Molecular Aspects of the Interaction with Gram-Negative and Gram-Positive Bacteria of Hydrothermal Carbon Nanoparticles Associated with Bac8c^2,5Leu Antimicrobial Peptide

Abstract

Antimicrobial peptides (AMPs) are widely studied as therapeutic agents due to their broad-spectrum efficacy against infections. However, their clinical use is hampered by the low in vivo bioavailability and systemic toxicity. Such limitations might be overcome by using appropriate drug delivery systems. Here, the preparation of a drug delivery system (DDS) by physical conjugation of an arginine-rich peptide and hydrothermal carbon nanoparticles (CNPs) has been explored, and its antimicrobial efficacy against Eschericia coli ( E. coli ) and Staphylococcus aureus investigated in comparison with the unloaded carrier and the free peptide. The mechanism of interaction between CNPs and the bacteria was investigated by scanning electron microscopy and a combined dielectrophoresis–Raman spectroscopy method for real-time analysis. In view of a possible systemic administration, the effect of proteins on the stability of the DDS was investigated by using albumin as a model protein. The peptide was bounded electrostatically to the CNPs surface, establishing an equilibrium modulated by pH and albumin. The DDS exhibited antimicrobial activity toward the two bacterial strains, albeit lower as compared to the free peptide. The decrease in effectiveness toward E. coli was likely due to the rapid formation of a particle-induced extracellular matrix. The present results are relevant for the future development of hydrothermal CNPs as drug delivery agents of AMPs.

Inhibitory Effect against Listeria monocytogenes of Carbon Nanoparticles Loaded with Copper as Precursors of Food Active Packaging

“…However, they do not explain the observed higher activity of the largest LCNP with respect to both the soluble copper and SCNP. In a previous study [66], we showed that CNPs strongly interact with E. coli and S. aureus by forming aggregates that might favor the transport of the loaded antimicrobial agents close to the bacterial cells. A similar effect might account for the higher bioactivity of LCNP-Cu; in fact, since the experiments were performed with equal concentrations of copper, the available surface for interactions with bacteria was 10 time higher for LCNP-Cu than with SCNP-Cu.…”

Photoresponsive Inorganic Nanomaterials in Oncology

“…112 Other important advantages of HCNPs are their biocompatibility. In fact, they exhibit low toxicity against the cells of the immune system and act as antioxidants 113 and are hemo compatible. 114 In addition, previous data suggest that HCNPs are slowly degraded by neutrophils.…”

In Situ Green Synthesis of Co3O4@ZnO Core-Shell Nanoparticles Using Datura stramonium Leaf Extract: Antibacterial and Antioxidant Studies

“…Nowadays, the most widely used techniques in the synthesis of the nanoparticle are chemical methods and biological methods. Te most common chemical methods such as vapor deposition, sol-gel, thermal evaporation, microwave-assisted, pulsed laser deposition, electrochemical reaction, sputtering, hydrothermal, solvothermal, and microemulsion are used in the fabrication of nanoparticles [41][42][43][44]. Similarly, Co 3 O 4 @ZnO core-shell NPs have been synthesized by using the chemical and physical methods.…”