Longitudinal photoacoustic monitoring of collagen evolution modulated by cancer-associated fibroblasts: simulation and experiment studies

TL;DR

This study demonstrates that photoacoustic spectrum analysis can noninvasively monitor collagen changes modulated by cancer-associated fibroblasts over time, combining simulations and experiments to support its potential in cancer therapy assessment.

Contribution

It introduces a novel application of PASA for longitudinal collagen monitoring modulated by CAFs, validated through simulations and in vivo experiments.

Findings

PA spectrum density correlates with collagen evolution during cancer growth

High CAF doses suppress collagen levels in tumors

PA detection system effectively reflects collagen changes over time

Abstract

Noninvasive in vivo detection of collagen facilitates the investigation of mechanisms by which cancer-associated fibroblast (CAF) regulates the extracellular matrix. This study explored the feasibility of photoacoustic spectrum analysis (PASA) in identifying longitudinal changes of collagen modulated by CAFs using simulations and experiment studies. Optical and acoustic simulations in tissues were performed based on the histological slides of maximum cross-sections of murine malignancies to verify the effectiveness of photoacoustic (PA) detection system and the parameter "relative area of power spectrum density (APSD)". Experiments were conducted on three groups of mouse models with incremental ratios of CAFs and breast cancer cells at 3 continuous time points. Results discovered that the system configuration and APSD were capable of reflecting the evolution of collagen during cancer growth. Furthermore, cancers receiving a high dose of CAFs exhibited a suppressed collagen level. The presented methods show great potential for clinical translation of PASA in the field of cancer therapies targeting CAFs.