(181af) Polymer Coated Nanoparticles for Photothermal Therapy and Prognosis of Breast Cancer

Poster Session: (Polymers 08 A)

Polymer Coated Nanoparticles for Photothermal
Therapy and Prognosis of Breast Cancer

Muhammad Raisul Abedin^a, Sutapa Barua^a,1

^a Department of Chemical and Biochemical
Engineering, Missouri University of Science and Technology, Rolla , MO-65409

¹ Corresponding Author: Email: baruas@mst.edu

ABSTRACT

Objective

A multifunctional magnetic
nanoparticle (NP) is designed to perform a near-infrared (NIR)-responsive
remote control photothermal ablation for the
treatment of breast cancer. The novelty of this work is to
generate a nanometer-thick PLL layer for the stable dispersion of Au–Fe₃O₄   NPs in biological fluids that results in
excellent optical, magnetic and therapeutic properties for the cancer
treatment.

Introduction

The
combination of Au-coated NPs has tremendous potential in improving optical
properties, thermal properties, tunable geometry, and imaging contrasts in MRI.
As a bifunctional NP,
Au–Fe₃O₄
can inherit excellent
surface chemistry characteristics, unique optical properties (attributed to Au)
and superparamagnetic characteristics attributed to Fe₃O₄. First of all, the
NPs offer size controllability, ranging from few to hundreds of nanometers with
different and unique size-dependent properties. Second, the NPs can be easily
controlled and manipulated from outside with the help of external magnetic field
being operated from a distance. Third, the NPs can provide enhanced contrast in
medical imaging that can be used to diagnose the situation efficiently. Given
the unstable nature of NP formulation, it is hypothesized that an optimum dose
of a cationic polymer coating onto Au–Fe₃O₄  NPs play a role in determining NP
configuration on cellular cytotoxicity as well as direct therapy. These characteristics
would enhance and broaden the application of these nanoparticles for theranostic applications.

Materials
and Methods

A Janus-like
nanostructure is synthesized with Fe₃O₄ NPs
decorated with Au resulting in an approximate size of 60 nm mean diameter. Poly- l-lysine
(PLL) was used for the surface functionalization of trisoctahedral Au–Fe₃O₄ NPs
to deliver the NPs inside cells and function as a hydrophilic block for steric
stabilization of the NPs in biological media. The PLL coating increased the
colloidal stability and robustness of Au–Fe₃O₄ NPs (PLL–Au–Fe₃O₄).
Taking advantage of the photothermal therapy, PLL–Au–Fe₃O₄ NPs
were incubated with BT-474 and MDA-MB-231 breast cancer cells, investigated for
the cytotoxicity and intracellular uptake, and remotely triggered by a NIR
laser of ~808 nm (1 W/cm² for 10 min).

Results

The unique properties
of both Au surface plasmon resonance and
superparamagnetic moment result in a multimodal platform for use as a nanothermal ablator and also as a magnetic resonance
imaging (MRI) contrast agent, respectively. It is revealed that no significant
(<10%) cytotoxicity was induced by PLL–Au–Fe₃O₄ NPs
itself in BT-474 and MDA-MB-231 cells at concentrations up to 100 mg/ml.
As soon as the NPs were triggered by a photothermal
NIR laser, approximately 40 and 60% of BT-474 and MDA-MB-231 breast cancer cell
death, respectively were observed using 100 mg/ml PLL–Au–Fe₃O₄ NPs,
while the cells with the NPs but without laser showed <10% cell death
compared to no laser treatment control. Combined together, the results
demonstrate a new polymer gold superparamagnetic nanostructure that integrates
both diagnostics function and photothermal ablation
of tumors into a single multimodal nanoplatform
exhibiting a significant cancer cell death.