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1.  Raman spectroscopy-based approach to detect aging-related oxidative damage in the mouse oocyte 
Detection of chemical modifications induced by aging-related oxidative damage in mouse metaphase II (MII) oocytes by Raman microspectroscopy.
CD-1 mice at the age of 4–8 weeks (young mice) and 48–52 weeks (old mice), were superovulated and oocytes at metaphase II stage were recovered from oviducts. MII oocytes from young animals were divided into three groups: A) young oocytes, processed immediately after collection; B) in vitro aged oocytes, cultured in vitro for 10 h before processing; C) oxidative-stressed oocytes, exposed to 10 mM hydrogen peroxide for 2 min before processing. Oocytes from reproductively old mice were referred to as old oocytes (D). All the oocytes were analyzed by confocal Raman microspectroscopy. The spectra were statistically analyzed using Principal Component Analysis (PCA).
PCA evidenced that spectra from young oocytes (A) were clearly distinguishable from those obtained from in vitro-aged, oxidative-damaged and old oocytes (B, C, D) and presented significant differences in the bands attributable to lipid components (C = C stretching, 1,659 cm−1; CH2 bending, 1,450 cm−1; CH3 deformation,1,345 cm−1; OH bending, C-N stretching, 1,211 cm-1) and protein components (amide I band,1,659 cm−1; CH2 bending modes and CH3 deformation, 1,450 cm−1; C-N and C-C stretching vibrations, 1,132 cm−1; phenylalanine’s vibration, 1,035 cm−1)
Raman spectroscopy is a valuable non-invasive tool for the identification of biochemical markers of oxidative damage and could represent a highly informative method of investigation to evaluate the oocyte quality.
PMCID: PMC3725222  PMID: 23860776
Raman spectroscopy; Aging; Oocyte; Oxidative stress
2.  The production of concentrated dispersions of few-layer graphene by the direct exfoliation of graphite in organosilanes 
Nanoscale Research Letters  2012;7(1):674.
We report the formation and characterization of graphene dispersions in two organosilanes, 3-glycidoxypropyl trimethoxysilane (GPTMS) and phenyl triethoxysilane (PhTES) as new reactive solvents. The preparation method was mild and easy and does not produce any chemical modification. The dispersions, which exhibit the Tyndall effect, were characterized by TEM and Raman spectroscopy to confirm the presence of few-layer graphene. Concentrations as high as 0.66 and 8.00 mg/ml were found for PhTES and GPTMS, respectively. The latter is one of the highest values reported for a dispersion of graphene obtained by any method. This finding paves the way for the direct synthesis of polymer nanofiller-containing composites consisting of graphene and reactive silanes to be used in sol–gel synthesis, without any need for solvent removal, thus preventing graphene reaggregation to form graphite flakes.
PMCID: PMC3533964  PMID: 23237423
Graphene; Organosilanes; High concentration; Liquid exfoliation
3.  Development of novel cationic chitosan-and anionic alginate–coated poly(d,l-lactide-co-glycolide) nanoparticles for controlled release and light protection of resveratrol 
Resveratrol, like other natural polyphenols, is an extremely photosensitive compound with low chemical stability, which limits the therapeutic application of its beneficial effects. The development of innovative formulation strategies, able to overcome physicochemical and pharmacokinetic limitations of this compound, may be achieved via suitable carriers able to associate controlled release and protection. In this context, nanotechnology is proving to be a powerful strategy. In this study, we developed novel cationic chitosan (CS)- and anionic alginate (Alg)-coated poly(d,l-lactide-co-glycolide) nanoparticles (NPs) loaded with the bioactive polyphenolic trans-(E)-resveratrol (RSV) for biomedical applications.
NPs were prepared by the nanoprecipitation method and characterized in terms of morphology, size and zeta potential, encapsulation efficiency, Raman spectroscopy, swelling properties, differential scanning calorimetry, and in vitro release studies. The protective effect of the nanosystems under the light-stressed RSV and long-term stability were investigated.
NPs turned out to be spherical in shape, with size ranging from 135 to about 580 nm, depending on the composition and the amount of polyelectrolytes, while the encapsulation efficiencies increased from 8% of uncoated poly(d,l-lactide-co-glycolide) (PLGA) to 23% and 32% of Alg- and CS-coated PLGA NPs, respectively. All nanocarriers are characterized by a biphasic release pattern, and more effective controlled release rates are obtained for NPs formulated with higher polyelectrolyte concentrations. Stability studies revealed that encapsulation provides significant protection against light-exposure degradation, by reducing the trans–cis photoisomerization reaction. Moreover, the nanosystems are able to prevent the degradation of trans isoform and the leakage of RSV from the carrier for a period of 6 months.
Our findings indicated that the newly developed CS- and Alg-coated PLGA NPs are suitable to be used for the delivery of bioactive RSV. The encapsulation of RSV into optimized polymeric NPs provides improved drug loading, effective controlled release, and protection against light-exposure degradation, thus opening new perspectives for the delivery of bioactive related phytochemicals to be used for (nano)chemoprevention/chemotherapy.
PMCID: PMC3477887  PMID: 23093904
resveratrol; nanochemoprevention; PLGA; chitosan; alginate; nanoparticles
4.  FTIR nanobiosensors for Escherichia coli detection 
Infections due to enterohaemorrhagic E. coli (Escherichia coli) have a low incidence but can have severe and sometimes fatal health consequences, and thus represent some of the most serious diseases due to the contamination of water and food. New, fast and simple devices that monitor these pathogens are necessary to improve the safety of our food supply chain. In this work we report on mesoporous titania thin-film substrates as sensors to detect E. coli O157:H7. Titania films treated with APTES ((3-aminopropyl)triethoxysilane) and GA (glutaraldehyde) were functionalized with specific antibodies and the absorption properties monitored. The film-based biosensors showed a detection limit for E. coli of 1 × 102 CFU/mL, constituting a simple and selective method for the effective screening of water samples.
PMCID: PMC3458592  PMID: 23019542
biosensors; E. coli; FTIR spectroscopy; foodborne pathogens; nanomaterials

Results 1-4 (4)