Laura Mihaela Stefan
CS II - Biologie Celulară și Moleculară
Biografie
Sunt biolog, cu titlul de doctor în Biologie obținut în anul 2016 la Universitate din Barcelona, Spania. Am expertiză în testarea in vitro a biocompatibilității biomaterialelor, dispozitivelor medicale, extractelor vegetale și a compușilor naturali bioactivi si în dezvoltarea de modele experimentale in vitro pentru evaluarea activității biologice a biomaterialelor, precum activitatea antioxidantă, regenerativă, antiinflamatorie, antiproliferativă sau gastroprotectoare. De asemenea, am experiență în dezvoltarea de sisteme de co-cultură utilizând diferite tipuri celulare și sisteme de co-cultura celule-probiotice, precum și în tehnici de biologie moleculară, imunofluorescență, imunocitochimie și imunohistochimie.
Am investigat interacțiile dintre gazde și paraziți, în special interacția dintre păsări și acarienii plumicoli la nivel morfologic, ecologic si evolutiv. Am realizat identificări morfologice și genetice ale acarienilor plumicoli și am contribuit la descrierea unor specii noi de acarieni.
Pe parcursul celor 18 ani de experiență în cercetare, dezvoltare și inovare, am fost implicată in proiecte de cercetare naționale și internaționale atat în calitate de director cât și ca membru in echipa de cercetare și am publicat ca autor principal sau co-autor peste 35 de articole indexate in baze de date ISI sau BDI și 11 brevete/cereri de brevete naționale.
Publicatii
Publication | Authors | Date | |
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article
Antioxidant And Antiproliferative Activity Of Small Peptides Isolated From Marine Algae By Green Methods |
Mihai E.; Gaspar-Pintiliescu A.; Tatia R.; Stefan L. M.; Coroiu V.; Craciunescu O. | Scientific Bulletin. Series F: Biotechnologies, 2024 | |
Rezumat |
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conference
Corrosion Inhibition Of Carbonate Coated Magnesium In Physiological Fluids |
Popa M. Stefan L.M. Drob S.I. Calderon Moreno J.M. | 23Rd Romanian International Conference On Chemistry And Chemical Engineering (Riccce 23), 2024 | |
Rezumat |
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article
Donkey Gelatin And Keratin Nanofibers Loaded With Antioxidant Agents For Wound Healing Dressings |
Rapa Maria; Gaidau Carmen; Stefan Laura Mihaela; Lazea-Stoyanova Andrada; Berechet Mariana Daniela; Iosageanu Andreea; Matei Ecaterina; Jankauskaite Virginija; Predescu Cristian; Valeika Virgilijus; Balciunaitiene Aiste; Cupara Snezana | Gels, 2024 | |
RezumatAcute and chronic wounds present a significant healthcare challenge, requiring innovative solutions for effective treatment. The exploitation of natural by-products with advanced cell regeneration potential and plant-based materials, which possess bioactive properties, is an innovative topic in wound management. This study investigates the potential of donkey gelatin and keratin for blending with natural bioactive extracts such as sumac, curcumin, and oak acorn to fabricate antioxidant and antimicrobial nanofibers with accelerated wound healing processes. The fabricated nanofibers possess good in vitro biocompatibility, except for the sumac-based donkey nanofibers, where cell viability significantly dropped to 56.25% (p < 0.05 compared to non-treated cells). The nanofiber dimensions showed structural similarities to human extracellular matrix components, providing an ideal microenvironment for tissue regeneration. The donkey nanofiber-based sumac and curcumin extracts presented a higher dissolution in the first 10 min (74% and 72%). Curcumin extract showed similar antimicrobial and antifungal performances to rivanol, while acorn and sumac extracts demonstrated similar values to each other. In vitro tests performed on murine fibroblast cells demonstrated high migration rates of 89% and 85% after 24 h in the case of acorn and curcumin nanofibers, respectively, underscoring the potential of these nanofibers as versatile platforms for advanced wound care applications. |
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article
Antioxidant And Antiproliferative Effect Of A Glycosaminoglycan Extract From Rapana Venosa Marine Snail |
Gaspar-Pintiliescu Alexandra; Stefan Laura M.; Mihai Elena; Sanda Catalina; Manoiu Vasile S.; Berger Daniela; Craciunescu Oana | Plos One, 2024 | |
RezumatMarine glycosaminoglycans (GAG) isolated from different invertebrates, such as molluscs, starfish or jellyfish, have been described as unique molecules with important pharmacological applications. Scarce information is available on GAG extract from Rapana venosa marine snail. The aim of this study was to isolate a GAG extract from R. venosa marine snail and to investigate its physicochemical, antioxidant and antiproliferative properties for further biomedical use. The morphology, chemical and elemental composition of the extract were established as well as the sulfate content and N- to O-sulfation ratio. Fourier transform infrared (FTIR) spectra indicated that GAG extract presented similar structural characteristics to bovine heparan sulfate and chondroitin sulfate. The pattern of extract migration in agarose gel electrophoresis and specific digestion with chondroitinase ABC and heparinase III indicated the presence of a mixture of chondroitin sulfate-type GAG, as main component, and heparan sulfate-type GAG. Free radical scavenging and ferric ion reducing assays showed that GAG extract had high antioxidant activity, which slightly decreased after enzymatic treatment. In vitro MTT and Live/Dead assays showed that GAG extract had the ability to inhibit cell proliferation in human Hep-2 cell cultures, at cytocompatible concentrations in normal NCTC clone L929 fibroblasts. This capacity decreased after enzymatic digestion, in accordance to the antioxidant activity of the products. Tumoral cell migration was also inhibited by GAG extract and its digestion products. Overall, GAG extract from R. venosa marine snail exhibited antioxidant and antiproliferative activities, suggesting its potential use as novel bioactive compound for biomedical applications. |
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article
Anti-Inflammatory And Wound Healing Properties Of Different Honey Varieties From Romania And Correlations To Their Composition |
Iosageanu Andreea; Stefan Laura Mihaela; Craciunescu Oana; Cimpean Anisoara | Life-Basel, 2024 | |
RezumatThe complex composition of honey plays a crucial role in wound healing, exhibiting varying effects at different stages of the healing process. This study investigated seven honey varieties sourced from different regions of Romania using in vitro experimental models developed in macrophage-like, fibroblast, and keratinocyte cell lines to explore the mechanisms by which honey promoted the healing process. This study assessed the impact of honey on inflammatory cytokine production in macrophage-like cells, cell proliferation and collagen synthesis in fibroblasts, and cell proliferation and migration in keratinocytes. Additionally, correlation analysis was conducted to examine the relationship between honey composition and its biological properties. Honey varieties presented both anti- and pro-inflammatory effects. Moreover, they displayed dose-dependent pro-proliferative effects, stimulating collagen synthesis and cell migration, thereby enhancing the re-epithelialization process. The Pearson coefficient analysis indicated a strong positive correlation between biological activities and phenolic content. Additionally, there was a medium positive correlation with the ascorbic acid content and a medium negative correlation with the glucose content in the different honey varieties. Romanian honey varieties rich in phenolics showed potential in modulating inflammation, proliferation, collagen synthesis, and cell migration, suggesting their suitability for further evaluation and development of innovative dressings for skin tissue regeneration. |
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article
Antibacterial Activity And Cell Viability Of Biomimetic Magnesian Calcite Coatings On Biodegradable Mg |
Popa Monica; Anastasescu Mihai; Stefan Laura M.; Prelipcean Ana-Maria; Calderon Moreno Jose | Journal Of Functional Biomaterials, 2023 | |
RezumatMg is a material of choice for biodegradable implants. The main challenge for using Mg in temporary implants is to provide protective surfaces that mitigate its rapid degradation in biological fluids and also confer sufficient cytocompatibility and bacterial resistance to Mg-coated surfaces. Even though carbonate mineralization is the most important source of biominerals, such as the skeletons and shells of many marine organisms, there has been little success in the controlled growth of carbonate layers by synthetic processes. We present here the formation mechanism, antibacterial activity, and cell viability of magnesian calcite biomimetic coatings grown on biodegradable Mg via a green, one-step route. Cell compatibility assessment showed cell viability higher than 80% after 72 h using fibroblast cells (NCTC, clone L929) and higher than 60% after 72 h using human osteoblast-like cells (SaOS-2); the cells displayed a normal appearance and a density similar to the control sample. Antimicrobial potential evaluation against both Gram-positive (Staphylococcus aureus (ATCC 25923)) and Gram-negative (Pseudomonas aeruginosa (ATCC 27853)) strains demonstrated that the coated samples significantly inhibited bacterial adhesion and biofilm formation compared to the untreated control. Calcite coatings grown on biodegradable Mg by a single coating process showed the necessary properties of cell compatibility and bacterial resistance for application in surface-modified Mg biomaterials for temporary implants. |
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article
Bioactive And Physico-Chemical Assessment Of Innovative Poly(Lactic Acid)-Based Biocomposites Containing Sage, Coconut Oil, And Modified Nanoclay |
Darie-Nita Raluca Nicoleta; Irimia Anamaria; Doroftei Florica; Stefan Laura Mihaela; Iwanczuk Andrzej; Trusz Agnieszka | International Journal Of Molecular Sciences, 2023 | |
RezumatThe bioactivity of the versatile biodegradable biopolymer poly(lactic acid) (PLA) can be obtained by combining it with natural or synthetic compounds. This paper deals with the preparation of bioactive formulations involving the melt processing of PLA loaded with a medicinal plant (sage) and an edible oil (coconut oil), together with an organomodifed montmorillonite nanoclay, and an assessment of the resulting structural, surface, morphological, mechanical, and biological properties of the biocomposites. By modulating the components, the prepared biocomposites show flexibility, both antioxidant and antimicrobial activity, as well as a high degree of cytocompatibility, being capable to induce the cell adherence and proliferation on their surface. Overall, the obtained results suggest that the developed PLA-based biocomposites could potentially be used as bioactive materials in medical applications. |
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article
Antibacterial Aloe Vera Based Biocompatible Hydrogel For Use In Dermatological Applications |
Chelu Mariana; Musuc Adina Magdalena; Aricov Ludmila; Ozon Emma Adriana; Iosageanu Andreea; Stefan Laura M.; Prelipcean Ana-Maria; Popa Monica; Moreno Jose Calderon | International Journal Of Molecular Sciences, 2023 | |
RezumatThe present research aims to describe a new methodology to obtain biocompatible hydrogels based on Aloe vera used for wound healing applications. The properties of two hydrogels (differing in Aloe vera concentration, AV5 and AV10) prepared by an all-green synthesis method from raw, natural, renewable and bioavailable materials such as salicylic acid, allantoin and xanthan gum were investigated. The morphology of the Aloe vera based hydrogel biomaterials was studied by SEM analysis. The rheological properties of the hydrogels, as well as their cell viability, biocompatibility and cytotoxicity, were determined. The antibacterial activity of Aloe vera based hydrogels was evaluated both on Gram-positive, Staphylococcus aureus and on Gram-negative, Pseudomonas aeruginosa strains. The obtained novel green Aloe vera based hydrogels showed good antibacterial properties. In vitro scratch assay demonstrated the capacity of both AV5 and AV10 hydrogels to accelerate cell proliferation and migration and induce closure of a wounded area. A corroboration of all morphological, rheological, cytocompatibility and cell viability results indicates that this Aloe vera based hydrogel may be suitable for wound healing applications. |
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article
Nutritional Profiling And Cytotoxicity Assessment Of Protein Rich Ingredients Used As Dietary Supplements |
Tihauan Bianca-Maria; Marinas Ioana-Cristina; Adascalului Marian; Dobre Alina; Pircalabioru Gratiela Gradisteanu; Axinie Madalina; Stefan Laura Mihaela; Duta Denisa Eglantina | Applied Sciences-Basel, 2023 | |
RezumatFeatured Application: Nutritional Profiling for subsequent dietary supplements/nutraceuticals development and formulation as well as by-products valorification. In recent years, the scientific community has made significant progress in understanding nutrition, leading consumers to shift their preferences away from animal-based protein products and towards natural, plant-based protein sources. This study aimed to determine the nutritional value, in vitro cytotoxicity and antioxidant activity for different sources of high protein content products (pea, yeast, almond, spirulina and Pleurotus spp.) with potential usage as raw materials for dietary supplements, especially since these products do not benefit from stricter regulation requirements regarding their actual health benefits. The characterization of raw materials consisted in evaluation of their nutritional profile (by addressing moisture content, crude protein content, extractable fat, ash, carbohydrates) and microbial contamination (TAMC, TYMC, Enterobacteriaceae and beta-glucuronidase positive Escherichia coli), total content of free amino acids, soluble proteins, phenols and flavonoids, as well as antioxidant activity through chemical assays. We used 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) release to evaluate the potential cytotoxicity of selected raw materials. Results obtained indicate high percentages of proteins for the pea powder (77.96%) and Spirulina powder (64.79%), Pleurotus spp. flour had strong antioxidant activity, while the highest contamination values were registered for Pleurotus spp. powder (4.6 +/- 10(5) CFU/g or 5.66 log CFU/g). Cytotoxicity results demonstrate that tested ingredients have an impact on the metabolic activity of cells, affecting cellular integrity and provoking leakage of DNA at several concentrations. While plant-based protein supplementation may appear to be a promising solution to balance our busy lives, there are several advantages and disadvantages associated with them, including issues related to their absorption rate, bioavailability, cytotoxicity and actual nutritional benefits. |
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article
Diversity And Structure Of Feather Mite Communities On Seabirds From The North-East Atlantic And Mediterranean Sea |
Stefan Laura M.; Isbert Wolf; Gomez-Diaz Elena; Mironov Sergey V.; Dona Jorge; McCoy Karen D.; Gonzalez-Solis Jacob | Scientific Reports, 2023 | |
RezumatThe richness and structure of symbiont assemblages are shaped by many factors acting at different spatial and temporal scales. Among them, host phylogeny and geographic distance play essential roles. To explore drivers of richness and structure of symbiont assemblages, feather mites and seabirds are an attractive model due to their peculiar traits. Feather mites are permanent ectosymbionts and considered highly host-specific with limited dispersal abilities. Seabirds harbour species-rich feather mite communities and their colonial breeding provides opportunities for symbionts to exploit several host species. To unravel the richness and test the influence of host phylogeny and geographic distance on mite communities, we collected feather mites from 11 seabird species breeding across the Atlantic Ocean and Mediterranean Sea. Using morphological criteria, we identified 33 mite species, of which 17 were new or recently described species. Based on community similarity analyses, mite communities were clearly structured by host genera, while the effect of geography within host genera or species was weak and sometimes negligible. We found a weak but significant effect of geographic distance on similarity patterns in mite communities for Cory's shearwaters Calonectris borealis. Feather mite specificity mainly occurred at the host-genus rather than at host-species level, suggesting that previously inferred host species-specificity may have resulted from poorly sampling closely related host species. Overall, our results show that host phylogeny plays a greater role than geography in determining the composition and structure of mite assemblages and pinpoints the importance of sampling mites from closely-related host species before describing mite specificity patterns. |
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article
Diversity And Structure Of Feather Mite Communities On Seabirds From The North–East Atlantic And Mediterranean Sea |
Stefan L.M.; Isbert W.; Gómez-Díaz E.; Mironov S.V.; Doña J.; McCoy K.D.; González-Solís J. | Scientific Reports, 2023 | |
RezumatThe richness and structure of symbiont assemblages are shaped by many factors acting at different spatial and temporal scales. Among them, host phylogeny and geographic distance play essential roles. To explore drivers of richness and structure of symbiont assemblages, feather mites and seabirds are an attractive model due to their peculiar traits. Feather mites are permanent ectosymbionts and considered highly host-specific with limited dispersal abilities. Seabirds harbour species-rich feather mite communities and their colonial breeding provides opportunities for symbionts to exploit several host species. To unravel the richness and test the influence of host phylogeny and geographic distance on mite communities, we collected feather mites from 11 seabird species breeding across the Atlantic Ocean and Mediterranean Sea. Using morphological criteria, we identified 33 mite species, of which 17 were new or recently described species. Based on community similarity analyses, mite communities were clearly structured by host genera, while the effect of geography within host genera or species was weak and sometimes negligible. We found a weak but significant effect of geographic distance on similarity patterns in mite communities for Cory’s shearwaters Calonectris borealis. Feather mite specificity mainly occurred at the host-genus rather than at host-species level, suggesting that previously inferred host species-specificity may have resulted from poorly sampling closely related host species. Overall, our results show that host phylogeny plays a greater role than geography in determining the composition and structure of mite assemblages and pinpoints the importance of sampling mites from closely-related host species before describing mite specificity patterns. © 2023, The Author(s). |
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article
Conversion Of Animal-Derived Protein By-Products Into A New Dual-Layer Nanofiber Biomaterial By Electrospinning Process |
Gaidau Carmen; Rapa Maria; Stefan Laura Mihaela; Matei Ecaterina; Berbecaru Andrei Constantin; Predescu Cristian; Mititelu-Tartau Liliana | Fibers, 2023 | |
RezumatThe aim of this study was to design a dual-layer wound dressing as a new fibrous biomaterial based on the valorization of animal-derived proteins. The first layer was fabricated by the deposition of poly(ethylene oxide) (PEO) loaded with keratin hydrolysate (KH) via a mono-electrospinning process onto a poly(lactic acid) (PLA) film, which was used as a support. The second layer consisted of encapsulating a bovine collagen hydrolysate (CH) into poly(vinyl pyrrolidone) (PVP) through a coaxial electrospinning process, which was added onto the previous layer. This assemblage was characterized by electronic microscopy for morphology and the controlled release of KH. In vitro biocompatibility was evaluated on the L929 (NCTC) murine fibroblasts using quantitative MTT assay and qualitative cell morphological examination after Giemsa staining. Additionally, in vivo biocompatibility methods were used to assess the impact of the biomaterial on white Swiss mice, including the evaluation of hematological, biochemical, and immunological profiles, as well as its impact on oxidative stress. The results revealed a nanofibrous structure for each layer, and the assembled product demonstrated antioxidant activity, controlled release of KH, a high degree of in vitro biocompatibility, negligible hematological and biochemical changes, and minimal impact of certain specific oxidative stress parameters compared to the use of patches with textile support. |
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article
Poly(3-Hydroxybutyrate-Co-3-Hydroxyvalerate) (P(3Hb-Co-3Hv))/Bacterial Cellulose (Bc) Biocomposites For Potential Use In Biomedical Applications |
Rapa Maria; Stefan Laura Mihaela; Seciu-Grama Ana-Maria; Gaspar-Pintiliescu Alexandra; Matei Ecaterina; Zaharia Catalin; Stanescu Paul Octavian; Predescu Cristian | Polymers, 2022 | |
RezumatThe aim of this study was to obtain biocomposites consisting of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), bacterial cellulose (BC) and alpha-tocopherol by a melt processing technique for potential use in biomedical applications. The melt processing and roughness of biocomposites were evaluated and compared to sample without BC. The degradation rate of PHBV/BC biocomposites was measured in phosphate buffer saline (PBS) by determining the mass variation and evidencing of thermal and structural changes by differential scanning calorimetry (DSC) and attenuated total reflectance-Fourier transformed infrared spectrometry (ATR-FTIR). The cell viability, cell morphology, cell cycle distribution and total collagen content were investigated on murine NCTC fibroblasts. Overall, the adding of BC to polyester matrix led to an adequate melt processing of biocomposites and increased surface roughness and cytocompatibility, allowing the cells to secrete the extracellular matrix (collagen) and stimulate cell proliferation. Results showed that the PHBV/BC biocomposites were favorable for long-term degradation and could be used for the design of medical devices with controlled degradability. |
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article
Inhibition Of Mg Corrosion In Physiological Fluids By Carbonate Coating |
Popa Monica; Stefan Laura M.; Prelipcean Ana-Maria; Drob Silviu I; Anastasescu Mihai; Moreno Jose M. Calderon | Corrosion Science, 2022 | |
RezumatCorrosion protective coatings were grown on pure magnesium in naturally carbonated mineral water containing Ca2+ using a simple, green conversion method. Dissolution of the native corrosion product, Mg(OH)2, mediates the surface nucleation of hydroxycarbonates. The pH increase due to CO2 degassing to atmospheric pressure leads to calcium carbonate nucleation and lateral growth by the incorporation of nanoparticles in a continuous layer of calcite -Ca(Mg)CO3- microcrystals. The coated surfaces have a much improved corrosion resistance in physiological fluids, measured by EIS, weight loss, corrosion rates and hydrogen release. Cell viability/ morphology assessment demonstrates that the coating is non-toxic and promotes the proliferation of osteoblastic cells. |
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article
Feather Mites Of The Genus Brephosceles Hull, 1934 (Acariformes: Alloptidae) From The European Storm Petrel Hydrobates Pelagicus (Procellariiformes: Hydrobatidae) |
Mironov Sergey V; Gonzalez-Solis Jacob; Mihalca Andrei D.; Stefan Laura M. | Systematic And Applied Acarology, 2022 | |
RezumatThree feather mite species of the genus Brephosceles Hull, 1934 (Alloptidae: Alloptinae) were found on the European storm petrel, Hydrobates pelagicus (Procellariiformes: Hydrobatidae), in the Mediterranean Sea and North-east Atlantic Ocean. Brephosceles holoplax sp. n. is described as a new species; B. pelagicus (Vitzthum, 1921) and B. longirostris (Vitzthum, 1921) comb. n. formerly known only from females are redescribed from both sexes. The latter species has been transferred from the genus Alloptes Canestrini, 1879. All descriptions are supported by DNA barcode data. |
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article
Bioactivity And Thermal Stability Of Collagen-Chitosan Containing Lemongrass Essential Oil For Potential Medical Applications |
Rapa Maria; Zaharescu Traian; Stefan Laura Mihaela; Gaidau Carmen; Stanculescu Ioana; Constantinescu Rodica Roxana; Stanca Maria | Polymers, 2022 | |
RezumatBioactive collagen-chitosan-lemongrass (COL-CS-LG) membranes were prepared by casting method and analyzed for potential biomedical applications. For COL-CS-LG membranes, LG essential oil release, antioxidant properties, in vitro cytotoxicity and antimicrobial assessments were conducted, as well as free radical determination after gamma irradiation by chemiluminescence, and structural characteristics analysis through Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Differential Scanning Calorimetry (DSC). The evaluation of non-isothermal chemiluminescence after gamma radiation exposure to COL-CS-LG membranes revealed a slowing down of the oxidation process at temperatures exceeding 200 degrees C, in correlation with antioxidant activity. Antimicrobial properties and minimum inhibitory concentrations were found to be in correlation with cytotoxicity limits, offering the optimum composition for designing new biomaterials. |
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article
Extracellular Matrix Biomimetic Polymeric Membranes Enriched With Silver Nanoparticles For Wound Healing |
Stefan Laura Mihaela; Iosageanu Andreea; Ilie Daniela; Stanciuc Ana-Maria; Matei Cristian; Berger Daniela; Craciunescu Oana | Biomedical Materials, 2021 | |
RezumatSevere skin injuries, including burns, represent a real concern for the global health-care system and therefore, there is an increased interest in developing wound dressings, in order to stimulate and enhance skin tissue repair. The aim of this study was to design novel hybrid materials, biomimetic to skin extracellular matrix and enriched with silver nanoparticles (nAg), in order to provide both dermal tissue regeneration and antimicrobial activity. Two material variants (variant A and variant B) consisting of type I collagen (COL), chondroitin sulfate (CS) and k-elastin peptides (EL) enriched with positively-charged nAg, were conditioned as membranes. UV exposure ensured both sterilisation and cross-linking of the materials. Physico-chemical characterization of the hybrid biomaterials showed values of density and swelling degree higher than those of COL membrane, while the process of in vitro degradation followed a similar pattern. Infrared spectroscopy and x-ray diffraction indicated alterations of the characteristic structural features and crystallinity of COL after blending with CS and EL and nAg embedding. Scanning electron microscopy observations revealed different surface morphologies of the hybrid membranes, according to their composition. In vitro studies on L929 fibroblasts and HaCaT keratinocytes showed that both hybrid membranes exhibited good cytocompatibility and promoted higher cell proliferation compared to COL sample, as evaluated by MTT and Live/Dead assays. The presence of actin filaments highlighted by fluorescent labelling confirmed the fibroblast and keratinocyte adhesion onto the surface of hybrid membranes. Most importantly, both materials showed an increased wound healing ability in an in vitro scratch assay model, stimulating cell migration at 24 h post-seeding. In addition, good antimicrobial activity was recorded, especially against Gram-positive bacterial strain. Altogether, our findings recommend COL-CS-EL-nAg hybrid membranes as good candidates for wound healing acceleration and bioengineering of skin tissue. |
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article
Sustainable Coated Nanostructures Based On Alginate And Electrospun Collagen Loaded With Antimicrobial Agents |
Matei Ecaterina; Gaidau Carmen; Rapa Maria; Stefan Laura Mihaela; Ditu Lia-Mara; Predescu Andra Mihaela; Stanca Maria; Pantilimon Mircea Cristian; Berechet Mariana Daniela; Predescu Cristian; Mosutiu Anamaria | Coatings, 2021 | |
RezumatIn this study, sodium alginate film (Alg) was coated with electrospun collagen glue (Col) extracted from rabbit skin waste, loaded with different commercial antimicrobial agents (chitosan, AG425K and ZnONPs) and investigated in terms of morphological, structural and biological properties. The coated nanostructures were characterized using scanning electron microscopy coupled with the energy-dispersive X-ray (SEM/EDS), Attenuated Total Reflectance Fourier-Transform Infrared spectroscopy (ATR FT-IR), and Atomic Force Microscopy (AFM) tests. The cytotoxicity was investigated on murine L929 fibroblasts using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide salt (MTT) and lactate dehydrogenase (LDH) assays. Microbiological tests were performed against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 27853 standard strains. In vitro cell culture tests showed a good cytocompatibility of the coated nanostructured systems, except the sample loaded with ZnONPs, which exhibited a highly cytotoxic effect. Alg-Col-ZnONPs nanostructure inhibited the growth and multiplication of the Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 bacterial strains. The results of new coated nanostructures may be useful for the development of sustainable biomaterials in a circular economy, with bioactive properties for medical wound dressings. |
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conference
Nutraceutical And Cosmeceutical Products Containing Low Molecular Weight Peptides From Fermented Colostrum |
Ionuț Moraru; Angela Moraru; Anca Oancea; Alexandra Gaspar-Pintiliescu; Viorica Coroiu; Laura Stefan; Andreea Iosăgeanu; Teodora Ciucan; Daniela Ilie; Cătălina Sanda; Ana-Maria Seciu-Grama; | Priorities Of Chemistry For A Sustainable Development” – Priochem Xvi, Bucharest, Romania, 2020 | |
Rezumat |
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article
Development Of Bionanocomposites Based On Pla, Collagen And Agnps And Characterization Of Their Stability And In Vitro Biocompatibility |
Rapa Maria; Stefan Laura Mihaela; Zaharescu Traian; Seciu Ana-Maria; Turcanu Anca Andreea; Matei Ecaterina; Predescu Andra Mihaela; Antoniac Iulian; Predescu Cristian | Applied Sciences-Basel, 2020 | |
RezumatBionanocomposites including poly(lactic acid) (PLA), collagen, and silver nanoparticles (AgNPs) were prepared as biocompatible and stable films. Thermal properties of the PLA-based bionanocomposites indicated an increase in the crystallinity of PLA plasticized due to a small quantity of AgNPs. The results on the stability study indicate the promising contribution of the AgNPs on the durability of PLA-based bionanocomposites. In vitro biocompatibility conducted on the mouse fibroblast cell line NCTC, clone 929, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed high values of cell viability (>80%) after cell cultivation in the presence of bionanocomposite formulations for 48 h, while the percentages of lactate dehydrogenase (LDH) released in the culture medium were reduced (<15%), indicating no damages of the cell membranes. In addition, cell cycle analysis assessed by flow cytometry indicated that all tested bionanocomposites did not affect cell proliferation and maintained the normal growth rate of cells. The obtained results recommend the potential use of PLA-based bionanocomposites for biomedical coatings. |
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article
Effects Of Foliar Treatment With A Trichoderma Plant Biostimulant Consortium On Passiflora Caerulea L. Yield And Quality |
Sesan Tatiana Eugenia; Oancea Anca Olguta; Stefan Laura Mihaela; Manoiu Vasile Sorin; Ghiurea Marius; Raut Iuliana; Constantinescu-Aruxandei Diana; Toma Agnes; Savin Simona; Bira Adriana Florina; Pomohaci Cristian Mihai; Oancea Florin | Microorganisms, 2020 | |
RezumatThe influence of spore concentration on the ability of a Trichoderma consortium to colonize the Passiflora caerulea phyllosphere was evaluated by determining the effects of foliar treatments with two spore concentrations, in two repeated treatments, on the morphological, physiological, and ultrastructural characteristics, and on the yield and quality of P. caerulea. The studied crop quality features were related to its nutraceutical use: the accumulation of polyphenols and flavonoids, antioxidant activity, and effects on mouse fibroblast L929 cells. The Trichoderma consortium consisted of two strains, T. asperellum T36b and T. harzianum Td50b, and the concentrations used were 10(6) colony forming units (cfu)/mL and 10(8) cfu/mL. As a reference treatment, a commercial product that was based on herbs and algal extracts was used. As compared to the negative control, the treatment with the Trichoderma consortium at 10(8) cfu/mL concentration determines the accumulation of higher level of polyphenols and flavonoids and increased antioxidant activity. This enhancement of P. caerulea quality characteristics after treatment with the higher concentration of Trichoderma consortium was associated with larger leaves, increased number and size of chloroplasts, improved plant physiology characteristics, and an increased yield. The treatment with high concentration of Trichoderma consortium spores promotes phyllosphere colonization and benefits both crop yield and quality. |
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article
New Nanofibers Based On Protein By-Products With Bioactive Potential For Tissue Engineering |
Rapa Maria; Gaidau Carmen; Stefan Laura Mihaela; Matei Ecaterina; Niculescu Mihaela; Berechet Mariana Daniela; Stanca Maria; Tablet Cristina; Tudorache Madalina; Gavrila Raluca; Predescu Cristian; Vidu Ruxandra | Materials, 2020 | |
RezumatConcentrated collagen hydrolysate (HC10CC), rabbit collagen glue (RCG), and keratin hydrolysate (KH) were investigated in terms of their extraction from mammalian by-products and processing by electrospinning. The electrospun nanofibers were characterized by scanning electron microscopy coupled with the energy dispersive X-ray spectroscopy (SEM/EDS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), and indentation tests. The cytotoxicity of the electrospun nanofibers was conducted on L929 fibroblast cells using MTT and LDH assays and cell morphology observations. The electrospun RCG and KH nanofibers morphology showed an average size of nanofibers ranging between 44 and 410 nm, while the electrospun HC10CC nanofibers exhibited higher sizes. The ATR-FTIR spectra performed both on extracted proteins and electrospun nanofibers showed that the triple helix structure of collagen is partially preserved. The results were in agreement with the circular dichroism analysis for protein extracts. Furthermore, the viscoelastic properties of electrospun KH nanofibers were superior to those of electrospun RCG nanofibers. Based on both in vitro quantitative and qualitative analysis, the electrospun nanofibers were not cytotoxic, inducing a healthy cellular response. The results of new electrospun protein-based nanofibers may be useful for further research on bioactive properties of these nanofibers for tissue engineering. |
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conference
Biomedical Potential Of Collagen Isolated From The Marine Gastropod Rapana Venosa |
Ana-Maria Stanciuc; Alexandra Gaspar Pintiliescu; Elena Anton; Laura Mihaela Stefan; Raul-Augustin Mitran; Ticuta Negreanu-Pirjol; Catalina Sanda; Lucia Moldovan | 2Nd Icgeb Workshop “Modern Biotechnological Advances For Human Health” (Bahh), Bucharest, Romania, 2019 | |
Rezumat |
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article, conference
Comparative Studies Concerning The Bioactivity Of Peptides Obtained By Kefir-Kombucha Fermentation Of Bovine Colostrum |
Anca Oancea; Elena Utoiu; Teodora Ciucan; Oana Craciunescu; Alexandra Gaspar-Pintiliescu; Viorica Coroiu; Ana Maria Stanciuc; Laura Mihaela Stefan | 10Th Probiotics, Prebiotics & New Foods, Nutraceuticals And Botanicals For Nutrition & Human And Microbiota Health, Rome, Italy, Journal Of Clinical Gastroenterology, 2019 | |
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patent
Procedeu De Biofortifiere Protectivă Cu Seleniu A Culturilor De Crucifere |
Oancea Anca Olguţa; Petruş Viorica; Petruş Aurel; Petruş Adrian-Mihai; Crăciunescu Oana; Ştefan Laura Mihaela; Seciu Ana-Maria; Coroiu Viorica | State Office For Inventions And Trademarks (Osim), 2019 | |
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patent
Procedeu De Biofortifiere Protectivă Cu Seleniu A Culturilor De Crucifer |
Oancea Anca Olguta; Petrus Viorica; Petrus Aurel; Petrus Adrian-Mihai; Craciunescu Oana; Stefan Laura; Seciu Ana-Maria; Coroiu Viorica | State Office For Inventions And Trademarks (Osim), 2019 | |
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article
Cerium-Containing Mesoporous Bioactive Glasses: Material Characterization, In Vitro Bioactivity, Biocompatibility And Cytotoxicity Evaluation |
Atkinson I.; Anghel E. M.; Petrescu S.; Seciu A. M.; Stefan L. M.; Mocioiu O. C.; Predoana L.; Voicescu M.; Somacescu S.; Culita D.; Zaharescu M. | Microporous And Mesoporous Materials, 2019 | |
RezumatBone defects due to trauma or diseases causing bone loss have led to an increased demand for new materials that have applications in therapies for bone pathologies. Mesoporous bioactive glasses (MBGs), based on 70SiO(2)-(26-x)CaO-4P(2)O(5)-xCeO(2) (x = 0, 1 and 5 mol % for MBGS, MBGS1Ce and MBGS5Ce) were synthesized by evaporation-induced self-assembly (EISA) method. Ceria was selected due to its antimicrobial and antioxidant properties and positive impact on cells differentiation and mineralization. The pore size values of 2.8 nm confirmed the mesoporosity of the obtained bio-glasses. The biocompatibility tests on mouse fibroblast cells (NCTC clone L929) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) activity assays revealed no cytotoxicity of Cerium containing MBGs. Formation of a hydroxycarbonate apatite (HCA) layer on MBGs surface, e.g. bioactivity of BMGs, was confirmed by XRD, FTIR, SEM and Raman Spectroscopy while presence of Ce3+/Ce4+ in the glasses before body simulated fluid (SBF) immersion was determined by XPS, UV-Vis measurements. The obtained results show that investigated MBGs are potential materials for applications in bone regeneration. |
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article
Physicochemical And Biological Properties Of Gelatin Extracted From Marine Snail Rapana Venosa |
Gaspar-Pintiliescu Alexandra; Stefan Laura Mihaela; Anton Elena Daniela; Berger Daniela; Matei Cristian; Negreanu-Pirjol Ticuta; Moldovan Lucia | Marine Drugs, 2019 | |
RezumatIn this study, we aimed to obtain gelatin from the marine snail Rapana venosa using acidic and enzymatic extraction methods and to characterize these natural products for cosmetic and pharmaceutical applications. Marine gelatins presented protein values and hydroxyproline content similar to those of commercial mammalian gelatin, but with higher melting temperatures. Their electrophoretic profile and Fourier transform infrared (FTIR) spectra revealed protein and absorption bands situated in the amide region, specific for gelatin molecule. Scanning electron microscopy (SEM) analysis showed significant differences in the structure of the lyophilized samples, depending on the type of gelatin. In vitro studies performed on human keratinocytes showed no cytotoxic effect of acid-extracted gelatin at all tested concentrations and moderate cytotoxicity of enzymatic extracted gelatin at concentrations higher than 0.5 mg/mL. Also, both marine gelatins favored keratinocyte cell adhesion. No irritant potential was recorded as the level of IL-1 alpha and IL-6 proinflammatory cytokines released by HaCaT cells cultivated in the presence of marine gelatins was significantly reduced. Together, these data suggest that marine snails are an alternative source of gelatins with potential use in pharmaceutical and skincare products. |
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article
Effect Of Hydrolyzed Collagen On Thermal, Mechanical And Biological Properties Of Poly(Lactic Acid) Bionanocomposites |
Rapa Maria; Stefan Laura M.; Preda Petruta; Darie-Nita Raluca N.; Gaspar-Pintiliescu Alexandra; Seciu Ana M.; Vasile Cornelia; Matei Ecaterina; Predescu Andra Mihaela | Iranian Polymer Journal, 2019 | |
RezumatBionanocomposites based on poly(lactic acid) (PLA), plasticized with commercial tributyl o-acetyl citrate (ATBC) and containing hydrolyzed collagen (HC) up to 10 wt% and silver nanoparticles (AgNPs), were prepared by a melt mixing procedure. The properties of antimicrobial PLA based formulations were investigated in terms of morphology (atomic force microscopy, AFM), mechanical, thermal (differential scanning calorimetry, DSC), spectral (by attenuated total reflectance, Fourier-transform infrared spectroscopy), cell proliferation (by flow cytometry) and immunohistochemical properties induced by collagen. The incorporation of HC into antimicrobial PLA biocomposites led to the slight reduction both in mechanical properties and the degree of crystallinity with respect to those of PLA/ATBC sample. These properties can be attributed to the smooth surface improvement of the bionanocomposite. In vitro testing using L929 fibroblasts in the presence of PLA-based bionanocomposites showed that all samples presented good biocompatibility, as it was indicated by the cell cycle distribution and DNA content analyses. Furthermore, these new biocomposites induced an increase of collagen production in vitro. Overall, PLA/HC5/AgNPs and PLA/HC10/AgNPs bionanocomposites showed very good in vitro biocompatibility, and therefore, could be considered as valuable materials for medical devices, such as tubes, catheters, drains or connectors, with a relatively long service life. |
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conference
Prebiotic Content And Probiotic Effect Of Kombucha Fermented Pollen |
Elena Utoiu; Anca Oancea; Ana-Maria Stanciuc; Laura M. Stefan; Agnes Toma; Angela Moraru; Camelia Filofteia Diguta; Florentina Matei; Calina Petru Cornea; Florin Oancea | The International Conference Of The University Of Agronomic Sciences And Veterinary Medicine Of Bucharest, „Agriculture For Life, Life For Agriculture”, Bucuresti, Romania, 2018 | |
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conference
Un Nou Polen De Albine, Fermentat Cu Un Consortiu De Microorganisme Din Kombucha, Cu Efecte Benefice Asupra Sanatatii |
Elena Uțoiu; Florentina Matei; Agnes Toma; Camelia Filofteia Diguță; Laura Mihaela Stefan; Sorin Mănoiu; Virgil Valeriu Vrăjmașu; Ionuț Moraru; Anca Oancea et al | Apiquality & Apimedica 2018 The Xi-Th Congress Of The Romanian Society Of Apitherapy, Sibiu, Romania, 2018 | |
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article
Bee Collected Pollen With Enhanced Health Benefits, Produced By Fermentation With A Kombucha Consortium |
Utoiu Elena; Matei Florentina; Toma Agnes; Diguta Camelia Filofteia; Stefan Laura Mihaela; Manoiu Sorin; Vrajmasu Virgil Valeriu; Moraru Ionut; Oancea Anca; Israel-Roming Florentina; Cornea Calina Petruta; Constantinescu-Aruxandei Diana; Moraru Angela; Oancea Florin | Nutrients, 2018 | |
RezumatThe bioavailability of pollen bioactive compounds for humans is limited. In this study, our aim was to enhance the health-related benefits of pollen by fermentation with a Kombucha/SCOBY (symbiotic culture of bacteria and yeasts) consortium. We performed the fermentation of pollen suspended from the beginning with SCOBY on sweetened green tea or on Kombucha vinegar, by adding pollen after 20 days of Kombucha fermentation. We analyzed: formation of bioactive compounds (anti-oxidant polyphenols, soluble silicon, hydroxy-acids, short chain fatty acids-SCFA); parameters related to Kombucha fermentation (dynamics of lactic acid bacteria-LAB, formation of organic acids, soluble sugar evolution on Kombucha vinegar); the influence of Kombucha fermentation on pollen morphology and ultrastructure; in vitro cytotoxic and antitumoral effects of the Kombucha fermented pollen. The pollen addition increases LAB proportion in the total number of SCOBY microbial strains. SEM images highlight the adhesion of the SCOBY bacteria to pollen. Ultrastructural analysis reveals the release of the pollen content. The content of bioactive compounds (polyphenols, soluble silicon species and SCFA) is higher in the fermented pollen and the product shows a moderate antitumoral effect on Caco-2 cells. The health benefits of pollen are enhanced by fermentation with a Kombucha consortium. |
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article, conference
Selenium Biofortification Treatment Of Cauliflower Enhances Their Content În Chemopreventive Compounds And In Vitro Antitumoral Activity |
Elena Utoiu; Anca Oancea; Alexandra Gaspar; Ana-Maria Seciu; Laura M. Stefan; Viorica Coroiu; Oana Craciunescu; Cristinel Dumitru Badiu; Florin Oancea | Scientific Bulletin. Series F: Biotechnologies, The International Conference Of The University Of Agronomic Sciences And Veterinary Medicine Of Bucharest „Agriculture For Life, Life For Agriculture”, Bucharest, Romania, 2017 | |
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article
Enhancement Of Chemopreventive Compounds Content În Cabbage By Treatment With A Selenium Based Plant Biostimulant |
Anca Oancea; Alexandra Gaspar; Ana-Maria Seciu; Laura Mihaela Stefan; Elena Utoiu; Lucia Moldovan; Danut Turcu; Dumitru Cristinel Badiu; Oana Craciunescu | Journal Of International Scientific Publications : Agriculture & Food, 2017 | |
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conference
Enhancement Of Chemopreventive Compounds Content In Cabbage By Treatment With A Selenium Based Plant Biostimulant |
Anca Oancea; Alexandra Gaspar; Ana-Maria Seciu; Laura Mihaela Stefan; Elena Utoiu; Lucia Moldovan; Danut Turcu; Dumitru Cristinel Badiu; Oana Craciunescu; | 5Th International Conference “Agriculture And Food”, Elenite, Burgas, Bulgaria, 2017 | |
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conference
Feather Mite Diversity And Community Structure In Ne Atlantic And Mediterranean Seabirds |
L.M. Stefan; W. Isbert; E. Gómez-Díaz; S.V. Mironov; K.D. McCoy; J. González-Solís | International Zoological Congress Of Grigore Antipa Museum, 2017 | |
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article
Riboflavin Cross-Linking Of Collagen Porous Scaffolds For Periodontal Regeneration |
Seciu A.-M.; Gaspar A.; Stefan L.M.; Moldovan L.; Craciunescu O.; Zarnescu O. | Studia Universitatis “Vasile Goldis”, Seria Stiintele Vietii, 2016 | |
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article
On Identification Of Species In The Feather Mite Genus Laminalloptes Dubinin |
S.V. Mironov; L.M. Stefan | (Acari: Alloptidae), Acarina, 2016 | |
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article
Botanical And Phytochemical Approach On Passiflora Spp. – New Nutraceutical Crop In Romania |
T E;Smarandache D;Jecu L;A F;Sesan T E;Oancea F;Bira A F;Savin S;Negru G;Vasilescu G;Toma A;Sarbu A;C M;Oancea A;Pomohaci C M;Ghiurea M;Vlasceanu G;Stefan L | Journal Of Plant Development, 2016 | |
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conference
Water Use Efficiency On Cabbage And Cauliflower Treated With A New Biostimulant Composition |
Ana-Maria Seciu; Anca Oancea; Alexandra Gaspar; Lucia Moldovan; Oana Craciunescu; Laura Stefan; Valentin Petrus; Florentina Georgescu | The International Conference Of Usamv “Agriculture For Life, Life For Agriculture”, Bucharest, Romania, 2016 | |
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conference
Influence Of Treatments With Trichoderma On Physiological And Phytochemical Parameters Of Passiflora Caerulea L. |
T. E. Şesan; F. Oancea; A. Oancea; S. Savin; A. Toma; L. Ştefan; G. Negru; I. Răut; M. Ghiurea; L. Jecu; G. Vasilescu; A. F. Bira; C. M. Pomohaci | 12Th Edition Of The International Symposium Priochem, Bucharest, Romania, 2016 | |
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conference
Land-Based Threats And Population Viability Of The Endemic Gadfly Petrel Of Cape Verde Island |
H. Dinis; T. Militão; L. Zango; L.M. Stefan; J. González-Solís | 14Th Pan-African Ornithological Congress, Dakar, Senegal, 2016 | |
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conference
Host-Specificity And Cryptic Diversity Of Seabird Feather Mites From Cape Verde Islands: Integrating Morphological And Genetic Data |
L.M. Stefan; E. Gómez-Díaz; J. González-Solís; K.D. McCoy | 6Th International Albatross And Petrel Conference, Barcelona, Spania, 2016 | |
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conference
On Land Threats And Population Viability Of The Endemic Gadfly Petrel Of Cape Verde Islands |
T. Militão; H. Dinis; L. Zango; L.M. Stefan; J. González-Solís | 6Th International Albatross And Petrel Conference, Barcelona, Spania, 2016 | |
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conference
Contrasting Patterns Of Diversity And Genetic Structure In Feather Mite Communities Of Calonectris Shearwaters |
L.M. Stefan; E. Gómez-Díaz; J. González-Solís; K.D. McCoy | 8Th Symposium Of The European Association Of Acarologists, Valencia, Spania, 2016 | |
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conference
Population Dynamics, Breeding Biology And Major Threats Of Fea’S Petrel (Pterodroma Feae) In Fogo Island, Cape Verde |
T. Militão; H. Dinis; L. Zango; L.M. Stefan; J. González-Solís | Ix Congresso De Ornitologia Da Spea & Vi Congresso Iberico De Ornitologia, Vila Real, Portugalia, 2016 | |
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article
Phyto-Mediated Nanostructured Carriers Based On Dual Vegetable Actives Involved In The Prevention Of Cellular Damage |
Istrati D.; Lacatusu I.; Bordei N.; Badea G.; Oprea O.; Stefan L. M.; Stan R.; Badea N.; Meghea A. | Materials Science And Engineering C-Materials For Biological Applications, 2016 | |
RezumatThe growing scientific interest in exploitation of vegetable bioactives has raised a number of questions regarding their imminent presence in pharmaceutical formulations. This study intends to demonstrate that a dual combination between vegetable oil (e.g. thistle oil, safflower oil, sea buckthorn oil) and a carrot extract represents an optimal approach to formulate safe carrier systems that manifest cell regeneration effect and promising antioxidant and anti-inflammatory activity. Inclusion of both natural actives into lipid carriers imparted a strong negative charge on the nanocarrier surface (up to -45 mV) and displayed average sizes of 70 nm to 140 nm. The entrapment efficiency of carrot extract into nanostructured carriers ranged between 78.3 and 88.3%. The in vitro release study has demonstrated that the entrapment of the extract represents a viable way for an equilibrated release of carotenoids. Besides the excellent antioxidant properties (e.g. scavenging up to 98% of the free oxygen radicals), the results of cellular integrity (e.g. cell viability of 133%) recommend these nanocarriers based on dual carrot extract-bioactive oil as a promising trend for the treatment of certain disorders in which oxidative stress plays a prominent role. In addition, the lipid nanocarriers based on safflower oil and sea buckthorn oil demonstrated an anti-inflammatory effect on LPS induced THP-1 macrophages, by inhibiting the secretion of two pro inflammatory cytokines, IL-6 and TNF-alpha. (C) 2016 Elsevier B.V. All rights reserved. |
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article
Development Of A New Technology For Protective Biofortification With Selenium Of Brassica Crops |
Oancea A.O.; Gaspar A.; Seciu A.-M.; Stefan L.; Craciunescu O.; Georgescu F.; Lacatusu R. | Agrolife Scientific Journal, 2015 | |
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conference
Morphological Diversity And Genetic Structure Of Seabird Feather Mites |
Laura M. Stefan; Elena Gómez-Díaz; Karen D. McCoy; Jacob González-Solís | Simpozionul Stiintific Anual Al Incdsb, Murighiol, Tulcea, 2015 | |
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conference
Cercetări Morfo-Anatomice Şi De Fitochimie La Passiflora L., Planta De Cultura Nutraceutica Nou Climatizata In Romania |
Tatiana Eugenia Şesan; Anca Sârbu; Daniela Smarandache; Florin Oancea; Anca Oancea; Simona Savin; Agnes Toma; Laura Stefan; Georgeta Negru | Sesiunea De Comunicări Stiinţifice A Grădinii Botanice “D. Brandza”, 2015 | |
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conference
Biotechnological Approach Of Protective Biofortification With Selenium Of Brassica Crop |
Oancea AO; Gaspar A; Seciu A-M; Stefan L; Georgescu F; Lacatusu R | Section 6 Biotechnology, Pag. 39, The International Conference Of Usamv “Agriculture For Life, Life For Agriculture”, Bucharest, Romania, 2015 | |
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conference
Diversitatea Morfologica Si Structura Genetica La Acarienii Pasarilor Marine |
Stefan L.M.; McCoy K.D.; González-Solís J. | Sesiunea Stiintifica Anuala A Incdsb, Bucuresti, Romania, 2014 | |
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article
Compatibility And Cytotoxicity Testing Of Some New Biomaterials Based On Polyurethane And Hydroxypropylcellulose Blends |
Raschip I. E.; Moldovan L.; Stefan L.; Oancea A.; Vasile C. | Optoelectronics And Advanced Materials-Rapid Communications, 2009 | |
RezumatThe aim of the present paper is to study the compatibility and biocompatibility of new polyester urethane with hydroxypropylcellulose (HPC) blends by FT-IR spectroscopy, contact angle measurements. It has been established on the basis of the results obtained and specific interactions that the optima compatibility compositions which assure the good properties of biomaterials is 60% HPC-20% HPC/40% PU-80% PU. The biocompatibility and cytotoxicity of novel materials has been also assessed. The biological analysis showed that the new blends present a good biocompatibility, fibroblast cells cultured in the presence of polymers maintaining their normal cellular phenotype. The obtained blends are not cytotoxic and exhibits good surface properties and could be candidates for medical and pharmaceutical applications. |
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article
Evaluation Of The Radioprotective Activity Of New Green Tea-Collagen Materials |
Craciunescu O.; Stefan L. M.; Balan M.; Moldovan L. | Journal Of Optoelectronics And Advanced Materials, 2007 | |
RezumatThe aim of this study was to compare the protective effect of a green tea (Camellia sinensis) extract (GTE) and mixtures of GTE with collagen (COL) (GTE-COL I-V) against ultraviolet (UV) radiation using a primary culture of human dermal fibroblasts. Concentrations of GTE up to 25 mu g/ml had a significant positive effect on dermal fibroblast proliferation, spectrophotometrically assayed by the MTT test. However, concentrations of GTE higher than 25 mu g/ml, added in the culture medium, induced a cytotoxic effect on dermal fibroblasts. Similar results were found after UV-irradiation, when cells were cultivated in presence of the same concentrations of GTE. On the contrary, the fibroblast growth rate was similar or higher than the control, when cells were seeded on GTE-COL mixtures, even for the variants containing 50 mu g/ml and, respectively, 100 mu g/ml GTE. These observations were found both before and after cell irradiation. Cell adhesion data were in agreement with these results. Microscopical examination of the cells showed maintenance of the normal fibroblast phenotype, in the presence of all GTE-COL mixtures, before and after irradiation. All these data suggest that the tested GTE-COL materials could be efficient agents for skin protection against UV radiation. |