6 - Biotecnología y Bioprocesos

GOLD@N-BUTIL POLYCYANOACRYLATE NANOSPHERE AS A COATING WITH ANTIBACTERIAL AND ANTI-BIOFILM PROPERTIES

Cruz Jorge, Erlen Yizenia¹,- Navarro Martínez, Nicolás^1,2,3-González, María José¹- Ramos Carriles, Yaquelín^4,5 - Méndez, Eduardo⁶- Robino, Luciana⁷ - Álvarez Brito, Rubén^4,5 - Scavone, Paola ¹.

1) Departamento de Microbiología - Laboratorio de Biofilms Microbianos - Instituto de Investigaciones Biológicas Clemente Estable - Montevideo - Uruguay
2) Advanced Center for Chronic Diseases (ACCDiS) - Santiago - Chile.
3) Center of New Drugs for Hypertension (CENDHY) - Santiago - Chile.
4) Universidad de la Habana - Facultad de Química - La Habana - Cuba
5) Centro de Ingeniería Genética y Biotecnología@Universidad de la Habana - Laboratorio conjunto de nano-biomedicina - La Habana - Cuba
6) Universidad de la República - Facultad de Ciencias - Laboratorio de Biomateriales - Montevideo - Uruguay
7) Universidad de la República - Facultad de Medicina - Departamento de Bacteriología y Virología - Montevideo - Uruguay.
Contacto: erlen85@gmail.com

Bacterial adhesion and biofilm formation on biomaterials represent serious economic and health problems. Biofilms, whether mono-microbial or poly-microbial, exhibit significant resistance to antimicrobials and host defenses. Although antibiotics are a common treatment and prevention strategy, their effectiveness decreases due to the resistance induced by biofilms and the increase in multi-resistant strains. As an alternative, new materials and coatings are being developed. Nano-structured coatings, such as gold nanoparticles (Au-NPs), have intrinsic antimicrobial properties. Additionally, alkyl pol cyanoacrylates (PCA) are biocompatible polymers with antimicrobial activity against Gram-positive and some Gram-negative bacteria. This study synthesizes and evaluates a coating based on gold@pol cyanoacrylate n-butyl nanoparticles (Au-PCAB-Nps) to combat biofilms on biomaterials. Au-PCAB-Nps were synthesized by nanoprecipitation using a non-ionic surfactant as a stabilizer. They were characterized by Transmission Electron Microscopy, with hydrodynamic radius determined by Dynamic Light Scattering and Z-potential measured by Electrophoretic Light Scattering. The viability of E. coli 144, P. mirabilis 2921, S. aureus ATCC 6538, S. epidermidis M20200221, A. baumannii ATCC 19606, and P. aeruginosa ATCC 902 against the nanoparticles (Nps) was assessed using resazurin assays. The ability of the Nps to inhibit and eradicate biofilms was evaluated in a static assay on 96-well plates, using concentrations of 1x, 2x, and 4x. The obtained dispersion revealed two nanoparticle populations with hydrodynamic diameters of 79±1nm and 167±2nm, and a polydispersity index of 0.169. The observed Z-potential was -18.15±0.02mV. Au-PCAB-Nps exhibited minimum inhibitory concentration and minimum bactericidal concentration values above 4x for all tested strains. The viability assay showed that Au-PCAB-Nps had no cytotoxic effect on E. coli, P. mirabilis, S. aureus, S. epidermidis, and A. baumannii under the tested conditions (24 h, concentrations of 0.002x to 4x), but did show cytotoxic effects on P. aeruginosa at 24 h and concentrations of 0.5x to 4x. Compared to Au-Nps, Au-PCAB-Nps had a similar effect, while PBCA-Nps showed no cytotoxic effects on any of the evaluated strains. Au-PCAB-Nps significantly reduced biofilm formation of E. coli, P. mirabilis, S. aureus, S. epidermidis, and A. baumannii compared to the control. PBCA-Nps showed a similar effect, while Au-Nps had no impact under any of the studied conditions. However, Au-PCAB-Nps did not reduce the biomass of mature biofilms of the studied bacteria, a behavior also observed with Au-Nps. PBCA-Nps reduced the biomass of mature biofilms only in P. mirabilis and S. aureus. These results suggest that Au-PCAB-Nps have promising potential as a coating for biomaterials to prevent bacterial biofilm-related infections. However, their efficacy does not surpass that of PBCA-Nps and is comparable to Au-Nps.

Palabras clave: Biofilms - Nanoparticles - Gold - n-Butyl Polycyanoacrylate - Coating Materials