# Killing of Gold Nanorods-Loaded Human Cardiac Fibroblasts Mediated by Photo-Thermal Activation

## TL;DR

This study explores using gold nanorods and laser light to selectively destroy heart fibroblasts, which could help treat heart diseases.

## Contribution

The paper introduces a novel method for targeted cardiac cell ablation using plasmonic photothermal therapy with gold nanorods.

## Key findings

- Human cardiac fibroblasts internalize gold nanorods without cytotoxicity.
- Laser irradiation of AuNR-loaded cells causes temperature increases leading to cell death.
- Nonloaded cells in coculture remain unaffected, showing selective ablation.

## Abstract

Cardiac fibrosis
is a pathological process associated with several
heart diseases, characterized by extracellular matrix deposition by
cardiac fibroblasts. Photothermal therapy is a minimally invasive
medical treatment that uses nanomaterials to convert external light
into localized heating. On these premises, we report an innovative
approach that exploits gold nanorods (AuNRs)-mediated plasmonic photothermal
therapy (PPTT) for selective ablation of AuNR-loaded human cardiac
fibroblasts (hCFs). Cellular uptake is confirmed by treating hCFs
with AuNRs, irradiating them with an 808 nm continuous-wave (CW) laser,
and performing ultrastructural electron microscopy analysis. Measurements
of extinction spectra, temperature variation, and cell viability were
conducted. Results show that hCFs internalize AuNRs effectively without
cytotoxicity, and extinction spectra reveal a concentration-dependent
redshift of the longitudinal plasmon bands. Upon laser irradiation,
AuNR-loaded hCFs experience a temperature increase, leading to cell
death in proportion to AuNRs concentration. In coculture systems,
AuNR-loaded hCFs are ablated while the viability of surrounding nonloaded
cells (fibroblasts or cardiomyocytes) remains unaffected, demonstrating
that hCFs can internalize AuNRs and be effectively ablated through
PPTT. Our results highlight the potential of AuNRs for targeted cardiac
cell ablation with minimal impact on adjacent cells.