# Curcumin Internalization in Streptococcus mutans Biofilms: A Confocal Microscopy Analysis

## TL;DR

This study shows that curcumin can effectively penetrate and damage Streptococcus mutans biofilms using photodynamic inactivation, monitored with confocal microscopy.

## Contribution

The in vitro demonstration of curcumin's dynamic efficacy in biofilm environments using confocal microscopy.

## Key findings

- Curcumin continues to penetrate biofilms even after photodegradation, replacing degraded molecules.
- Curcumin generates reactive species that damage bacteria in biofilms.
- Confocal microscopy proved essential for visualizing and quantifying curcumin's effects.

## Abstract

Streptococcus mutans
is one of the main harmful agents to oral health, exhibiting high resistance in its biofilm form. This study evaluated curcumin as a photosensitizer in photodynamic inactivation (PDI), monitoring its internalization time and activity. The biofilm was cultured for 24 h and treated with curcumin activated by two‐photon excitation (800 nm). After photodegradation, curcumin continued to penetrate effectively into the biofilms, replacing previously degraded molecules with new ones and constantly generating reactive species (ROS and singlet oxygen) capable of damaging the bacteria. This contrasts with previous studies that reported limitations of natural photosensitizers in this context. Therefore, the principal contribution of this study is the in vitro demonstration of the dynamic efficacy of curcumin in the complex biofilm environment. The use of confocal microscopy was essential to visualize and quantify the effects of curcumin, highlighting its value as an analytical tool in the evaluation of biofilm treatments.

Streptococcus mutans are harmful bacteria to oral health, exhibiting high resistance in their biofilm form. This study evaluated, through Confocal Microscopy, curcumin extracted from Curcuma longa as a photosensitizer in photodynamic inactivation (PDI), monitoring its internalization time and activity. The study demonstrated, in vitro, the dynamic efficacy of curcumin within the complex biofilm environment.