Advances in Hydrogels for Periodontitis Treatment

Periodontitis is a common condition characterized by a bacterial infection and the disruption of the body's immune-inflammatory response, which causes damage to the teeth and supporting tissues and eventually results in tooth loss. Current therapy involves the systemic and local administration of antibiotics. However, the existing treatments cannot exert effective, sustained release and maintain an effective therapeutic concentration of the drug at the lesion site. Hydrogels are used to treat periodontitis due to their low cytotoxicity, exceptional water retention capability, and controlled drug release profile. Hydrogels can imitate the extracellular matrix of periodontal cells while offering suitable sites to load antibiotics. This article reviews the utilization of hydrogels for periodontitis therapy based on the pathogenesis and clinical manifestations of the disease. Additionally, the latest therapeutic strategies for smart hydrogels and the main techniques for hydrogel preparation have been discussed. The information will aid in designing and preparing future hydrogels for periodontitis treatment.

UV-Triggered Drug Release from Mesoporous Titanium Nanoparticles Loaded with Berberine Hydrochloride: Enhanced Antibacterial Activity

Mesoporous titanium nanoparticles (MTN) have always been a concern and are considered to have great potential for overcoming antibiotic-resistant bacteria. In our study, MTN modified with functionalized UV-responsive ethylene imine polymer (PEI) was synthesized. The characterization of all products was performed by different analyses, including SEM, TEM, FT-IR, TGA, XRD, XPS, and N2 adsorption-desorption isotherms. The typical antibacterial drug berberine hydrochloride (BH) was encapsulated in MTN-PEI. The process exhibited a high drug loading capacity (22.71 ± 1.12%) and encapsulation rate (46.56 ± 0.52%) due to its high specific surface area of 238.43 m2/g. Moreover, UV-controlled drug release was achieved by utilizing the photocatalytic performance of MTN. The antibacterial effect of BH@MTN-PEI was investigated, which showed that it could be controlled to release BH and achieve a corresponding antibacterial effect by UV illumination for different lengths of time, with bacterial lethality reaching 37.76% after only 8 min of irradiation. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the nanoparticles have also been studied. The MIC of BH@MTN-PEI was confirmed as 1 mg/mL against Escherichia coli (E. coli), at which the growth of bacteria was completely inhibited during 24 h and the concentration of 5 mg/mL for BH@MTN-PEI was regarded as MBC against E. coli. Although this proof-of-concept study is far from a real-life application, it provides a possible route to the discovery and application of antimicrobial drugs.

Effects of Maturation on Antibacterial Properties of Vietnamese Mango (Mangifera indica) Leaves

This study, for the first time, has investigated the relationships between alterations of mangiferin contents in mango leaves at different maturity stages and their antibacterial properties. Leaves were classified into six different maturity stages based on their color: (1) young dark reddish brown, (2) young yellow, (3) young light green, (4) mature green, (5) old dark green, and (6) old yellow leaves. Ethanol extracts were then examined against Gram-positive and Gram-negative bacteria, applying broth dilution and agar well diffusion methods. In addition, we also measured the mangiferin contents in leaves at different stages for the purpose of evaluating how the changes in this phytochemistry value affects their activities against bacteria. The results showed that extracts from leaves at young ages had better antibacterial properties than those from old leaves, as evidenced by the lower minimum inhibitory concentrations and larger inhibitory zones. In addition, we also found that the contents of mangiferin were significantly decreased followed the maturation process. These results suggest that mango leaves at young stages, especially dark reddish brown and young yellow leaves, are preferable for application in bacterial infections and other therapies related to mangiferin's constituents.

Confining the Growth of AgNPs onto Epigallocatechin Gallate-Decorated Zein Nanoparticles for Constructing Potent Protein-Based Antibacterial Nanocomposites

Sliver nanoparticles (AgNPs) have attracted tremendous interest as an alternative to commercially available antibiotics due to their low microbial resistance and broad-spectrum antimicrobial activity. However, AgNPs are highly reactive and unstable and are susceptible to fast oxidation. Synthesizing stable and efficient AgNPs using green chemistry principles remains a major challenge. To address this issue, we establish a facile route to form AgNP-doped zein nanoparticle core-satellite superstructures with ultralow minimum bactericidal concentration (MBC). In brief, polyphenol surface-functionalization of zein nanoparticles was performed, and the epigallocatechin gallate (EGCG) layer on zein nanoparticles served as a reducing-cum-stabilizing agent. We used EGCG-decorated zein nanoparticles (ZE) as a template to direct the nucleation and growth of AgNPs to develop metallized hybrid nanoparticles (ZE-Ag). The highly monodispersed core-satellite nanoparticles (∼150 nm) decorated with ∼4.9 nm AgNPs were synthesized successfully. The spatial restriction of EGCG by zein nanoparticles confined the nucleation and growth of AgNPs only on the surface of the particles, which prevented the formation of entangled clusters of polyphenols and AgNPs and concomitantly inhibited the coalescence and oxidation of AgNPs. Thus, this strategy improved the effective specific surface area of AgNPs, and as a result, ZE-Ag efficiently killed the indicator bacteria, Escherichia coli (E. coli) and Methicillin-resistant Staphylococcus aureus(MRSA) after 20 min of incubation, with MBCs of 2 and 4 μg/mL, respectively. This situation indicated that as-prepared core-satellite nanoparticles possessed potent short-term sterilization capability. Moreover, the simulated wound infection model also confirmed the promising application of ZE-Ag as an efficient antimicrobial composite. This work provides new insights into the synthesis and emerging application of AgNPs in food preservation, packaging, biomedicine, and catalysis.

Silver Nanoparticles-Chitosan Nanocomposites: A Comparative Study Regarding Different Chemical Syntheses Procedures and Their Antibacterial Effect

Nanocomposites based on silver nanoparticles and chitosan present important advantages for medical applications, showing over time their role in antibacterial evaluation. This work presents the comparative study of two chemical synthesis procedures of nanocomposites, based on trisodium citrate dihydrate and sodium hydroxide, using various chitosan concentrations for a complex investigation. The nanocomposites were characterized by AFM and DLS regarding their dimensions, while FT-IR and UV-VIS spectrometry were used for the optical properties and to reveal the binding of silver nanoparticles with chitosan. Their antibacterial effect was determined using a disk diffusion method on two bacteria strains, E. coli and S. aureus. The results indicate that, when using both methods, the nanocomposites obtained were below 100 nm, yet the antibacterial effect proved to be stronger for the nanocomposites obtained using sodium hydroxide. Furthermore, the antibacterial effect can be related to the nanocomposites' sizes, since the smallest dimension nanocomposites exhibited the best bacterial growth inhibition on both bacteria strains we tested and for both types of silver nanocomposites.

Comparative evaluation of antioxidant activity, total phenolic content, anti-inflammatory, and antibacterial potential of Euphorbia-derived functional products

This study assessed the medicinal properties of Euphorbia resinifera O. Berg (E. resinifera) and Euphorbia officinarum subsp echinus (Hook.f. and Coss.) Vindt (Euphorbia echinus, known for their pharmaceutical benefits. Extracts from their flowers, stems, propolis, and honey were examined for phenolic content, antioxidant, anti-inflammatory, and antibacterial activities. Total phenolic content (TPC), total flavonoid content (TFC), and total condensed tannin (TCC) were determined using specific methods. Antioxidant potential was assessed through various tests including DPPH, FRAP, ABTS, and Total antioxidant capacity. Anti-inflammatory effects were evaluated using phenol-induced ear edema in rats, while antibacterial activity was measured against Gram-positive (Staphylococcus aureus ATCC 6538) and Gram-negative (E. coli ATCC 10536) bacteria. Among the extracts, the aqueous propolis extract of E. resinifera demonstrated exceptional antioxidant capabilities, with low IC50 values for DPPH (0.07 ± 0.00 mg/mL) and ABTS (0.13 ± 0.00 mg/mL), as well as high TAC (176.72 ± 0.18 mg AA/mg extract) and FRAP (86.45 ± 1.45 mg AA/mg extract) values. Furthermore, the anti-inflammatory effect of E. resinifera propolis extracts surpassed that of indomethacin, yielding edema percentages of 3.92% and 11.33% for the aqueous and ethanolic extracts, respectively. Microbiological results indicated that the aqueous extract of E. resinifera flower exhibited the most potent inhibitory action against S. aureus, with an inhibition zone diameter (IZD) of 21.0 ± 0.00 mm and a minimum inhibitory concentration (MIC) of 3.125 mg/mL. Additionally, only E. resinifera honey displayed the ability to inhibit E. coli growth, with an inhibition zone diameter of 09.30 ± 0.03 mm and a MIC of 0.0433 mg/mL.

Activity of extracts and terpenoids from Tontelea micrantha (Mart. ex Schult.) A.C.Sm. (Celastraceae) against pathogenic bacteria

The pharmacological properties of plant extracts and phytochemicals, such as flavonoids and terpenoids, remain of great interest. In this work, the effect of extracts, friedelan-3,21-dione, and 3β-O-D-glucosyl-sitosterol isolated from Tontelea micrantha roots was evaluated against Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, Klebsiella oxytoca and Escherichia coli. The antibacterial activity was evaluated by the minimum inhibitory and bactericidal concentrations (MIC and MBC, respectively), and the synergistic effect was assessed by the Checkerboard assay. Furthermore, the cytotoxicity of the plant-derived compounds against Vero cells was measured by the 3-(4 5-dimethylthiazol-2-yl)-2 5-diphenyltetrazolium bromide (MTT) method. The biological effects of the isolated compounds were predicted using the PASS online software. The chloroform and hexane extracts of T. micrantha roots showed promising antibacterial effect, with MIC in the range of 4.8-78.0 µg/mL. Further analyses showed that these compounds do not affect the integrity of the membrane. The combination with streptomycin strongly reduced the MIC of this antibiotic and extracts. The extracts were highly toxic to Vero cells, and no cytotoxicity was detected for the two terpenoids isolated from them (i.e. friedelan-3,21-dione and 3β-O-D-glucosyl-sitosterol; CC50 > 1000 μg/mL). Therefore, extracts obtained from T. micrantha roots significantly inhibited bacterial growth and are considered promising agents against pathogenic bacteria. The cytotoxicity results were very relevant and can be tested in bioassays.

Effects of chitooligosaccharide on the in vitro antibacterial activity against avian Escherichia coli and the pharmacokinetics of florfenicol in healthy chickens

This study investigates the combined effects of chitooligosaccharide (COS) and florfenicol (FLO) on the inhibition of Escherichia coli in vitro, as well as the pharmacokinetic interactions between these compounds in healthy chickens. The minimum inhibitory concentration (MIC) of COS and FLO alone and the fractional inhibitory concentration index (FICI) after combined treatment were determined using the broth microdilution method and checkerboard method, respectively. Additionally, we evaluated the pharmacokinetic interactions between the 2 types of COS and FLO in healthy chickens. Thirty chickens were randomly divided into 3 groups: Florfenicol group (30 mg/kg), COS J85 group (COS J85 20 mg/kg + florfenicol 30 mg/kg), COS H85 group (COS H85 20 mg/kg + florfenicol 30 mg/kg). Either FLO or COS was orally administered by gavage. The concentrations of FLO in chicken plasma were measured at different time points after the drug withdrawal using high-performance liquid chromatography (HPLC), and pharmacokinetic parameters were calculated by a compartmental method. The results showed that COS J85 and COS H85, when combined with FLO, had FICI values of 0.1875 to 0.75 and 0.3125 to 1, respectively, indicating good synergistic or additive effects against Escherichia coli. The pharmacokinetics of FLO alone and in combination with COS followed a 1-compartment model with first-order absorption and elimination. Furthermore, the pharmacokinetic analysis revealed that the elimination half-life (t1/2ke) of florfenicol was significantly increased in the COS H85 group compared to oral administration of florfenicol alone (P < 0.05). Other pharmacokinetic parameters did not show significant changes (P > 0.05), except between the 2 combined treatment groups, where statistical differences were observed for various parameters, excluding the area under the concentration-time curve from the time of dosing to infinity (AUC) and peak concentration (Cmax).

Antibacterial Effect and Possible Mechanism of Sesamol against Foodborne Pathogens

Food safety problems caused by foodborne pathogens have become a major public issue, and the search for efficient and safe bacteriostatic agents has gained attention. Sesamol (SE), a phenolic compound abundant in sesame oil, offers numerous health benefits and exhibits certain antibacterial properties. The purpose of this study was to evaluate the antibacterial effect and potential mechanisms of SE against representative foodborne pathogens, including Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Salmonella serovar Enteritidis. The results showed that SE significantly inhibited the growth of the five pathogenic bacteria in sterile saline and pasteurized milk by 2.16-4.16 log10 CFU/g within 48 h. The results of the minimum bactericidal concentration and time-kill assay showed that SE had a greater inhibitory effect on L. monocytogenes compared with other bacteria. Additionally, SE was found to alter the cell membranes' permeability in these bacteria, resulting in the release of intercellular proteins and DNA. A scanning electron microscopy analysis showed that exposure to SE resulted in significant changes in bacterial morphology, producing cell shrinkage and deformation. These findings suggest that SE could inhibit both Gram-negative and Gram-positive bacteria by interfering with the function and morphology of bacterial cells.

In Vitro Antibacterial and Antioxidative Activity and Polyphenolic Profile of the Extracts of Chokeberry, Blackcurrant, and Rowan Berries and Their Pomaces

The chemical composition of berries and berry pomaces is diverse, containing polyphenolic components that may have both antibacterial and antioxidative properties. In the present study, in vitro antibacterial effect of the extracts of chokeberry, blackcurrant, and rowan berries and berry pomaces against L. monocytogenes, S. aureus, E. coli, and C. jejuni was studied. In addition, the polyphenolic profile and antioxidant activity of these extracts were investigated. The polyphenolic profiles in the aqueous and 30% ethanolic extracts were determined chromatographically by HPLC-MS, and the total polyphenol content was estimated spectrophotometrically by HPLC-DAD-UV. The minimal inhibition concentrations (MICs) of the extracts against tested bacteria were determined by the broth microdilution method. The content of total polyphenols was highest and good antioxidative properties of the extracts were determined for chokeberry and blackcurrant berries and their pomaces. The highest proportions of total quercetin derivatives and anthocyanins were found in the extracts of chokeberry berry/pomace and blackcurrant berry/pomace, respectively. The sensitivity of tested microbes to the extracts of berries and berry pomaces was as follows: S. aureus > L. monocytogenes > E. coli and C. jejuni. In vitro antibacterial activity of tested extracts depended on the extraction solvent, mainly for the ethanolic extracts. Findings suggest that chokeberry and blackcurrant berries and their pomaces can be used as a good source of polyphenols with antioxidative properties, and they also have antibacterial activity against some foodborne pathogenic bacteria. It is important that the valuable compounds are extracted from juice press residues before their disposal.

Genomic characterization of a multidrug-resistant uropathogenic Escherichia coli and evaluation of Echeveria plant extracts as antibacterials

Uropathogenic Escherichia coli (UPEC) is the most common bacterial agent associated with urinary tract infections, threatening public health systems with elevated medical costs and high morbidity rates. The successful establishment of the infection is associated with virulence factors encoded in its genome, in addition to antibacterial resistance genes, which could limit the treatment and resolution of the infection. In this sense, plant extracts from the genus Echeveria have traditionally been used to treat diverse infectious diseases. However, little is known about the effects of these extracts on bacteria and their potential mechanisms of action. This study aims to sequence a multidrug-resistant UPEC isolate (UTI-U7) and assess the multilocus sequence typing (MLST), virulence factors, antimicrobial resistance profile, genes, serotype, and plasmid content. Antimicrobial susceptibility profiling was performed using the Kirby-Bauer disk diffusion. The antibacterial and anti-adherent effects of the methanol extracts (ME) of Echeveria (E. craigiana, E. kimnachii, and E. subrigida) against UTI-U7 were determined. The isolate was characterized as an O25:H4-B2-ST2279-CH40 subclone and had resistant determinants to aminoglycosides, β-lactams, fluoroquinolones/quinolones, amphenicols, and tetracyclines, which matched with the antimicrobial resistance profile. The virulence genes identified encode adherence factors, iron uptake, protectins/serum resistance, and toxins. Identified plasmids belonged to the IncF group (IncFIA, IncFIB, and IncFII), alongside several prophage-like elements. After an extensive genome analysis that confirmed the pathogenic status of UTI-U7 isolate, Echeveria extracts were tested to determine their antibacterial effects; as an extract, E. subrigida (MIC, 5 mg/mL) displayed the best inhibitory effect. However, the adherence between UTI-U7 and HeLa cells was unaffected by the ME of the E. subrigida extract.

Antibacterial effect of Ag-containing hydroxyapatite thin film fabricated by sputtering

BACKGROUND

Infections related to joint prosthesis are still a major concern for orthopedic surgeons. Hydroxyapatite (HA) is a useful biocompatible material because of its good osteocompatibility. Antibacterial HA coatings have been fabricated with addition of antibacterial agents such as Ag to HA using the plasma spraying method. However, the plasma-sprayed HA coating suffers from fractures at large thicknesses. The sputter-coated HA thin film has a high density, and has been applied clinically for dental implants. However, there are no extensive studies on Ag-containing HA thin films.

OBJECTIVE

The aim of this study was to prepare an Ag-containing HA thin film by sputtering, and evaluate its antibacterial effect and cytotoxicity.

METHODS

The Ag-containing HA thin films were prepared by radio-frequency magnetron sputtering. The films were characterized using X-ray photoelectron spectroscopy, X-ray diffractometry, and scanning electron microscopy (SEM). The antibacterial activities and cytotoxicities of the films were also evaluated.

RESULTS

The Ag/Ca molar ratio of the films increased with the Ag ratio in the target. The SEM observation of the hydrothermally treated films showed surfaces covered with globular particles. All Ag-containing HA films exhibited an antibacterial effect against E. Coli. The number of cells of the films decreased with the Ag ratio. The films subjected to the hydrothermal treatment exhibited a higher number of cells than the as-sputtered films.

CONCLUSION

The Ag-containing HA thin film was effective in terms of antibacterial effect, and had a low cytotoxicity in the proliferation of osteoblast cells at a low Ag ratio in the target.

Commercially Pure Titanium Implants With Selenium and Hyaluronic Acid Coating for Dental Applications

Background The current study demonstrated improved efficiency of commercially pure titanium (CP-Ti) dental implants with a biocompatible coating of selenium (Se) and hyaluronic acid (HA).  Methods The sol-gel solution was made with hyaluronic acid and selenium nitrate in a 1:1 ratio. The coating sample was subjected to characterization studies such as Fourier Transform Infrared (FTIR) spectroscopy, surface morphology analysis, contact angle, etc., to confirm the coating. The antimicrobial activity of the coating was studied by analyzing the zone of inhibition. Results The FTIR spectroscopy was analyzed to confirm the functional groups of Se/HA. The surface morphology of the coated sample appeared as tiny needles with a plate-like surface. The potentiodynamic polarization studies revealed that the coated Ti samples exhibit superior corrosion resistance. The antimicrobial activity of Staphylococcus aureus was found to be more effective at a concentration of 100 mg. Furthermore, the basic criteria of biomaterials were analyzed for hemocompatibility studies, which suggested a non-hemolytic character. Conclusion The biocompatible coating of Se and HA has proven to be of superior corrosion resistance and antimicrobial activity resistance, which validate the usage of dental implants.

Antibacterial Activity against Escherichia coli and Cytotoxicity of Maillard Reaction Product of Chitosan and Glucosamine Prepared by Gamma Co-60 Ray Irradiation

In this study, the gamma ray-induced Maillard reaction method was carried out for chitosan (CTS) and glucosamine (GA) to improve the water solubility and antibacterial activity. The mixture solution of CTS and GA was exposed to gamma rays at a dose of 25 kGy and freeze-dried to obtain a Maillard reaction product (MRP) powder. The physicochemical and biological properties of the CTS-GA MRP powder were investigated. The CTS-GA MRP powder expressed good solubility at a concentration of 0.05 g/mL. In addition, the result of the antibacterial activity test against Escherichia coli revealed that the CTS-GA MRP powder exhibited highly antibacterial activity at pH 7; in particular, bacterial density was reduced by over 4 logs. Furthermore, the cytotoxicity test of the CTS-GA MRP powder on mouse fibroblast cells (L929) showed non-cytotoxicity with high cell viability (>90%) at concentrations of 0.1-1 mg/mL. Owing to the high antibacterial activity and low cytotoxicity, the water-soluble CTS-GA MRP powder can be used as a favorable natural preservative for food and cosmetics.

Effects of Roasting Conditions on Antibacterial Properties of Vietnamese Turmeric (Curcuma longa) Rhizomes

Processing with heat treatment has been reported to alter several therapeutic effects of turmeric. In Vietnamese traditional medicine, turmeric has been long used for bacterial infections, and roasting techniques are sometimes applied with this material. However, there have been no studies investigating the effects of these thermal processes on the plant's antibacterial properties. Our study was therefore performed to examine the changes that roasting produced on this material. Slices of dried turmeric were further subjected to light-roasting (80 °C in 20 min) or dark-roasting (160 °C in 20 min) processes. Broth dilution and agar-well diffusion methods were applied to examine and compare the effects of ethanol extracts obtained from non-roasted, light-roasted and dark-roasted samples, on a set of 6 gram-positive and gram-negative bacteria. In both investigations, dark-roasted turmeric was significantly less antibacterial than non-roasted and light-roasted materials, as evident by the higher values of minimum inhibitory concentrations and the smaller diameters of induced inhibitory zones. In addition, dark-roasting was also found to clearly reduce curcumin contents, total polyphenol values and antioxidant activities of the extracts. These results suggest that non-roasting or light-roasting might be more suitable for the processing of turmeric materials that are aimed to be applied for bacterial infections.

The Use of Graphene Oxide in Orthodontics-A Systematic Review

BACKGROUND

Graphene-based materials have great prospects for application in dentistry and medicine due to their unique properties and biocompatibility with tissues. The literature on the use of graphene oxide in orthodontic treatment was reviewed.

METHODS

This systematic review followed the PRISMA protocol and was conducted by searching the following databases: PubMed, Scopus, Web of Science, and Cochrane. The following search criteria were used to review the data on the topic under study: (Graphene oxide) AND (orthodontic) ALL FIELDS. For the Scopus database, results were narrowed to titles, authors, and keywords. A basic search structure was adopted for each database. Initially, a total of 74 articles were found in the considered databases. Twelve articles met the inclusion criteria and were included in the review.

RESULTS

Nine studies demonstrated the antibacterial properties of graphene oxide, which can reduce the demineralization of enamel during orthodontic treatment. Seven studies showed that it is biocompatible with oral tissues. Three studies presented that graphene oxide can reduce friction in the arch-bracket system. Two studies showed that it can improve the mechanical properties of orthodontic adhesives by reducing ARI (Adhesive Remnant Index). Three studies demonstrated that the use of graphene oxide in the appropriate concentration can also increase the SBS (shear bond strength) parameter. One research study showed that it can increase corrosion resistance. One research study suggested that it can be used to accelerate orthodontic tooth movement.

CONCLUSION

The studies included in the systematic review showed that graphene oxide has numerous applications in orthodontic treatment due to its properties.

Assessment of Polydopamine to Reduce Streptococcus mutans Adhesion to a Dental Polymer

Bacterial adhesion to the surface of materials is the first step in biofilm formation, which will lead to conditions that may compromise the health status of patients. Recently, polydopamine (PDA) has been proposed as an antibacterial material. Therefore, the objective of the current work was to assess and compare the adhesion of Streptococcus mutans to the surface of poly(methyl methacrylate) (PMMA) discs that were modified using PDA following a biomimetic approach versus smooth PDA-coated PMMA surfaces. In addition, an assessment of the growth inhibition by PDA was performed. PMMA discs were manufactured and polished; soft lithography, using the topography from the Crocosmia aurea leaf, was used to modify their surface. PDA was used to smooth-coat PMMA discs by dip-coating. The growth inhibition was measured using an inhibition halo. The surfaces were characterized by means of atomic force microscopy (AFM), the contact angle (CA), and Fourier-transform infrared spectroscopy (FTIR). Polydopamine exhibited a significant antibacterial effect when used directly on the S. mutans planktonic cells, but such an effect was not as strong when modifying the PMMA surfaces. These results open the possibility of using polydopamine to reduce the adhesion and growth of S. mutans, which might have important consequences in the dental field.

UPLC-Q-TOF-MS, network analysis, and molecular docking to investigate the effect and active ingredients of tea-seed oil against bacterial pathogens

Object: This research intended to probe the antibacterial effect and pharmacodynamic substances of Tea-Seed Oil (TSO) through the use of ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) analysis, network analysis, and molecular docking. Methods: The major chemical components in the methanol-extracted fractions of TSO were subjected to UPLC-Q-TOF-MS. Network pharmacology and molecular docking techniques were integrated to investigate the core components, targets, and potential mechanisms of action through which the TSO exert their antibacterial properties. To evaluate the inhibitory effects, the minimum inhibitory concentration and diameter of the bacteriostatic circle were calculated for the potential active ingredients and their equal ratios of combinatorial components (ERCC) against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. Moreover, the quantification of the active constituents within TSO was achieved through the utilization of high-performance liquid chromatography (HPLC). Results: The methanol-extracted fractions contained a total of 47 chemical components, predominantly consisting of unsaturated fatty acids and phenolic compounds. The network pharmacology analysis and molecular docking analysis revealed that various components, including gallocatechin, gallic acid, epigallocatechin, theophylline, chlorogenic acid, puerarin, and phlorizin, have the ability to interact with critical core targets such as serine/threonine protein kinase 1 (AKT1), epidermal growth factor receptor (EGFR), a monoclonal antibody to mitogen-activated protein kinase 14 (MAPK14), HSP90AA1, and estrogen receptor 1 (ESR1). Furthermore, these components can modulate the phosphatidylinositol-3-kinase protein kinase B (PI3K-AKT), estrogen, MAPK and interleukin 17 (IL-17) signaling pathways, hereby exerting antibacterial effects. In vitro validation trials have found that seven components, namely gallocatechin, gallic acid, epigallocatechin, theophylline, chlorogenic acid, puerarin, and phloretin, displayed substantial inhibitory effects on E. coli, S. aureus, P. aeruginosa, and C. albicans, and are typically present in tea oil, with a total content ranging from 15.87∼24.91 μg·g-1. Conclusion: The outcomes of this investigation possess the possibility to expand our knowledge base concerning the utilization of TSO, furnish a theoretical framework for the exploration of antibacterial drugs and cosmetics derived from inherently occurring TSO, and establish a robust groundwork for the advancement and implementations of TOS products within clinical settings.

Pharmacological Activities and Safety of Ganoderma lucidum Spores: A Systematic Review

Ganoderma lucidum is traditionally used to prevent and treat some diseases such as liver disorders, hypertension, insomnia, diabetes, and cancer. G. lucidum spore extracts are also reported to share similar bioactivities as extracts from its other parts. However, there is no systematic review that elucidates its pharmacological effect. Our aim is to comprehensively summarise current evidence of G. lucidum spore extracts to clarify its benefits to be applied in further studies. We searched five primary databases: PubMed, Virtual Health Library (VHL), Global Health Library (GHL), System for Information on Grey Literature in Europe (SIGLE), and Google Scholar on September 13, 2021. Articles were selected according to inclusion and exclusion criteria. A manual search was applied to find more relevant articles. Ninety studies that reported the pharmacological effects and/or safety of G. lucidum spores were included in this review. The review found that G. lucidum spore extracts showed quite similar effects as other parts of this medicinal plant including anti-tumor, anti-inflammatory, antioxidant effects, and immunomodulation. G. lucidum sporoderm-broken extract demonstrated higher efficiency than unbroken spore extract. G. lucidum extracts also showed their effects on some genes responsible for the body's metabolism, which implied the benefits in metabolic diseases. The safety of G. lucidum should be investigated in depth as high doses of the extract could increase levels of cancer antigen (CA)72-4, despite no harmful effect shown on body organs. Generally, there is a lot of potential in the studies of compounds with pharmacological effects and new treatments. Sporoderm breaking technique could contribute to the production of extracts with more effective prevention and treatment of diseases. High doses of G. lucidum spore extract should be used with caution as there was a concern about the increase in CA.

LED Lights Influenced Phytochemical Contents and Biological Activities in Kale (Brassica oleracea L. var. acephala) Microgreens

Light-emitting diodes (LEDs) are regarded as an effective artificial light source for producing sprouts, microgreens, and baby leaves. Thus, this study aimed to investigate the influence of different LED lights (white, red, and blue) on the biosynthesis of secondary metabolites (glucosinolates, carotenoids, and phenolics) and the biological effects on kale microgreens. Microgreens irradiated with white LEDs showed higher levels of carotenoids, including lutein, 13-cis-β-carotene, α-carotene, β-carotene, and 9-cis-β-carotene, than those irradiated with red or blue LEDs. These findings were consistent with higher expression levels of carotenoid biosynthetic genes (BoPDS and BoZDS) in white-irradiated kale microgreens. Similarly, microgreens irradiated with white and blue LEDs showed slightly higher levels of glucosinolates, including glucoiberin, progoitrin, sinigrin, and glucobrassicanapin, than those irradiated with red LEDs. These results agree with the high expression levels of BoMYB28-2, BoMYB28-3, and BoMYB29 in white- and blue-irradiated kale microgreens. In contrast, kale microgreens irradiated with blue LEDs contained higher levels of phenolic compounds (gallic acid, catechin, ferulic acid, sinapic acid, and quercetin). According to the total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition assays, the extracts of kale microgreens irradiated with blue LEDs had slightly higher antioxidant activities, and the DPPH inhibition percentage had a positive correlation with TPC in the microgreens. Furthermore, the extracts of kale microgreens irradiated with blue LEDs exhibited stronger antibacterial properties against normal pathogens and multidrug-resistant pathogens than those irradiated with white and red LEDs. These results indicate that white-LED lights are suitable for carotenoid production, whereas blue-LED lights are efficient in increasing the accumulation of phenolics and their biological activities in kale microgreens.

Silk Fibroin/ZnO Coated TiO2 Nanotubes for Improved Antimicrobial Effect of Ti Dental Implants

The aim of the present research is to develop a novel hybrid coating for a Ti dental implant that combines nature-inspired biomimetic polymers and TiO2 nanostructures with an entrapped ZnO antimicrobial agent. ZnO was used in other studies to cover the surface of Ti or Ti-Zr to reduce the need of clinical antibiotics, prevent the onset of peri-implantitis, and increase the success rate of oral clinical implantation. We developed an original coating that represents a promising approach in clinical dentistry. The titanium surface was first anodized to obtain TiO2 nanotubes (NT). Subsequently, on the NT surface, silk fibroin isolated from Bombyx mori cocoons was deposited as nanofibers using the electrospun technique. For an improved antibacterial effect, ZnO nanoparticles were incorporated in this biopolymer using three different methods. The surface properties of the newly created coatings were assessed to establish how they are influenced by the most important features: morphology, wettability, topography. The evaluation of stability by electrochemical methods in simulated physiological solutions was discussed more in detail, considering that it could bring necessary information related to the behavior of the implant material. All samples had improved roughness and hydrophilicity, as well as corrosion stability (with protection efficiency over 80%). The antibacterial test shows that the functional hybrid coating has good antibacterial activity because it can inhibit the proliferation of Staphylococcus aureus up to 53% and Enterococcus faecalis up to 55%. All Ti samples with the modified surface have proven superior properties compared with unmodified TiNT, which proved that they have the potential to be used as implant material in dentistry.

Biocompatible Gallium Nanodots against Drug-Resistant Bacterial Pneumonia and Liver Abscess

Resistant bacterial infection remains a severe public health threat, and conventional antibiotic drugs work poorly in effectively treating infectious diseases. Here, we developed gallium-based nanodots (Ga NDs), consisting of specific disruption of bacterial iron ability, to treat multidrug-resistant (MDR) Gram-negative bacteria-infected diseases. The Ga NDs significantly suppress the proliferation of two typical MDR bacteria strains (P. aeruginosa and ESBL E. coli) compared with clinically used antibacterial drugs, including penicillin and levofloxacin. Ga NDs could also disrupt the biofilms of these two bacterial strains. In P. aeruginosa infected pneumonia and ESBL E. coli infected acute liver abscess models, the Ga NDs enable substantial inhibition of bacterial growth and reduce the organs' inflammation that resulted in significant improvement of survival. Further, the Ga NDs demonstrated excellent biocompatibility and biosafety characteristics. Together, we believe that our gallium containing nanotherapeutics are expected to be developed into promising alternative therapies to combat drug-resistant bacterial infection.

Antimicrobial Effect of Ocimum gratissimum L. Essential Oil on Shewanella putrefaciens: Insights Based on the Cell Membrane and External Structure

The main objective of this study was to assess the in vitro antibacterial effectiveness of Ocimum gratissimum L. essential oil (OGEO) against Shewanella putrefaciens. The minimum inhibitory concentration and minimum bactericidal concentration of OGEO acting on S. putrefaciens were both 0.1% and OGEO could inhibit the growth of S. putrefaciens in a dose-dependent manner. The restraint of the biofilm growth of S. putrefaciens was found in the crystal violet attachment assay and confocal laser scanning microscopy. The disruption of cell membranes and exudation of contents in S. putrefaciens with OGEO treatment were observed by scanning electron microscopy, hemolysis and ATPase activity. The results demonstrated that OGEO had a positive inhibitory effect on the growth of S. putrefaciens, which primarily developed its antibacterial function against S. putrefaciens by disrupting the formation of biofilms and cell membranes. This study could provide a new method of inhibiting the spoilage of food in which the dominant spoilage bacteria are S. putrefaciens.

Propolis as a Cariostatic Agent in Lozenges and Impact of Storage Conditions on the Stability of Propolis

Propolis is known as a source of compounds with strong antibacterial activity. Due to the antibacterial effect against streptococci of the oral cavity, it seems to be a useful agent in decreasing the accumulation of dental plaque. It is rich in polyphenols which are responsible for a beneficial impact on the oral microbiota and antibacterial effect. The aim of the study was to evaluate the antibacterial effect of Polish propolis against cariogenic bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined on cariogenic streptococci related to the occurrence of dental caries. Lozenges based on xylitol, glycerin, gelatin, water, and ethanol extract of propolis (EEP) were prepared. The effect of prepared lozenges on cariogenic bacteria was assessed. Propolis was compared to chlorhexidine which is used in dentistry as the gold standard. In addition, the prepared propolis formulation was stored under stress conditions to assess the influence of physical conditions (i.e., temperature, relative humidity, and UV radiation). In the experiment, thermal analyses were also performed to evaluate the compatibility of propolis with the substrate used to create the base of lozenges. The observed antibacterial effect of propolis and prepared lozenges with EEP may suggest directing subsequent research on prophylactic and therapeutic properties decreasing the accumulation of dental plaque. Therefore, it is worth highlighting that propolis may play an important role in the management of dental health and bring advantages in preventing periodontal diseases and caries as well as dental plaque. The colorimetric analyses carried out in the CIE L*a*b* system, microscopic examinations, and TGA/DTG/c-DTA measurements indicate the unfavorable effect of the tested storage conditions on the lozenges with propolis. This fact is particularly evident for lozenges stored under stress conditions, i.e., 40 °C/75% RH/14 days, and lozenges exposed to UVA radiation for 60 min. In addition, the obtained thermograms of the tested samples indicate the thermal compatibility of the ingredients used to create the formulation of lozenges.

Nano-Chitosan/Eucalyptus Oil/Cellulose Acetate Nanofibers: Manufacturing, Antibacterial and Wound Healing Activities

Accelerated wound healing in infected skin is still one of the areas where current therapeutic tactics fall short, which highlights the critical necessity for the exploration of new therapeutic approaches. The present study aimed to encapsulate Eucalyptus oil in a nano-drug carrier to enhance its antimicrobial activity. Furthermore, in vitro, and in vivo wound healing studies of the novel nano-chitosan/Eucalyptus oil/cellulose acetate electrospun nanofibers were investigated. Eucalyptus oil showed a potent antimicrobial activity against the tested pathogens and the highest inhibition zone diameter, MIC, and MBC (15.3 mm, 16.0 μg/mL, and 256 μg/mL, respectively) were recorded against Staphylococcus aureus. Data indicated a three-fold increase in the antimicrobial activity of Eucalyptus oil encapsulated chitosan nanoparticle (43 mm inhibition zone diameter against S. aureus). The biosynthesized nanoparticles had a 48.26 nm particle size, 19.0 mV zeta potential, and 0.45 PDI. Electrospinning of nano-chitosan/Eucalyptus oil/cellulose acetate nanofibers was conducted, and the physico-chemical and biological properties revealed that the synthesized nanofibers were homogenous, with a thin diameter (98.0 nm) and a significantly high antimicrobial activity. The in vitro cytotoxic effect in a human normal melanocyte cell line (HFB4) proved an 80% cell viability using 1.5 mg/mL of nano-chitosan/Eucalyptus oil/cellulose acetate nanofibers. In vitro and in vivo wound healing studies revealed that nano-chitosan/Eucalyptus oil/cellulose acetate nanofibers were safe and efficiently enhanced the wound-healing process through enhancing TGF-β, type I and type III collagen production. As a conclusion, the manufactured nano-chitosan/Eucalyptus oil/cellulose acetate nanofiber showed effective potentiality for its use as a wound healing dressing.

Antibacterial Effects of a Carbon Nitride (CN) Layer Formed on Non-Woven Polypropylene Fabrics Using the Modified DC-Pulsed Sputtering Method

In the present study, the surface of non-woven polypropylene (NW-PP) fabric was modified to form CN layers using a modified DC-pulsed (frequency: 60 kHz, pulse shape: square) sputtering with a roll-to-roll system. After plasma modification, structural damage in the NW-PP fabric was not observed, and the C-C/C-H bonds on the surface of the NW-PP fabric converted into C-C/C-H, C-N(CN), and C=O bonds. The CN-formed NW-PP fabrics showed strong hydrophobicity for H₂O (polar liquid) and full-wetting characteristics for CH₂I₂ (non-polar liquid). In addition, the CN-formed NW-PP exhibited an enhanced antibacterial characteristic compared to NW-PP fabric. The reduction rate of the CN-formed NW-PP fabric was 89.0% and 91.6% for Staphylococcus aureus (ATCC 6538, Gram-positive) and Klebsiella pneumoniae (ATCC4352, Gram-negative), respectively. It was confirmed that the CN layer showed antibacterial characteristics against both Gram-positive and Gram-negative bacteria. The reason for the antibacterial effect of CN-formed NW-PP fabrics can be explained as the strong hydrophobicity due to the CH₃ bond of the fabric, enhanced wetting property due to CN bonds, and antibacterial activity due to C=O bonds. Our study presents a one-step, damage-free, mass-productive, and eco-friendly method that can be applied to most weak substrates, allowing the mass production of antibacterial fabrics.

Facile synthesis of zinc acetate/niacin MOFs for use in wound healing

Niacin (NA) and Zinc (Zn) were used to fabricate metal organic frameworks (Zn-NA MOFs), based on coordination chemistry via a simple, rapid technique conducted at room temperature. The identity of the prepared MOFs was confirmed by FTIR, XRD, SEM, and TEM, which showed cubic shaped, crystalline, microporous MOFs with an average size of 150 nm. Release of the active ingredients from the MOFs was proved to be pH dependent in a slightly alkaline medium (pH 8.5) with a sustained release rate of its two ingredients, NA and Zn, which have wound healing activity. Zn-NA MOFs proved to be biocompatible in the tested concentrations range (5 - 100 mg/mL), with no cytotoxic effect on WI-38 cell line. Zn-NA MOFs at 10 and 50 mg/mL concentrations and their components, NA and Zn, exerted antibacterial effects against S. aureus, E. coli, and P. aeruginosa. Wound healing effect of the Zn-NA MOFs (50 mg/mL) was evaluated on full excisional rat wounds. Significant reduction of the wound area was observed after 9 days of treatment using the Zn-NA MOFs compared to the other treatment groups. Additionally, wounds were fully healed after 10 days of treatment with the Zn-NA MOFs with histological and immunohistochemical evidence of re-epithelization, collagen formation, and angiogenesis. Similar histological evidence was also observed in wounds treated with niacin only; however, with no significant wound closure rates. Nevertheless, the formation of new blood vessels, as confirmed by the VEGF protein expression, was highest in the niacin group. Zn-NA MOFs synthesized using a facile, low-cost method are potentially capable of healing wounds rapidly and effectively. &#xD.

Improvement of Chitosan Films Properties by Blending with Cellulose, Honey and Curcumin

Chitosan is a natural biopolymer that can be used in biomedical applications, tissue engineering, and wound dressing because of its biodegradability, biocompatibility, and antibacterial activity. The blending of chitosan films with natural biomaterials such as cellulose, honey, and curcumin was studied at different concentrations in order to improve their physical properties. Fourier transform infrared (FTIR) spectroscopy, mechanical tensile properties, X-ray diffraction (XRD), antibacterial effects, and scanning electron microscopy (SEM) were studied for all blended films. The XRD, FTIR, and mechanical results showed that films blended with curcumin were more rigid and compatible and had higher antibacterial effects than other blended films. In addition, XRD and SEM showed that blending chitosan films with curcumin decreases the crystallinity of the chitosan matrix compared to cellulose and honey blending films due to increased intermolecular hydrogen bonding, which reduces the close packing of the CS matrix.

Combined effect of apigenin and reduced graphene oxide against Enterococcus faecalis biofilms

PURPOSE

Enterococcus faecalis (E. faecalis) is one of the major microorganisms that causes failure of endodontic treatment. This study aimed to investigate the antibacterial activity of apigenin and its synergistic effect with reduced graphene oxide (RGO) in treating E. faecalis biofilms.

METHODS

The antibacterial activities were characterized by viability analysis including colony forming units and confocal laser scanning microscopy (CLSM) analyses. The effect on biofilm biomass was measured using a crystal violet staining method. Live and dead bacteria bio-volumes were determined by CLSM analysis, and the morphology of E. faecalis biofilm after treatment with apigenin and apigenin + RGO was observed by scanning electron microscopy (SEM).

RESULTS

The viability of E. faecalis in biofilms decreased by apigenin treatment in a dose-dependent manner. While apigenin alone did not significantly affect the biofilm biomass, apigenin + RGO reduced the biomass in an apigenin concentration-dependent manner. Likewise, the bio-volume of live bacteria decreased and the bio-volume of dead bacteria increased in apigenin-treated biofilms. According to SEM images, apigenin + RGO-treated samples showed less E. faecalis in biofilms than apigenin-only treated samples.

CONCLUSION

The results suggested that the combined use of apigenin and RGO could be a potential strategy for effective endodontic disinfection.

Antibacterial Effect of Shrimp By-Products Hydrolysate on Specific Spoilage Organisms of Squid

In order to further develop and utilize shrimp processing by-products, in this study, a novel antibacterial hydrolysate of shrimp by-products by pepsin hydrolysis (SPH) was prepared. The antibacterial effect of SPH on specific spoilage organisms of squid after end storage at room temperature (SE-SSOs) was investigated. SPH showed an antibacterial effect on the growth of SE-SSOs, with (23.4 ± 0.2) mm of inhibition zone diameter. The cell permeability of SE-SSOs was enhanced after SPH treatment for 12 h. Some bacteria were twisted and shrunk, while pits and pores formed and intracellular contents leaked under scanning electron microscopy observation. The flora diversity of SE-SSOs treated with SPH was determined by a 16S rDNA sequencing technique. Results showed that SE-SSOs were mainly composed of the phyla of Firmicutes and Proteobacteria, among which Paraclostridium (47.29%) and Enterobacter (38.35%) were dominant genera. SPH treatment resulted in a significant reduction in the relative abundance of the genus Paraclostridium and increased the abundance of Enterococcus. Linear discriminant analysis (LDA) of LEfSe conveyed that SPH treatment had a significant impact on altering the bacterial structure of SE-SSOs. The 16S PICRUSt of Cluster of Orthologous Group (COG) annotation revealed that SPH treatment for 12 h could significantly increase the function of transcription level [K], while SPH treatment for 24 h could downregulate post-translational modifications, protein turnover, and chaperone metabolism functions [O]. In conclusion, SPH has a proper antibacterial effect on SE-SSOs and can change the flora structure of SE-SSOs. These findings will provide a technical basis for the development of inhibitors of squid SSOs.

In Situ Fabrication of Silver Peroxide Hybrid Ultrathin Co-Based Metal-Organic Frameworks for Enhanced Chemodynamic Antibacterial Therapy

Bacterial-induced infectious diseases have always caused an unavoidable problem and lead to an increasing threat to human health. Hence, there is an urgent need for effective antibacterial strategies to treat infectious diseases. Current methods are often ineffective and require large amounts of hydrogen peroxide (H₂O₂), with harmful effects on normal healthy tissue. Chemodynamic therapy (CDT) provides an ideal infection microenvironment (IME)-activated paradigm to tackle bacterial-related diseases. To take full advantage of the specificity of IME and enhanced CDT for wounds with bacterial infection, we have designed an intelligent antibacterial system that exploits nanocatalytic ZIF-67@Ag₂O₂ nanosheets. In this system, silver peroxide nanoparticles (Ag₂O₂ NPs) were grown on ultrathin zeolitic imidazolate framework-67 (ZIF-67) nanosheets by in situ oxidation, and then, ZIF-67@Ag₂O₂ nanosheets with the ability to self-generate H₂O₂ were triggered by the mildly acidic environment of IME. Lamellar ZIF-67 nanosheets were shown to rapidly degrade and release Co²⁺, allowing the conversion of less reactive H₂O₂ into the highly toxic reactive oxygen species hydroxyl radicals (^•OH) for enhanced CDT antibacterial properties. In vivo results revealed that the ZIF-67@Ag₂O₂ nanosheet system exhibits excellent antibacterial performance against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The proposed hybrid strategy demonstrates a promising therapeutic strategy to enable antibacterial agents with IME-responsive nanocatalytic activity to circumvent antibiotic resistance against bacterial infections.

Design of silicone interfaces with antibacterial properties

Silicone implants are widely used for plastic or reconstruction medical applications. However, they can cause severe infections of inner tissues due to bacterial adhesion and biofilm growth on implant surfaces. The development of new antibacterial nanostructured surfaces can be considered as the most promising strategy to deal with this problem. In this article, we studied the influence of nanostructuring parameters on the antibacterial properties of silicone surfaces. Nanostructured silicone substrates with nanopillars of various dimensions were fabricated using a simple soft lithography technique. Upon testing of the obtained substrates, we identified the optimal parameters of silicone nanostructures to achieve the most pronounced antibacterial effect against the bacterial culture of Escherichia coli. It was demonstrated that up to 90% reduction in bacterial population compared to flat silicone substrates can be achieved. We also discussed possible underlying mechanisms behind the observed antibacterial effect, the understanding of which is essential for further progress in this field.

Plasma-Activated Hydrogels for Microbial Disinfection

A continuous risk from microbial infections poses a major environmental and public health challenge. As an emerging strategy for inhibiting bacterial infections, plasma-activated water (PAW) has proved to be highly effective, environmental-friendly, and non-drug resistant to a broad range of microorganisms. However, the relatively short lifetime of reactive oxygen and nitrogen species (RONS) and the high spreadability of liquid PAW inevitably limit its real-life applications. In this study, plasma-activated hydrogel (PAH) is developed to act as reactive species carrier that allow good storage and controlled slow-release of RONS to achieve long-term antibacterial effects. Three hydrogel materials, including hydroxyethyl cellulose (HEC), carbomer 940 (Carbomer), and acryloyldimethylammonium taurate/VP copolymer (AVC) are selected, and their antibacterial performances under different plasma activation conditions are investigated. It is shown that the composition of the gels plays the key role in determining their biochemical functions after the plasma activation. The antimicrobial performance of AVC is much better than that of PAW and the other two hydrogels, along with the excellent stability to maintain the antimicrobial activity for more than 14 days. The revealed mechanism of the antibacterial ability of the PAH identifies the unique combination of short-lived species (¹ O₂ , ∙OH, ONOO^- and O₂ ^- ) stored in hydrogels. Overall, this study demonstrates the efficacy and reveals the mechanisms of the PAH as an effective and long-term disinfectant capable of delivering and preserving antibacterial chemistries for biomedical applications.

Antimicrobial Diterpenes from Rough Goldenrod (Solidago rugosa Mill.)

Solidago rugosa is one of the goldenrod species native to North America but has sporadically naturalized as an alien plant in Europe. The investigation of the root and leaf ethanol extracts of the plant using a bioassay-guided process with an anti-Bacillus assay resulted in the isolation of two antimicrobial components. Structure elucidation was performed based on high-resolution tandem mass spectrometric and one- and two-dimensional NMR spectroscopic analyses that revealed (-)-hardwickiic acid (Compound 1) and (-)-abietic acid (Compound 2). The isolates were evaluated for their antimicrobial properties against several plant pathogenic bacterial and fungal strains. Both compounds demonstrated an antibacterial effect, especially against Gram-positive bacterial strains (Bacillus spizizenii, Clavibacter michiganensis subsp. michiganensis, and Curtobacterium flaccumfaciens pv. flaccumfaciens) with half maximal inhibitory concentration (IC₅₀) between 1 and 5.1 µg/mL (5-20 times higher than that of the positive control gentamicin). In the used concentrations, minimal bactericidal concentration (MBC) was reached only against the non-pathogen B. spizizenii. Besides their activity against Fusarium avenaceum, the highest antifungal activity was observed for Compound 1 against Bipolaris sorokiniana with an IC₅₀ of 3.8 µg/mL.

Development and Evaluation of Silver Nanomix as a Next-Generation Tool for Wound Healing and Dressing Applications

This investigation reports silver nanomix as a next-generation, cost-effective, and clinically translatable nanomaterial tool for wound healing and dressing applications. Silver nanomix was developed by systematically hybridizing silver nanoparticles (AgNPs; sub-15 nm; Design Expert tool) with ionic Ag. The silver nanomix elicited significantly higher antibacterial potential than conventional silver products and marketed reference antibiotics, as studied in Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. Furthermore, the biomechanics of action, safety profile, and intracellular silver organization by silver nanomix are also studied exhaustively. This research presents a viewpoint and direction in designing silver-based antimicrobial dressings with a 40% reduction in their cost.

Conjugation of Short Oligopeptides to a Second-Generation Polyamidoamine Dendrimer Shows Antibacterial Activity

The growing evolution of bacterial resistance to antibiotics represents a global issue that not only impacts healthcare systems but also political and economic processes. This necessitates the development of novel antibacterial agents. Antimicrobial peptides have shown promise in this regard. Thus, in this study, a new functional polymer was synthesized by joining a short oligopeptide sequence (Phe-Lys-Phe-Leu, FKFL) to the surface of a second-generation polyamidoamine (G2 PAMAM) dendrimer as an antibacterial component. This method of synthesis proved simple and resulted in a high conjugation yield of the product FKFL-G2. To determine its antibacterial potential, FKFL-G2 was subsequently analyzed via mass spectrometry, a cytotoxicity assay, bacterial growth assay, colony-forming unit assay, membrane permeabilization assay, transmission electron microscopy, and biofilm formation assay. FKFL-G2 was found to exhibit low toxicity to noncancerous NIH3T3 cells. Additionally, FKFL-G2 had an antibacterial effect on Escherichia coli and Staphylococcus aureus strains by interacting with and disrupting the bacterial cell membrane. Based on these findings, FKFL-G2 shows promise as a potential antibacterial agent.

Visible Light-Responsive Selenium Nanoparticles Combined with Sonodynamic Therapy to Promote Wound Healing

In this paper, we synthesized selenium nanoparticles (SeNPs) that could be effectively excited by pure yellow light (YL) source to enhance antibacterial ability. Meanwhile, YL could also play the role of anti-inflammatory and promote wound healing. In addition, in order to overcome the problem of low penetration depth of photodynamic therapy (PDT), SeNPs were encapsulated with polyethylenimine (PEI), then modified with the sound sensitive agent indocyanine green (ICG), realizing the combined photoacoustic therapy to promote the healing of wounds infected by drug-resistant bacteria. The antibacterial efficiency of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) reached more than 99% in in vitro and in vivo experiments within 10 min, which could safely and quickly kill drug-resistant bacteria to repair and heal wounds.

Antibacterial and Antibiofilm Effect of Unifloral Honeys against Bacteria Isolated from Chronic Wound Infections

Honey is known as an alternative remedy for the treatment of wounds. To evaluate the potential of five Hungarian honey types against wound-associated bacteria, in vitro microbiological assays were conducted on Pseudomonas aeruginosa, Staphylococcus epidermidis and methicillin-resistant Staphylococcus aureus (MRSA). Minimum inhibitory concentration (MIC) was determined with the broth macrodilution method, and biofilm degradation capacity was tested with a crystal violet assay. To understand the underlying mechanisms, the effects of honey treatments were assessed on bacterial membrane integrity and quorum sensing (QS). The highest antibacterial activity, indicated by the lowest MIC values, as well as the highest biofilm inhibition rates and membrane disruption, was displayed by chestnut and linden honeys. The most sensitive bacterium was S. epidermidis. Bacterial membrane degradation took place 40 min after treatment with honey solutions of at least a 40% concentration. Each honey sample exhibited anti-QS activity, which was most pronounced in the case of chestnut honey. It was concluded that the antibacterial, biofilm-inhibiting and anti-QS activities of linden and chestnut honeys were superior to those of acacia, goldenrod and milkweed honeys. In addition to the floral source, the antibacterial effect of honey is influenced by the microbial species treated. The use of honey in wound treatment can be justified by its diverse antibacterial mechanisms.

Chemical Profile, Antioxidant and Antibacterial Activities, Mechanisms of Action of the Leaf Extract of Aloe arborescens Mill

Aloe arborescens Mill's extracts have been explored for antibacterial and antioxidant efficacies. However, there is limited information on its chemical composition and mechanism of action. The purpose of this study was to assess the chemical composition, antibacterial and antioxidant activities and mechanism of the whole leaf extract of A. arborescens Mill. The phytochemical profile was analysed with gas chromatography mass spectrometry (GC-MS). The antioxidant and antibacterial activities were screened using 1,1diphenyl2picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and micro-dilution assays, respectively. The effects of the extract on the bacterial respiratory chain dehydrogenase, membrane integrity and permeability were analysed using iodonitrotetrazolium chloride, 260 absorbing materials and relative electrical conductivity assays. GC-MS spectrum revealed 26 compounds with N,N'-trimethyleneurea (10.56%), xanthine (8.57%) and 4-hexyl-1-(7-ethoxycarbonylheptyl)bicyclo[4.4.0]deca-2,5,7-triene (7.10%), being the major components. The extract also exhibited antioxidant activity with median concentration (IC₅₀) values of 0.65 mg/mL on DPPH and 0.052 mg/mL on ABTS. The extract exhibited minimum inhibitory concentration (MIC) values ranging from 0.07 to 1.13 mg/mL. The extract inhibited the bacterial growth by destructing the activity of the respiratory chain dehydrogenase, membrane integrity and permeability. Therefore, the leaf extract has the potential to serve as a source of antibacterial and antioxidant compounds.

Effects of Carbohydrates on Rosmarinic Acid Production and In Vitro Antimicrobial Activities in Hairy Root Cultures of Agastache rugosa

Agastache rugosa (popularly known as Korean mint) belongs to the Lamiaceae family and comprises 22 species of perennial aromatic medicinal species native to East Asian countries, such as Korea, Taiwan, Japan, and China. A. rugosa contains many phenolic compounds that exhibit pharmacological and physiological activities, including antioxidant, anticancer, antiviral, antifungal, and antibacterial activities. The highest concentrations of rosmarinic acid and its isomers have been reported in the roots of A. rugosa. In this in vitro study, hairy roots of A. rugosa were obtained and the carbohydrates (sorbitol, mannitol, glucose, maltose, galactose, mannose, and sucrose) were evaluated to determine those that were optimal for rosmarinic acid production and hairy root growth. Antioxidant and antibacterial activities of extracts of A. rugosa were also assessed. The best carbon source for A. rugosa hairy root cultures was sucrose, considering biomass productivity (0.460 ± 0.034 mg/30 mL), rosmarinic acid production (7.656 ± 0.407 mg/g dry weight), and total phenolic content (12.714 ± 0.202 mg/g gallic acid equivalent). Antioxidant and antimicrobial activities were displayed by A. rugosa hairy roots cultured in liquid medium supplemented with 100 mM sucrose. Twenty-five bacterial strains, including multidrug-resistant bacteria and one pathogenic yeast strain, were used for antimicrobial screening of A. rugosa hairy roots. The hairy root extracts displayed antibacterial activity against Micrococcus luteus (KCTC 3063) and Bacillus cereus (KCTC 3624). The inhibition of these bacteria was greater using A. rugosa hairy roots with the highest levels of phenolic compounds cultured in the presence of sucrose, compared to hairy roots with the lowest levels of phenolic compounds cultured in the presence of fructose. Considering hairy root biomass, phenolic compound production, and antibacterial activity, sucrose is the best carbon source for A. rugosa hairy root cultures.

Antibacterial Effects of X-ray and MRI Contrast Media: An In Vitro Pilot Study

Some radiological contrast agents have been shown to have effects on bacterial growth. In this study, the antibacterial effect and mechanism of action of iodinated X-ray contrast agents (Ultravist 370, Iopamiro 300, Telebrix Gastro 300 and Visipaque) and complexed lanthanide MRI contrast solutions (MultiHance and Dotarem) were tested against six different microorganisms. Bacteria with high and low concentrations were exposed to media containing different contrast media for various lengths of time and at pH 7.0 and 5.5. The antibacterial effect of the media was examined in further tests using agar disk diffusion analysis and the microdilution inhibition method. Bactericidal effects were found for microorganisms at low concentrations and low pH. Reductions were confirmed for Staphylococcus aureus and Escherichia coli.

Effect of Some Plant-Based Substances on Microbial Content and Sperm Quality Parameters of Bull Semen

The rapid emergence of antibacterial resistance requires alternatives to antibiotics to be found, including for semen preservation. One of the possible alternatives would be to use plant-based substances with known antimicrobial effects. The objective of this study was to test the antimicrobial effect of pomegranate powder, ginger, and curcumin extract in two concentrations on bull semen microbiota after exposure for <2 h and 24 h. An additional aim was to evaluate the effect of these substances on sperm quality parameters. The bacterial count in semen was low from the beginning; however, a reduction was present for all tested substances compared with control. A reduction in bacterial count in control samples was also observed with time. Curcumin at a concentration of 5%, reduced bacterial count by 32% and was the only substance that had a slight positive effect on sperm kinematics. The other substances were associated with a decline in sperm kinematics and viability. Neither concentration of curcumin had a deleterious effect on sperm viability parameters measured by flow cytometry. The results of this study indicate that curcumin extract at a concentration of 5% can reduce the bacterial count and does not have a negative influence on bull sperm quality.

Antibacterial Effect of Carbon Nanomaterials: Nanotubes, Carbon Nanofibers, Nanodiamonds, and Onion-like Carbon

The increasing resistance of bacteria and fungi to antibiotics is one of the health threats facing humanity. Of great importance is the development of new antibacterial agents or alternative approaches to reduce bacterial resistance to available antibacterial drugs. Due to the complexity of their properties, carbon nanomaterials (CNMs) may be of interest for a number of biomedical applications. One of the problems in studying the action of CNMs on microorganisms is the lack of universally standardized methods and criteria for assessing antibacterial and antifungal activity. In this work, using a unified methodology, a comparative study of the antimicrobial properties of the CNM systemic kit against common opportunistic microorganisms, namely Escherichia coli and Staphylococcus aureus, was carried out. Multiwalled carbon nanotubes (MWNTs), catalytic filamentous carbon with different orientations of graphene blocks (coaxial-conical and stacked, CFC), ionic carbon (OLC), and ultrafine explosive nanodiamonds (NDs) were used as a system set of CNMs. The highest antimicrobial activity was shown by NDs, both types of CFCs, and carboxylated hydrophilic MWCNTs. The SEM results point out the difference between the mechanisms of action of UDD and CFC nanotubes.

Effect of Zinc Oxide Incorporation on the Antibacterial, Physicochemical, and Mechanical Properties of Pit and Fissure Sealants

This study aimed to evaluate the antibacterial, physicochemical, and mechanical properties of pit and fissure sealants containing different weight percentages of zinc oxide nanoparticles (ZnO NPs). The following amounts of ZnO NPs were added to a commercially available pit and fissure sealant (BeautiSealant, Shofu, Japan) to prepare the experimental materials: 0 wt.% (commercial control (CC)), 0.5 wt.% (ZnO 0.5), 1 wt.% (ZnO 1.0), 2 wt.% (ZnO 2.0), and 4 wt.% (ZnO 4.0). The antibacterial effect against S. mutans was confirmed by counting the colony-forming units (CFUs) and observing live/dead bacteria. In addition, ion release, depth of cure, water sorption and solubility, and flexural strength tests were conducted. When compared with the CC, the experimental groups containing ZnO NPs showed zinc ion emission and significantly different CFUs (p < 0.05) with fewer live bacteria. ZnO NP addition reduced the depth of cure and water solubility and increased water sorption in comparison with the CC (p < 0.05). However, all groups showed similar flexural strength (p > 0.05). The pit and fissure sealants containing ZnO NPs exhibited antibacterial activity against S. mutans with no negative effects on physicochemical and mechanical properties, and thus, these sealants can be ideal secondary caries prevention material.

Curcumae Rhizoma: A botanical drug against infectious diseases

Curcumae Rhizoma is the dry rhizome coming from Curcuma longa L. which grow widely in tropical south and southwest Asia. It has been used to treat conditions such as dermatoses, infections, stress, and depression. Moreover, in China, Curcumae Rhizoma and its active constituents have been made into different pharmaceutical preparations. Growing evidence suggests that these preparations can exert antioxidant, anti-inflammatory, and anti-cancer effects, which may play crucial roles in the treatment of various diseases, including cancer, infectious-, autoimmune-, neurological-, and cardiovascular diseases, as well as diabetes. The anti-infective effect of Curcumae Rhizoma has become a popular field of research around the world, including for the treatment of COVID-19, influenza virus, hepatitis B virus, human immunodeficiency virus, and human papilloma virus, among others. In this paper, the basic characteristics of Curcumae Rhizoma and its active constituents are briefly introduced, and we also give an overview on their applications and mechanisms in infectious diseases.

Antibacterial Effect of Acoustic Cavitation Promoted by Mesoporous Silicon Nanoparticles

As-prepared mesoporous silicon nanoparticles, which were synthesized by electrochemical etching of crystalline silicon wafers followed by high-energy milling in water, were explored as a sonosensitizer in aqueous media under irradiation with low-intensity ultrasound at 0.88 MHz. Due to the mixed oxide-hydride coating of the nanoparticles' surfaces, they showed both acceptable colloidal stability and sonosensitization of the acoustic cavitation. The latter was directly measured and quantified as a cavitation energy index, i.e., time integral of the magnitude of ultrasound subharmonics. The index turned out to be several times greater for nanoparticle suspensions as compared to pure water, and it depended nonmonotonically on nanoparticle concentration. In vitro tests with Lactobacillus casei revealed a dramatic drop of the bacterial viability and damage of the cells after ultrasonic irradiation with intensity of about 1 W/cm² in the presence of nanoparticles, which themselves are almost non-toxic at the studied concentrations of about 1 mg/mL. The experimental results prove that nanoparticle-sensitized cavitation bubbles nearby bacteria can cause bacterial lysis and death. The sonosensitizing properties of freshly prepared mesoporous silicon nanoparticles are beneficial for their application in mild antibacterial therapy and treatment of liquid media.

Z-Scheme CuO(x)/Ag/TiO(2) Heterojunction as Promising Photoinduced Anticorrosion and Antifouling Integrated Coating in Seawater

In the marine environment, steel materials usually encounter serious problems with chemical or electrochemical corrosion and fouling by proteins, bacteria, and other marine organisms. In this work, a green bifunctional Z-scheme CuO_x/Ag/P25 heterostructure coating material was designed to achieve the coordination of corrosion prevention and antifouling by matching the redox potential of the reactive oxygen species and the corrosion potential of 304SS. When CuO_x/Ag/P25 heterostructure was coupled with the protected metal, the open circuit potential under illumination negatively shifted about 240 mV (vs. Ag/AgCl) and the photoinduced current density reached 16.6 μA cm^-2. At the same time, more reactive oxygen species were produced by the Z-shape structure, and then the photocatalytic sterilization effect was stronger. Combined with the chemical sterilization of Ag and the oxide of Cu, the bacterial survival rate of CuO_x/Ag/P25 was low (0.006%) compared with the blank sample. This design provides a strategy for developing green dual-functional coating materials with photoelectrochemical anticorrosion and antifouling properties.

Investigating Biological Properties of Zinc Oxide/Curcumin Nanocomposites Synthesized from Stachys byzantina Extract by Green Synthesis

AIM AND OBJECTIVE

Nanotechnology attempts to solve the problem of antibiotic resistance. Zinc oxide nanoparticles and curcumin have been shown to be antimicrobial agents and promising anticancer agents, both on their own as well as in combination, and this incorporation will likely improve these properties via a possible additive effect.

MATERIALS AND METHODS

In this study, the synthesis of zinc oxide nanoparticles was done by the distilled extract of Stachys byzantina via the co-precipitation method, which is an economical and eco-friendly green synthesis method. Then, curcumin was loaded to zinc oxide nanoparticles. Antibacterial efficacy of the synthesized nanoparticles was evaluated against five intracellular bacteria; moreover, cytotoxicity was evaluated on breast cancer cells.

RESULTS

To confirm the synthesis and characterization of the nanoparticles, some techniques, such as XRD, FTIR, FESEM, and EDX were used. In addition, the antimicrobial activity of biosynthetic zinc oxide/curcumin nanocomposites was evaluated against selected bacterial strains. The uniform spherical nature of the zinc oxide nanoparticles was observed in the FESEM images, with the particle sizes ranging from 20 to 40 nm. The EDX spectrum showed the presence of C, O, and Zn and curcumin uptake on zinc oxide nanoparticles.

CONCLUSION

The zinc oxide/curcumin nanocomposites demonstrated an effective antibacterial effect in the disk diffusion method against five bacterial species. Furthermore, the zinc oxide/ curcumin nanocomposites showed a significant inhibitory effect on the growth of breast cancer cells in the MTT test. Thus, it seems that the synthesized zinc oxide/curcumin nanocomposites have promising high potential antimicrobial and cytotoxic effects.

The Antibacterial Effect, Biocompatibility, and Osteogenesis of Vancomycin-Nanodiamond Composite Scaffold for Infected Bone Defects

Purpose

The repair and treatment of infected bone defects (IBD) is a common challenge faced by orthopedic clinics, medical materials science, and tissue engineering.

Methods

Based on the treatment requirements of IBD, we utilized multidisciplinary knowledge from clinical medicine, medical materials science, and tissue engineering to construct a high-efficiency vancomycin sustained-release system with nanodiamond (ND) and prepare a composite scaffold. Its effect on IBD treatment was assessed from materials, cytology, bacteriology, and zoology perspectives.

Results

The results demonstrated that the Van-ND-45S5 scaffold exhibited an excellent antibacterial effect, biocompatibility, and osteogenesis in vitro. Moreover, an efficient animal model of IBD was established, and a Van-ND-45S5 scaffold was implanted into the IBD. Radiographic and histological analyses and bone repair-related protein expression, confirmed that the Van-ND-45S5 scaffold had good biocompatibility and osteogenic and anti-infective activities in vivo.

Conclusion

Collectively, our findings support that the Van-ND-45S5 scaffold is a promising new material and approach for treating IBD with good antibacterial effects, biocompatibility, and osteogenesis.

Antibacterial Effect of Zirconia Nanoparticles on Polyethyl Methacrylate Resin for Provisional Crowns

Objective

Mid-to-long term use of provisional crowns in the oral cavity is associated with bacterial adhesion and biofilm formation, thus necessitating provisional crowns exhibiting antibacterial properties to prevent the occurrence of gingivitis and periodontal disease. This study aimed to evaluate the antibacterial effect of zirconia nanoparticle-containing polyethyl methacrylate (PEMA) resin for provisional restorations.

Methods

Zirconia nanoparticles were added to the monomer of PEMA resin for provisional restorations, and the mixture was stirred for 2 h using a magnetic stirrer. Disk-shaped specimens were prepared by mixing the polymer with the nanoparticle solution. The control group contained pure PEMA resin samples, and the experimental groups Group Z2, Group Z4, and Group Z8 included PEMA resin specimens containing 2, 4, and 8% w/v zirconia nanoparticles, respectively. After analyzing the sample surfaces, the antibacterial effect of the specimens was evaluated using Streptococcus mutans. Statistical analysis was performed using Tukey's test and Mann-Whitney U-test, according to the normality result in the Shapiro-Wilk test.

Results

FE-SEM and EDX analyses revealed the successful addition of zirconia nanoparticles. Results showed no significant difference in the measured values for surface roughness and contact angle between the experimental and control groups; however, adhesion and biofilm thickness of S. mutans were significantly decreased in Group Z2, Group Z4, and Group Z8 compared to the control group (P < 0.05, P < 0.01, P < 0.01, respectively).

Conclusion

The addition of zirconia nanoparticles can lower the incidence of adhesion and biofilm thickness of S. mutans on PEMA resin used for provisional crowns. Thus, incorporating zirconia nanoparticles in repair materials for provisional crowns and PEMA resin can produce an antibacterial effect and prevent gingivitis, periodontal disease, and dental caries.