Tetracycline Nanoparticles as Antibacterial and Gene‐Silencing Agents

Abstract

The spread of antibiotic-resistant bacteria and parasites calls for the development of new therapeutic strategies with could potentially reverse this trend. Here, a proposal is presented to exploit a sonochemical method to restore the antibiotic activity of tetracycline (TTCL) against resistant bacteria by converting the antibiotic into a nanoparticulate form. The demonstrated sonochemical method allows nanoscale TTCL assembly to be driven by supramolecular hydrogen bond formation, with no further modification to the antibiotic's chemical structure. It is shown that tetracycline nanoparticles (TTCL NPs) can act as antibacterial agents, both against TTCL sensitive and against resistant bacterial strains. Moreover, the synthesized antibiotic nanoparticles (NPs) can act as effective gene-silencing agents through the use of a TTCL repressor in Trypanosome brucei parasites. It is demonstrated that the NPs are nontoxic to human cells and T. brucei parasites and are able to release their monomer components in an active form in a manner that results in enhanced antimicrobial activity relative to a homogeneous solution of the precursor monomer. As the TTCL NPs are biocompatible and biodegradable, sonochemical formation of TTCL NPs represents a new promising approach for generation of pharmaceutically active nanomaterials.

Escherichia coli and Pseudomonas aeruginosa eradication by nano-penicillin G

“…This effect has already been observed when tetracycline was formulated into nanoparticles using the same sonochemical method. 15 Moreover, the peaks assigned to penicillin found at 1600 cm -1 and corresponding to amide I band were not significantly changed, suggesting that no other major changes were induced in the structure of Penicillin G upon spherization. The remaining peaks were assigned to the surfactant and oil as it could be seen in their IR spectra.…”

“…7 The transformation of the active agents themselves into nanosize entities has been only sparsely reported. 15 This can be done using an ultrasonic emulsification method that allows obtaining oil-filled nano/microspheres (NMSs), in which the antibiotic is located at the interface of the droplet, i.e. not encapsulated but the shell itself.…”

Design and synthesis of theranostic antibiotic nanodrugs that display enhanced antibacterial activity and luminescence

“…The enhanced bacterial-killing efficiency of PNDs can be in part attributed to the colocalization of the nanoaggregates with the bacterium (Fig. 5) leading to a higher local drug concentration, and enhanced uptake of drug molecules when delivered in the nanosized particles (45). The present study represents a strategy in the design and development of antimicrobial therapies for combating drug-resistant bacterial infections.…”

Enhanced pharmacological activity of Vitamin B12 and Penicillin as nanoparticles

“…The tube was then placed in the EPR cavity, and the spectra were recorded on a Bruker EPR 100d X-band spectrometer (Bruker Corporation, Billerica, MA, USA). The conditions of the EPR measurement were as follows: frequency -9.74 GHz; microwave power -20 mW; scan width -65 G; resolution -1,024; receiver gain -2×10 5 ; conversion time -8 ms; time constant -655 ms; sweep time -84 s; scans -2; modulation frequency -100 kHz.…”

“…During implosion, the molecules shell collapses into the bubble center and thereby creates a nanoparticle (NP) that contains many small molecules (a magnification of the NP is presented in the last phase of the process described in Figure 1). 5 Nanomaterials have an important advantage compared with their bulk counterparts. It is well known that when the particle size decreases, the proportion of the surface …”