curcumin and Peri-Implantitis

Curcumin has been used as a photosensitizer (PS) for antimicrobial photodynamic chemotherapy (PACT). However, its low solubility, instability, and poor bioavailability challenge its in vivo application. This study aimed to synthesize curcumin-loaded polymeric nanoparticles (curcumin-NP) and determine their antimicrobial and cytotoxic effects. Nanoparticles (NP) were synthesized using polycaprolactone (PCL) as a polymer by the nanoprecipitation method. Curcumin-NP was characterized by particle size, polydispersity index and zeta potential, scanning electron microscopy, and curcumin encapsulation efficiency (EE). Curcumin-NP was compared to free curcumin solubilized in 10% DMSO as photosensitizers for PACT in single and multispecies Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus oralis biofilms. Chlorhexidine 0.12% (CHX) and ultrapure water were used as positive and negative controls. The cytotoxic effect of curcumin-NP was evaluated on human periodontal ligament fibroblast cells (HPLF). Data were analyzed by ANOVA (α=0.05). Curcumin-NP exhibited homogeneity and stability in solution, small particle size, and 67.5% EE of curcumin. Curcumin-NP presented reduced antibiofilm activity at 500 µg/ml, although in planktonic cultures it showed inhibitory and bactericidal effect. Curcumin-NP and curcumin with and without photoactivation were not cytotoxic to HPLF cells. Curcumin-NP has antimicrobial and antibiofilm properties, with better effects when associated with blue light, being a promising therapy for preventing and treating peri-implant diseases.

Topics: Biofilms; Curcumin; Humans; Peri-Implantitis; Photochemotherapy; Photosensitizing Agents; Polymers

Recently, antimicrobial photodynamic therapy (aPDT) as an alternative treatment modality has been used adjunctively in the treatment of periodontitis and peri-implantitis. Photosensitizing agents in the form of nanoparticles have been designed for improving the efficiency of aPTD. Graphene quantum dots are a special type of nanocrystals that can promote aPDT when coupled with curcumin (Cur). The main objective of the present study was to investigate the effects of photoexcited GQD-Cur on the metabolic activity of perio-pathogen mixed biofilms.. GQD-Cur was synthesized and characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible spectrometry (UV-Vis), and X-ray diffraction (XRD). The cell cytotoxicity effect of GQD-Cur was evaluated on primary human gingival fibroblast (HuGu) cells. Perio-pathogen mixed biofilms including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia photosensitized with GQD doped with Cur were irradiated with a blue LED at a wavelength of 435 ± 20 nm for 1 min, and then bacterial viability measurements were performed. The antimicrobial susceptibility profile, biofilm formation ability, amount of reactive oxygen species (ROS) released, and variations of gene expressions involved in biofilm formation were assessed.. The SEM, DLS, FTIR, UV-Vis spectrometry, and XRD pattern confirmed that GQD-Cur was synthesized successfully. According to the results, GQD-Cur exhibited no cytotoxicity against HuGu cells. Photoexcited GQD-Cur resulted in a significant reduction in cell viability (93%) and biofilm formation capacity (76%) of peri-pathogens compared to the control group (P < 0.05). According to the results, a significant concentration-dependent increase in the ROS generation was observed in perio-pathogens mixed cells treated with different doses of GQD-Cur-aPDT. Moreover, rcpA, fimA, and inpA gene expression profiles were downregulated by 8.1-, 9.6-, and 11.8-folds, respectively.. Based on the results, photoexcited GQD-Cur have a high potency of perio-pathogens suppression in planktonic and biofilm forms and downregulation of the biofilm genes expression pattern was exploited as a nanoscale-based platform for periodontitis.

Topics: Aggregatibacter actinomycetemcomitans; Biofilms; Cell Survival; Curcumin; Graphite; Peri-Implantitis; Periodontitis; Photochemotherapy; Photosensitizing Agents; Porphyromonas gingivalis; Prevotella intermedia; Quantum Dots; Reactive Oxygen Species

The bystander effects, whereby naive (bystander) microbial cells near microbial cells directly exposed to certain treatment show responses that would not have happened in the absence of the directly targeted microbial cells, is recently documented in the field of microbiology. In this article, we discuss that substantial bystander responses are also observed after antimicrobial photodynamic therapy (aPDT) using curcumin (Cur).. Bystander effects induced by whole bacterial cell suspension (WBCS. A. actinomycetemcomitans cell survival reduced by 82.7% (P = 0.001) and 76.2% (P = 0.01) after exposure to WBCS. The results of the current study revealed that Cur-aPDT could significantly reduce microbial cell survival, cell metabolic activity, efflux capacity, and QS ability through the bystander effects. As a result, the bystander effects of Cur-aPDT along with the direct effect of Cur-aPDT can enhance the efficiency of aPDT as an adjunct therapeutic strategy for treatment of local infections.

Topics: Aggregatibacter actinomycetemcomitans; Anti-Bacterial Agents; Bystander Effect; Cell Survival; Curcumin; Microbial Viability; Peri-Implantitis; Periodontitis; Photochemotherapy; Photosensitizing Agents; Quorum Sensing