Persistent infection caused by biofilm is an urgent in medicine that should be tackled by new alternative strategies. Low efficiency of classical treatments and antibiotic resistance are the main concerns of the persistent infection due to biofilm formation which increases the risk of morbidity and mortality. The gene expression patterns in biofilm cells differed from those in planktonic cells. One of the promising approaches against biofilms is nanoparticle (NP)-based therapy in which NPs with multiple mechanisms hinder the resistance of bacterial cells in planktonic or biofilm forms. For instance, NPs such as silver (Ag), zinc oxide (ZnO), titanium dioxide (TiO₂), copper oxide (Cu), and iron oxide (Fe₃O₄) through the different strategies interfere with gene expression of bacteria associated with biofilm. The NPs can penetrate into the biofilm structure and affect the expression of efflux pump, quorum-sensing, and adhesion-related genes, which lead to inhibit the biofilm formation or development. Therefore, understanding and targeting of the genes and molecular basis of bacterial biofilm by NPs point to therapeutic targets that make possible control of biofilm infections. In parallel, the possible impact of NPs on the environment and their cytotoxicity should be avoided through controlled exposure and safety assessments. This study focuses on the biofilm-related genes that are potential targets for the inhibition of bacterial biofilms with highly effective NPs, especially metal or metal oxide NPs.

Aim:This study was conducted to determine the potentials of egg lecithin (egg-l) and soy lecithin (soy-l) liposomes in antioxidative and wound healing properties.Materials & methods:The suspensions of egg-l and soy-l were prepared using the fusion technique. The free radical scavenging activity of both lecithin liposomes was evaluated by DPPH and ABTS methods. Tissue staining was used to assess wound-healing parameter.Results:Liposomal lecithins showed an increasing trend of 1–10 mg/ml in radical-scavenging activities (p < 0.0001). Wound-healing assessments showed a significant effect (p < 0.0001) in treatment with topical lecithin liposomes. The results of wound healing also showed better outcomes of egg-l in comparison with phenytoin 1% cream.Conclusion:Antioxidant lecithin liposomes may enhance the treatment of wound injuries.

Oral health problems and the emergence of antimicrobial resistance among pathogenic bacterial strains have become major global challenges and are essential elements that negatively affect general well-being. Antimicrobial photodynamic therapy (APDT) is based on a light source and oxygen that activates a nontoxic photosensitizer, resulting in microbial destruction. Synthetic and natural products can be used to help the APDT against oral microorganisms. The undesirable consequences of conventional photosensitizers, including toxicity, and cost encourage researchers to explore new promising photosensitizers based on natural compounds such as curcumin, chlorella, chlorophyllin, phycocyanin, 5-aminolevulinic acid, and riboflavin. In this review, we summarize in vitro studies describing the potential use of APDT therapy conjugated with some natural products against selected microorganisms that are considered to be responsible for oral infections.