D. scholarship
SFRH/BD/97658/2013 granted by FCT. This work was also supported by the Slovak Scientific Grant Agency
projects VEGA 2/033/19.
