R Najafloo - Department of Bioinformatics, Faculty of Interdisciplinary Science and Technology, Tarbiat Modares University, Tehran, Iran
N Baheiraei - Tissue Engineering and Applied Cell Sciences Division, Department of Hematology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
R Imani - Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran

Objective: Despite the continuous progression in surgical tech-niques and antibiotics therapies, the simultaneously bone repair and inhibit infection is difficult. Among antimicrobial agents, thymol (۲-isopropyl-۵-methyl phenol) has revealed favora-ble antimicrobial activity in many reports. This study aimed to develop a novel niosomal nanocarrier embedded into the collagen/β-TCP scaffold for local delivery of thymol as a natu-ral antibacterial reagent.Materials and Methods: Niosomal nanocarrier loaded with thymol was synthesized by lipid film hydration technique. Mor-phology and size of the synthesized niosomes were evaluated by Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS), respectively. Collagen/β-TCP scaffold incor-porating niosomal thymol was also prepared using the freeze-drying technique. Thymol release from scaffolds was calculated with the Uv-visible method. The viability and morphology of L۹۲۹ fibroblast cells were investigated on niosomal contain-ing scaffolds, and the antimicrobial activities of the prepared samples were assessed by agar diffusion method against Es-cherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.Results: The synthesized niosome showed uniformed size dis-tribution and high efficacy of loading with being successfully incorporated into the composite scaffolds. The release profile of niosomal thymol from the composite scaffolds exhibited a sus-tained manner. Niosome added scaffolds showed significantly higher values of cell viability, and excellent cell adhesion and spreading when compared to that for other groups. Also, nio-somal scaffolds showed greater effectiveness of antibacterial activity towards all three types of bacteria with higher activity against Staphylococcus aureus.Conclusion: The results of this study highlight the potential of niosomal-thymol loaded Col/β-TCP scaffold as an antibacterial bone substitute for possible osteomyelitis treatment.

Bone Infection, Scaffolds, Antibacterial, Thymol, Tissue Engineering