# Engineering Two-in-One Nanoparticles for Simultaneous Delivery of Graphene Quantum Dot and Pemetrexed

## TL;DR

This paper introduces a new nanoparticle system that delivers both a chemotherapy drug and fluorescent imaging probes for better cancer treatment and monitoring.

## Contribution

A novel multifunctional nanocarrier system for simultaneous drug delivery and bioimaging in cancer treatment is developed.

## Key findings

- The optimized nanoparticles showed high drug and quantum dot encapsulation efficiency.
- Nanoparticle-loaded pemetrexed significantly enhanced cytotoxicity against MCF-7 cells.
- Confocal microscopy confirmed efficient intracellular uptake and strong fluorescence signals.

## Abstract

The simultaneous
delivery of therapeutic agents and imaging probes
using polymeric nanoparticles (NPs) has gained significant attention
for cancer treatment. In this work, we developed a multifunctional
nanocarrier system composed of an amphiphilic block copolymer, poly­(2-ethyl-2-oxazoline)-b-poly­(ε-caprolactone) (PEtOx-b-PCL),
and dimethyldidodecylammonium bromide (DDAB), for the codelivery of
the chemotherapeutic drug pemetrexed (PMT) and nitrogen- or sulfur-doped
graphene quantum dots (N-GQDs or S-GQDs) as fluorescent probes. Critical
formulation parameters were optimized using a central composite design
(CCD). The optimized NPs exhibited favorable physicochemical properties,
including positive surface charge (6–8 mV), hydrodynamic diameters
of ∼140 nm, and high encapsulation efficiency for both PMT
(46–56%) and GQDs (>98%). In vitro assays
revealed that PMT-loaded nanoparticles (NPs) significantly enhanced
cytotoxicity against MCF-7 cells. At a concentration of 2 ppm after
72 h, N-PMT NPs and S-PMT NPs inhibited cell proliferation by 50.7%
and 53.8%, respectively, compared to 37.8% inhibition with free PMT
at the same dose. Confocal microscopy confirmed efficient intracellular
uptake and strong fluorescence signals, supporting their potential
for bioimaging. Collectively, these results demonstrate that this
two-in-one nanocarrier system significantly enhances chemotherapeutic
efficacy while enabling real-time imaging, establishing a promising
platform for drug delivery and noninvasive treatment monitoring in
cancer nanomedicine.