Nanoparticles: Alternatives Against Drug-Resistant Pathogenic Microbes

Application of essential oils as natural antimicrobials in lactic acid bacteria contaminating fermentation for the production of organic cachaça

Sugarcane-based fermentation is an essential process for different sectors of economic importance, such as the food industry with fermented and distilled beverages. However, this process can suffer from high contamination by wild yeasts and bacteria, especially lactic acid bacteria (LAB). This makes it necessary to use decontamination strategies and search for new methods that have a low environmental impact and contribute to the production of organic products. Among the options, oregano and thyme essential oils stand out for their antibacterial compounds. The aim of this study was to use oregano and thyme essential oils as natural antimicrobials in the alcoholic fermentation of sugar cane juice. Initially, the minimum inhibitory concentration of the essential oils in the fermentation was assessed through turbidity in the sensitivity test, which allowed us to determine which concentrations of essential oils would inhibit the contaminants, 3 morphologically selected LAB strains, as well as assessing the viability of CA-11. For LAB, 3 concentrations of each essential oil were tested, ranging from 0.1 to 0.4 μl/mL, while for CA-11 it was 0.06, to 0.1 μl/mL. The results indicated a maximum total value of essential oils per ml of 0.06 μl. Based on this result, a 24-1 fractional factorial was established, with 8 conditions +3 central points, with 4 variables, oregano essential oil (0, 0.03 and 0.06 μl/ml), thyme (0, 0.03 and 0.06 μl/ml), initial soluble solids (14, 16 and 18°Brix) and initial yeast concentration (2.5, 3 and 3.5 g/l), with the temperature set at 32 °C for a period of 12 h. The results showed that the center point condition with 0.03 μl/ml of oregano EO, 0.03 μl/ml of thyme controlled the proliferation of contaminating bacteria compared to the control condition. In the experimental validation, the treatment with essential oils had a lower final population of LAB (5.95 log) than the final population of the control treatment (6.53 log), and it was also observed that the treatment with EOs had an alcohol production around 3 % higher than the treatment without antimicrobials. The experimental validation phase confirmed the synergistic action of oregano and thyme essential oils in controlling the proliferation of contaminating bacteria. In conclusion, it was possible to determine the synergistic antimicrobial action of essential oils against LAB during alcoholic fermentation based on organic sugar cane.

Initial therapeutic evidence of a borosilicate bioactive glass (BSG) and Fe3O4 magnetic nanoparticle scaffold on implant-associated Staphylococcal aureus bone infection

Implant-associated Staphylococcus aureus (S. aureus) osteomyelitis is a severe challenge in orthopedics. While antibiotic-loaded bone cement is a standardized therapeutic approach for S. aureus osteomyelitis, it falls short in eradicating Staphylococcus abscess communities (SACs) and bacteria within osteocyte-lacuna canalicular network (OLCN) and repairing bone defects. To address limitations, we developed a borosilicate bioactive glass (BSG) combined with ferroferric oxide (Fe3O4) magnetic scaffold to enhance antibacterial efficacy and bone repair capabilities. We conducted comprehensive assessments of the osteoinductive, immunomodulatory, antibacterial properties, and thermal response of this scaffold, with or without an alternating magnetic field (AMF). Utilizing a well-established implant-related S. aureus tibial infection rabbit model, we evaluated its antibacterial performance in vivo. RNA transcriptome sequencing demonstrated that BSG + 5%Fe3O4 enhanced the immune response to bacteria and promoted osteogenic differentiation and mineralization of MSCs. Notably, BSG + 5%Fe3O4 upregulated gene expression of NOD-like receptor and TNF pathway in MSCs, alongside increased the expression of osteogenic factors (RUNX2, ALP and OCN) in vitro. Flow cytometry on macrophage exhibited a polarization effect towards M2, accompanied by upregulation of anti-inflammatory genes (TGF-β1 and IL-1Ra) and downregulation of pro-inflammatory genes (IL-6 and IL-1β) among macrophages. In vivo CT imaging revealed the absence of osteolysis and periosteal response in rabbits treated with BSG + 5%Fe3O4 + AMF at 42 days. Histological analysis indicated complete controls of SACs and bacteria within OLCN by day 42, along with new bone formation, signifying effective control of S. aureus osteomyelitis. Further investigations will focus on the in vivo biosafety and biological mechanism of this scaffold within infectious microenvironment.

Effect of silver nanoparticles and REP-PCR typing of Staphylococcus aureus isolated from various sources

This is the primary study at Matrouh Governorate to unveil antibiotic resistance, biofilm formation, silver nanoparticles (Ag-NPs) effect using electron microscopy, and REP-PCR analysis of Staphylococcus aureus strains isolated from COVID-19 patients, contaminated food, and Morel's diseased sheep and goats. A total of 15 S. aureus strains were isolated; five from each of the COVID-19 patients, Morel's diseased sheep and goats, and contaminated food. All strains were considered multidrug-resistant (MDR). All strains showed the presence of biofilm. Morphological changes in the cell surface of the bacterium were evidenced, and penetration with the rupture of some bacterial cells. Based on REP-PCR analysis, 4 clusters (C1-C4) with dissimilarity between clusters C1 and C2 8% and between C3 and C4 15%. Cluster I included 3 strains from contaminated food with a similarity of 97%, and Cluster II included 2 strains from contaminated food and 2 from COVID-19-infected patients with a similarity of 96% (confirming the zoonotic nature of this pathogen). Cluster III contained 4 strains isolated from Morel's diseased sheep & goats with a similarity ratio of 99% in comparison the 4th cluster contained 3 strains isolated from COVID-patients and one from Morel's diseased sheep & goats with a similarity ratio of 92%.

Excellent antibacterial and anti-inflammatory efficacy of amoxicillin by AgNPs and their conjugates synthesized using Micromeria biflora crude flavonoid extracts

Antibacterial resistance is considered to be one of the major causes for mortality in coming years. In recent years green nanotechnology played a key role in addressing this problem. Biocompatible metal nanoparticles have gained popularity owing to their excellent therapeutic effects and minimal side effects.

Method

We report the synthesis of AgNPs and their amoxicillin conjugates (Ag-amoxi) using Micromeria biflora crude flavonoid extracts. The physicochemical properties of the synthesized NPs and Ag-amoxi conjugates were systematically evaluated using scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR), and UV-visible (UV-Vis) spectroscopic techniques.

Results

The average sizes of AgNPs and Ag-amoxi conjugates were 45 and 62 nm, respectively. We have also explored the antibacterial, antioxidant, anti-inflammatory, and analgesic properties of the AgNPs and Ag-amoxi conjugates through in vivo and in vitro analysis. The Ag-amoxi conjugates showed better antibacterial potential against Streptococcus Pneumoniae (S.P), Staphylococcus aureus (S.A), Pseudomonas aeruginosa (P.A), and Methicillin resistance Staphylococcus aureus (MRSA) strain both the drug and AgNPs. Similarly, in vivo anti-inflammatory studies revealed that both Ag-amoxi (68 %) and AgNPs (64 %) had strong anti-inflammatory effects, with (***p < 0.001) significance at a dose of 10 mg kg-1 body weight as compared to standard, amoxicillin (45 %), and flavonoids extract (48 %) at a dose of 100 mg kg-1. The findings of the antinociceptive activities (writhing and hot plate tests) demonstrated that the Ag-amoxi conjugates produced fewer writhing (15 in 20 s) and a shorter latency time of 22 s as compared to vehicle-treated (tramadol) animals, amoxicillin, and P.E at much lower doses. In vitro antioxidant studies revealed that the Ag-amoxi conjugate has the potential to be used as an antioxidant with an IC50 value of 43.58, compared with AgNPs (46.34), amoxicillin (58.17), compared to the standard of ascorbic acid (34.14).

Conclusion

These results reveals that these biologically inspired AgNPs and Ag-amoxi conjugate could be used to improve antibiotic efficiency and could play a critical role in addressing the multidrug resistance problem in coming years.

Advancements in the use of nanopharmaceuticals for cancer treatment

OBJECTIVE

Advances in nanotechnology make it possible to specifically target therapies to cancer cells and neoplasms, guide the surgical resection of tumors, and optimize the effectiveness of radiological treatments. This research article provides a concise synthesis of current knowledge in the field of galenic pharmacy focused on targeted drug delivery in oncology. This research article synthesizes current knowledge in galenic pharmacy, focusing on targeted drug delivery in oncology and reviewing recent advancements in nanopharmaceuticals for cancer treatment.

DATA SOURCE

The data for this review are derived from a comprehensive analysis of the most cited scientific literature (Pubmed). Recent studies, clinical trials, and technological breakthroughs related to nanopharmaceuticals have been rigorously examined. This diverse source ensures a comprehensive representation of the latest developments in the field.

SUMMARY OF DATA

The results highlight the emergence of nanopharmaceuticals as a promising approach to cancer treatment. The most common in oncology remain liposomes, nanopolymers, and nanocrystals. From a galenic point of view, these three forms offer a wide range of improvements compared to conventional forms such as improvement in solubility as well as stability. The same observation is in the clinic where treatment response rates are significantly improved. The most advantageous form will depend on the specific characteristics of each patient and each type of cancer. The precise design of nanocarriers allows for targeted drug delivery, enhancing therapeutic efficacy while reducing side effects. Concrete examples of clinical applications are presented, illustrating the practical potential of these advancements.

CONCLUSION

In conclusion, this review provides a holistic overview of recent developments in galenic pharmacy for targeted drug delivery in oncology. The stability of nanocarriers is a crucial challenge because it conditions the effectiveness and safety of the drugs transported. Environmental and biological variations encountered in the body can compromise this stability, jeopardizing the therapeutic effectiveness and safety of treatments. Likewise, personalized approaches are essential to address interindividual variations in treatment response, as well as patients' pharmacogenomic profiles, in order to optimize therapeutic effectiveness and minimize adverse effects.

Cilostazol is a promising anti-pseudomonal virulence drug by disruption of quorum sensing

Resistance to antibiotics is a critical growing public health problem that desires urgent action to combat. To avoid the stress on bacterial growth that evokes the resistance development, anti-virulence agents can be an attractive strategy as they do not target bacterial growth. Quorum sensing (QS) systems play main roles in controlling the production of diverse virulence factors and biofilm formation in bacteria. Thus, interfering with QS systems could result in mitigation of the bacterial virulence. Cilostazol is an antiplatelet and a vasodilator FDA approved drug. This study aimed to evaluate the anti-virulence activities of cilostazol in the light of its possible interference with QS systems in Pseudomonas aeruginosa. Additionally, the study examines cilostazol's impact on the bacterium's ability to induce infection in vivo, using sub-inhibitory concentrations to minimize the risk of resistance development. In this context, the biofilm formation, the production of virulence factors and influence on the in vivo ability to induce infection were assessed in the presence of cilostazol at sub-inhibitory concentration. Furthermore, the outcome of combination with antibiotics was evaluated. Cilostazol interfered with biofilm formation in P. aeruginosa. Moreover, swarming motility, biofilm formation and production of virulence factors were significantly diminished. Histopathological investigation revealed that liver, spleen and kidney tissues damage was abolished in mice injected with cilostazol-treated bacteria. Cilostazol exhibited a synergistic outcome when used in combination with antibiotics. At the molecular level, cilostazol downregulated the QS genes and showed considerable affinity to QS receptors. In conclusion, Cilostazol could be used as adjunct therapy with antibiotics for treating Pseudomonal infections. This research highlights cilostazol's potential to combat bacterial infections by targeting virulence mechanisms, reducing the risk of antibiotic resistance, and enhancing treatment efficacy against P. aeruginosa. These findings open avenues for repurposing existing drugs, offering new, safer, and more effective infection control strategies.

Ocimum basilicum and Lagenaria siceraria Loaded Lignin Nanoparticles as Versatile Antioxidant, Immune Modulatory, Anti-Efflux, and Antimicrobial Agents for Combating Multidrug-Resistant Bacteria and Fungi

Lignin nanoparticles emerged as a promising alternative for drug delivery systems owing to their biodegradability and bioactive properties. This study investigated the antimicrobial activity of the ethanolic extract of Ocimum basilicum-loaded lignin nanoparticles (OB-LNPs) and Lagenaria siceraria seed oil-loaded lignin nanoparticles (LS-LNPs) to find a solution for antimicrobial resistance. OB-LNPs and LS-LNPs were tested for their antimicrobial potential against Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella enterica, Trichophyton mentagrophytes, Trichophyton rubrum, and Microsporum canis. OB-LNPs and LS-LNPs were further tested for their anti-efflux activity against ciprofloxacin-resistant Salmonella enterica strains and for treating Salmonella infection in a rat model. We also investigated the antifungal efficacy of OB-LNPs and LS-LNPs for treating T. rubrum infection in a guinea pig model. Both OB-LNPs and LS-LNPs showed strong antimicrobial potential against S. Typhimurium and T. rubrum infections. LS-LNPs showed antibacterial activity against Salmonella enterica species with a MIC range of 0.5-4 µg/mL and antifungal activity against T. rubrum with a MIC range of 0.125-1 µg/mL. OB-LNPs showed antibacterial activity against Salmonella enterica species with a MIC range of 0.5-2 µg/mL and antifungal activity against T. rubrum with a MIC range of 0.25-2 µg/mL. OB-LNPs and LS-LNPs downregulated the expression of ramA and acrB efflux pump genes (fold change values ranged from 0.2989 to 0.5434; 0.4601 to 0.4730 for ramA and 0.3842-0.6199; 0.5035-0.8351 for acrB). Oral administration of OB-LNPs and LS-LNPs in combination with ciprofloxacin had a significant effect on all blood parameters, as well as on liver and kidney function parameters. Oxidative stress mediators, total antioxidant capacity, and malondialdehyde were abolished by oral administration of OB-LNPs and LS-LNPs (0.5 mL/rat once daily for 5 days). Interferon-γ and tumor necrosis factor-α were also reduced in comparison with the positive control group and the ciprofloxacin-treated group. Histopathological examination of the liver and intestine of OB-LNPs and LS-LNPs-treated rats revealed an elevation in Salmonella clearance. Treatment of T. rubrum-infected guinea pigs with OB-LNPs and LS-LNPs topically in combination with itraconazole resulted in a reduction in lesion scores, microscopy, and culture results. In conclusion, OB-LNPs and LS-LNPs possess immunomodulatory and antioxidant potential and can be used as naturally derived nanoparticles for drug delivery and treatment of Salmonellosis and dermatophytosis infections.

Unveiling the mechanism of essential oil action against skin pathogens: from ancient wisdom to modern science

Essential oils are among the most well-known phyto-compounds, and since ancient times, they have been utilized in medicine. Over 100 essential oils have been identified and utilized as therapies for various skin infections and related ailments. While numerous commercial medicines are available in different dosage forms to treat skin diseases, the persisting issues include their side effects, toxicity, and low efficacy. As a result, researchers are seeking novel classes of compounds as substitutes for synthetic drugs, aiming for minimal side effects, no toxicity, and high efficacy. Essential oils have shown promising antimicrobial activity against skin-associated pathogens. This review presents essential knowledge and scientific information regarding essential oil's antimicrobial capabilities against microorganisms that cause skin infections. Essential oils mechanisms against different pathogens have also been explored. Many essential oils exhibit promising activity against various microbes, which has been qualitatively assessed using the agar disc diffusion experiment, followed by determining the minimum inhibitory concentration for quantitative evaluation. It has been observed that Staphylococcus aureus and Candida albicans have been extensively researched in the context of skin-related infections and their antimicrobial activity, including established modes of action. In contrast, other skin pathogens such as Staphylococcus epidermidis, Streptococcus pyogens, Propionibacterium acnes, and Malassezia furfur have received less attention or neglected. This review report provides an updated understanding of the mechanisms of action of various essential oils with antimicrobial properties. This review explores the anti-infectious activity and mode of action of essential against distinct skin pathogens. Such knowledge can be valuable in treating skin infections and related ailments.

Evaluating Molecular Mechanism of Viral Inhibition of Aerosolized Smart Nano-Enabled Antiviral Therapeutic (SNAT) on SARS-CoV-2-Infected Hamsters

Smart Nano-enabled Antiviral Therapeutic (SNAT) is a promising nanodrug that previously demonstrated efficacy in preclinical studies to alleviate SARS-CoV-2 pathology in hamsters. SNAT comprises taxoid (Tx)-decorated amino (NH2)-functionalized near-atomic size positively charged silver nanoparticles (Tx-[NH2-AgNPs]). Herein, we aimed to elucidate the molecular mechanism of the viral inhibition and safety of aerosolized SNAT treatment in SARS-CoV-2-infected golden Syrian hamsters. High-resolution transmission electron microscopy (HR-TEM) coupled with energy dispersive spectroscopy (EDS) and ELISAs showed SNAT binds directly to the SARS-CoV-2 virus by interacting with intact spike (S) protein, specifically to S2 subunit. SNAT (≥1 µg/mL) treatment significantly lowered SARS-CoV-2 infections of Calu-3 cells. Extraction-free whole transcriptome assay was used to detect changes in circulatory micronome in hamsters treated intranasally with SNAT (two doses of 10 µg/mL of 2 mL each administered 24 h apart). Uninfected hamsters treated with SNAT had altered circulatory concentrations of 18 microRNAs (8 miRNAs upregulated, 10 downregulated) on day 3 post-treatment compared to uninfected controls. SNAT-induced downregulation of miR-141-3p and miR-200b-3p may reduce viral replication and inflammation by targeting Ythdf2 and Slit2, respectively. Further, SNAT treatment significantly lowered IL-6 expression in infected hamster lungs compared to untreated infected hamsters. Taken together, we demonstrate that SNAT binds directly to SARS-CoV-2 via the S protein to prevent viral entry and propose a model by which SNAT alters the cellular miRNA-directed milieu to promote antiviral cellular processes and neutralize infection. Our results provide insights into the use of low-dose intranasally delivered SNAT in treating SARS-CoV-2 infections in a hamster model.

Use of nanotechnology-based nanomaterial as a substitute for antibiotics in monogastric animals

Nanotechnology has emerged as a promising solution for tackling antibiotic resistance in monogastric animals, providing innovative methods to enhance animal health and well-being. This review explores the novel use of nanotechnology-based nanomaterials as substitutes for antibiotics in monogastric animals. With growing global concerns about antibiotic resistance and the need for sustainable practices in animal husbandry, nanotechnology offers a compelling avenue to address these challenges. The objectives of this review are to find out the potential of nanomaterials in improving animal health while reducing reliance on conventional antibiotics. We examine various forms of nanomaterials and their roles in promoting gut health and also emphasize fresh perspectives brought by integrating nanotechnology into animal healthcare. Additionally, we delve into the mechanisms underlying the antibacterial properties of nanomaterials and their effectiveness in combating microbial resistance. By shedding light on the transformative role of nanotechnology in animal production systems. This review contributes to our understanding of how nanotechnology can provide safer and more sustainable alternatives to antibiotics.

Antimicrobial Activity of Drimanic Sesquiterpene Compounds from Drimys winteri against Multiresistant Microorganisms

In this work, a group of ten sesquiterpene drimanes, including polygodial (1), isopolygodial (2), and drimenol (3) obtained from the bark of Drimys winteri F. and seven synthetic derivatives, were tested in vitro against a unique panel of bacteria, fungi, and oomycetes with standardized procedures against bacterial strains K. pneumoniae, S. tiphy, E. avium, and E. coli. The minimum inhibitory concentrations and bactericidal activities were evaluated using standardized protocols. Polygodial (1) was the most active compound, with MBC 8 μg/mL and MIC 16 μg/mL in E. avium; MBC 16 μg/mL and MIC 32 μg/mL in K. pneumoniae; MBC 64 μg/mL and MIC 64 μg/mL in S. typhi; and MBC 8 μg/mL and MIC 16 μg/mL and MBC 32 μg/mL and MIC 64 μg/mL in E. coli, respectively. The observed high potency could be attributed to the presence of an aldehyde group at the C8-C9 position. The antifungal activity of 1 from different microbial isolates has been evaluated. The results show that polygodial affects the growth of normal isolates and against filamentous fungi and oomycetes with MFC values ranging from 8 to 64 μg/mL. Sesquiterpene drimanes isolated from this plant have shown interesting antimicrobial properties.

Green biologically synthesized metal nanoparticles: biological applications, optimizations and future prospects

In green biological synthesis, metal nanoparticles are produced by plants or microorganisms. Since it is ecologically friendly, economically viable and sustainable, this method is preferable to other traditional ones. For their continuous groundbreaking advancements and myriad physiochemical and biological benefits, nanotechnologies have influenced various aspects of scientific fields. Metal nanoparticles (MNPs) are the field anchor for their outstanding optical, electrical and chemical capabilities that outperform their regular-sized counterparts. This review discusses the most current biosynthesized metal nanoparticles synthesized by various organisms and their biological applications along with the key elements involved in MNP green synthesis. The review is displayed in a manner that will impart assertiveness, help the researchers to open questions, and highlight many points for conducting future research.

Unleashing the promise of emerging nanomaterials as a sustainable platform to mitigate antimicrobial resistance

The emergence and spread of antibiotic-resistant (AR) bacterial strains and biofilm-associated diseases have heightened concerns about exploring alternative bactericidal methods. The WHO estimates that at least 700 000 deaths yearly are attributable to antimicrobial resistance, and that number could increase to 10 million annual deaths by 2050 if appropriate measures are not taken. Therefore, the increasing threat of AR bacteria and biofilm-related infections has created an urgent demand for scientific research to identify novel antimicrobial therapies. Nanomaterials (NMs) have emerged as a promising alternative due to their unique physicochemical properties, and ongoing research holds great promise for developing effective NMs-based treatments for bacterial and viral infections. This review aims to provide an in-depth analysis of NMs based mechanisms combat bacterial infections, particularly those caused by acquired antibiotic resistance. Furthermore, this review examines NMs design features and attributes that can be optimized to enhance their efficacy as antimicrobial agents. In addition, plant-based NMs have emerged as promising alternatives to traditional antibiotics for treating multidrug-resistant bacterial infections due to their reduced toxicity compared to other NMs. The potential of plant mediated NMs for preventing AR is also discussed. Overall, this review emphasizes the importance of understanding the properties and mechanisms of NMs for the development of effective strategies against antibiotic-resistant bacteria.

Nanoformulated herbal compounds: enhanced antibacterial efficacy of camphor and thymol-loaded nanogels

Herbal components are highly useful assets for the advancement of novel antibacterial drugs. Nanotechnology holds great promise as an approach to enhance the effectiveness and develop the composition of these substances. The study developed nanogels incorporating camphor, thymol, and a combination derived from the initial nanoemulsions with particle sizes of 103, 85, and 135 nm, respectively. The viscosity of nanogels and the successful loading of compounds in them were examined by viscometery and ATR-FTIR studies. The bactericidal properties of the nanogels were examined against four bacterial strains. The nanogel containing camphor and thymol at 1250 µg/mL concentration exhibited complete growth suppression against Pseudomonas aeruginosa and Staphylococcus aureus. The thymol nanogel at 1250 µg/mL and the camphor nanogel at 2500 µg/mL exhibited complete inhibition of growth on Listeria monocytogenes and Escherichia coli, respectively. Both nanogels showed favorable effectiveness as antibacterial agents and could potentially examine a wide range of pathogens and in vivo studies.

Antibacterial Effect of Eight Essential Oils against Bacteria Implicated in Bovine Mastitis and Characterization of Primary Action Mode of Thymus capitatus Essential Oil

During the current investigation, eight essential oils (EOs) were tested for their antimicrobial activity against six species, belonging to the genus of staphylococcus, multi-resistant to antibiotics (S. epidermidis, S. cohni, S. wareneri, S. scuiri, S. chromogenes, S. pasteuri), three methicillin-resistant Staphylococcus aureus strains (MRSA) and two strains of Escherichia coli, producing extended-spectrum β-lactamase (ESBL) responsible for bovine mastitis. Our results indicated that the antimicrobial activities of eight EOs varied significantly among the types of EOs and bacterial species. Thymus capitatus and Trachyspermum ammi EOs display important antibacterial activity against all tested strains, with the inhibition zone diameters situated between 20 and 45 mm, while EOs of Artemisia absinthium, Eucalyptus globulus, Eucalyptus camaldulensis, Myrtus communis and Mentha pulegium exerted an intermediate activity. For Cymbopogon citratus, this effect depends on bacteria species. In fact, an important effect was observed against S. warneri, S. epidermidis, S. cohenii, S. pasteuri and MRSA (EC 39+) strains. In addition, the important lytic effect was observed against MRSA strains, showing that Gram-positive bacteria were more sensitive to T. capitatus EO than Gram-negative ones. Concerning the characterization of the mode action of T. capitatus, experiments of kill-time, bacteriolytic, loss of salt tolerance and loss of cytoplasmic material showed that the used EO was able to destroy cell walls and membranes followed by the loss of vital intracellular materials. In addition, it inhibits the normal synthesis of DNA, causing the bacterial death of E. coli and MRSA strains. This study shows the potential of using of EOs, particularly T. capitaus, to inhibit the growth of Gram-positive and Gram-negative bacteria multi-resistant to antibiotics causing bovine mastitis.

A Comprehensive Review on Novel Lipid-Based Nano Drug Delivery

Novel drug delivery system opens the doors towards nano/micro formulation strategies to overcome the challenges associated with the poorly soluble and permeable drugs. Lipid based nanoparticles are widely accepted that includes liposomes, niosomes and micelles which are FDA approved. Such lipid based drug delivery allows delivery for natural phytoconstituents, biopharmaceutical classification system (BCS) class II and class IV drugs are effectively delivered to improve its solubility, permeability and bioavailability. The article provides the recent advances and application of lipid based dosage form for improvement of therapeutic efficacy.

Nanotechnology's frontier in combatting infectious and inflammatory diseases: prevention and treatment

Inflammation-associated diseases encompass a range of infectious diseases and non-infectious inflammatory diseases, which continuously pose one of the most serious threats to human health, attributed to factors such as the emergence of new pathogens, increasing drug resistance, changes in living environments and lifestyles, and the aging population. Despite rapid advancements in mechanistic research and drug development for these diseases, current treatments often have limited efficacy and notable side effects, necessitating the development of more effective and targeted anti-inflammatory therapies. In recent years, the rapid development of nanotechnology has provided crucial technological support for the prevention, treatment, and detection of inflammation-associated diseases. Various types of nanoparticles (NPs) play significant roles, serving as vaccine vehicles to enhance immunogenicity and as drug carriers to improve targeting and bioavailability. NPs can also directly combat pathogens and inflammation. In addition, nanotechnology has facilitated the development of biosensors for pathogen detection and imaging techniques for inflammatory diseases. This review categorizes and characterizes different types of NPs, summarizes their applications in the prevention, treatment, and detection of infectious and inflammatory diseases. It also discusses the challenges associated with clinical translation in this field and explores the latest developments and prospects. In conclusion, nanotechnology opens up new possibilities for the comprehensive management of infectious and inflammatory diseases.

Bioactive silver nanoparticles fabricated using Lasiurus scindicus and Panicum turgidum seed extracts: anticancer and antibacterial efficiency

Applying extracts from plants is considered a safe approach in biomedicine and bio-nanotechnology. The present report is considered the first study that evaluated the seeds of Lasiurus scindicus and Panicum turgidum as biogenic agents in the synthesis of silver nanoparticles (AgNPs) which had bioactivity against cancer cells and bacteria. Assessment of NPs activity against varied cell lines (colorectal cancer HCT116 and breast cancer MDA MBA 231 and MCF 10A used as control) was performed beside the antibacterial efficiency. Different techniques (DLS, TEM, EDX and FTIR) were applied to characterize the biosynthesized AgNPs. The phytochemicals from both L. scindicus and Panicum turgidum were identified by GC-MS analysis. Spherical monodisperse NPs at average diameters of 149.6 and 100.4 nm were obtained from seed extract of L. scindicus (L-AgNPs) and P. turgidum, (P-AgNPs) respectively. A strong absorption peak at 3 keV is observed by the EDX spectrum in the tested NPs. Our study provided effective NPs in mitigating the tested cell lines and the lowest IC50 were 7.8 and 10.30 for MDA MB231 treated by L-AgNPs and P-AgNPs, respectively. Both fabricated NPs might differentially target the MDA MB231 cells compared to HCT116 and MCF10A. Ultrastructural changes and damage for the NPs-treated MDA MB231 cells were studied using TEM and LSM analysis. Antibacterial activity was also observed. About 200 compounds were identified in L. scindicus and P. turgidum by GC-MS analysis might be responsible for the NPs reduction and capping abilities. Efficient NPs against cancer cells and microbes were obtained, however large-scale screening is needed to validate our findings.

Design and synthesis of vancomycin-functionalized ZnFe2 O4 nanoparticles as an effective antibacterial agent against methicillin-resistant Staphylococcus aureus

The emergence of antibiotic-resistant bacterial infections is a principal threat to global health. Functionalization of nanomaterial with antibiotics is known as a useful method for increasing the effectiveness of existing antibiotics. In this study, vancomycin-functionalized ZnFe2 O4 nanocomposite (ZnFe2 O4 @Cell@APTES@Van) was synthesized, and its functional groups and particle size were characterized using Fourier-transform infrared spectroscopy, thermogravimetric analysis, dynamic light scattering, scanning electron microscope, and transmission electron microscopy. The antibacteria activity of the synthesized nanocomposite was evaluated using minimum inhibitory concentration and minimum bactericidal concentration against Escherichia coli, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA). Cytotoxicity assay was done by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide method. Characterization analyses of synthesized nanocomposite confirmed the binding of vancomysin on the surface of ZnFe2 O4 @Cell@APTES. Nanocomposite exhibited an aggregated semi-spherical structure with hydrodynamic radii of ∼382 nm. In vitro antibacterial activity test showed that vancomycin and vancomycin functionalized ZnFe2 O4 have no antibacterial effect against E. coli. S. aureus was sensitive to vancomycin and ZnFe2 O4 @Cell@APTES@Van NPs and ZnFe2 O4 NPs did not improve vancomycin antibacterial activity against these bacteria. MRSA is resistant to vancomycin while ZnFe2 O4 @Cell@APTES@Van NPs was efficient in inhibiting MRSA growth. In summary, this study showed that attachment of vancomycin to ZnFe2 O4 NPs was increased its antibacterial activity against MRSA.

The use of nanoparticles in the treatment of infectious diseases and cancer, dental applications and tissue regeneration: a review

The emergence of nanotechnology as a field of study can be traced back to the 1980s, at which point the means to artificially produce, control, and observe matter on a nanometer level was made viable. Recent advancements in technology have enabled us to extend our reach to the nanoscale, which has presented an unparalleled opportunity to directly target biomolecular interactions. As a result of these developments, there is a drive to arise intelligent nanostructures capable of overcoming the obstacles that have impeded the progress of conventional pharmacological methodologies. After four decades, the gradual amalgamation of bio- and nanotechnologies is initiating a revolution in the realm of disease detection, treatment, and monitoring, as well as unsolved medical predicaments. Although a significant portion of research in the field is still confined to laboratories, the initial application of nanotechnology as treatments, vaccines, pharmaceuticals, and diagnostic equipment has now obtained endorsement for commercialization and clinical practice. The current issue presents an overview of the latest progress in nanomedical strategies towards alleviating antibiotic resistance, diagnosing and treating cancer, addressing neurodegenerative disorders, and an array of applications, encompassing dentistry and tuberculosis treatment. The current investigation also scrutinizes the deployment of sophisticated smart nanostructured materials in fields of application such as regenerative medicine, as well as the management of targeted and sustained release of pharmaceuticals and therapeutic interventions. The aforementioned concept exhibits the potential for revolutionary advancements within the field of immunotherapy, as it introduces the utilization of implanted vaccine technology to consistently regulate and augment immune functions. Concurrently with the endeavor to attain the advantages of nanomedical intervention, it is essential to enhance the unceasing emphasis on nanotoxicological research and the regulation of nanomedications' safety. This initiative is crucial in achieving the advancement in medicine that currently lies within our reach.

Nano-Drug Delivery Systems Based on Natural Products

Natural products have proven to have significant curative effects and are increasingly considered as potential candidates for clinical prevention, diagnosis, and treatment. Compared with synthetic drugs, natural products not only have diverse structures but also exhibit a range of biological activities against different disease states and molecular targets, making them attractive for development in the field of medicine. Despite advancements in the use of natural products for clinical purposes, there remain obstacles that hinder their full potential. These challenges include issues such as limited solubility and stability when administered orally, as well as short durations of effectiveness. To address these concerns, nano-drug delivery systems have emerged as a promising solution to overcome the barriers faced in the clinical application of natural products. These systems offer notable advantages, such as a large specific surface area, enhanced targeting capabilities, and the ability to achieve sustained and controlled release. Extensive in vitro and in vivo studies have provided further evidence supporting the efficacy and safety of nanoparticle-based systems in delivering natural products in preclinical disease models. This review describes the limitations of natural product applications and the current status of natural products combined with nanotechnology. The latest advances in nano-drug delivery systems for delivery of natural products are considered from three aspects: connecting targeting warheads, self-assembly, and co-delivery. Finally, the challenges faced in the clinical translation of nano-drugs are discussed.

New Antimicrobial Strategies to Treat Multi-Drug Resistant Infections Caused by Gram-Negatives in Cystic Fibrosis

People with cystic fibrosis (CF) suffer from recurrent bacterial infections which induce inflammation, lung tissue damage and failure of the respiratory system. Prolonged exposure to combinatorial antibiotic therapies triggers the appearance of multi-drug resistant (MDR) bacteria. The development of alternative antimicrobial strategies may provide a way to mitigate antimicrobial resistance. Here we discuss different alternative approaches to the use of classic antibiotics: anti-virulence and anti-biofilm compounds which exert a low selective pressure; phage therapies that represent an alternative strategy with a high therapeutic potential; new methods helping antibiotics activity such as adjuvants; and antimicrobial peptides and nanoparticle formulations. Their mechanisms and in vitro and in vivo efficacy are described, in order to figure out a complete landscape of new alternative approaches to fight MDR Gram-negative CF pathogens.

Spotlight on therapeutic efficiency of green synthesis metals and their oxide nanoparticles in periodontitis

Periodontitis, one of the most prevalent dental diseases, causes the loss of bone and gum tissue that hold teeth in place. Several bacteria, commonly present in clinically healthy oral cavities, may induce and perpetuate periodontitis when their concentration rises in the gingival sulcus. Antibacterial effect against various Gram-negative and Gram-positive bacteria, including pathogenic and drug-resistant ones, has been shown for several distinct transient metal and metal oxide NPs. Therefore, NPs may be used in biomedicine to treat periodontal problems and in nanotechnology to inhibit the development of microorganisms. Instead of using harmful chemicals or energy-intensive machinery, biosynthesis of metal and metal oxide nanoparticles (NPs) has been suggested. To produce metal and metal oxide NPs, the ideal technique is "Green" synthesis because of its low toxicity and safety for human health and the environment. Gold NPs (AuNPs) appear to be less toxic to mammalian cells than other nanometals because their antibacterial activity is not dependent on reactive oxygen species (ROS). AgNPs also possess chemical stability, catalytic activity, and superior electrical and thermal conductivity, to name a few of their other advantageous characteristics. It was observed that zinc oxide (ZnO) NPs and copper (Cu) NPs exhibited discernible inhibitory effects against gram-positive and gram-negative bacterial strains, respectively. ZnO NPs demonstrated bactericidal activity against the microorganisms responsible for periodontitis. Medications containing magnetic NPs are highly effective against multidrug-resistant bacterial and fungal infections. The titanium dioxide (TiO2) NPs are implicated in elevating salivary peroxidase activity in individuals diagnosed with chronic periodontitis. Furthermore, specific metallic NPs have the potential to enhance the antimicrobial efficacy of periodontitis treatments when combined. Therefore, these NPs, as well as their oxide NPs, are only some of the metals and metal oxides that have been synthesized in environmentally friendly ways and shown to have therapeutic benefits against periodontitis.

Hyphae-specific genes: Possible molecular targets for magnetic iron oxide nanoparticles alone and combined with visible light in Candida albicans

Candida albicans readily develops resistance to fluconazole. Magnetic iron oxide nanoparticles (denoted as MION) and antimicrobial photodynamic therapy are attracting attention as therapeutic agents. This study aims to investigate the inhibitory efficacy of MION alone and combined with visible light against C. albicans and expression analysis of hyphal wall protein 1 (HWP1) and agglutinin-like sequence 1 (ALS1) genes in C. albicans. Antifungal susceptibility testing, photodynamic activity assay, reactive oxygen species (ROS) production assay and gene expression analysis were determined in C. albicans treated with MION alone and combined with visible light. MION at 1 × minimum inhibitory concentration (MIC) level (500 μg/mL) exhibited antifungal activity against C. albicans isolates. Further, 1 × MIC levels of MION alone and combined with visible light displayed remarkable fungicidal effects at 24 and 48 h after treatment. The MION combined with visible light caused the highest levels of ROS production by all C. albicans isolates. The relative RT-PCR data showed significant downregulation of HWP1 and ALS1 genes which are the key virulence genes in C. albicans. Differences in gene expression of  HWP1 and ALS1 were more significant in MION combined with visible light treatments than MION alone. Our study sheds a novel light on facile development of effective treatment of C. albicans especially fluconazole-resistant C. albicans infections. The hyphae-specific genes HWP1 and ALS1 could be probable molecular targets for MION alone and combined with visible light in C. albicans.

Cancer treatment and toxicity outlook of nanoparticles

Diversified nanosystems with tunable physicochemical attributes have emerged as potential solution to globally devastating cancer by offering novel possibilities for improving the techniques of cancer detection, imaging, therapies, diagnosis, drug delivery and treatment. Drug delivery systems based on nanoparticles (NPs) with ability of crossing different biological barriers are becoming increasingly popular. Besides, NPs are utilized in pharmaceutical sciences to mitigate the toxicity of conventional cancer therapeutics. However, significant NPs-associated toxicity, off-targeted activities, and low biocompatibility limit their utilization for cancer theranostics and can be hazardous to cancer patients up to life-threatening conditions. NPs interact with the biomolecules and disturb their regular function by aggregating inside cells and forming a protein corona, and the formulation turns ineffective in controlling cancer cell growth. The adverse interactions between NPs and biological entities can lead to life-threatening toxicities. This review focuses on the widespread use of various NPs including zinc oxide, titanium oxide, silver, and gold, which serve as efficient nano-vehicles and demonstrate notable pharmacokinetic and pharmacodynamic advantages in cancer therapy. Subsequently, the mechanism of nanotoxicity attached with these NPs, alternate solutions and their prospect to revolutionize cancer theranostics are highlighted. This review will serve as guide for future developments associated with high-performance NPs with controlled toxicity for establishing them as modern-age nanotools to manage cancer in tailored manner.

Microalga Broths Synthesize Antibacterial and Non-Cytotoxic Silver Nanoparticles Showing Synergy with Antibiotics and Bacterial ROS Induction and Can Be Reused for Successive AgNP Batches

The era of increasing bacterial antibiotic resistance requires new approaches to fight infections. With this purpose, silver-based nanomaterials are a reality in some fields and promise new developments. We report the green synthesis of silver nanoparticles (AgNPs) using culture broths from a microalga. Broths from two media, with different compositions and pHs and sampled at two growth phases, produced eight AgNP types. Nanoparticles harvested after several synthesis periods showed differences in antibacterial activity and stability. Moreover, an evaluation of the broths for several consecutive syntheses did not find relevant kinetics or activity differences until the third round. Physicochemical characteristics of the AgNPs (core and hydrodynamic sizes, Z-potential, crystallinity, and corona composition) were determined, observing differences depending on the broths used. AgNPs showed good antibacterial activity at concentrations producing no or low cytotoxicity on cultured eukaryotic cells. All the AgNPs had high levels of synergy against Escherichia coli and Staphylococcus aureus with the classic antibiotics streptomycin and kanamycin, but with ampicillin only against S. aureus and tetracycline against E. coli. Differences in the synergy levels were also dependent on the types of AgNPs. We also found that, for some AgNPs, the killing of bacteria started before the massive accumulation of ROS.

Iron Oxide Nanoparticles: Green Synthesis and Their Antimicrobial Activity

The rise of antimicrobial resistance caused by inappropriate use of these agents in various settings has become a global health threat. Nanotechnology offers the potential for the synthesis of nanoparticles (NPs) with antimicrobial activity, such as iron oxide nanoparticles (IONPs). The use of IONPs is a promising way to overcome antimicrobial resistance or pathogenicity because of their ability to interact with several biological molecules and to inhibit microbial growth. In this review, we outline the pivotal findings over the past decade concerning methods for the green synthesis of IONPs using bacteria, fungi, plants, and organic waste. Subsequently, we delve into the primary challenges encountered in green synthesis utilizing diverse organisms and organic materials. Furthermore, we compile the most common methods employed for the characterization of these IONPs. To conclude, we highlight the applications of these IONPs as promising antibacterial, antifungal, antiparasitic, and antiviral agents.

Dual nanocarrier of chlorhexidine and fluconazole: Physicochemical characterization and effects on microcosm biofilms and oral keratinocytes

OBJECTIVES

This study assembled and characterized a dual nanocarrier of chlorhexidine (CHX) and fluconazole (FLZ), and evaluated its antibiofilm and cytotoxic effects.

METHODS

CHX and FLZ were added to iron oxide nanoparticles (IONPs) previously coated by chitosan (CS) and characterized by physical-chemical analyses. Biofilms from human saliva supplemented with Candida species were grown (72 h) on glass discs and treated (24 h) with IONPs-CS carrying CHX (at 39, 78, or 156 µg/mL) and FLZ (at 156, 312, or 624 µg/mL) in three growing associations. IONPs and CS alone, and 156 µg/mL CHX + 624 µg/mL FLZ (CHX156-FLZ624) were tested as controls. Next, microbiological analyses were performed. The viability of human oral keratinocytes (NOKsi lineage) was also determined (MTT reduction assay). Data were submitted to ANOVA or Kruskal-Wallis, followed by Fisher's LSD or Tukey's tests (α=0.05).

RESULTS

Nanocarriers with spherical-like shape and diameter around 6 nm were assembled, without compromising the crystalline property and stability of IONPs. Nanocarrier at the highest concentrations was the most effective in reducing colony-forming units of Streptococcus mutans, Lactobacillus spp., Candida albicans, and Candida glabrata. The other carriers and CHX156-FLZ624 showed similar antibiofilm effects, and significantly reduced lactic acid production (p<0.001). Also, a dose-dependent cytotoxic effect against oral keratinocytes was observed for the dual nanocarrier. IONPs-CS-CHX-FLZ and CHX-FLZ significantly reduced keratinocyte viability at CHX and FLZ concentrations ≥7.8 and 31.25 µg/mL, respectively (p<0.05).

CONCLUSION

The nanotherapy developed outperformed the effect of the combination CHX-FLZ on microcosm biofilms, without increasing the cytotoxic effect of the antimicrobials administered.

CLINICAL SIGNIFICANCE

The dual nanocarrier is a promising topically-applied therapy for the management of oral candidiasis considering that its higher antibiofilm effects allow the use of lower concentrations of antimicrobials than those found in commercial products.

Fabrication of versatile poly(xylitol sebacate)-co-poly(ethylene glycol) hydrogels through multifunctional crosslinkers and dynamic bonds for wound healing

Poly(polyol sebacate) (PPS) polymer family has been recognized as promising biomaterials for biomedical applications with their characteristics of easy production, elasticity, biodegradation, and cytocompatibility. Poly(xylitol sebacate)-co-poly(ethylene glycol) (PXS-co-PEG) has been developed to fabricate PPS-based hydrogels; however, current PXS-co-PEG hydrogels presented limited properties and functions due to the limitations of the crosslinkers and crosslinking chemistry used in the hydrogel formation. Here, we fabricate a new type of PXS-co-PEG hydrogels through the use of multifunctional crosslinkers as well as dynamic bonds. In our design, polyethyleneimine-polydopamine (PEI-PDA) macromers are utilized to crosslink aldehyde-functionalized PXS-co-PEG (APP) through imine bonds and hydrogen bonds. PEI-PDA/APP hydrogels present multiple functional properties (e.g., fluorescent, elastomeric, biodegradable, self-healing, bioadhesive, antioxidant, and antibacterial behaviors). These properties of PEI-PDA/APP hydrogels can be fine-tuned by changing the PDA grafting degrees in the PEI-PDA crosslinkers. Most importantly, PEI-PDA/APP hydrogels are considered promising wound dressings to promote tissue remodeling and prevent bacterial infection in vivo. Taken together, PEI-PDA/APP hydrogels have been demonstrated as versatile biomaterials to provide multiple tailorable properties and desirable functions to expand the utility of PPS-based hydrogels for advanced biomedical applications. STATEMENT OF SIGNIFICANCE: Various strategies have been developed to fabricate poly(polyol sebacate) (PPS)-based hydrogels. However, current PPS-based hydrogels present limited properties and functions due to the limitations of the crosslinkers and crosslinking chemistry used in the hydrogel formation. This work describes that co-engineering crosslinkers and interfacial crosslinking is a promising approach to synthesizing a new type of poly(xylitol sebacate)-co-poly(ethylene glycol) (PXS-co-PEG) hydrogels as multifunctional hydrogels to expand the utility of PPS-based hydrogels for advanced biomedical applications. The fabricated hydrogels present multiple functional properties (e.g., fluorescent, biodegradable, elastomeric, self-healing, bioadhesive, antioxidative, and antibacterial), and these properties can be fine-tuned by the defined crosslinkers. The fabricated hydrogels are also used as promising wound dressing biomaterials to exhibit promoted tissue remodeling and prevent bacterial infection in vivo.

Controlling biofilm and virulence properties of Gram-positive bacteria by targeting wall teichoic acid and lipoteichoic acid

Wall teichoic acid (WTA) and lipoteichoic acid (LTA) are structural components of Gram-positive bacteria's peptidoglycan and cell membrane, which are mostly anionic glycopolymers. WTA confers numerous physiological, virulence, and pathogenic features to bacterial pathogens. It controls cell shape, cell division, and the localisation of autolytic enzymes and ion homeostasis. In the context of virulence and pathogenicity, it aids bacterial cell attachment and colonisation and protects against the host defence system and antibiotics. Having such a broad function in pathogenic bacteria's lifecycle, WTA/LTA become one of the potential targets for antibacterial agents to reduce bacterial infection in the host. The number of reports for targeting the WTA/LTA pathway has risen, mostly by focusing on three distinct targets: antivirulence targets, β-lactam potentiator targets, and essential targets. The current review looked at the role of WTA/LTA in biofilm development and virulence in a range of Gram-positive pathogenic bacteria. Furthermore, alternate strategies, such as the application of natural and synthetic compounds that target the WTA/LTA pathway, have been thoroughly discussed. Moreover, the application of nanomaterials and a combination of drugs have also been discussed as a viable method for targeting the WTA/LTA in numerous Gram-positive bacteria. In addition, a future perspective for controlling bacterial infection by targeting the WTA/LTA is proposed.

Antibacterial efficiency over time and barrier properties of wood coatings with colloidal silver

This work aims to represent a standard application for understanding the extent of the antibacterial efficacy of coatings with different amounts of colloidal silver on wooden surfaces over time. The key variable that was intended to be evaluated in this study was the "time efficiency," with concerns about the possible efficacy in the durability of the surfaces. By highlighting the "expiry date" of the agents, as in the case with other products, the study aimed to confirm the validity of the simulation tests conducted in the laboratory with degradation tests. Furthermore, the role of the silver amount on the barrier performance of the coatings was assessed by liquid resistance, water uptake, and perspiration tests, evaluating the aesthetic durability of the coatings by means of colorimetric analyses. Ultimately, this work demonstrates that these coatings may represent alternatives in terms of prolonged antimicrobial activity when compared with the biocide agents currently in use, capable to offer good resistance to detergent solutions and to water. Nevertheless, due to silver's susceptibility to extended exposure to acidic solutions, the findings of the research discourage the utilization of colloidal silver in wood paints intended for use in public settings. KEY POINTS: • Colloidal silver does not alter the deposition process and does not introduce defects in the wood paint. • Coatings containing silver show high antimicrobial activity over time, against both E.coli and S.aureus. • The silver-based filler resists contact with detergents and aqueous solutions but suffers oxidation processes in acidic environments.

Dendritic systems for bacterial outer membrane disruption as a method of overcoming bacterial multidrug resistance

The alarming rise of multi-drug resistant microorganisms has increased the need for new approaches through the development of innovative agents that are capable of attaching to the outer layers of bacteria and causing permanent damage by penetrating the bacterial outer membrane. The permeability (disruption) of the outer membrane of Gram-negative bacteria is now considered to be one of the main ways to overcome multidrug resistance in bacteria. Natural and synthetic permeabilizers such as AMPs and dendritic systems seem promising. However, due to their advantages in terms of biocompatibility, antimicrobial capacity, and wide possibilities for modification and synthesis, highly branched polymers and dendritic systems have gained much more interest in recent years. Various forms of arrangement, and structure of the skeleton, give dendritic systems versatile applications, especially the possibility of attaching other ligands to their surface. This review will focus on the mechanisms used by different types of dendritic polymers, and their complexes with macromolecules to enhance their antimicrobial effect, and to permeabilize the bacterial outer membrane. In addition, future challenges and potential prospects are illustrated in the hope of accelerating the advancement of nanomedicine in the fight against resistant pathogens.

Silver nanoparticle technology in orthopaedic infections

The irrational and prolonged use of antibiotics in orthopaedic infections poses a major threat to the development of antimicrobial resistance. To combat antimicrobial resistance, researchers have implemented various novel and innovative modalities to curb infections. Nanotechnology involves doping ions/metals onto the scaffolds to reach the target site to eradicate the infective foci. In this connotation, we reviewed silver nanoparticle technology in terms of mechanism of action, clinical applications, toxicity, and regulatory guidelines to treat orthopaedic infections.

How Combined Macrolide Nanomaterials are Effective Against Resistant Pathogens? A Comprehensive Review of the Literature

Macrolide drugs are among the broad-spectrum antibiotics that are considered as "miracle drugs" against infectious diseases that lead to higher morbidity and mortality rates. Nevertheless, their effectiveness is currently at risk owing to the presence of devastating, antimicrobial-resistant microbes. In view of this challenge, nanotechnology-driven innovations are currently being anticipated for promising approaches to overcome antimicrobial resistance. Nowadays, various nanostructures are being developed for the delivery of antimicrobials to counter drug-resistant microbial strains through different mechanisms. Metallic nanoparticle-based delivery of macrolides, particularly using silver and gold nanoparticles (AgNPs & AuNPs), demonstrated a promising outcome with worthy stability, oxidation resistance, and biocompatibility. Similarly, macrolide-conjugated magnetic NPs resulted in an augmented antimicrobial activity and reduced bacterial cell viability against resistant microbes. Liposomal delivery of macrolides also showed favorable synergistic antimicrobial activities in vitro against resistant strains. Loading macrolide drugs into various polymeric nanomaterials resulted in an enhanced zone of inhibition. Intercalated nanomaterials also conveyed an outstanding macrolide delivery characteristic with efficient targeting and controlled drug release against infectious microbes. This review abridges several nano-based delivery approaches for macrolide drugs along with their recent achievements, challenges, and future perspectives.

Antimicrobial Wound Dressings: A Concise Review for Clinicians

Wound management represents a substantial clinical challenge due to the growing incidence of chronic skin wounds resulting from venous insufficiency, diabetes, and obesity, along with acute injuries and surgical wounds. The risk of infection, a key impediment to healing and a driver of increased morbidity and mortality, is a primary concern in wound care. Recently, antimicrobial dressings have emerged as a promising approach for bioburden control and wound healing. The selection of a suitable antimicrobial dressing depends on various parameters, including cost, wound type, local microbial burden and the location and condition of the wound. This review covers the different types of antimicrobial dressings, their modes of action, advantages, and drawbacks, thereby providing clinicians with the knowledge to optimize wound management.

Antibacterial study of carbopol-mastic gum/silver nanoparticle-based topical gels with carvacrol/neem bark extract in vitro

BACKGROUND

Resistance to antimicrobial drugs as a result of prolonged use usually results in clinical failure, especially in wound infections. Development of effective antimicrobial therapeutics for the management of infected wounds from a natural source with improved therapeutic effects is a pressing need.

OBJECTIVE

In this study, carbopol-mastic gum-based topical gels were loaded with silver nanoparticles in combination with either neem bark extract or carvacrol oil. The effect of combining silver nanoparticles with neem bark extract or the essential oil carvacrol in the prepared gel formulations was investigated on selected bacterial strains.

METHOD

The prepared gels were characterised by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and ultraviolet-visible (UV-vis) spectroscopy, followed by antimicrobial analysis against selected strains of bacteria.

RESULTS

There was no interaction between the loaded natural extract or essential oil and the polymer used for the preparation of the formulations, which was visible from the FTIR spectra of the formulations. The gels were selective and effective against selected strains of bacteria. However, the combination of the silver nanoparticles with essential oil or natural extract in some of the gel formulations rendered the formulation ineffective against some of the bacterial strains.

CONCLUSION

The gel formulations were effective against bacterial strains such as Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis which are the common causes of wound infections. Incorporation of silver nanoparticles into the topical formulations with natural extracts is usually a good approach to overcome antibiotic-resistant infections. However, the combination of antibacterial agents must be managed carefully.

Nano-based techniques: A revolutionary approach to prevent covid-19 and enhancing human awareness

In every century of history, there are many new diseases emerged, which are not even cured by many developed countries. Today, despite of scientific development, new deadly pandemic diseases are caused by microorganisms. Hygiene is considered to be one of the best methods of avoiding such communicable diseases, especially viral diseases. Illness caused by SARS-CoV-2 was termed COVID-19 by the WHO, the acronym derived from "coronavirus disease 2019. The globe is living in the worst epidemic era, with the highest infection and mortality rate owing to COVID-19 reaching 6.89% (data up to March 2023). In recent years, nano biotechnology has become a promising and visible field of nanotechnology. Interestingly, nanotechnology is being used to cure many ailments and it has revolutionized many aspects of our lives. Several COVID-19 diagnostic approaches based on nanomaterial have been developed. The various metal NPs, it is highly anticipated that could be viable and economical alternatives for treating drug resistant in many deadly pandemic diseases in near future. This review focuses on an overview of nanotechnology's increasing involvement in the diagnosis, prevention, and therapy of COVID-19, also this review provides readers with an awareness and knowledge of importance of hygiene.

Alleviating the virulence of Pseudomonas aeruginosa and Staphylococcus aureus by ascorbic acid nanoemulsion

The high incidence of persistent multidrug resistant bacterial infections is a worldwide public health burden. Alternative strategies are required to deal with such issue including the use of drugs with anti-virulence activity. The application of nanotechnology to develop advanced Nano-materials that target quorum sensing regulated virulence factors is an attractive approach. Synthesis of ascorbic acid Nano-emulsion (ASC-NEs) and assessment of its activity in vitro against the virulence factors and its protective ability against pathogenesis as well as the effect against expression of quorum sensing genes of Pseudomonas aeruginosa and Staphylococcus aureus isolates. Ascorbic acid Nano-emulsion was characterized by DLS Zetasizer Technique, Zeta potential; Transmission Electron Microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The antibacterial activity of ASC-NEs was tested by the broth microdilution method and the activity of their sub-MIC against the expression of quorum sensing controlled virulence was investigated using phenotypic experiments and RT-PCR. The protective activity of ASC-NEs against P. aeruginosa as well as S. aureus pathogenesis was tested in vivo. Phenotypically, ASC-NEs had strong virulence inhibitory activity against the tested bacteria. The RT-PCR experiment showed that it exhibited significant QS inhibitory activity. The in vivo results showed that ASC-NEs protected against staphylococcal infection, however, it failed to protect mice against Pseudomonal infection. These results suggest the promising use of nanoformulations against virulence factors in multidrug resistant P. aeruginosa and S. aureus. However, further studies are required concerning the potential toxicity, clearance and phamacokinetics of the nanoformulations.

Bio-functionalized nickel-silica nanoparticles suppress bacterial leaf blight disease in rice (Oryza sativa L.)

Introduction

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most devastative diseases that threatens rice plants worldwide. Biosynthesized nanoparticle (NP) composite compounds have attracted attention as environmentally safe materials that possess antibacterial activity that could be used in managing plant diseases.

Methods

During this study, a nanocomposite of two important elements, nickel and silicon, was biosynthesized using extraction of saffron stigmas (Crocus sativus L.). Characterization of obtained nickel-silicon dioxide (Ni-SiO2) nanocomposite was investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission/Scanning electron microscopy (TEM/SEM), and energy-dispersive spectrum (EDS). Antibacterial activities of the biosynthesized Ni-SiO2 nanocomposite against Xoo were tested by measuring bacterial growth, biofilm formation, and dead Xoo cells.

Results and discussions

The bacterial growth (OD600) and biofilm formation (OD570) of Xoo treated with distilled water (control) was found to be 1.21 and 1.11, respectively. Treatment with Ni-SiO2 NPs composite, respectively, reduced the growth and biofilm formation by 89.07% and 80.40% at 200 μg/ml. The impact of obtained Ni-SiO2 nanocomposite at a concentration of 200 μg/ml was assayed on infected rice plants. Treatment of rice seedlings with Ni-SiO2 NPs composite only had a plant height of 64.8 cm while seedlings treated with distilled water reached a height of 45.20 cm. Notably, Xoo-infected seedlings treated with Ni-SiO2 NPs composite had a plant height of 57.10 cm. Furthermore, Ni-SiO2 NPs composite sprayed on inoculated seedlings had a decrease in disease leaf area from 43.83% in non-treated infected seedlings to 13.06% in treated seedlings. The FTIR spectra of biosynthesized Ni-SiO2 nanocomposite using saffron stigma extract showed different bands at 3,406, 1,643, 1,103, 600, and 470 cm-1. No impurities were found in the synthesized composite. Spherically shaped NPs were observed by using TEM and SEM. EDS revealed that Ni-SiO2 nanoparticles (NPs) have 13.26% Ni, 29.62% Si, and 57.11% O. Xoo treated with 200 µg/ml of Ni-SiO2 NPs composite drastically increased the apoptosis of bacterial cells to 99.61% in comparison with 2.23% recorded for the control.

Conclusions

The application of Ni-SiO2 NPs significantly improved the vitality of rice plants and reduced the severity of BLB.

Nanobiotics and the One Health Approach: Boosting the Fight against Antimicrobial Resistance at the Nanoscale

Antimicrobial resistance (AMR) is a growing public health concern worldwide, and it poses a significant threat to human, animal, and environmental health. The overuse and misuse of antibiotics have contributed significantly and others factors including gene mutation, bacteria living in biofilms, and enzymatic degradation/hydrolyses help in the emergence and spread of AMR, which may lead to significant economic consequences such as reduced productivity and increased health care costs. Nanotechnology offers a promising platform for addressing this challenge. Nanoparticles have unique properties that make them highly effective in combating bacterial infections by inhibiting the growth and survival of multi-drug-resistant bacteria in three areas of health: human, animal, and environmental. To conduct an economic evaluation of surveillance in this context, it is crucial to obtain an understanding of the connections to be addressed by several nations by implementing national action policies based on the One Health strategy. This review provides an overview of the progress made thus far and presents potential future directions to optimize the impact of nanobiotics on AMR.

Copper oxide nanoparticles: In vitro and in vivo toxicity, mechanisms of action and factors influencing their toxicology

Copper oxide nanoparticles (CuO NPs) have received increasing interest due to their distinctive properties, including small particle size, high surface area, and reactivity. Due to these properties, their applications have been expanded rapidly in various areas such as biomedical properties, industrial catalysts, gas sensors, electronic materials, and environmental remediation. However, because of these widespread uses, there is now an increased risk of human exposure, which could lead to short- and long-term toxicity. This review addresses the underlying toxicity mechanisms of CuO NPs in cells which include reactive oxygen species generation, leaching of Cu ion, coordination effects, non-homeostasis effect, autophagy, and inflammation. In addition, different key factors responsible for toxicity, characterization, surface modification, dissolution, NPs dose, exposure pathways and environment are discussed to understand the toxicological impact of CuO NPs. In vitro and in vivo studies have shown that CuO NPs cause oxidative stress, cytotoxicity, genotoxicity, immunotoxicity, neurotoxicity, and inflammation in bacterial, algal, fish, rodents, and human cell lines. Therefore, to make CuO NPs a more suitable candidate for various applications, it is essential to address their potential toxic effects, and hence, more studies should be done on the long-term and chronic impacts of CuO NPs at different concentrations to assure the safe usage of CuO NPs.

Using SMART Magnetic Fluids and Gels for Prevention and Destruction of Bacterial Biofilms

Biofouling is a major problem in all natural and artificial settings where solid surfaces meet liquids in the presence of living microorganisms. Microbes attach to the surface and form a multidimensional slime that protects them from unfavorable environments. These structures, known as biofilms, are detrimental and very hard to remove. Here, we used SMART magnetic fluids [ferrofluids (FFs), magnetorheological fluids (MRFs), and ferrogels (FGs) containing iron oxide nano/microparticles] and magnetic fields to remove bacterial biofilms from culture tubes, glass slides, multiwell plates, flow cells, and catheters. We compared the ability of different SMART fluids to remove biofilms and found that commercially available, as well as homemade, FFs, MRFs, and FGs can successfully remove biofilm more efficiently than traditional mechanical methods, especially from textured surfaces. In tested conditions, SMARTFs reduced bacterial biofilms by five orders of magnitude. The ability to remove biofilm increased with the amount of magnetic particles; therefore, MRFs, FG, and homemade FFs with high amounts of iron oxide were the most efficient. We showed also that SMART fluid deposition can protect a surface from bacterial attachment and biofilm formation. Possible applications of these technologies are discussed.

Prospect of nanomaterials as antimicrobial and antiviral regimen

In recent years studies of nanomaterials have been explored in the field of microbiology due to the increasing evidence of antibiotic resistance. Nanomaterials could be inorganic or organic, and they may be synthesized from natural products from plant or animal origin. The therapeutic applications of nano-materials are wide, from diagnosis of disease to targeted delivery of drugs. Broad-spectrum antiviral and antimicrobial activities of nanoparticles are also well evident. The ratio of nanoparticles surface area to their volume is high and that allows them to be an advantageous vehicle of drugs in many respects. Effective uses of various materials for the synthesis of nanoparticles impart much specificity in them to meet the requirements of specific therapeutic strategies. The potential therapeutic use of nanoparticles and their mechanisms of action against infections from bacteria, fungi and viruses were the focus of this review. Further, their potential advantages, drawbacks, limitations and side effects are also included here. Researchers are characterizing the exposure pathways of nano-medicines that may cause serious toxicity to the subjects or the environment. Indeed, societal ethical issues in using nano-medicines pose a serious question to scientists beyond anything.

The role of bismuth nanoparticles in the inhibition of bacterial infection

Bismuth (Bi) combinations have been utilized for the treatment of bacterial infections. In addition, these metal compounds are most frequently utilized for treating gastrointestinal diseases. Usually, Bi is found as bismuthinite (Bi sulfide), bismite (Bi oxide), and bismuthite (Bi carbonate). Newly, Bi nanoparticles (BiNP) were produced for CT imaging or photothermal treatment and nanocarriers for medicine transfer. Further benefits, such as increased biocompatibility and specific surface area, are also seen in regular-size BiNPs. Low toxicity and ecologically favorable attributes have generated interest in BiNPs for biomedical approaches. Moreover, BiNPs offer an option for treating multidrug-resistant (MDR) bacteria because they communicate directly with the bacterial cell wall, induce adaptive and inherent immune reactions, generate reactive oxygen compounds, limit biofilm production, and stimulate intracellular impacts. In addition, BiNPs in amalgamation with X-ray therapy as well as have the capability to treat MDR bacteria. BiNPs as photothermal agents can realize the actual antibacterial through continuous efforts of investigators in the near future. In this article, we summarized the properties of BiNPs, and different preparation methods, also reviewed the latest advances in the BiNPs' performance and their therapeutic effects on various bacterial infections, such as Helicobacter pylori, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli.

Silver nanoparticles affect wheat (Triticum aestivum L.) germination, seedling blight and yield

The aim of the study was to evaluate the effect of two types of negatively charged quasi-spherical silver nanoparticles (AgNPs) at concentrations of 10, 20 and 30mgL-1 and silver ions at a concentration of 30mgL-1 on the growth, selected physiological aspects and yielding of wheat (Triticum aestivum L.) cv. Tybalt, and on plant resistance to seedling blight. Seed germination, α-amylase activity in seeds, morphology and infestation of seedlings by pathogens were assessed in a hydroponic treatment. Growth rate, PSII efficiency, heading and yield of the same plants were then analysed in pot culture. Results showed that the AgNPs and silver ions had a negative effect on roots, but reduced seedling blight and improved leaf area compared to the control. In addition, the AgNPs reduced with sodium borohydride in the presence of trisodium citrate at concentrations of 10 and 20mgL-1 stimulated germination, α-amylase activity and shoot length, which was not observed in the case of silver ions and the AgNPs reduced with sodium hypophosphite in the presence of sodium hexametaphosphate. In a pot experiment, the AgNPs improved plant growth, PSII efficiency, accelerated heading and increased yield-related parameters compared with the control. Results revealed the interaction strength in the following order: TCSB-AgNPs>SHSH-AgNPs>silver ions. TCSB-AgNPs in the lowest concentration had the most favourable effect, indicating their great potential for use in improving wheat cultivation.

Antimicrobial and Antibiofilm Properties of Latvian Honey against Causative Agents of Wound Infections

Honey is widely used in traditional medicine and modern wound healing biomaterial research as a broad-spectrum antimicrobial, anti-inflammatory and antioxidant agent. The study's objectives were to evaluate the antibacterial activity and polyphenolic profiles of 40 monofloral honey samples collected from beekeepers in the territory of Latvia. The antimicrobial and antifungal activity of Latvian honey samples were compared with commercial Manuka honey and the honey analogue sugar solutions-carbohydrate mixture and tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, clinical isolates Extended-Spectrum Beta-Lactamases produced Escherichia coli, Methicillin-resistant Staphylococcus aureus and Candida albicans. Antimicrobial activity was evaluated with the well-diffusion method (80% honey solution w/v) and microdilution method. The honey samples with the highest antimicrobial potential were tested to prevent biofilm development and activity against a preformed biofilm. The principal component analysis of the antimicrobial properties of honey samples vs. polyphenolic profile was performed. Eleven honey samples exhibited antibacterial activity to all investigated bacteria. The antibacterial effect of the samples was most significant on the Gram-positive bacteria compared to the studied Gram-negative bacteria. Latvian honey presents promising potential for use in wound healing biomaterials, opening the possibility of achieving long-term antibacterial effects.

Combined Catalysis: A Powerful Strategy for Engineering Multifunctional Sustainable Lignin-Based Materials

The production and engineering of sustainable materials through green chemistry will have a major role in our mission of transitioning to a more sustainable society. Here, combined catalysis, which is the integration of two or more catalytic cycles or activation modes, provides innovative chemical reactions and material properties efficiently, whereas the single catalytic cycle or activation mode alone fails in promoting a successful reaction. Polyphenolic lignin with its distinctive structural functions acts as an important template to create materials with versatile properties, such as being tough, antimicrobial, self-healing, adhesive, and environmentally adaptable. Sustainable lignin-based materials are generated by merging the catalytic cycle of the quinone-catechol redox reaction with free radical polymerization or oxidative decarboxylation reaction, which explores a wide range of metallic nanoparticles and metal ions as the catalysts. In this review, we present the recent work on engineering lignin-based multifunctional materials devised through combined catalysis. Despite the fruitful employment of this concept to material design and the fact that engineering has provided multifaceted materials able to solve a broad spectrum of challenges, we envision further exploration and expansion of this important concept in material science beyond the catalytic processes mentioned above. This could be accomplished by taking inspiration from organic synthesis where this concept has been successfully developed and implemented.

Wound Dressing Modifications for Accelerated Healing of Infected Wounds

Infections that occur during wound healing involve the most frequent complications in the field of wound care which not only inhibit the whole process but also lead to non-healing wound formation. The diversity of the skin microbiota and the wound microenvironment can favor the occurrence of skin infections, contributing to an increased level of morbidity and even mortality. As a consequence, immediate effective treatment is required to prevent such pathological conditions. Antimicrobial agents loaded into wound dressings have turned out to be a great option to reduce wound colonization and improve the healing process. In this review paper, the influence of bacterial infections on the wound-healing phases and promising modifications of dressing materials for accelerated healing of infected wounds are discussed. The review paper mainly focuses on the novel findings on the use of antibiotics, nanoparticles, cationic organic agents, and plant-derived natural compounds (essential oils and their components, polyphenols, and curcumin) to develop antimicrobial wound dressings. The review article was prepared on the basis of scientific contributions retrieved from the PubMed database (supported with Google Scholar searching) over the last 5 years.