Print Email Facebook Twitter Effects of silver nanoparticle- containing 3D printed antibacterial implants on macrophages Title Effects of silver nanoparticle- containing 3D printed antibacterial implants on macrophages Author van Poll, Mathijs (TU Delft Mechanical, Maritime and Materials Engineering) Contributor Fratila-Apachitei, Lidy (mentor) Zadpoor, Amir (graduation committee) Degree granting institution Delft University of Technology Programme Biomedical Engineering Date 2019-12-13 Abstract Orthopedic implants used for total joint replacements are under a high clinical demand. Although most total joint replacements are successful, premature failures are still affecting tens of thousands of people annually. The major causes of implant failure are aseptic loosening and bacterial infections. To overcome these issues, multifunctional biomaterials that can on one hand battle implant associated infections (IAI), while on the other hand enhance osseointergration are being researched. Additive manufacturing and surface modification of titanium and its alloys are very promising strategies to enhance osseointergration, as the micro-architectural structures generated by these techniques have been shown to improve bone tissue integration. However, bacteria can more easily evade defense mechanisms in porous structures. To battle possible IAI, silver nanoparticles (AgNPs) can be incorporated into the surface. However, it is crucial that such antibacterial mechanisms do not interfere with tissue regeneration processes or impact cells that play a key role in regulating bone regeneration, such as macrophages. Therefore, the aim of this study was to generate an implant which could inhibit bacterial activity, while preventing adverse effects towards macrophages. 3D printed Ti-6Al-4V implants were modified by plasma electrolytic oxidation (PEO), during which different concentrations of AgNPs were incorporated into the surface. Surfaces were characterized by scanning electron microscopy (SEM) and energy- dispersive X-ray (EDX). The viability of human mesenchymal stem cells, mouse J774A.1 macrophages and primary human macrophages was determined following the culture of each cell type on the surface of implants. Additionally, inflammatory gene and secreted protein levels were determined following the culture of human primary macrophages on the surface of the most promising implant. Finally, antibacterial activity of these implants was investigated. Implants that were surface modified in the presence of 0.3 g AgNPs/L were identified as the most promising implant to support cellular viability. Furthermore, human macrophages cultured on the surface of PEO + 0.3 g AgNPs/L implants had comparable inflammatory gene expression and cytokine production levels compared to cells cultured on implants not containing AgNPS. Moreover, metabolic activity assessment of S. aureus and E. coli in the presence of PEO + 0.3 g AgNPs/L implants showed that E. coli was affected, while S. aureus was not. Interestingly, SEM images showed none of the bacteria were able to colonize the surface, highlighting the generation of an implant which can inhibit bacterial colonization, while not showing adverse effects towards macrophages. Subject Silver Nanoparticlesplasma electrolytic oxidationOrthopedic implantsMacrophagesAntibacterial To reference this document use: http://resolver.tudelft.nl/uuid:0abd5c96-4675-423a-a12a-9c0ab16d1246 Part of collection Student theses Document type master thesis Rights © 2019 Mathijs van Poll Files PDF Repository_Thesis_Mathijs ... anPoll.pdf 25.65 MB Close viewer /islandora/object/uuid:0abd5c96-4675-423a-a12a-9c0ab16d1246/datastream/OBJ/view