Mesoporous Calcium-Silicate Nanoparticles Loaded with Prussian Blue Promotes Enterococcus Faecalis Ferroptosis-Like Death by Regulating Bacterial Redox Pathway ROS/GSH

Abstract

Background: Mesoporous calcium-silicate nanoparticles (MCSNs) are advanced biomaterials that have been used to control drug delivery for many years. Ultrasmall Prussian blue nanoparticles (UPBNPs) showed high peroxidase and catalase-like activities. This study evaluated the antibacterial and antibiofilm properties, mechanism and cytotoxicity of UPBNPs-MCSNs composites synthesized by both as precursors. Methods: UPBNPs-MCSNs were prepared and characterized. The antibacterial effect of UPBNPs-MCSNs was evaluated by the MTT assay and CFU counting method, and their biosafety was tested by CCK8. Then explore the antibacterial mechanism, including TEM observation of bacterial morphology, and detection of bacterial ROS, LPO and GSH levels. The antibiofilm activity of UPBNPs-MCSNs was tested by E. faecalis biofilm model in human roots. The roots were pretreated with materials and cultured with E. faecalis, and the survival of E. faecalis on the root canal wall was observed by SEM and CLSM. Results: The results showed that UPBNPs-MCSNs had potent antibacterial and antibiofilm activities. They can aggregate on the dentin surface and significantly inhibit E. faecalis adhesion and colonization. Their antibacterial activity is as effective as NaClO and calcium hydroxide (CH), can significantly prolong the time of bacterial colonization than CH, but have lower cytotoxicity to normal cells. We found that UPBNPs-MCSNs trigger a like classic ferroptosis pathway in bacteria. UPBNPs-MCSNs can induce bacteria to produce ROS and LPO, and reduce GSH level. Moreover, we observed that the metal ions chelator and the antioxidant could block their antibacterial activity. Conclusion: These results reveal that UPBNPS-MCSNs have high antibacterial and antibiofilm, and can mediate the bacterial redox pathway ROS/GSH like the classical pathway of ferroptosis, providing a theoretical basis for them to develop into a safe and effective novel root canal disinfectant.

Construction of a pH-responsive nanoreactor and its specific inhibition of oral squamous cell carcinoma growth via TME and xCT/GSH/GPX4 axis

“…For The material characterization results showed that UPM exhibited pH-dependent enzyme activity and can continuously release Fe ions. Combined with our previous research on bacteria treated with nanoparticles loaded with USPBNPs, we found ferroptosis, 27 suggesting that UPM-induced OSCC cells death may be related to the mechanism of ferroptosis. The System x c -/GSH/GPX4 pathway holds signi cant importance in maintaining cellular redox homeostasis and emerges as a critical player in ferroptosis processes.…”

“…To develop nanoreactors with high enzymatic activity and biocompatibility, in this study, sub-5nm ultrasmall PBNPs (USPBNPs) were synthesized by a single precursor synthesis technique, 26 and about 100 nm MCSNs were prepared by a template method. [27][28][29] Subsequently, utilizing USPBNPs and MCSNs as raw materials, the USPBNPs@MCSNs (UPM) nanoreactor was constructed by a straightforward mixing-coupling method. Notably, due to the incorporation of MCSNs as carriers, the synthesized UPM exhibited superior pH-responsive enzymatic activity, demonstrating higher antitumor activity than any individual component and improved biocompatibility.…”

Preparation of Luvangetin Nanoemulsions: Antimicrobial Mechanism and Role in Infected Wound Healing

“…Elevated ROS levels arise from bacterial damage, and excessive ROS further accelerates damage and leads to bacterial death. 55 Malondialdehyde (MDA) levels act as indicators of lipid peroxidation rate and intensity, offering an indirect reflection of tissue peroxidative damage. 56 Higher concentrations of LNs corresponded to higher MDA content, indicating increasingly severe bacterial damage.…”

An Acid-Responsive Iron-Based Nanocomposite for OSCC Treatment

“…The biological carrier MCSN was synthesized by a template method (Zhu et al 2017), and the USPBNPs of sub–5 nm were synthesized by a single precursor synthesis technique (Qin et al 2020). Then, the UPM was synthesized by a mixing-coupling method (Zhao et al 2022). Scanning electron microscopy (SEM; JSM-7900F; JEOL), transmission electron microscopy (TEM; JEM-2100; JEOL), and EDS element mapping (JEM-ARM200F; JEOL) were used for characterization.…”

“…We have previously successfully synthesized sub-5-nm ultra-small PBNPs (USPBNPs) and used MCSNs as a biological carrier to synthesize USPBNPs@MCSN (UPM) nanoparticles (Qin et al 2020; Zhao et al 2022) and found that they have a good effect for OSCC treatment. The results showed that the synthesized UPM exhibited POD-like activity more than 40-fold higher than the classical iron-based nanozymes Fe 3 O 4 and had a higher activity to inhibit OSCC cells than any individual component.…”