Scholarlink

Introduction <p><i>Enterococcus faecalis</i> (<i>E. faecalis</i>) is a predominant pathogen associated with persistent endodontic infections due to its resistance to conventional disinfectants and ability to form robust biofilms. This study aimed to evaluate the antibacterial efficacy and biocompatibility of a novel near-infrared (NIR)-activated photosensitizer, Rose Bengal-conjugated upconversion nanoparticles (UCNP-RB), against <i>E. faecalis</i> both in vitro and in vivo.</p> Methods <p>UCNP-RB nanocomposites were synthesized and characterized using transmission electron microscopy (TEM) and spectral analysis. Reactive oxygen species (ROS) generation under 808&#xa0;nm NIR irradiation was quantified using the 1,3-diphenylisobenzofuran (DPBF) probe. Cytotoxicity was assessed in human dental pulp cells (hDPCs) via the Cell Counting Kit-8 (CCK-8) assay. In vitro antibacterial efficacy against planktonic <i>E. faecalis</i> and 14-day mature biofilms was evaluated at a concentration of 100&#xa0;µg/mL using colony-forming unit (CFU) counts, adenosine triphosphate (ATP) bioluminescence, and scanning electron microscopy (SEM). Additionally, a murine model of apical periodontitis was established to assess the in vivo therapeutic efficacy of UCNP-RB-mediated antimicrobial photodynamic therapy (aPDT) compared to 1% sodium hypochlorite (NaClO) irrigation, with outcomes measured by micro-computed tomography (micro-CT).</p> Results <p>The synthesized UCNP-RB nanocomposite successfully converted near-infrared (NIR) light into visible emission, triggering efficient reactive oxygen species (ROS) generation. An optimal concentration of 100&#xa0;µg/mL was identified for subsequent experiments. UCNP-RB-mediated aPDT demonstrated potent antibacterial efficacy, achieving a &gt; 99% reduction in planktonic <i>E. faecalis</i> and approximately 90% inhibition of mature biofilm viability (<i>p</i> &lt; 0.05). In vivo, micro-CT analysis revealed that the UCNP-RB aPDT group exhibited a 67% reduction in periapical bone defect volume compared to the untreated control group, indicating significant promotion of periapical healing.</p> Conclusions <p>The UCNP-RB nanocomposites synthesized in this study exhibited uniform morphology and potent photodynamic activity. At an optimal concentration of 100&#xa0;µg/mL, the system demonstrated significant antibacterial efficacy against <i>E. faecalis</i> both in vitro and in vivo, highlighting its potential as an effective agent for endodontic disinfection.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Antimicrobial effects of rose red upconversion nanoparticles (UCNPs-RB) based photodynamic therapy on Enterococcus faecalis infection

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年5月19日

查看全文
  • Wenzhi Li,
  • Yuqian Pan,
  • Jiaming Luo,
  • Zhiyao Hou,
  • Xuechao Yang

摘要

Introduction

Enterococcus faecalis (E. faecalis) is a predominant pathogen associated with persistent endodontic infections due to its resistance to conventional disinfectants and ability to form robust biofilms. This study aimed to evaluate the antibacterial efficacy and biocompatibility of a novel near-infrared (NIR)-activated photosensitizer, Rose Bengal-conjugated upconversion nanoparticles (UCNP-RB), against E. faecalis both in vitro and in vivo.

Methods

UCNP-RB nanocomposites were synthesized and characterized using transmission electron microscopy (TEM) and spectral analysis. Reactive oxygen species (ROS) generation under 808 nm NIR irradiation was quantified using the 1,3-diphenylisobenzofuran (DPBF) probe. Cytotoxicity was assessed in human dental pulp cells (hDPCs) via the Cell Counting Kit-8 (CCK-8) assay. In vitro antibacterial efficacy against planktonic E. faecalis and 14-day mature biofilms was evaluated at a concentration of 100 µg/mL using colony-forming unit (CFU) counts, adenosine triphosphate (ATP) bioluminescence, and scanning electron microscopy (SEM). Additionally, a murine model of apical periodontitis was established to assess the in vivo therapeutic efficacy of UCNP-RB-mediated antimicrobial photodynamic therapy (aPDT) compared to 1% sodium hypochlorite (NaClO) irrigation, with outcomes measured by micro-computed tomography (micro-CT).

Results

The synthesized UCNP-RB nanocomposite successfully converted near-infrared (NIR) light into visible emission, triggering efficient reactive oxygen species (ROS) generation. An optimal concentration of 100 µg/mL was identified for subsequent experiments. UCNP-RB-mediated aPDT demonstrated potent antibacterial efficacy, achieving a > 99% reduction in planktonic E. faecalis and approximately 90% inhibition of mature biofilm viability (p < 0.05). In vivo, micro-CT analysis revealed that the UCNP-RB aPDT group exhibited a 67% reduction in periapical bone defect volume compared to the untreated control group, indicating significant promotion of periapical healing.

Conclusions

The UCNP-RB nanocomposites synthesized in this study exhibited uniform morphology and potent photodynamic activity. At an optimal concentration of 100 µg/mL, the system demonstrated significant antibacterial efficacy against E. faecalis both in vitro and in vivo, highlighting its potential as an effective agent for endodontic disinfection.