Nontoxic Silicon Nanocrystals and Nanodiamonds as Substitution for Harmful Quantum Dots

2009 ◽  
Vol 1241 ◽  
Author(s):  
Anna Fucikova ◽  
Jan Valenta ◽  
Ivan Pelant ◽  
Vitezslav Brezina
Keyword(s):  
Quantum Dots ◽  
Chemical Composition ◽  
Silicon Nanocrystals ◽  
Nanocrystalline Silicon ◽  
Semiconductor Quantum Dots ◽  
In Vivo Studies ◽  
Long Term Stability

AbstractThe commercially available semiconductor quantum dots have been proven to be slightly to significantly toxic by recent publications depending on the chemical composition. We are developing new non-toxic fluorescent labels based on (i) nanocrystalline silicon, suitable for in vivo studies due to their biodegrability, and on (ii) nanodiamonds, intended mainly for in vitro use due to their long-term stability and nondegradilibity.

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

scholarly journals Prosopis Plant Chemical Composition and Pharmacological Attributes: Targeting Clinical Studies from Preclinical Evidence

Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 777 ◽  
Author(s):  
Javad Sharifi-Rad ◽  
Farzad Kobarfard ◽  
Athar Ata ◽  
Seyed Abdulmajid Ayatollahi ◽  
Nafiseh Khosravi-Dehaghi ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Clinical Studies ◽  
Positive Impact ◽  
Biological Effects ◽  
Food Supplement ◽  
In Vivo Studies ◽  
Plant Chemical ◽  
Food Applications

Members of the Prosopis genus are native to America, Africa and Asia, and have long been used in traditional medicine. The Prosopis species most commonly used for medicinal purposes are P. africana, P. alba, P. cineraria, P. farcta, P. glandulosa, P. juliflora, P. nigra, P. ruscifolia and P. spicigera, which are highly effective in asthma, birth/postpartum pains, callouses, conjunctivitis, diabetes, diarrhea, expectorant, fever, flu, lactation, liver infection, malaria, otitis, pains, pediculosis, rheumatism, scabies, skin inflammations, spasm, stomach ache, bladder and pancreas stone removal. Flour, syrup, and beverages from Prosopis pods have also been potentially used for foods and food supplement formulation in many regions of the world. In addition, various in vitro and in vivo studies have revealed interesting antiplasmodial, antipyretic, anti-inflammatory, antimicrobial, anticancer, antidiabetic and wound healing effects. The phytochemical composition of Prosopis plants, namely their content of C-glycosyl flavones (such as schaftoside, isoschaftoside, vicenin II, vitexin and isovitexin) has been increasingly correlated with the observed biological effects. Thus, given the literature reports, Prosopis plants have positive impact on the human diet and general health. In this sense, the present review provides an in-depth overview of the literature data regarding Prosopis plants’ chemical composition, pharmacological and food applications, covering from pre-clinical data to upcoming clinical studies.

scholarly journals Development and test for long-term stability of a synthetic standard for a quantitative Cryptosporidium parvum LightCycler™ PCR assay

2005 ◽  
Vol 3 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Renata Filkorn-Kaiser ◽  
Konrad Botzenhart ◽  
Albrecht Wiedenmann
Keyword(s):  
Cryptosporidium Parvum ◽  
Surrogate Marker ◽  
Target Sequence ◽  
Positive Trend ◽  
Long Term Stability ◽  
Synthetic Standard ◽  
One Year

A recently described quantitative rapid cycle real time PCR (LightCycler™) assay detects Cryptosporidium parvum after in vitro excystation, which is a surrogate marker for the viability of the organisms. In the original assay the quantification standard is a dilution series of C. parvum oocysts with a microscopically determined excystation rate. The need to keep suspensions of viable oocysts in stock and to continuously monitor their excystation rate, however, renders the assay impracticable for routine application. A synthetic standard was developed to replace the in vivo standard and was calibrated using oocysts with known excystation rates. The standard consists of a 486 bp DNA segment ranging from 229 bp upstream to 79 bp downstream of the actual PCR target site. Aliquots of the standard were frozen and stored at −20 °C and at −70 °C or lyophilised and stored at room temperature in the dark. For a period of one year samples preserved with each of the three methods were restored every four or five weeks. They were amplified in the LightCycler™ and the crossing points (CP) were monitored. No significant trend in the raw CP values could be observed for any of the three storage methods. However, when the methods were compared to each other by calculating the CP ratios (−20 °C/−70 °C; −20 °C/lyophilised; −70 °C/lyophilised) at the 10 monitoring dates, the CP ratios −20 °C/−70 °C and −20 °C/lyophilised showed a highly significant positive trend (p<0.0001) while the CP ratio −70 °C/lyophilised did not differ from the null hypothesis (p=0.53). It can be concluded that the latter two preservation methods are both appropriate, while storage at −20 °C is less advisable. Calculations based on the molecular weight of the standard and on the assumption of an average yield of three sporozoites per oocyst led to the conclusion that the target sequence is probably located on a double copy gene

scholarly journals Loading Graphene Quantum Dots into Optical-Magneto Nanoparticles for Real-Time Tracking In Vivo

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2191 ◽  
Author(s):  
Yu Wang ◽  
Nan Xu ◽  
Yongkai He ◽  
Jingyun Wang ◽  
Dan Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Real Time ◽  
Fluorescent Dyes ◽  
Graphene Quantum Dots ◽  
Shell Nanoparticles ◽  
One Pot ◽  
Real Time Tracking

Fluorescence imaging offers a new approach to visualize real-time details on a cellular level in vitro and in vivo without radioactive damage. Poor light stability of organic fluorescent dyes makes long-term imaging difficult. Due to their outstanding optical properties and unique structural features, graphene quantum dots (GQDs) are promising in the field of imaging for real-time tracking in vivo. At present, GQDs are mainly loaded on the surface of nanoparticles. In this study, we developed an efficient and convenient one-pot method to load GQDs into nanoparticles, leading to longer metabolic processes in blood and increased delivery of GQDs to tumors. Optical-magneto ferroferric oxide@polypyrrole (Fe3O4@PPy) core-shell nanoparticles were chosen for their potential use in cancer therapy. The in vivo results demonstrated that by loading GQDs, it was possible to monitor the distribution and metabolism of nanoparticles. This study provided new insights into the application of GQDs in long-term in vivo real-time tracking.

scholarly journals Bioconjugated Pluronic Triblock-Copolymer Micelle-Encapsulated Quantum Dots for Targeted Imaging of Cancer: In Vitro and In Vivo Studies

Theranostics ◽  
2012 ◽  
Vol 2 (7) ◽  
pp. 705-713 ◽  
Author(s):  
Liwei Liu ◽  
Ken-Tye Yong ◽  
Indrajit Roy ◽  
Wing-Cheung Law ◽  
Ling Ye ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Triblock Copolymer ◽  
In Vivo Studies ◽  
Targeted Imaging ◽  
Copolymer Micelle

scholarly journals Tedizolid: new data and experiences for clinical practice

2021 ◽  
pp. 22-25
Author(s):  
Miguel Salavert Lletí ◽  
◽  
Víctor García-Bustos ◽  
Laura Morata Ruiz ◽  
Marta Dafne Cabañero-Navalon
Keyword(s):  
Relevant Information ◽  
In Vivo Studies ◽  
Recent Trial ◽  
Important Data ◽  
Gram Positive Bacteria ◽  
Osteoarticular Infections ◽  
Potential Use

The most relevant information on the clinical uses of tedizolid from studies published in the last 18 months is presented in this brief review. The most important data indicate better tolerance and safety profile of long-term therapeutic regimes in off-label indications, such as osteoarticular infections and those caused by mycobacteria. Its lower risk of hazardous interactions compared to linezolid should be emphasized. Furthermore, tedizolid in its combination with rifampicin shows a more favourable way of acting as demonstrated in vitro and in vivo studies. A recent trial also opens the door for its potential use in nosocomial pneumonia caused by Gram-positive bacteria.

scholarly journals Phytochemical composition and biological screening of two Lophophytum species

2021 ◽  
Vol 20 (6) ◽  
pp. 598-610
Author(s):  
Carola A. Torres ◽  
◽  
Cristina M. Perez Zamora ◽  
Hector A. Sato ◽  
Maria B. Nuñez ◽  
...  
Keyword(s):  
Chemical Composition ◽  
In Vivo Studies ◽  
Tree Roots ◽  
In Vitro Methods ◽  
Phytochemical Composition ◽  
First Results ◽  
Anti Inflammatory ◽  
Β Carotene

Lophophytum species are holoparasites that grow on tree roots. The objectives of the work were to explore the chemical composition of the tubers of two Lophophytum species and to analyze the antioxidant, anti-inflammatory and antilithiatic activity of their extracts using in vitro methods. The chemical composition was determined by histochemical, phytochemical and TLC tests. In addition, the profile of phenolic compounds was determined by HPLC-MS. The presence of secondary metabolites of recognized activity was demonstrated. The results of the HPLC-MS/MS allowed the tentative identification of catechin, luteolin and glycosides of eriodictyol, naringenin and luteolin in the extract of Lophophytum leandri and eriodictyol, naringenin, luteolin and their glycosylated derivatives in Lophophytum mirabile. The extracts showed promising antioxidant (DPPH, ABTS and β-carotene-linoleic acid), anti-inflammatory (inhibition of 5-LOX) and anti-urolytic (by bioautographic TLC) activity. It is noteworthy that these are the first results of the phytochemical composition and biological activity of L. mirabile. However, in vivo studies are required to corroborate these activities.

Robust oil-core nanocapsules with hyaluronate-based shells as promising nanovehicles for lipophilic compounds

Nanoscale ◽  
2017 ◽  
Vol 9 (47) ◽  
pp. 18867-18880 ◽  
Author(s):  
Joanna Szafraniec ◽  
Agnieszka Błażejczyk ◽  
Edyta Kus ◽  
Małgorzata Janik ◽  
Gabriela Zając ◽  
...  
Keyword(s):  
Lipophilic Compounds ◽  
Term Stability ◽  
Long Term Stability ◽  
Free Process

Biocompatible hyaluronate-based nanocapsules with liquid oil cores exhibiting long-term stability and tunable size were obtained in a versatile surfactant-free process and their biodistribution was studied in vivo and in vitro.

scholarly journals Detoxification of Implant Surfaces Affected by Peri-Implant Disease: An Overview of Surgical Methods

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Pilar Valderrama ◽  
Thomas G. Wilson Jr
Keyword(s):  
In Vivo Studies ◽  
Surgical Approaches ◽  
Validity And Reliability ◽  
Implant Surface ◽  
Advantages And Disadvantages ◽  
Surgical Methods ◽  
Term Evaluation

Purpose. Peri-implantitis is one of the major causes of implant failure. The detoxification of the implant surface is necessary to obtain reosseointegration. The aim of this review was to summarize in vitro and in vivo studies as well as clinical trials that have evaluated surgical approaches for detoxification of the implant body surfaces.Materials and Methods. A literature search was conducted using MEDLINE (PubMed) from 1966 to 2013. The outcome variables were the ability of the therapeutic method to eliminate the biofilm and endotoxins from the implant surface, the changes in clinical parameters, radiographic bone fill, and histological reosseointegration.Results. From 574 articles found, 76 were analyzed. The findings, advantages, and disadvantages of using mechanical, chemical methods and lasers are discussed.Conclusions. Complete elimination of the biofilms is difficult to achieve. All therapies induce changes of the chemical and physical properties of the implant surface. Partial reosseointegration after detoxification has been reported in animals. Combination protocols for surgical treatment of peri-implantitis in humans have shown some positive clinical and radiographic results, but long-term evaluation to evaluate the validity and reliability of the techniques is needed.

scholarly journals Comparison of the Efficacy of Two Novel Antitubercular Agents in Free and Liposome-Encapsulated Formulations

2021 ◽  
Vol 22 (5) ◽  
pp. 2457
Author(s):  
Nikoletta Kósa ◽  
Ádám Zolcsák ◽  
István Voszka ◽  
Gabriella Csík ◽  
Kata Horváti ◽  
...  
Keyword(s):  
Cellular Uptake ◽  
Drug Carrier ◽  
Antimycobacterial Activity ◽  
Size Exclusion ◽  
In Silico Docking ◽  
Term Stability ◽  
Long Term Stability

Tuberculosis is one of the top ten causes of death worldwide, and due to the appearance of drug-resistant strains, the development of new antituberculotic agents is a pressing challenge. Employing an in silico docking method, two coumaran (2,3-dihydrobenzofuran) derivatives—TB501 and TB515—were determined, with promising in vitro antimycobacterial activity. To enhance their effectiveness and reduce their cytotoxicity, we used liposomal drug carrier systems. Two types of small unilamellar vesicles (SUV) were prepared: multicomponent pH-sensitive stealth liposome (SUVmixed) and monocomponent conventional liposome. The long-term stability of our vesicles was obtained by the examination of particle size distribution with dynamic light scattering. Encapsulation efficiency (EE) of the two drugs was determined from absorption spectra before and after size exclusion chromatography. Cellular uptake and cytotoxicity were determined on human MonoMac-6 cells by flow cytometry. The antitubercular effect was characterized by the enumeration of colony-forming units on Mycobacterium tuberculosis H37Rv infected MonoMac-6 cultures. We found that SUVmixed + TB515 has the best long-term stability. TB515 has much higher EE in both types of SUVs. Cellular uptake for native TB501 is extremely low, but if it is encapsulated in SUVmixed it appreciably increases; in the case of TB515, quasi total uptake is accessible. It is concluded that SUVmixed + TB501 seems to be the most efficacious antitubercular formulation given the presented experiments; to find the most promising antituberculotic formulation for therapy further in vivo investigations are needed.

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