Preparation and Study of the Antibacterial Applications and Oxidative Stress Induction of Copper Maleamate-Functionalized Mesoporous Silica Nanoparticles

Abstract

Mesoporous silica nanoparticles (MSNs) are an interesting class of nanomaterials with potential applications in different therapeutic areas and that have been extensively used as drug carriers in different fields of medicine. The present work is focused on the synthesis of MSNs containing a maleamato ligand (MSN-maleamic) and the subsequent coordination of copper(II) ions (MSN-maleamic-Cu) for the exploration of their potential application as antibacterial agents. The Cu-containing nanomaterials have been characterized by different techniques and the preliminary antibacterial effect of the supported maleamato-copper(II) complexes has been tested against two types of bacteria (Gram positive and Gram negative) in different assays to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The biological results showed a moderate antibacterial activity against Escherichia coli which motivated a more detailed study of the antibacterial mechanism of action of the synthesized maleamate-containing nanosystems and whose findings showed oxidative stress generation in bacterial cells. All the prepared nanomaterials were also tested as catalysts in the “solvent free” selective oxidation of benzyl alcohol, to observe if there is a potential correlation between the catalytic oxidation capacity of the materials and the observed oxidative stress in bacteria. This may help in the future, for a more accurate rational design of antibacterial nanosystems, based on their observed catalytic oxidation activity.

Role of Folic Acid in the Therapeutic Action of Nanostructured Porous Silica Functionalized with Organotin(IV) Compounds against Different Cancer Cell Lines

“…In this context, since 2009 our team has been working on the use of porous silica-based nanostructured materials such as MCM-41, SBA-15, hexagonal mesoporous silica (HMS), MSU-2, KIT-6 or mesoporous silica nanoparticles (MSNs) functionalized with different metallodrugs [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Previous studies have shown that these systems usually work as “non-classical” drug delivery systems, namely, acting as an entire nanoparticulated therapeutic system, without the need of the released metallodrug to be cytotoxic.…”

“…Considering that most of the studied systems do not bear any potential targeting molecule to detect and potentiate the active and selective transport of the therapeutic species to the cancer cell line, an enhanced permeability and retention (EPR) effect was considered to be responsible for their slight selectivity towards cancer cell lines (in comparison with normal cell lines) [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Nevertheless, very recent reports have studied the possibility of including a folate fragment for a more effective targeting of cancer cells, which has been partially achieved both in vitro [ 33 ] and in vivo [ 34 ] when using organotin(IV)-functionalized mesoporous silica nanoparticles.…”

Mesoporous Silica‐Based Materials with Bactericidal Properties

“…Gómez‐Ruiz and co‐workers prepared MS NPs containing a maleamato ligand (MS NP‐maleamic) which was used to coordinate copper(II) ions (MS NP‐maleamic‐Cu) and explored their potential application as antibacterial agents against E. coli and S. aureus (see Figure ) . The results showed a low activity of MS NP‐maleamic and MS NP‐maleamic‐Cu against S. aureus , while a good activity against E. coli was found.…”

Enlarged Pore Size Chiral Mesoporous Silica Nanoparticles Loaded Poorly Water-Soluble Drug Perform Superior Delivery Effect

“…In recent years, mesoporous silica nanoparticles (MSN) fabricated based on various kinds of templates have aroused a lot of interest owing to their rigid frame, good biocompatibility and biodegradability, unique structural features (tunable mesopores in the range of 2–50 nm, large pore volume as well as total surface area), and facile surface modification [1,2,3,4]. To better play the bio-recognition performance, MSN will be modified by chiral small molecules [5,6,7,8], whereas the chiral mesoporous silica nanoparticles (CMSN) will tend to reduce the mesopores size. Enlarging the mesopores of CMSN can load biomacromolecule and protect its activity [9].…”