Nanomaterials with active targeting as advanced antimicrobials

Abstract

With a growing health threat of bacterial resistance to antibiotics, the nanomaterials have been extensively studied as an alternative. It is assumed that antimicrobial nanomaterials can affect bacteria by several mechanisms simultaneously and thereby overcome antibiotic resistance. Another promising potential use is employing nanomaterials as nanocarriers for antibiotics in order to overcome bacterial defense mechanisms. The passive targeting of nanomaterials is the often used strategy for bacterial treatment, including intracellular infections of macrophages. Furthermore, the specific targeting enhances the efficacy of antimicrobials and reduces side effects. This review aims to discuss advantages, disadvantages, and challenges of nanomaterials in the context of the targeting strategies for antimicrobials as advanced tools for treatments of bacterial infections. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease

Biostimulation and toxicity: The magnitude of the impact of nanomaterials in microorganisms and plants

“…The mechanisms by which NMs exert biostimulation and toxicity processes are not well understood. The most widely considered hypothesis is that they generate ROS [77] , and that depending on the concentration of ROS they can activate cellular defense mechanisms (eustress) or can lead the cell to a state of distress and even cell death [78] . Other reactive species, such as nitrogen reactive species (RNS), also intervene in the signaling processes through NO, causing nitrosative stress [79] , [80] .…”

“…When an NM comes into close contact with a cell, the NM-cell interfacial interaction and the subsequent cell signaling process induce a primary stimulus or first phase of cellular modulation responses: changes in membrane potential, modification of integral proteins for energy transduction, and generation of elicitors and antioxidants in response to the changes or damages in the membranes, followed by an alteration in the gene expression [52] , [77] . The second phase of cellular responses occurs when the metallic NMs transform to ionic forms of the element, either in the growth medium of the microorganisms or in the plant apoplast; these extracellular ionic forms, depending on the concentration and the chemical speciation resulting from pH, ionic strength, oxidation–reduction potential, interaction with other inorganic ions and complexation with biomolecules, cause biostimulation or toxicity on cells by modifying the membrane potential and interacting with the membrane receptors [32] , [81] .…”

Nanoscopy for endosomal escape quantification

“…Using nanoparticles (NP) to deliver drugs to cells (nanomedicine) was foreseen to be a true game-changer of the 21 st century in improving the prevention, diagnosis and therapy of various therapeutic areas (1)(2)(3)(4)(5)(6). The potential of these nanosized carriers in pharmaceutical applications has been envisioned since the 1970's to improve the delivery of therapeutic and imaging agents to specific target sites (7)(8)(9)(10)(11).…”

Smart nanomicelles with bacterial infection-responsive disassembly for selective antimicrobial applications

“…2 Excessive usage of antibiotics in human medicine and livestock farming over the past seven decades, and transmission by horizontal gene transfer, have contributed to the selective expansion and mutagenic development of multidrug-resistant bacteria. [3][4][5] Worldwide extensive efforts to develop new antibiotics are lagging behind the rapid spread of resistant pathogens, as indicated by no new class of antibiotic being approved to treat Gram-negative bacteria in over five decades. 6 In general, the mechanisms for resistance involve intrinsic or metabolic functions in bacteria, such as enzymatic scission or inactivation of antibiotic structure, modification of antibiotic target binding sites, efflux pumps, and biofilm formation.…”