Weak Antibacterial Effect Research Articles

Comprehensive Metabolomics Profiling and Bioactivity Study of Lycium shawii (Awsaj) Extracts with Particular Emphasis on Potential Anti-Malarial Properties

Background/Objectives: Although malaria is one of the oldest known human diseases, it continues to be a major global health challenge. According to UNICEF, the global malaria mortality rate exceeded 600,000 annually in 2022, which includes more than 1000 children dying each day. This study aimed to investigate the comprehensive chemical profile and biological activities, particularly the antimalarial activity, of Lycium shawii (Awsaj), a shrub traditionally used in the Arabian Peninsula, Middle East, India, and Africa to treat a myriad of ailments. Methods: Crude extracts of L. shawii were prepared using water, ethanol, methanol, and acetone. Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) were utilized to perform untargeted metabolomics to maximize metabolite detection and tentatively identify bioactive phytochemicals. The total phenolic content (TPC) was measured for each extract, and bioassays were conducted to evaluate their antimalarial, antibacterial, and anti-inflammatory activities, particularly those of the water extract, which is the traditional method of consumption in Arabian folk medicine. Results: A total of 148 metabolites were detected, 45 of which were classified as phytochemicals. The bioassays revealed that the water extract that is traditionally used showed promising antimalarial potential by significantly inhibiting β-hematin formation in vitro at 1 mg/mL (with an absorbance of 0.140 ± 0.027). This is likely due to the rich presence of quinoline in the aqueous extract among several other bioactive phytochemicals, such as phenylpropanoids, alkaloids, flavonoids, and benzenoids. However, their anti-inflammatory and antibacterial activities were found to be weak, with only a minor inhibition of nitric oxide (NO) production in LPS-induced RAW 264.7 cells at a concentration of 500 µg/mL and weak antibacterial effects against pathogens like P. aeruginosa, MRSA, A. baumannii, and K. pneumoniae with an MIC of 500 μg/mL. The results also revealed that the methanolic extract had the highest TPC at 26.265 ± 0.005 mg GAE/g. Conclusions: The findings support the traditional medicinal use of L. shawii and highlight its potential as a source of novel therapeutic compounds, particularly for treating malaria. This study encourages further research to isolate and develop effective plant-based anti-malarial agents.

Manipulated Slow Release of Florfenicol Hydrogels for Effective Treatment of Anti-Intestinal Bacterial Infections.

The difficulty of establishing slow release at intestinal infection sites, weak antibacterial effects, as well as the limited broad use of florfenicol oral formulations are the main targets of the current study. Novel hydrogels derived from sodium alginate were developed using a complexation form for florfenicol delivery to achieve slow release at the site of intestinal infection and enhance its antibacterial activity against Escherichia coli. The optimal formulation, physicochemical properties, stability, pH-responsive performance, antibacterial activity, and in vitro biosafety of the florfenicol hydrogels have been studied systematically. The created hydrogels had a consistent spherical morphology, with an average diameter of 531.9±12.6 nm. Energy dispersive spectroscopy and Fourier transform infrared indicated that florfenicol hydrogels have been successfully prepared through complexation force. Furthermore, it is shown that florfenicol hydrogels hold outstanding stability, excellent sustained release, and faster swelling and release at intestinal pH due to pH-responsiveness. The florfenicol hydrogels had no obvious structural destruction in simulated gastric juice (pH=1.2) for 12 hrs and were highly stable. However, the hydrogels began to be destroyed after 5minutes in simulated intestinal fluid (SIF), and this decomposition was continuous. With the decomposition of the structure of florfenicol hydrogels, the encapsulated florfenicol was also slowly released, and thus, it achieves the slow-release effect. Additionally, the florfenicol hydrogels showed a low hemolytic ratio and greater antibacterial activity compared with florfenicol. The blended formulation creates a promising oral matrix intended for the slow-release of florfenicol along the gastrointestinal tract.

A cinnamon and clove essential oil mix microencapsulated with hydroxypropyl-β-cyclodextrin: Study on physicochemical, antibacterial, and low salt pickles preservation properties.

In order to overcome the technical challenges of poor stability and weak antibacterial effects of individual essential oil in food preservation applications, the present study aimed to encapsulate cinnamon and clove essential oil compound by using spray-drying technique. The combination of cinnamon and clove essential oils was determined to have good synergistic bacteriostatic effects by the checkerboard dilution method, and the best bacteriostatic effect could be obtained when the volume ratio was 7:3 for compounding. Microcapsules were prepared using hydroxypropyl-β-cyclodextrin (HPCD) as wall material and compound essential oil as core material, the optimal conditions for the microcapsule preparation process through a one-way test were: homogenizing speed of 8000r/min, wall material addition of 2%, HPCD to EO ratio of 1:3, EO to T-80 ratio of 1.5:1, and homogenizing time of 8min. The physicochemical properties of the prepared compound essential oil microcapsules (EOM) were characterized, and the results showed that the EOM was successfully encapsulated in HPCD with good physicochemical properties, and the encapsulation rate of the prepared microcapsules was measured to be 65.82±4.00%. The thermal stability of the encapsulated EOM was improved, and volatilization of the essential oils was effectively inhibited. In addition, the EOM showed antibacterial activity against the five types of bacteria tested, and the number of surviving bacteria decreased by about 17-18% after 72h. The preservation experiment of low salt pickles showed that the EOM was more effective in maintaining the quality and prolonging the shelf life of the pickles compared with commercial sodium benzoate, which also demonstrated the potential application of EOM in preserving low-salt pickles. This study provides a feasible and new technical strategy for more effective application of plant essential oils in food preservation.

Investigations on the Endemic Species Taraxacum mirabile Wagenitz: HPLC-MS and GC-MS Studies, Evaluation of Antioxidant, Anti-Inflammatory, and Antimicrobial Properties, and Isolation of Several Phenolic Compounds.

In this study, the aim was to investigate the chemical content and in vitro antioxidant, antimicrobial, and anti-inflammatory activities of petroleum ether (PE), dichloromethane (DCM), ethyl acetate (EA), and n-butanol (n-BuOH) fractions obtained from ethanol extracts of the aerial parts and roots of the endemic Taraxacum mirabile Wagenitz. This plant is found in the Aksaray-Eskil region and has not been studied in phytochemical studies before. In this context, the chemical content of the aerial parts and root PE fractions was analyzed by GC-MS analysis in terms of terpenes and steroid substances. The composition of phenolic compounds in the aerial parts and root DCM and EA fractions was determined by HPLC-MS analysis. Apigenin, luteolin, and caffeic acid were isolated from the EA fraction of aerial parts. The total amounts of phenolic substances and the DPPH, ABTS, and FRAP antioxidant activities of PE, DCM, EA, and n-BuOH fractions were investigated, and it was found that the fractions had the ability to scavenge DPPH• and ABTS•+ radicals, as well as to reduce Fe (III) to Fe (II); however, all of the fractions were significantly less effective (p < 0.05) than the reference antioxidant quercetin. Considering that antioxidants can also exert an anti-inflammatory effect, these fractions were evaluated for their ability to inhibit cyclooxygenases (COX-1 and COX-2), the key enzymes of arachidonic acid metabolism that lead to the production of important mediators of inflammation. It was observed that fractions had the ability to inhibit both enzymes, suggesting their possible beneficial effects against inflammation. However, no extract had greater inhibitory activity than the positive control, indomethacin. The antimicrobial activity was determined against different bacterial and fungal strains. It was observed that the aerial parts and root n-BuOH and EA fractions showed weak antibacterial effects. No antifungal activity has been detected against Candida sp.

Bi2Se3/PAAS Hydrogels with Photothermal and Antioxidant Properties for Bacterial Infection Wound Therapy by Improving Vascular Function and Regulating Glycolipid Metabolism.

Skin is the largest organ in the human body, and it is also the most important natural barrier. However, some accidents can cause skin damage. Bacterial infections and inflammatory reactions can hinder wound healing. Therefore, eliminating bacterial infections and regulating oxidative stress are essential. The use of antibiotics is no longer sufficient because of bacterial resistance. The development of new nanomaterials provides another way of thinking about bacterial drug resistance. In this study, bismuth selenide is modified with polyethylpyrrolidone to obtain a 2D nanomaterial with negligible toxicity and then added to a sodium polyacrylate hydrogel, which is nontoxic and has strong tissue adhesion and a weak antibacterial effect. To further enhance antibacterial performance, photothermal therapy is a good strategy. Under near-infrared light, Bi2Se3/PAAS shows a strong bactericidal effect. Bi2Se3/PAAS hydrogels also have certain antioxidant effects and are used to remove excess free radicals from wound infections. The effective therapeutic effect of Bi2Se3/PAAS/NIR on methicillin-resistant Staphylococcus aureus (MRSA) infection is further verified in animal models. Transcriptome analysis reveals that the Bi2Se3/PAAS hydrogel improves the function of vascular endothelial cells, regulates glucose and lipid metabolism, and promotes the healing of infected wounds.

Study of antibacterial effects of Transcarpathian clinoptilolite compositions modified in different chemical ways

Background. Natural clinoptilolite (CL) meets most of the requirements for the multifunctional mineral nanomaterials. It is considered biologically neutral and non-toxic. CL is the only representative of natural zeolites that has been approved for use in medical practice and food industry. Antibacterial activity of Transcarpathian clinoptilolite was shown to be enhanced via its modification using thermal, chemical and mechanochemical treatments. The natural form of this mineral contains a significant concentration of surface silanol (-OH) groups. An increase in the efficiency of zeolite-based materials in terms of biological activity can be achieved by means of thermal and chemical treatments, replacement of cations in the exchange complex, doping with heavy metal cations, or mechanochemical treatment. Materials and Methods. FTIR spectroscopy, Electronic spectroscopy, Particle size distribution, IR spectroscopy, Crystal structure and morphology, Measurement of antibacterial activity. Results. Intact and thermally modified CL was shown to exhibit weak antibacterial effect, while its mechanical modification led to an enhanced activity. It was established that H-form of clinoptilolite demonstrated higher efficiency in inhibiting the growth of Gram-positive bacteria, compared to the Na-form of the clinoptilolite, but their effect on growth of Gram-negative bacteria was insignificant. Such an activity was accompanied by an increase in the specific surface area and porosity that promoted better contact with bacteria. Conclusions: Different samples of CL had dissimilar effect on specific types of bacteria. Intact CL has a weak antibacterial activity of inhibiting growth of microorganisms, while thermal, chemical, and mechanical modifications of the CL structure differentially increased such an activity. The H-form of CL inhibited the growth of Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) more effectively compared to the Na-form of CL. However, H-form of CL has a weak effect on growth of the Gram-negative bacteria (Pseudomonas aeruginosa, Pseudomonas fluorescens).

Antibacterial and Antioxidant Activities of Triterpenoids Isolated from Endemic Euphorbia arbuscula Stem Latex.

This research study aimed to investigate the chemical constituents and evaluate the antibacterial and antioxidant activities of stem latex extracts from the endemic medicinal plant Euphorbia arbuscula found on Socotra Island, Yemen. The study aimed to assess the potential medicinal and veterinary uses of this plant, representing the first evaluation of its properties. The stem latex was extracted using ethanol, and the resulting oil underwent analysis using GC-MS to identify eight compounds. In addition, chromatographic techniques were employed to isolate two triterpenoids, lanosterol and lupeol, from the stem latex. The structures of these compounds were confirmed using IR, MS, and NMR techniques. The antibacterial activity of the extracts and isolated compounds was evaluated against three bacterial strains using the disc diffusion method, revealing only weak antibacterial effects. The study also investigated the antioxidant activity using the DPPH assay, where the ethyl acetate extract exhibited the highest activity with an IC50 value of ±13.55 µg/mL, followed by the chloroform extract with an IC50 of ±21.87 µg/mL. These findings emphasize the potential of Euphorbia arbuscula in the development of new medicines, particularly due to its notable antioxidant activity. The research methodology employed a scientifically rigorous approach, utilizing a comprehensive range of analytical techniques. However, further investigation is required to fully assess the plant's potential as a therapeutic agent.

A new 30-norfriedelane triterpnoid from Caloncoba lophocarpa (Oliv.) Gilg. (Achariaceae)

The chemical investigation of the methanol extract of the roots of Caloncoba lophocarpa (Oliv.) Gilg. exhibited a new 30-norfriedelane triterpenoid, laphocarpanol (1), together with seven known compounds, caloncobalactone (2), friedelin (3), friedelanol (4), asperphernamate (5), stigmasterol (6), sitosterol (7) and sitosterol-3-O-β-D-glucopyranoside (8). The structures of the compounds were elucidated by extensive spectroscopic and spectrometric analyses (1D and 2D NMR, ESI-MS) and by comparison with previously reported data. All the compounds were tested for their antifungal and antibacterial activities. Compound 1 displayed weak antibacterial effect with MIC value of 62.5 μg/mL against Shigella flexineri. All the isolates were found to be inactive against the tested fungal strains.

Synthesis and antibacterial activity of the cyclic 2-substituted thyenopyrimidin-4-ones by bubbling with hydrochloric gas of cycloalkane[&lt;i&gt;b&lt;/i&gt;]-2-(&lt;i&gt;n&lt;/i&gt;-acylamino)-3-cyanothiophenes

The reaction of acylation of some 2-amino-3-cyanocycloalkane[ b ]thiophenes with chlorides of various carboxylic acids gave the corresponding cycloalkane[ b ]-2-( N -acylamino)-3-cyanothiophenes, bubbling with hydrochloric gas from an alcoholic solution of amidonitriles to obtain cyclic 2-substituted thienopyrimidin-4-ones. The study of the antibacterial activity of the compounds against gram-positive and gram-negative microorganisms showed that most of them exhibit a weak antibacterial effect against staphylococci.

Two new 30-norfriedelane triterpenes from Caloncoba glauca (P. Beauv.) Gilg (Achariaceae)

The chemical investigation of the methanolic root extract of Caloncoba glauca (P. Beauv.) Gilg exhibited two new 30-norfriedelane triterpenes, glaucalactones A and B (1–2), together with eight known compounds, caloncobalactone (3), friedelin (4), friedelanol (5), 3-oxo-friedelan-28-oic acid (6), stigmasterol (7), β-sitosterol (8), β-sitosterol-3-O-β-D-glucopyranoside (9) and pentacosanoic acid (10). The structures of the isolates were elucidated by extensive spectroscopic and spectrometric analyses (1D and 2D NMR, ESI-MS) and by comparison with previously reported data. All the compounds were tested for their antioxidant, antifungal and antibacterial activities. Compound 1 displayed weak antibacterial effect with MIC value of 125 μg/mL against Staphylococcus aureus and Escherishia coli. Compound 6 exhibited moderated antifungal activity against Candida krusei with MIC value of 62.5 μg/mL. All the isolates were found to be inactive as antioxidants in the DPPH, ABTS and FRAP assays.

Bioactive constituents from Flacourtia vogelii Hook.f. (Flacourtiaceae)

The chemical investigation of the methanolic root extract of Flacourtia vogelii led to the isolation of a new arylbenzoate derivative, vogelinal (1), together with thirteen known compounds (2–14). The structures of the isolates were elucidated by extensive spectroscopic and spectrometric analyses (1D and 2D NMR, ESI-MS) and by comparison with previously reported data. All the compounds were tested for their antioxidant, antifungal and antibacterial activities. Compound 7 exhibited the highest antioxidant potential, with RSa 50 of 11.80 ± 2.13 µg/mL, RSa 50 of 42.60 ± 6.32 µg/mL and RC50 of 51.60 ± 7.71 µg/mL for the DPPH, ABTS and FRAP assay, respectively. Compound 13 displayed weak antifungal effect with MIC value of 125 μg/mL against Candida parapsilosis. Compound 8 showed weak antibacterial effect with MIC value of 125 μg/mL, against Shigella dysenteria. The present study, conclude that this species could be a promising source of antioxidant and antibacterial constituents.

Bacteriostasis of Platelet-Rich Plasma and Its Derivatives in Vitro and Its Relationship with PF4

To investigate the bacteriostatic effect of platelet-rich plasma (PRP) and its derivative platelet gel (PG) supernatant on Escherichia coli in vitro and its relationship with platelet factor 4 (PF4). Apheresis platelets donated by healthy volunteers were obtained from the Blood station of Lu an Blood Center as the source of PRP. The counts of platelet, white blood cell and red blood cell in PRP and its derivative PG supernatant were detected by automatic hematology analyzer. Bacterial growth of PRP and PG supernatants co-cultured with bacteria for different time was observed by plate coating culture method, and the contents of PF4 in PRP and PG supernatants were detected by ELISA. Apheresis platelets were collected from 28 healthy volunteers with a median age of 33 (21-56) years old. PRP can inhibit the growth of escherichia coli, but there were individual differences in antibacterial effect within 24 hours. PRP of 13 healthy volunteers had strong antibacterial effect at 24 hours, 7 cases had weak antibacterial effect at 24 hours, and 8 cases had no antibacterial effect at 24 hours. PG supernatant showed no significant individual difference, and all of them had bacteriostatic effect within 12 hours, but no bacteriostatic effect after 12 hours. There was no statistical difference in the bacteriostatic effect of PRP at 24 hours between healthy volunteers aged ≤30 years and >30 years (P>0.05), and there was no statistical difference between the white blood cell count ≤0.1×109/L and (0.1-1) ×109/L groups (P>0.05). There was significant difference in the bacteriostatic effect of PRP between the two groups with platelet content ≤1 000×109/L and >1 000×109/L (P<0.05). The platelet count in PRP was higher than that in PG supernatant ［(911.57±160.52) ×109/L vs 0］. The PF4 level in PRP was higher than that in PG supernatant (23623.34±9822.14 vs 6664.74±4065.83, P<0.05). Both PRP and PG supernatant have antibacterial effects in Escherichia coli. The bacteriostatic effect of PRP was better than that of PG supernatant, and the platelet and PF4 contents in PRP were higher than those in PG supernatant, suggesting that the platelet and PF4 levels play an important role in bacteriostasis.

Study the antibacterial effect of N_butanol extract of Urtica dioica

Since ancient times Urtica dioica has been used as an herbal medicine in Western Asia. The current study demonstrates the anti-bacterial effect of N_butanol extraction of Urtica dioica. The antibacterial effect was tested against some of gram-positive bacteria and gram-negative bacteria isolated&#x0D; &#x0D; from hospitalized patients having urinary tract infection. Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa was used. Urticasea is a family of plant known for their medicinal activity from folk medicine. Urtica dioica is a member of urticasea and it is known for it is antibacterial effect.&#x0D; Methods&#x0D; The leaves of Urtica dioica were collected in Iraq from jisr dayla district in Baghdad province in april 2019.The N_butanol extraction was compared with the drug ciprofloxacin. Disc diffusion method was used to determine the sensitivity of the samples.&#x0D; Results &#x0D; The N_ butanol extract shows weak inhibitory effect on Escherichia coli while other strain does not affect by extract comparing with ciprofloxacin.&#x0D; Conclusion&#x0D; The N_butanol extract of urtica dioica have weak antibacterial effect when compared with ciproflxacine

Synthesis and Characterization of Pyrazole-Enriched Cationic Nanoparticles as New Promising Antibacterial Agent by Mutual Cooperation.

A pyrazole derivative (CB1) was previously evaluated in vivo for various pharmacological activities (with the exception of antimicrobial effects), using DMSO as the administrative medium, mainly due to its water insolubility. Considering the global necessity for new antimicrobial agents, CB1 attracted our attention as a candidate to meet this need, mainly because the secondary amine group in its structure would make it possible to obtain its hydrochloride salt (CB1H), thus effortlessly solving its water-solubility drawbacks. In preliminary microbiologic investigations on Gram-negative and Gram-positive bacteria, CB1H displayed weak antibacterial effects on MDR isolates of Gram-positive species, nonetheless better than those displayed by the commonly-used available antibiotics. Therefore, aiming at improving such activity and extending the antibacterial spectrum of CB1H to Gram-negative pathogens, in this first work CB1 was strategically formulated in nanoparticles using a cationic copolymer (P7) previously developed by us, possessing potent broad-spectrum bactericidal activity. Using the nanoprecipitation method, CB1H-loaded polymer nanoparticles (CB1H-P7 NPs) were obtained, which were analyzed by attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy to confirm the successful loading. Additionally, CB1H-P7 NPs were fully characterized in terms of morphology, size, polydispersity indices, surface charge, DL%, and EE%, as well as release and potentiometric profiles.

In Vitro Evaluation of the Antibacterial Activity of EndoSeal MTA, iRoot SP, and AH Plus against Planktonic Bacteria.

This study aimed to investigate the antibacterial activity of three endodontic sealers, AH Plus, iRoot SP, and EndoSeal MTA, against four planktonic bacteria species. The antibacterial activity of the three endodontic sealers was assessed using a modified direct contact test. Bacteria suspension of Actinomycoses viscosus, Enterococcus faecalis, Staphylococcus aureus, and Streptococcus mutans were left in contact with the sealers that were pre-set or set for 1, 3, 7, and l4 days for an hour. Freshly mixed AH Plus and EndoSeal MTA were highly effective against all four tested bacteria as no surviving bacteria were recovered after treatment. Meanwhile, freshly mixed iRoot SP was not able to kill all bacteria, regardless of the species, demonstrating a weak antibacterial effect. After 24 h, AH Plus lost its antibacterial activity. EndoSeal MTA showed a strong and extended bactericidal effect against S. aureus and S. mutans for 3 days and A. viscosus for 7 days. In conclusion, fresh AH Plus and EndoSeal MTA exhibited a potent effect against all four bacteria species. EndoSeal MTA remained effective after setting when tested against A. viscosus, S. aureus, and S. mutans. Among all tested sealers, iRoot SP demonstrates the weakest antibacterial activity.

Development of Functional Synbiotic Flavored Fermented Skim Milk Drinks Supplemented with Doum (&amp;lt;i&amp;gt;Hyphaene thebaica&amp;lt;/i&amp;gt; L.) and Carob (&amp;lt;i&amp;gt;Ceratonia siliqua&amp;lt;/i&amp;gt;) Fruits Powder for Nutritional, Antimicrobial and High Antioxidant Activities

The present study was carried out to make new healthy synbiotic flavored fermented skim milk drinks (SFFSD) supplemented with either Doum (Hyphaene thebaica L.) or Carob (Ceratonia siliqua) fruits powder for nutritional, antioxidant and antimicrobial activities. The HPLC analysis showed higher phenolic and flavonoid content in Doum extract than that of Carob. The antimicrobial activity of the methanolic extracts of both Doum and Carob against foodborne pathogens showed that the most sensitive indicators were Bacillus cereus, C. albicans and S. aureus, followed by T. mentagrophyte and E. coli wherein, the diameter of clear zones was, 29, 27, 24, 23 and 13 mm, respectively. While no effect was noticed against Aspergillus flavus. On the other hand, the methanolic extract of Carob fruit exhibited only a weak antibacterial effect against B. cereus (20 mm). Six treatments of SFFSD were made using both Doum or Carob fruit powder as prebiotic and Lactobacillus paracasei as probiotic bacteria. The added levels from Doum were 2%, 4% and 6%, while that added from Carob were 5%, 10% and 15%. Adding Doum and Carob powder increased the containing of minerals; Ca, K, Mg and iron compared with control. Both viscosity and viability of L. paracasei for the SFFSD were increased with increasing the added levels from either Doum or Carob, compared with the control. Samples of SFFSD containing Carob powder, show superior sensory for all parameters and total score points during storage period, especially at a level of 10%. It seems evident that samples supplemented with Doum powder were also acceptable.

Antibacterial Meroterpenoids, Merochlorins G-J from the Marine Bacterium Streptomyces sp.

Four new chlorinated meroterpenoids, merochlorins G−J (1−4), and 10, a dihydronaphthalenedione precursor, along with known merochlorins A (5) and C−F (6−9), were obtained from cultivation of the bacterium strain Streptomyces sp. CNH-189, which was isolated from marine sediment. The planar structures of compounds 1−4 and 10 were elucidated by interpretation of MS, UV, and NMR spectroscopic data. The relative configurations of compounds 1−4 were determined via analysis of nuclear Overhauser effect (NOE) spectroscopic data, after which their absolute configurations were established by comparing the experimental electronic circular dichroism (ECD) spectra of compounds 1−4 to those of previously reported possible enantiomer models and DP4 calculations. Compound 3 displayed strong antibacterial activities against Bacillus subtilis, Kocuria rhizophila, and Staphylococcus aureus, with MIC values of 1, 2, and 2 μg/mL, respectively, whereas compound 1 exhibited weak antibacterial effects on these three strains, with a 16−32 μg/mL MIC value range.

Silver Nanoparticles Formation by Jatropha integerrima and LC/MS-QTOF-Based Metabolite Profiling.

The broad application of metal nanoparticles in different fields encourages scientists to find alternatives to conventional synthesis methods to reduce negative environmental impacts. Herein, we described a safe method for preparing silver nanoparticles (J-AgNPs) using Jatropha integerrima leaves extract as a reducing agent and further characterize its physiochemical and pharmacological properties to identify its therapeutic potential as a cytotoxic and antimicrobial agent. The biogenic synthesized J-AgNPs were physiochemically characterized by ultraviolet-visible spectroscopy, dynamic light scattering (DLS), transmission electron microscope (TEM), and energy-dispersive X-ray spectroscopy. HPLC-DAD, followed by LC/MS and the Fourier-transform infrared spectroscopy (FTIR), was applied to detect the biomolecules of J. integerrima involved in the fabrication of NPs. Furthermore, J-AgNPs and the ampicillin-nanocomposite conjugate were investigated for their potential antibacterial effects against four clinical isolates. Finally, cytotoxic effects were also investigated against cancer and normal cell lines, and their mechanism was assessed using TEM analysis and confocal laser scanning microscopy (LSM). Ag ions were reduced to spherical J-AgNPs, with a zeta potential of −34.7 mV as well as an average size of 91.2 and 22.8 nm as detected by DLS and TEM, respectively. HPLC GC/MC analysis identified five biomolecules, and FTIR suggested the presence of proteins besides polyphenolic molecules; together, these molecules could be responsible for the reduction and capping processes during NP formation. Additionally, J-AgNPs displayed a strong antibacterial effect, although the ampicillin conjugated form had a very weak antibacterial effect. Furthermore, the NPs caused a reduction in cell viability of all the treated cells by initiating ultrastructural changes and apoptosis, as identified by TEM and LSM analysis. Therefore, J-AgNPs can be formed using the leaf extract from the J. integerrima plant. Furthermore, J-AgNPs may serve as a candidate for further biochemical and pharmacological testing to identify its therapeutic value.

Preparation and Performance Study of Antibacterial Materials Based on GO−TiO2

AbstractA composite of graphene oxide (GO) and titanium (IV) oxide was prepared through a hydrothermal treatment by mixing TiO2 with GO. The GO was obtained by using an improved Hummers’ method. The composite (TiO2‐GO) only indicated a weak antibacterial effect against Escherichia coli under dark conditions. Upon introduction of silver‐based nanomaterials, two new composites viz. GO−TiO2−Ag and GO−TiO2−Ag2S were prepared also through hydrothermal reaction. While both composites exhibit stronger antibacterial activities against E. coli than TiO2‐GO in dark, GO−TiO2−Ag composite exhibited higher bactericidal rate (92 %) than GO−TiO2−Ag2S (40 %).

Novel dental implant modifications with two-staged double benefits for preventing infection and promoting osseointegration in vivo and in vitro

Peri-implantitis are a major problem causing implant failure these days. Accordingly, anti-infection during the early stage and subsequent promotion of osseointegration are two main key factors to solve this issue. Micro-arc oxidation (MAO) treatment is a way to form an oxidation film on the surface of metallic materials. The method shows good osteogenic properties but weak antibacterial effect. Therefore, we developed combined strategies to combat severe peri-implantitis, which included the use of a novel compound, PD, comprising dendrimers poly(amidoamine) (PAMAM) loading dimethylaminododecyl methacrylate (DMADDM) as well as MAO treatment. Here, we explored the chemical properties of the novel compound PD, and proved that this compound was successfully synthesized, with the loading efficiency and encapsulation efficiency of 23.91% and 31.42%, respectively. We further report the two-stage double benefits capability of PD + MAO: (1) in the first stage, PD + MAO could decrease the adherence and development of biofilms by releasing DMADDM in the highly infected first stage after implant surgery both in vitro and in vivo; (2) in the second stage, PD + MAO indicated mighty anti-infection and osteoconductive characteristics in a rat model of peri-implantitis in vivo. This study first reports the two-staged, double benefits of PD + MAO, and demonstrates its potential in clinical applications for inhibiting peri-implantitis, especially in patients with severe infection risk.