Cavaniol, C. | bioRxiv Science

bioRxiv2025

Magnetite Nanoparticle Photothermal Therapy in a Pancreatic Tumor-on-Chip: A Dual-Action Approach Targeting Cancer Cells and their Microenvironment

The application of magnetite nanoparticles (MagNPs) for photothermal therapy (MagNP-PTT) has recently expanded in cancer treatment. This study introduces MagNP-PTT in a tumor-on-chip model to target highly aggressive pancreatic ductal adenocarcinoma (PDAC). A tumor-on-chip system was developed using PANC-1 PDAC cells embedded in a collagen type I extracellular matrix and cultured for one week to form tumor spheroids. This platform serves as the foundation for applying PTT in a model system that is aimed to mimic the native tumor microenvironment. MagNPs efficiently penetrate the tumor spheroids, achieving controlled heating via near-infrared (NIR) light. By adjusting nanoparticle concentration and laser power, temperature increments of 2{degrees}C between 38-48{degrees}C were established. Temperatures above 44{degrees}C significantly increased cell death, while lower temperatures allowed partial recovery. Beyond inducing cancer cell death, MagNP-PTT altered the extracellular matrix, and triggered a slight epithelial-mesenchymal transition marked by increased vimentin expression. These findings highlight MagNP-PTT as a dual-action therapy, targeting both tumor cells and their microenvironment, offering a novel approach for overcoming stromal barriers in pancreatic cancer treatment. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=99 SRC="FIGDIR/small/636875v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@9b9c20org.highwire.dtl.DTLVardef@272c7aorg.highwire.dtl.DTLVardef@1d91021org.highwire.dtl.DTLVardef@1b1ea8d_HPS_FORMAT_FIGEXP M_FIG SYNOPSIS TABLE OF CONTENTS C_FIG

cancer biology↗

bioRxiv2021

Evolution of a confluent gut epithelium under cyclic stretching

The progress of food in the gastrointestinal (GI) tract is driven by a peristaltic motion generated by the muscle belt surrounding the GI tract. In turn, the response of the intestinal epithelial cells to the peristaltic stresses affects the dynamics of the epithelial structure. In this work, we study the effect of cyclic stretching (0.125 Hz, 10% strain) on the spatial organization of the intestinal epithelium using intestinal cells deposited on a flat elastomeric substrate to mimic the peristaltic motion in vitro. A confluent monolayer of Caco-2 cells is grown on a PDMS chip to probe the morphological and orientational response of the tissue to cyclic stretching. The PDMS chips are either covalently or non-covalently coated with laminin to recapitulate the basement membrane. We observe a significant orientational response where the cells rearrange their long axes perpendicular to the stretching direction for both coating conditions. The experiment is modeled by a vertex model where the cells store elastic energy with varying strain and effectively have a rotational diffusive motion through rearrangements of their shapes. The model also predicts a transition between the perpendicular orientation and orientation at an oblique angle determined by the level of the cell elastic anisotropy. It provides a general framework to study cell response and relaxation dynamics under cyclic stretching across different cell types. We also discuss potential relevance of peristalsis in determining planar cell polarity in 3D architectures.

biophysics↗