Papers by Oana Elena Nicolaescu
Journal of Science and Arts, 2021
Osteomyelitis continues to be a major concern when orthopedic surgery is performed. Orthopedic in... more Osteomyelitis continues to be a major concern when orthopedic surgery is performed. Orthopedic infections have an incidence of 5% to 10% but their management proves to be quite difficult due to both biofilm formation and limited access of the drug to the infected area when systemic treatment is employed. The aim of the study was to optimize the synthesis process of a gentamicin loaded poly(-lactic-co-glycolic) acid (PLGA) based biodegradable composite by varying parameters that affect both efficiency encapsulation and nanoparticle size. Furthermore, a kinetic study was conducted to study the biodegradation process of the polymer. Gentamicin loaded PLGA nanoparticles were obtained using the double emulsion technique which allows the variation of several factors such as gentamycin concentration, PLGA concentration, buffer concentration and stirring speed. Out of the four factors evaluated, gentamicin concentration had the highest impact on both encapsulation efficiency and nanoparticl...
Herbal extracts with antimicrobial potential represent an important research directive, in the cu... more Herbal extracts with antimicrobial potential represent an important research directive, in the current medical world, aiming to isolate active components, to develop new chemotherapeutic agents with applicability in the treatment or use as adjuvant therapy in infectious states. Antimicrobial properties of plants are conferred by their ability to synthesize certain secondary metabolites with relatively complex structures. The last century has been marked by sustained efforts to search for new natural compounds with antibacterial therapeutic properties, due to the gradual reduction in the number of effective allopathic antibiotics and the toxic effects of antibiotic residues. Numerous in vitro studies have shown that plants have antibacterial efficacy, discovering the importance of little-studied natural resources in this regard, as being effective in fighting against bacterial resistance and destroying bacterial agents. In this study, the antibacterial effect of the fresh onion and g...
Coatings, 2019
There is an increased interest in developing biocomposite implants with high biocompatibility in ... more There is an increased interest in developing biocomposite implants with high biocompatibility in order to be used as grafts or prostheses in orthopedic surgery. The purpose of the study was to determine the biocompatibility of titanium implants coated with synthesized hydroxyapatite-alendronate composites. The implants were obtained using Matrix Assisted Pulsed Laser Evaporation technique (MAPLE). The hydroxyapatite-alendronate composites were synthesized using the wet precipitation method. Immunofluorescence microscopy showed that composites support mesenchymal stem cells (MSCs) adhesion. Bone cells as well as human MSCs adhere to hydroxyapatite (HA)-based thin films obtained by matrix assisted laser deposition onto titanium. Alendronate doping into the films increased the number of cell-biomaterial focal points as compared to HA only. Thus, the synthesis of hydroxyapatite-alendronate composite (HA-AL) may be considered a viable solution for including the bisphosphonate on the surf...
Revista de Chimie, 2018
A design of experiment (DoE) approach is presented for the optimization of Alendronate-hydroxyapa... more A design of experiment (DoE) approach is presented for the optimization of Alendronate-hydroxyapatite nanoparticles� synthesis. The synthesis was performed using the chemical precipitation technique from calcium nitrate, diammonium hydrogen phosphate and alendronate. Synthesis temperature, reactant addition rate and ripening time were chosen as the most relevant experimental factors for our synthesis. Design of Experiments was used in order to measure these conclusive process parameters and their effect on controlling some final nanoparticles parameters, such us: alendronate incorporation efficiency (IncorporationEfficiency, %), hydroxyapatite crystallite size (Size_XRD, nm), hydroxyapatite particle size distribution (Size_DLS, �). Our study found that better HA-AL incorporation efficiency and small nonoparticles can be obtained using the following chemical process parameters: reaction temperature 30oC or smaller, ripening time 108h and addition rate 0.1mol/min. The analysis of more...
Revista de Chimie, 2019
Dorycnium herbaceum (DH) is a perennial herb or small shrub 10-80 cm high, which can be found in ... more Dorycnium herbaceum (DH) is a perennial herb or small shrub 10-80 cm high, which can be found in Central and Southeastern Europe. It is a little studied plant, which is known to have antibacterial and antifungal effect. In the present study we determined by spectrophotometric methods the total polyphenolic, flavonoidic, carotenic and chlorophyllic content of DH species, comparative to the bilberry. We also monitored the status of antioxidant enzymes using mice with oxidative stress induced by streptozotocinic diabet. For the induction of diabetes we used Swiss albino mice to which we injected streptozotocin intraperitoneally at a single dose of 180 mg / kg b.w.. The results showed that both chemical composition tinctures contain appreciable amounts of polyphenols, the highest content starring DH tincture species, but bilberry fruits have higher content of flavonoids, carotene and chlorophyll. Both plant extracts regulate the status of antioxidant enzymes, DH having superior efficacy.
Revista de Chimie, 2018
Plant extracts with antimicrobial potential are an important research directive in the current me... more Plant extracts with antimicrobial potential are an important research directive in the current medical world, aiming to isolate active components in order to develop new chemotherapeutic agents that can be used in the treatment of various infectious disease. In the present study we determined the content of polyphenol carboxylic acids and flavonoids for two vegetal extracts, by means of TLC, GC-MS and HPLC techniques. Antimicrobial activity was determined on five bacterial species by performing agar diffusion method, using discs impregnated with standard antimicrobial substances and tested plant extracts. Our results showed that the alcoholic extracts Tragoponis pratensis folium and Myrtilli fructus contain polyphenolic compounds and had antimicrobial effect on a wide range of microorganisms (gram positive and negative).
Revista de Chimie, 2018
Tamarix ramosissima (Tamaricaceae) is a small tree that grows spontaneously in Europe and Asia, b... more Tamarix ramosissima (Tamaricaceae) is a small tree that grows spontaneously in Europe and Asia, being considered an invasive species in geographical areas with warm climates. The chemical composition is partially elucidated, being empirically used for antiinflammatory, analgesic, antibacterial and antioxidant effect. Our study aimed to evaluate the total polyphenol and flavonoid content of vegetal extracts and to test in vivo antioxidant therapeutic effect of it, comparative with Vaccinium myrtillus, using streptozotocin-induced diabetic mice. After five weeks the animals were sacrificed and we determined erythrocyte activities of superoxide dismutase, glutathione peroxidase, glutathione reductase and level of lipid peroxides as thiobarbituric acid reactive substances. Antioxidant enzymes had highest activities in mice treated with T. ramosissima extract and the level of lipid peroxides was the lowest. The tested extract had higher content of polyphenols comparative with V. myrtillu...
Pharmaceutical Chemistry Journal, 2020
This experimental study was aimed at assessing the total polyphenol and flavonoid content of Trag... more This experimental study was aimed at assessing the total polyphenol and flavonoid content of Tragopogon pratensis (folium) vegetal extract and evaluating the histopathological status of mice with liver problems and diabetes during therapy with 20% hydroalcoholic extract of T. pratensis (folium). The diabetes in mice was induced by single intraperitoneal (i.p.) dose of 180 mg/kg b.w. streptozotocin. The experiment involved two congtrol groups: the first (I) group consisted of mice with normal pancreatic function; the second (II) group consisted of mice with experimentally induced diabetes. The third (III) group of mice with experimentally induced diabetes was treated with T. pratensis extract at a dose of 150 mg/kg b.w.. The first and second groups were not treated, while the third group received daily the established medication once a day, in the morning at the same time (9 a.m), for five weeks. The ob tained results showed that the administration of T. pratensis tincture triggers the hepatic regenerative processes, restores functional activity of the liver, and positively influences functionality of the pancreas. The molecular docking analysis supports results of the experimental study.
Acta pharmaceutica (Zagreb, Croatia), 2018
The main objective of this study was to synthesize hydroxyapatite-ciprofloxacin composites using ... more The main objective of this study was to synthesize hydroxyapatite-ciprofloxacin composites using a chemical precipitation method and to evaluate the properties and in vitro release profile of the drug from the hydroxyapatite-ciprofloxacin composites. Composite characterization was achieved by FT-IR, XRD and DLS. Ciprofloxacin determination was accomplished by HPLC, resulting in good incorporation efficiency of the drug (18.13 %). The in vitro release study (Higuchi model C = K t1/2 and Ritger-Peppas model, C = K t0.6) showed a diffusion-controlled mechanism. The antibacterial activity showed that the bacterial growth inhibition zones were approximately equal for the synthesis composites and for the mechanical mixture on the Staphylococcus aureus germ. The use of hydroxyapatite, which is a biocompatible, bioactive and osteoconductive material, with ciprofloxacin, which has good antibacterial activity in this composite, makes it suitable for the development of bone grafts. Furthermore...
NAD+ is known classically as a metabolite that participates in catabolic and anabolic pathways th... more NAD+ is known classically as a metabolite that participates in catabolic and anabolic pathways throughout the metabolism that is taught to students in introductory biochemistry courses. However, non-classical studies starting over a decade ago found that NAD+ is also involved in higher order functions, in part because of its involvement in the activation of SIRTs and the support of the mitochondrial unfolded protein response. Many studies since have suggested that NAD+ is involved in an extensive spectrum of human pathologies, including neurodegenerative disorders, cardiomyopathy, obesity, and diabetes, Further, healthy aging and longevity appear to be closely related to NAD+ and its related metabolites, including NAR and NMN. Together, these studies show that this system has value as a dietary supplement to improve general health overall, as well as mitigating specific disease conditions. Accordingly, many are now recommending the consumption of materials in this system as dietary ...
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Papers by Oana Elena Nicolaescu