scholarly journals PLGA/Nano-ZnO Composite Particles for Use in Biomedical Applications: Preparation, Characterization, and Antimicrobial Activity

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Ana Stanković ◽  
Meltem Sezen ◽  
Marina Milenković ◽  
Sonja Kaišarević ◽  
Nebojša Andrić ◽  
...  

Copolymer poly (DL-lactide-co-glycolide) (PLGA) is extensively investigated for various biomedical applications such as controlled drug delivery or carriers in the tissue engineering. In addition, zinc oxide (ZnO) is widely used in biomedicine especially for materials like dental composites, as a constituent of creams for the treatment of a variety of skin irritations, to enhance the antibacterial activity of different medicaments and so on. Uniform, spherical ZnO nanoparticles (nano-ZnO) have been synthesized via microwave synthesis method. In addition to obtaining nano-ZnO, a further aim was to examine their immobilization in the PLGA polymer matrix (PLGA/nano-ZnO) and this was done by a simple physicochemical solvent/nonsolvent method. The samples were characterized by X-ray diffraction, scanning electron microscopy, laser diffraction particle size analyzer, differential thermal analysis, and thermal gravimetric analysis. The synthesized PLGA/nano-ZnO particles are spherical, uniform, and with diameters below 1 µm. The influence of the different solvents and the drying methods during the synthesis was investigated too. The biocompatibility of the samples is discussed in terms of in vitro toxicity on human hepatoma HepG2 cells by application of MTT assay and the antimicrobial activity was evaluated by broth microdilution method against different groups of microorganisms (Gram-positive bacteria, Gram-negative bacteria, and yeastCandida albicans).

2018 ◽  
Vol 7 (3) ◽  
pp. 122-129
Author(s):  
Fatma Youcefi ◽  
Ali Riazi ◽  
Meriem Mokhtar ◽  
Tefiani Choukri ◽  
Khaouani Naima

Chitosan is the most abundant natural organic polymer in nature. Its positive charge and its molecular arrangement confer interesting properties on the plane food, pharmaceutical, medical, cosmetic, water treatment. The present study was undertaken to study the physiochemical parameters and the in vitro antimicrobial activity of chitosan extracted from shrimp shells waste. The molecular weight of chitosan is 1414.33±16.99 kDa with, the percent of Ash 0,345±0,040 %, moisture is 2,98 ±0,13 % , and protein is 0.3 ±0,041 %.Chitosan produced (5 %) was also characterized with Fourier Transform Infrared Spectroscopy (FTIR) the spectrum of the chitosan sample from the shell recorded 16 peaks in the range of 689.40/cm and 3430.02 /cm. The antibacterial and antifungul activities of chitosan were examined against Escherichia coli ATCC10536, Pseudomonas aeruginosa ATCC 27853, Listeria monocytogenes ATCC7644, Staphylococcus aureus ATCC29213, Aspergillus niger ATCC 16888 and Candida albicans ATCC 10231 by agar wells diffusion the tests inhibitions zones diameters were 49,74± 0,75 , 54,35±0,93 , 42,27±1,07 , 32,95±0,28 and 53,73±0,64mm respectively. The minimum inhibitory concentration (MIC) using a broth microdilution method against tested microorganisms was ranging from 008% to 1.22%. These results open interesting perspectives of the chitosan. It can be used as new biomaterial with utility in many industrial areas.


2008 ◽  
Vol 3 (2) ◽  
pp. 149-154 ◽  
Author(s):  
Zoran Maksimović ◽  
Marina Milenković ◽  
Dragana Vučićević ◽  
Mihailo Ristić

AbstractThis paper presents the results of a study on chemical composition and antimicrobial activity of Thymus pannonicus All. (Lamiaceae) essential oil from Vojvodina province (north of Serbia). The investigated oil was hydrodistilled from a flowering plant and analysed by GC and GC-MS. Fifty-three constituents were identified (>97% of total oil), with geranial (41.42%, w/w) and neral (29.61%, w/w) as the most prominent. The antimicrobial activity of the oil was evaluated using agar disc diffusion and broth microdilution method against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, two strains of Klebsiella pneumoniae and two strains of Candida albicans. The essential oil exhibited antimicrobial activity to varying degrees against all tested strains. The maximum activity of T. Pannonicus oil was observed against E. coli, S. aureus and both tested strains of C. Albicans (MIC = 50 µ/ml, each). Moderate activity was observed against P. aeruginosa and one of the tested strains of K. Pneumoniae (MIC = 200 µ/ml), while E. faecalis and the other strain of K. Pneumoniae expressed a higher degree of resistance (MIC > 200 µ/ml). This study confirms that essential oil of T. pannonicus possesses remarkable in vitro antimicrobial activity against several medicinally important pathogens. This is attributable to lemon-scented citral, a mixture of geranial and neral, which has well-documented antimicrobial activity against a range of bacteria and fungi.


2019 ◽  
Vol 12 (1) ◽  
pp. 211-217 ◽  
Author(s):  
Luay Abu-Qatouseh ◽  
Eyad Mallah ◽  
Kenza Mansour

Acne vulgaris is one of the most common health problem where medical treatment is sought in adults worldwide. It has been long described the integral role of Propionibacterium acnes in the pathogenesis of this disease. In this study, a group of local herbs known for their antimicrobial effects were selected for the evaluation of potential anti-acnes effects in vitro. Phenolics and flavonoid contents of methanolic extracts of Eucalyptus globulus, Mentha rotundifolia, Inula viscosa, Utrica dioica, Malva sylvestris, Quercus calliprinos, Arum palaestinum and Achille aodorata collected from different regions in Jordan during 2016-2017 were screened for antimicrobial activity against Propionibacterium acnes by disc diffusion and by broth microdilution method. Measurement of release of interleukin 1 alpha from human skin explants by ELISA was used for the evaluation of anti-inflammatory effects of the herbal preparations and extracts. M. rotundifolia and E. globulus, showed the highest phenolic and flavonoid contents in contrast to M. sylvestris which showed the least phenolic contents. Moreover, polyphenolic fractions exhibited modest anti-acne activity of herbal extracts of E. globulus and A. palaestinum (MIC 0.125 mg/ml), U. dioica (0.25 mg/ml) and I. viscosa (0.5 mg/ml), compared to not significant antimicrobial activity for others (MIC >1mg/ml). Regarding anti-inflammatory effects of the tested fractions, E. globulus and A. palaestinum extracts showed inhibition of interleukin 1 alpha release by more than 60 % for concentrations of 0.5 mg/ml respectively. The presence of anti-inflammatory and anti-acne activities in the polyphenolic extracts of local medicinal plants would increase the potential of using these herbs in the control of Acne vulgaris.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Danny Ellen Meireles Leme ◽  
Allan Belarmino Rodrigues ◽  
Adriana Araújo de Almeida-Apolonio ◽  
Fabiana Gomes da Silva Dantas ◽  
Melyssa Fernanda Norman Negri ◽  
...  

The roots of Cochlospermum regium, popularly known as “algodãozinho-do-cerrado,” are used for the treatment of genitourinary infections. However, the removal of their subterranean structures results in the death of the plant, and the use of the leaves becomes a viable alternative. Therefore, the antimicrobial activity of Cochlospermum regium leaf’s ethanolic extract and its action on the biofilm formation of microorganisms associated with urinary infection were evaluated. The total phenolic compounds, flavoids, and tannins were quantified using the reagents Folin-Ciocalteu, aluminum chloride, and vanillin, respectively. The antimicrobial activity was evaluated by the broth microdilution method and the effect of the extract in the biofilm treatment was measured by the drop plate method. Cytotoxicity was evaluated by the method based on the reduction of MTS and the mutagenicity by the Ames test. The ethanolic extract of C. regium leaves presented 87.4 mg/EQ of flavonoids, 167.2 mg/EAG of total phenolic compounds, and 21.7 mg/ECA of condensed tannins. It presented reduction of the biofilm formation for E. coli and C. tropicalis and antimicrobial action of 1 mg/mL and 0.5 mg/mL, respectively. The extract showed no cytotoxicity and mutagenicity at the concentrations tested. This study demonstrated that C. regium leaves are a viable option for the treatment of genitourinary infections and for the species preservation.


2019 ◽  
Vol 15 (1) ◽  
pp. 38-50 ◽  
Author(s):  
Felipe R.S. Santos ◽  
Jéssica T. Andrade ◽  
Carla D.F. Sousa ◽  
Joice S. Fernandes ◽  
Lucas F. Carmo ◽  
...  

Background: Microbial infections is a global public health problem. The aim of this work was to synthesize and evaluate the antimicrobial activity of novel triazoles, morpholines and thiosemicarbazones. </P><P> Methods: Compounds were synthesized using 2,4-Dihydroxyacetophenone and 4-hydroxybenzaldehyde as starting materials. The antimicrobial activity of these compounds against bacteria and yeast was evaluated by the broth microdilution method. Results: The proposed route for synthesis gave high to moderate yields, moreover these compounds were successfully characterized by 1H NMR, 13C NMR and LC-MS. Antimicrobial testing indicated that the thiosemicarbazone and morphine derivatives had the best antimicrobial activity against the microorganisms tested with minimum inhibitory concentrations (MIC) between 0.29 and 5.30 µM. Thiosemicarbazone derivative (12) was able to inhibit the growth of C. tropicalis, with minimum fungicidal concentration (MFC) of 0.55 µM. In addition, this compound was active against E. coli, S. aureus and S. epidermidis, with MIC values ranging from 0.29 to 1.11 µM. Moreover, the morpholine derivative (15) had an MIC value of 0.83 µM against C. albicans and E. coli. Conclusion: We have efficiently synthesized a series of eleven novel triazoles, thiosemicarbazones and morpholine derivatives using 2,4-Dihydroxyacetophenone and 4-hydroxybenzaldehyde as starting materials. Thiosemicarbazone derivative (12) showed promising antifungal and antibacterial activity and these findings suggest that this compound can be used as scaffolds to design new antimicrobial drugs.


2012 ◽  
Vol 77 (6) ◽  
pp. 741-750 ◽  
Author(s):  
Vesna Vitnik ◽  
Marina Milenkovic ◽  
Sanda Dilber ◽  
Zeljko Vitnik ◽  
Ivan Juranic

A series of ?,?-unsaturated and ?-bromo carboxylic acids were identified as potent antimicrobial agents. Antimicrobial activity was evaluated using broth microdilution method. All acids 1-12 exhibit a significant activity against nine laboratory control strains of bacteria and two strains of yeast Candida albicans. The tested acids were efficiently prepared by optimized phase-transfer-catalyzed (PTC) reactions of ketones with bromoform and aqueous lithium hydroxide in alcoholic solvent with TEBA as catalyst.


2016 ◽  
Vol 62 (2) ◽  
pp. 67-77 ◽  
Author(s):  
Małgorzata Kikowska ◽  
Jolanta Długaszewska ◽  
Marcelina Maria Kubicka ◽  
Izabela Kędziora ◽  
Jaromir Budzianowski ◽  
...  

SummaryIntroduction:Due to increasing resistance against antibiotics and antifungal agents, crude plant extracts, fractions, and isolated pure compounds became a new interest as antimicrobial agents.Objectives:The antimicrobial activity of methanolic extracts and fractions ofEryngium planumL.,E. campestreL., andE. maritimumL. was evaluated against selected bacteria, yeast and mould, and compared in testedEryngiumspecies and in their organs.Methods:The antimicrobial activity was studied with use of broth microdilution method. The antibacterial (Staphylococcus aureus,Pseudomonas aeruginosa) and antifungal (Candida albicans,Aspergillus niger) activity of selected extracts and fractions compared with the reference substance was expressed by Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal/Fungicidal Concentration (MBC/MFC). The extract and fraction compounds were identified on the basis of TLC examination.Results:The saponin-phenolic acid fractions ofE. maritimumandE. planumand a saponin fraction ofE. planumshowed the highest activity againstS. aureus(MIC = 1–2.5 mg·ml−1). The growth ofC. albicanswas inhibited by methanolic extract ofE. planumcell suspension culture (MIC = 7.8 mg·ml−1).Conclusion:The antimicrobial activity depends on theEryngiumspecies, tested biomass, and microorganism.


2021 ◽  
Vol 19 (3) ◽  
pp. e0504-e0504
Author(s):  
Diana C. Pimentel-Betancurt ◽  

Aim of study: To evaluate the antimicrobial activity of the hexanic extract (HE) of Achyrocline satureioides on Paenibacillus larvae - a gram-positive spore-forming bacillus that affects the larval stage and causes American Foulbrood (AFB) - and its oral and contact toxicity on larvae and adult honey bees. Area of study: A. satureioides plants were collected in Santa Monica (32° 05’ 29” S, 64° 36’ 54” W, Córdoba. Argentina). The larvae and adults of Apis mellifera were obtained from the experimental apiary of the University of Córdoba, Spain. Material and methods: P. larvae 9 was previously isolated and identified in the Laboratory of General Microbiology (Dept. of Microbiology, National University of Río Cuarto, Argentina). The HE was obtained by liquid-liquid extraction. The minimum inhibitory concentration (MIC) of HE was determined by a microdilution method. This concentration and 2 ½ MIC were used for in vitro toxicity tests. Oral toxicity was tested on larvae, feeding them with both concentrations of the HE, while on adult bees the HE was spread to determine contact toxicity. Main results: The HE showed antimicrobial activity, the MIC obtained was 0.4 μg/mL. The HE presented very low toxicity at the MIC and 2 ½ MIC, with survival percentages to be around 95% for adult bees and larvae. Research highlights: The results show that this extract could be used for the development of an alternative product for a safe and effective treatment of AFB.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2835
Author(s):  
Anna Stochmal ◽  
Bartosz Skalski ◽  
Rostyslav Pietukhov ◽  
Beata Sadowska ◽  
Joanna Rywaniak ◽  
...  

Although the major components of various organs of sea buckthorn have been identified (particularly phenolic compounds), biological properties of many of these phytochemicals still remain poorly characterized. In this study, we focused on the chemical composition and biological activity of preparations that were obtained from sea buckthorn twigs and leaves. The objective was to investigate cytotoxicity of these preparations against human fibroblast line HFF-1, using MTT reduction assay, their anti- or pro-oxidant activities against the effects of a biological oxidant -H2O2/Fe—on human plasma lipids and proteins in vitro (using TBARS and carbonyl groups as the markers of oxidative stress). Antimicrobial activity of the tested preparations against Gram-positive (Staphylococcus aureus, S. epidermidis, Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), as well as against fungi (Candida albicans, C. glabrata) by the EUCAST-approved broth microdilution method, followed by growth on solid media, were also assessed. Our analysis showed significant differences in chemical composition and biological properties of the tested preparations (A–F). All tested preparations from sea buckthorn twigs (D–F) and one preparation from sea buckthorn leaves (preparation C) may be a new source of phenolic antioxidants for pharmacological and cosmetic applications.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2319
Author(s):  
Klara Lalouckova ◽  
Lucie Mala ◽  
Petr Marsik ◽  
Eva Skrivanova

Ultra-high performance liquid chromatography/mass spectrometry showed soyasaponin I and the isoflavones daidzein, genistein, and glycitein to be the main components of the methanolic extract of the Korean soybean fermented product doenjang, which is known to be a rich source of naturally occurring bioactive substances, at average contents of 515.40, 236.30, 131.23, and 29.00 ng/mg, respectively. The antimicrobial activity of the methanolic extract of doenjang against nine Staphylococcusaureus strains was determined in vitro by the broth microdilution method to investigate its potential to serve as an alternative antibacterial compound. The results suggest that the extract is an effective antistaphylococcal agent at concentrations of 2048–4096 µg/mL. Moreover, the tested extract also showed the ability to inhibit the growth of both methicillin-sensitive and methicillin-resistant animal and clinical S. aureus isolates. The growth kinetics of the chosen strains of S. aureus at the minimum inhibitory concentration of the methanolic extract of doenjang support the idea that the tested extract acts as an antibacterial compound. To the best of our knowledge, this is the first report on the antistaphylococcal action of the methanolic extract of doenjang thus, additional studies including in vivo testing are necessary to confirm this hypothesis.


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