Cristian Matea

In Vitro Administration of Gold Nanoparticles Functionalized with MUC-1 Protein Fragment Generates Anticancer Vaccine Response via Macrophage Activation and Polarization Mechanism

Therapeutic cancer vaccines (or active immunotherapy) aim to guide the patients personal immune system to eradicate cancer cells. An exciting approach to cancer vaccines has been offered by nanoscale drug delivery systems containing tumor associated antigens (TAAs). Their capacity to stimulate the immune system has been suggested during late years. However, the role of the macrophages as key-elements in antigen-presentation process following TAAs-containing nanosystems is not completely understood. We aimed to evaluate the effect of gold nanoparticles functionalized with mucin-1 peptide (MUC-1) on murine peritoneal macrophages. Gold nanoparticles, obtained using a modified Turkevich method, were functionalized with MUC-1 protein using Clealands reagent. The obtained GNP-MUC-1 solution was used to treat at various concentrations monolayers of peritoneum-derived macrophages that were further analyzed using confocal and hyperspectral microscopy, ELISA assays and spectroscopic techniques. The GNP-MUC-1 nano-construct had proven to function as a powerful macrophage activator with consequent release of cytokines such as: TNF-ɑ, IL-6, IL-10 and IL-12 on peritoneal macrophages we have isolated from mice. Our results demonstrate optimization of antigen-presenting process and predominant M1 polarization following exposure GNP-MUC-1. To our best knowledge this is the first study to evaluate the anticancer effects of a newly designed nano-biocompound on the complex antigen- processing apparatus of peritoneal macrophages.

Enhanced laser thermal ablation for the in vitro treatment of liver cancer by specific delivery of multiwalled carbon nanotubes functionalized with human serum albumin

The main goal of this investigation was to develop and test a new method of treatment for human hepatocellular carcinoma (HCC). We present a method of carbon nanotube-enhanced laser thermal ablation of HepG2 cells (human hepatocellular liver carcinoma cell line) based on a simple multiwalled carbon nanotube (MWCNT) carrier system, such as human serum albumin (HSA), and demonstrate its selective therapeutic efficacy compared with normal hepatocyte cells. Both HepG2 cells and hepatocytes were treated with HSA–MWCNTs at various concentrations and at various incubation times and further irradiated using a 2 W, 808 nm laser beam. Transmission electron, phase contrast, and confocal microscopy combined with immunochemical staining were used to demonstrate the selective internalization of HSA–MWCNTs via Gp60 receptors and the caveolin-mediated endocytosis inside HepG2 cells. The postirradiation apoptotic rate of HepG2 cells treated with HSA–MWCNTs ranged from 88.24% (for 50 mg/L) at 60 sec to 92.34% (for 50 mg/L) at 30 min. Significantly lower necrotic rates were obtained when human hepatocytes were treated with HSA–MWCNTs in a similar manner. Our results clearly show that HSA–MWCNTs selectively attach on the albondin (aka Gp60) receptor located on the HepG2 membrane, followed by an uptake through a caveolin-dependent endocytosis process. These unique results may represent a major step in liver cancer treatment using nanolocalized thermal ablation by laser heating.

Carotenoids, total polyphenols and antioxidant activity of grapes ( Vitis vinifera ) cultivated in organic and conventional systems

BackgroundOrganic agriculture involve plants which are cultivated without using synthetic pesticides, herbicides or fertilizers and promotes biodiversity, biological cycles and improve the product quality. The carotenoids, total polyphenols and the antioxidant activity from skins of some wine and table grapes cultivated in organic and conventional agriculture were studied.ResultsThe main carotenoids identified using high performance liquid chromatography were lutein and ß-carotene. Muscat Ottonel variety has the highest ß-carotene concentration 504.9 μg/kg for organic and 593.2 μg/kg for conventional grapes. For the organic farming, the total polyphenols content were in the range of 163.23 – 1341.37 mg GAE/kg fresh weight (FW) and 148.47 – 1231.38 mg GAE/kg FW for the conventional grapes. The highest ORAC values were obtained for blue-black variety Napoca in both farming system (43.5 ± 0.95 μmol TE/g organic; 40.4 ± 0.5 μmol TE/g conventional) and lowest for Aromat de Iaşi (16.8 ± 0.6 μmol TE/g organic; 14.7 ± 1.6 μmol TE/g conventional). Napoca variety showed also the highest antioxidant activity measured by DPPH method in both cultivated system.ConclusionNine grape varieties cultivated in organic and conventional systems were compared regarding the carotenoids, total polyphenols and antioxidant activity. The white grape varieties have a higher carotenoids content compared with the blue-black cultivars while the blue-black varieties contain higher TPC and exhibit higher antioxidant activity (except for Muscat Hamburg-ORAC). Vitis vinifera grape skins originating from wine or table grape varieties can be used as a potential source of natural antioxidants.

Photothermal Treatment of Human Pancreatic Cancer Using PEGylated Multi-Walled Carbon Nanotubes Induces Apoptosis by Triggering Mitochondrial Membrane Depolarization Mechanism

Pancreatic cancer (PC) is one of the most lethal solid tumor in humans, with an overall 5-year survival rate of less than 5%. Thermally active carbon nanotubes have already brought to light promising results in PC research and treatment. We report here the construct of a nano-biosystem based on multi-walled carbon nanotubes and polyethylene glycol (PEG) molecules validated through AFM, UV-Vis and DLS. We next studied the photothermal effect of these PEG-ylated multi-walled carbon nanotubes (5, 10 and 50 μg/mL, respectively) on pancreatic cancer cells (PANC-1) and further analyzed the molecular and cellular events involved in cell death occurrence. Using cell proliferation, apoptosis, membrane polarization and oxidative stress assays for ELISA, fluorescence microscopy and flow cytometry we show here that hyperthermia following MWCNTs-PEG laser mediated treatment (808 nm, 2W) leads to mitochondrial membrane depolarization that activates the flux of free radicals within the cell and the oxidative state mediate cellular damage in PC cells via apoptotic pathway. Our results are of decisive importance especially in regard with the development of novel nano-biosystems capable to target mitochondria and to synergically act both as cytotoxic drug as well as thermally active agents in order to overcome one of the most common problem met in oncology, that of intrinsic resistance to chemotherapeutics.

Surface plasmon resonance-induced photoactivation of gold nanoparticles as bactericidal agents against methicillin-resistant Staphylococcus aureus.

Systemic infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and other bacteria are responsible for millions of deaths worldwide, and much of this mortality is due to the rise of antibiotic-resistant organisms as a result of natural selection. Gold nanoparticles synthesized using the standard wet chemical procedure were photoexcited using an 808 nm 2 W laser diode and further administered to MRSA bacteria. Flow cytometry, transmission electron microscopy, contrast phase microscopy, and fluorescence microscopy combined with immunochemical staining were used to examine the interaction of the photoexcited gold nano-particles with MRSA bacteria. We show here that phonon–phonon interactions following laser photoexcitation of gold nanoparticles exhibit increased MRSA necrotic rates at low concentrations and short incubation times compared with MRSA treated with gold nanoparticles alone. These unique data may represent a step forward in the study of bactericidal effects of various nanomaterials, with applications in biology and medicine.

Photothermal treatment of liver cancer with albumin-conjugated gold nanoparticles initiates Golgi Apparatus–ER dysfunction and caspase-3 apoptotic pathway activation by selective targeting of Gp60 receptor

We present a method of enhanced laser thermal ablation of HepG2 cells based on a simple gold nanoparticle (GNP) carrier system such as serum albumin (Alb), and demonstrate its selective therapeutic efficacy compared with normal hepatocyte cells. HepG2 or hepatocytes were treated with Alb-GNPs at various concentrations and various incubation times, and further irradiated using a 2 W, 808 nm laser. Darkfield microscopy and immunochemical staining was used to demonstrate the selective internalization of Alb-GNPs inside the HepG2 cells via Gp60 receptors targeting. The postirradiation apoptotic rate of HepG2 cells treated with Alb-GNPs ranged from 25.8% (for 5 μg/mL) to 48.2% (for 50 μg/mL) at 60 seconds, while at 30 minutes the necrotic rate increased from 35.7% (5 μg/mL) to 52.3% (50 μg/mL), P-value <0.001. Significantly lower necrotic rates were obtained when human hepatocytes were treated with Alb-GNPs in a similar manner. We also showed by means of immunocytochemistry that photothermal treatment of Alb-conjugated GNPs in liver cancer initiates Golgi apparatus–endoplasmic reticulum dysfunction with consequent caspase-3 apoptotic pathway activation and cellular apoptosis. The presented results may become a new method of treating cancer cells by selective therapeutic vectors using nanolocalized thermal ablation by laser heating.

Quantum dots in imaging, drug delivery and sensor applications

Quantum dots (QDs), also known as nanoscale semiconductor crystals, are nanoparticles with unique optical and electronic properties such as bright and intensive fluorescence. Since most conventional organic label dyes do not offer the near-infrared (>650 nm) emission possibility, QDs, with their tunable optical properties, have gained a lot of interest. They possess characteristics such as good chemical and photo-stability, high quantum yield and size-tunable light emission. Different types of QDs can be excited with the same light wavelength, and their narrow emission bands can be detected simultaneously for multiple assays. There is an increasing interest in the development of nano-theranostics platforms for simultaneous sensing, imaging and therapy. QDs have great potential for such applications, with notable results already published in the fields of sensors, drug delivery and biomedical imaging. This review summarizes the latest developments available in literature regarding the use of QDs for medical applications.

Comparative analysis of lipophilic compounds in eggs of organically raised ISA Brown and Araucana hens

Hens’ eggs represent a rich source of important nutrients, including lipids and carotenoids. The lipid composition of hens’ eggs is influenced by genetic factors, age, and diet. The aim of this study was to compare the fatty acids, cholesterol, and carotenoids content of the egg yolk of ISA Brown and Araucana hens grown in free-range housing systems. Fatty acids and cholesterol were analysed by GC-FID and GC-MS and carotenoids were quantified by RP-HPLC-PDA.The Araucana egg yolk has a higher lipid content and higher egg-to-albumen ratio than the ISA Brown yolk, while the total cholesterol, carotenoids content and profile are not significantly different. The lipids of the Araucana egg yolk have a higher content of mono-unsaturated fatty acids (MUFAs), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and a better n-6/n-3 ratio than the ISA Brown egg yolk lipids. The major carotenoids were lutein and zeaxanthin, which account for more than 83 % in egg yolk. Eggs of both breeds, when raised organically, represent very good sources of highly bio-available lutein and zeaxanthin, pigments which are related to lower risk of age-related macular degeneration. We report for the first time on the fatty acids composition in lipid fractions and the profile and content of carotenoids of the Araucana egg yolk.

Development of nanoparticle-based optical sensors for pathogenic bacterial detection

BackgroundPathogenic bacteria contribute to various globally important diseases, killing millions of people each year. Various fields of medicine currently benefit from or may potentially benefit from the use of nanotechnology applications, in which there is growing interest. Disease-related biomarkers can be rapidly and directly detected by nanostructures, such as nanowires, nanotubes, nanoparticles, cantilevers, microarrays, and nanoarrays, as part of an accurate process characterized by lower sample consumption and considerably higher sensitivity. There is a need for accurate techniques for pathogenic bacteria identification and detection to allow the prevention and management of pathogenic diseases and to assure food safety.ConclusionThe focus of this review is on the current nanoparticle-based techniques for pathogenic bacterial identification and detection using these applications.

Seasonal changes of buffalo colostrum: physicochemical parameters, fatty acids and cholesterol variation

BackgroundColostrum has many beneficial effects on newborns due to its main compounds(proteins, fats, lactose, essential fatty acids, amino acids) as well asprotective antibodies that confer to the body. The buffaloes are the secondimportant species for milk production in the world after cows. The importance ofthe species is also conferred by a longer longevity, high dry content of milk anda strong organic resistance when compared with cows. The purpose of this study wasto investigate the changes of buffalo colostrum compounds such as fatty acids,cholesterol and physicochemical parameters during the first seven dayspostpartum and under the impact of the season, summer on pasture andwinter on dry diet (hay based).ResultsFat from colostrum differs depending on the postpartum day showing meanvalues of 11.31-7.56% (summer season) and 11.22-7.51% (winter season). Thesevalues gradually decreased starting with first day postpartum until dayseven. Dry substance and protein presented a similar evolution to fat reaching thelowest values at the end of the colostral period. Lactose, ash and pH showed agradually increase reaching the maximum on day seven postpartum. Thehighest titres of fatty acids from colostrum are: butyric acid (C4:0), myristicacid (C14:0), palmitic acid (C16:0), oleic acid (C18:1) and the lowest valuesshowed up in myristoleic acid (C14:1), cis-10-pentadecanoic acid (C15:1),pentadecylic acid (C15:0) and margaric acid (C17:0) for both seasons. Higherconcentrations have been recorded for the summer season in general. Cholesterolconcentration decreased from 12.93 and 12.68 mg/100 mL (summer and winter season)to 9.02 and 7.88 mg/100 mL in the end of the colostral period.ConclusionsPhysicochemical compounds of buffalo colostrum were influenced by season andpostpartum day of milking. Excepting lactose all other parametersgradually decreased during colostral period. Fatty acids and cholesterol showedthe same evolution, presenting higher values for the summer season. Specificfeeding in the summer season (on pasture) did lead in more concentrated colostrumin dry substance, fatty acids and cholesterol.