Synergistic Antimicrobial Activity of Magnetite and Vancomycin-Loaded Mesoporous Silica Embedded in Alginate Films

Georgiana Dolete; Cornelia-Ioana Ilie; Cristina Chircov; Bogdan Purcăreanu; Ludmila Motelica; Alina Moroșan; Ovidiu Cristian Oprea; Denisa Ficai; Ecaterina Andronescu; Lia-Mara Dițu

doi:10.3390/gels9040295

Synergistic Antimicrobial Activity of Magnetite and Vancomycin-Loaded Mesoporous Silica Embedded in Alginate Films

Gels. 2023 Apr 2;9(4):295. doi: 10.3390/gels9040295.

Authors

Georgiana Dolete^{1

2}, Cornelia-Ioana Ilie^{1

2}, Cristina Chircov^{1

2}, Bogdan Purcăreanu^{1

3}, Ludmila Motelica^{1

2}, Alina Moroșan⁴, Ovidiu Cristian Oprea^{2

5

6}, Denisa Ficai^{1

2

6}, Ecaterina Andronescu^{1

2

6}, Lia-Mara Dițu^{7

8}

Affiliations

¹ Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, Gh. Polizu 1-7, 011061 Bucharest, Romania.
² National Center for Micro and Nanomaterials, University Politehnica of Bucharest, Splaiul Independenței 313, 060042 Bucharest, Romania.
³ BIOTEHNOS SA, Gorunului Street 3-5, 075100 Otopeni, Romania.
⁴ Department of Organic Chemistry "Costin Nenițescu", Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, Gh. Polizu 1-7, 011061 Bucharest, Romania.
⁵ Department of Inorganic Chemistry, Physical Chemistry, and Electrochemistry, Faculty of Chemical Engineering and Biotechnologies, University Politehnica of Bucharest, Gh. Polizu 1-7, 011061 Bucharest, Romania.
⁶ Academy of Romanian Scientists, Ilfov Street 3, 050044 Bucharest, Romania.
⁷ Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, 1-3 Aleea Portocalelor, 060101 Bucharest, Romania.
⁸ Research Institute of the University of Bucharest, 91-95 Splaiul Independenței, 050095 Bucharest, Romania.

Abstract

The aim of the present study was to obtain a hydrogel-based film as a carrier for the sustained and controlled release of vancomycin, an antibiotic commonly used in various types of infections. Considering the high-water solubility of vancomycin (>50 mg/mL) and the aqueous medium underlying the exudates, a prolonged release of vancomycin from an MCM-41 carrier was sought. The present work focused on the synthesis of malic acid coated magnetite (Fe₃O₄/malic) by co-precipitation, synthesis of MCM-41 by a sol-gel method and loading of MCM-41 with vancomycin, and their use in alginate films for wound dressing. The nanoparticles obtained were physically mixed and embedded in the alginate gel. Prior to incorporation, the nanoparticles were characterized by XRD, FT-IR and FT-Raman spectroscopy, TGA-DSC and DLS. The films were prepared by a simple casting method and were further cross-linked and examined for possible heterogeneities by means of FT-IR microscopy and SEM. The degree of swelling and the water vapor transmission rate were determined, considering their potential use as wound dressings. The obtained films show morpho-structural homogeneity, sustained release over 48 h and a strong synergistic enhancement of the antimicrobial activity as a consequence of the hybrid nature of these films. The antimicrobial efficacy was tested against S. aureus, two strains of E. faecalis (including vancomycin-resistant Enterococcus, VRE) and C. albicans. The incorporation of magnetite was also considered as an external triggering component in case the films were used as a magneto-responsive smart dressing to stimulate vancomycin diffusion.

Keywords: antimicrobial wound dressings; dual release mechanism; hybrid nanostructured alginate films; magnetite; mesoporous silica; synergistic activity.

Grants and funding

The authors acknowledge the financial support of the “Sisteme inteligente cu eliberare controlata pentru tratarea cancerului utilizand o abordare personalizata (SmartACT)” project PN-III-P1-1.1-TE-2021-1342, contract TE 96/17.05.2022.