Curcumin-Loaded Lipid Nanoparticles: A Promising Antimicrobial Strategy Against in Endodontic Infections.

This study aims to evaluate the efficacy of curcumin (CUR), a natural polyphenol with potent antimicrobial and anti-inflammatory properties, when formulated as solid lipid nanoparticles (CUR-loaded SLN) against . Solid lipid nanoparticles (SLNs) were prepared as a carrier for CUR, which significantly improved its solubility. SLNs made with cetyl palmitate and Tween 80 were obtained via the hot ultrasonication method. The physicochemical properties of CUR-loaded SLNs were evaluated, including their size, stability, and release profile. Antimicrobial testing was conducted against both sessile and planktonic populations. Cytotoxicity was assessed on human gingival fibroblasts. The CUR-loaded SLNs exhibited about 200 nm and a -25 mV surface potential, and the encapsulation of CUR did not affect the physicochemical properties of SLNs. CURs were released from SLNs in a controlled and sustained manner over 100 h. The nanoparticles remained stable for at least two months when stored at 4 °C or 25 °C, making them suitable for clinical use. Antioxidant activity was confirmed through DPPH and ABTS assays. Free CUR significantly reduced the planktonic CFU counts by approximately 65% after 24 h of exposure. However, this inhibitory effect diminished with longer exposure times (48 and 72 h). Antimicrobial activity studies of CUR-loaded SLNs showed dose- and time-dependent effects, in the 2.5-10 µg/mL range, against both sessile and planktonic populations, over 24 to 72 h. The CUR-loaded SLNs showed good cytocompatibility with human fibroblasts up to 2.5 μg/mL, suggesting low toxicity. CUR-loaded SLNs demonstrate significant antimicrobial activity against , along with good cytocompatibility, indicating their potential as an effective adjunct therapy in endodontic treatments.