Antimicrobial property of zinc based nanoparticles

Phosphatase-degradable nanoparticles providing sustained drug release

AIM

The study aimed to develop enzyme-degradable nanoparticles comprising polyphosphates and metal cations providing sustained release of the antibacterial drug ethacridine (ETH).

METHODS

Calcium polyphosphate (Ca-PP), zinc polyphosphate (Zn-PP) and iron polyphosphate nanoparticles (Fe-PP NPs) were prepared by co-precipitation of sodium polyphosphate with cations and ETH. Developed nanocarriers were characterized regarding particle size, PDI, zeta potential, encapsulation efficiency and drug loading. Toxicological profile of nanocarriers was assessed via hemolysis assay and cell viability on human blood erythrocytes and HEK-293 cells, respectively. The enzymatic degradation of NPs was evaluated in presence of alkaline phosphatase (ALP) monitoring the release of monophosphate, shift in zeta potential and particle size as well as drug release. The antibacterial efficacy against Escherichia coli was determined via microdilution assay.

RESULTS

NPs were obtained in a size range between 300 - 480 nm displaying negative zeta potential values. Encapsulation efficiency was in the range of 83.73 %- 95.99 %. Hemolysis assay underlined sufficient compatibility of NPs with blood cells, whereas drug and NPs showed a concentration dependent effect on HEK-293 cells viability. Ca- and Zn-PP NPs exhibited remarkable changes in zeta potential, particle size, monophosphate and drug release upon incubation with ALP, compared to Fe-PP NPs showing only minor differences. The released ETH from Ca- and Zn-PP nanocarriers retained the antibacterial activity against E. coli, whereas no antibacterial effect was observed with Fe-PP NPs.

CONCLUSION

Polyphosphate nanoparticles cross-linked with divalent cations and ETH hold promise for sustained drug delivery triggered by ALP for parental administration.

Tiny but mighty: metal nanoparticles as effective antimicrobial agents for plant pathogen control

Metal nanoparticles (MNPs) have gained significant attention in recent years for their potential use as effective antimicrobial agents for controlling plant pathogens. This review article summarizes the recent advances in the role of MNPs in the control of plant pathogens, focusing on their mechanisms of action, applications, and limitations. MNPs can act as a broad-spectrum antimicrobial agent against various plant pathogens, including bacteria, fungi, and viruses. Different types of MNPs, such as silver, copper, zinc, iron, and gold, have been studied for their antimicrobial properties. The unique physicochemical properties of MNPs, such as their small size, large surface area, and high reactivity, allow them to interact with plant pathogens at the molecular level, leading to disruption of the cell membrane, inhibition of cellular respiration, and generation of reactive oxygen species. The use of MNPs in plant pathogen control has several advantages, including their low toxicity, selectivity, and biodegradability. However, their effectiveness can be influenced by several factors, including the type of MNP, concentration, and mode of application. This review highlights the current state of knowledge on the use of MNPs in plant pathogen control and discusses the future prospects and challenges in the field. Overall, the review provides insight into the potential of MNPs as a promising alternative to conventional chemical agents for controlling plant pathogens.

Nano-enabled antimicrobial thin films: design and mechanism of action

Antimicrobial thin films are types of protective coatings that are applied to surfaces such as medical devices, food packaging materials, water-resistant coatings, and other systems. These films prevent and reduce the spread of microbial organisms, including bacteria, fungi, and viruses. Antimicrobial thin films can be prepared from a variety of nanostructured materials including metal nanoparticles, metal oxides, plant materials, enzymes, bacteriocins and polymers. Their antimicrobial mechanism varies mostly based on the types of active agents from which the film is made of. Antimicrobial thin films are becoming increasingly popular microbial treatment methods due to their advantages such as enhanced stability, reduced toxicity levels, extended effectiveness over time and broad spectrum antimicrobial action without side effects on human health or the environment. This popularity and enhanced performance is mainly due to the extended possibility of film designs. Thin films offer convenient formulation methods which makes them suitable for commercial practices aiming at high turnover rates along with residential applications requiring frequent application cycles. This review focuses on recent developments in the possible processing methods and design approaches for assembling the various types of antimicrobial materials into nanostructured thin film-based delivery systems, along with mechanisms of action against microbes.

Green synthesis of ZnO nanoparticles using a Dysphania ambrosioides extract. Structural characterization and antibacterial properties

The Structural properties of Zinc oxide nanoparticles (ZnO-NPs) as well as their antibacterial properties against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa; as well as bacteria that are usually found in the mouth of humans and are related to dental conditions, such as Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Streptococcus mutans and Streptococcus sanguinis, are presented in this report. ZnO-NPs were grown by green synthesis, using the Mexican plant Dysphania ambrosioides known in Mexico as "epazote", which was used by native populations of Mexico as a dewormer, is currently used widely in traditional Mexican cuisine and is rich in organic compounds as flavonoids and terpenes which may favor the synthesis of nanoparticles (NPs). ZnO-NPs were synthesized by the mentioned technology and were compared with commercial ZnO-NPs as a reference. Synthesized and commercial ZnO-NPs were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray energy dispersive spectroscopy (EDS), Fourier transformed infrared spectroscopy (FTIR) and thermogravimetry (TG). Antibacterial properties were evaluated using a disc diffusion test (Kirby-Bauer method). The results indicate that ZnO-NPs were synthesized in the size range of 5-30 nm. The presence of the ZnO crystalline phase was identified by high resolution transmission electron microscopy (HRTEM) and XRD analysis. The commercial ZnO-NPs were in the size range of 15-35 nm. The antibacterial test indicates that most of the bacterial strains used in this study were sensitive to synthesized and commercial NPs, with Prevotella intermedia being the most sensitive to ZnO-NPs.

Recent Advances in Metal Decorated Nanomaterials and Their Various Biological Applications: A Review

Nanoparticles (nanoparticles) have received much attention in biological application because of their unique physicochemical properties. The metal- and metal oxide-supported nanomaterials have shown significant therapeutic effect in medical science. The mechanisms related to the interaction of nanoparticles with animal and plant cells can be used to establish its significant role and to improve their activity in health and medical applications. Various attempts have been made to discuss the antibiotic resistance and antimicrobial activity of metal-supported nanoparticles. Despite all these developments, there is still a need to investigate their performance to overcome modern challenges. In this regard, the present review examines the role of various types of metal-supported nanomaterials in different areas such as antibacterial, antifungal, anticancer, and so on. Based on the significant ongoing research and applications, it is expected that metal-supported nanomaterials play an outstanding role not only in medical but also in other important areas.

Recent advances in nanomaterials for water protection and monitoring

Nanomaterials (NMs) for adsorption, catalysis, separation, and disinfection are scrutinized. NMs-based sensor technologies and environmental transformations of NMs are highlighted.