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Role of the chemical modification of titanium dioxide surface on the interaction with silver nanoparticles and the capability to enhance antimicrobial properties of poly(lactic acid) composites

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Abstract

In this work, the antimicrobial activity of neat and silanized titanium dioxide deposited with silver nanoparticles was evaluated when it was used as filler in a poly(lactic acid) matrix. The silanization and deposition processes were evaluated by scanning transmission electron microscopy and X-ray photoelectron spectroscopy confirming the chemical modification on the titanium dioxide surface by 3-aminopropyltriethoxy silane and the formation of silver nanoparticles. According to the elemental analysis conducted by energy-dispersive X-ray spectroscopy, more silver, 7.4% higher, was deposited on the oxide when this was previously silanized and when 30% w/w of silver nitrate was used as a precursor. The antimicrobial effect was confirmed for the nanoparticles through the disk diffusion method and for the composites by drop test, against Staphylococcus aureus and Escherichia coli bacteria; the results showed that the inhibition rate increased by 14.2% and 39.1% for nanoparticles and by 57.6% and 38.8% for composites against each bacteria, respectively, when deposition was performed on silanized titanium dioxide. Also, better mechanical properties were obtained in the composites filled with silanized oxide; the best results were obtained in the PLA/sTiO2–Ag 20% system with an improvement of 45.7% in tensile stress and of 38.73% for Young’s modulus. Finally, the toxicity of the composites was evaluated by seeding peripheral blood mononuclear cells; results show evidence that composites filled with these nanoparticles are non-toxic since these do not migrate from the polymeric matrix, which helps to enhance the prolonged surface antibacterial effect and to open a broad perspective of the commercial use of these composites.

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Acknowledgements

The authors express their gratitude to Carlos Benavides Muñiz for experimental assistance in the microbial experiments. M.G. Peña-Juárez and J.A. Gonzalez-Calderón wish to thank Consejo Nacional de Ciencia y Tecnología (Conacyt México) for Ph.D. scholarship (No: 744689) and for the support with the program “Cátedras-Conacyt,” respectively. R. Lopez-Esparza wishes to thank Universidad de Sonora by financial support through project USO315005347 and to Mora R. of the DIFUS by the assistance in XPS experiments.

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  1. Doctorado Institucional en Ingeniería y Ciencia de Materiales, Universidad Autónoma de San Luis Potosí, Sierra Leona No. 550 Col. Lomas 2da. Sección, 78210, San Luis Potosí, SLP, Mexico

    M. G. Peña-Juárez & M. Robles-Martínez

  2. Centro de Investigación Aplicada en Ambiente y Salud, CIACYT, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, Av. Venustiano Carranza 2405, 78290, San Luis Potosí, SLP, Mexico

    K. B. Méndez-Rodríguez

  3. Departamento de Física, Universidad de Sonora, 1626, 83000, Hermosillo, Sonora, Mexico

    R. López-Esparza

  4. Instituto de Física, Universidad Autónoma de San Luis Potosí, Alvaro Obregón 64, 78000, San Luis Potosí, SLP, Mexico

    Elías Pérez

  5. Cátedras CONACYT-Instituto de Física, Universidad Autónoma de San Luis Potosí, Av. Manuel Nava #6, Zona Universitaria, 78290, San Luis Potosí, SLP, Mexico

    J. A. Gonzalez-Calderon

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Peña-Juárez, M.G., Robles-Martínez, M., Méndez-Rodríguez, K.B. et al. Role of the chemical modification of titanium dioxide surface on the interaction with silver nanoparticles and the capability to enhance antimicrobial properties of poly(lactic acid) composites. Polym. Bull. 78, 2765–2790 (2021). https://doi.org/10.1007/s00289-020-03235-y

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