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1.
J Equine Vet Sci ; 108: 103801, 2022 01.
Article in English | MEDLINE | ID: mdl-34839079

ABSTRACT

Among biotechnologies of reproduction in the equine species, artificial insemination remains the most used technology especially for cooled transported sperm. Although the use of INRA96 extender has demonstrated its efficiency for long-term sperm storage at 4°C or 15°C, some stallions ("bad coolers") are excluded from such technology. Some years ago, we demonstrated that liposomes produced from egg yolk (EY) phospholipids could be an alternative to egg yolk plasma in stallion freezing extenders. To develop a new extender for sperm chilling, we evaluated the protective effect of liposomes produced from EY phospholipids on stallion sperm storage at 4°C. The sperm of stallions from two studs was diluted in INRA96 extender (as control) or an experimental extender (EE) composed of INRA96 supplemented with liposomes of EY phospholipids. After 24H (D1), 72H (D3), and 6 days (D6) or 7 days (D7), motility parameters were evaluated using Computer Assisted Semen Analyzer. Our results demonstrated that total and progressive motility decreased significantly after dilution and storage in INRA96 between D1 and D3 (P < .05) while no significant decrease was observed between D1 and D3 with EE. Regarding VAP parameter, no significant difference was observed between extenders except at D7 in stud 2. Moreover, total and progressive motility were maintained at a significantly higher level (D3, D6, D7) when sperm was stored in EE compared to INRA96. These promising results demonstrate that the supplementation of INRA96 extender with egg-yolk phospholipids liposomes allows a higher protection to stallion sperm cells.


Subject(s)
Semen Preservation , Animals , Dietary Supplements , Horses , Liposomes , Male , Phospholipids , Semen Preservation/veterinary , Sperm Motility , Spermatozoa
2.
J Am Chem Soc ; 130(27): 8596-7, 2008 Jul 09.
Article in English | MEDLINE | ID: mdl-18549203

ABSTRACT

Smart nanohybrids were prepared by conjugation of CrAsH to hydrosoluble and biocompatible quantum dots (QDs). The resulting probes were shown to bind efficiently and selectively to Cys-tagged proteins. The interaction with the protein was detected by an increase of the fluorescence emission of CrAsH. While the latter faded rapidly under continuous excitation, emission of the QD remained unaffected. The persistent fluorescence of the QD should thus allow extended monitoring of the target protein.


Subject(s)
Biocompatible Materials/chemistry , Fluorescent Dyes/chemistry , Organometallic Compounds/chemistry , Quantum Dots , Recombinant Proteins/chemistry , Cysteine/chemistry , Fluoresceins/chemistry , Fluorescent Dyes/chemical synthesis , Phospholipids/chemistry
3.
Langmuir ; 24(7): 3016-9, 2008 Apr 01.
Article in English | MEDLINE | ID: mdl-18303920

ABSTRACT

Water soluble fluorescent nanocrystals were obtained by encapsulation of hydrophobic quantum dots (QDs) with amphiphilic phospholipids derived from the ring opening metathesis of norbornene-based monomers. The robustness of the newly coated quantum dots was assessed by comparative studies under various ionic conditions which indicated an overall enhancement of their fluorescence stability.


Subject(s)
Fluorescence , Nanoparticles/chemistry , Phospholipids/chemistry , Polyethylene Glycols/chemistry , Ions , Quantum Dots , Solubility , Water
4.
Nat Protoc ; 2(10): 2383-90, 2007.
Article in English | MEDLINE | ID: mdl-17947980

ABSTRACT

A detailed protocol for the synthesis of core/shell semiconductor nanocrystal, their encapsulation into phospholipid micelles, their purification and their coupling to a controlled number of small molecules is given. The protocol for the core/shell quantum dot (QD) CdSe/CdZnS synthesis has been specifically designed with two constraints in mind: green and reproducible core/shell QD synthesis with thick shell structure and QDs that can easily be encapsulated in poly(ethylene glycol)-phospholipid micelles with one QD per micelle. We present two procedures for the QD purification that are suitable for the use of QD micelles for in vivo imaging: ultracentrifugation and size-exclusion chromatography. We also discuss the different coupling chemistry for covalently linking a controlled number of molecules to the QD micelles. The total time durations for the different protocols are as follows: QD synthesis: 6 h; encapsulation: 15 min; purification: 1-4 h; coupling: reaction dependent.


Subject(s)
Micelles , Nanotechnology/methods , Phospholipids/chemistry , Quantum Dots , Fluorescence , Nanoparticles/chemistry , Nanotechnology/instrumentation , Polyethylene Glycols/chemistry , Toluene/chemistry , Water/chemistry
5.
Chembiochem ; 8(3): 315-22, 2007 Feb 12.
Article in English | MEDLINE | ID: mdl-17226879

ABSTRACT

Polycarbonate (PC) is a useful substrate for the preparation of microfluidic devices. Recently, its utility in bioanalysis has attracted much attention owing to the possibility of using compact discs as platforms for the high-throughput analysis of biomolecular interactions. In this article we report a novel method for the chemical micropatterning of polycarbonate based on the printing of functionalized silica nanoparticles. The semicarbazide groups present on the surface of the nanoparticles were used for the site-specific semicarbazone ligation of unprotected peptides derivatized by an alpha-oxoaldehyde group. The peptide micropatterns permitted the specific capture of antibodies. We report also the characterization of micropatterns on PC by using a wide-field optical imaging technique called Sarfus; this allows the detection of nm-thick films by using nonreflecting PC substrates and an optical microscope working with reflected differential interference contrast. The method described here is an easy way to modify polycarbonate surfaces for biomolecular interaction studies and should stimulate the use of PC for developing plastic biosensors.


Subject(s)
Microarray Analysis/instrumentation , Microfluidic Analytical Techniques/instrumentation , Peptides/chemistry , Polycarboxylate Cement/chemistry , Enzymes, Immobilized/chemistry , Nanoparticles/chemistry , Semicarbazides/chemistry , Silicon Dioxide/chemistry , Substrate Specificity
6.
Chembiochem ; 7(5): 817-26, 2006 May.
Article in English | MEDLINE | ID: mdl-16550626

ABSTRACT

Polysaccharide microarrays have great potential for the high-throughput analysis of polysaccharide-protein interactions. Here we demonstrate that a polysaccharide microarray prepared by printing a library of dextran polymers derivatized by methylcarboxylate, benzylamide, and sulfate groups (DMCBSu compounds) on to glass slides permitted the rapid identification of a set of compounds able to interact with the platelet-derived growth factor BB (PDGF-BB) isoform, a growth factor involved in wound healing. Microarray interaction results were compared to the capacity of DMCBSu compounds to potentiate the in vitro PDGF-BB-induced proliferation of human dermal fibroblasts.


Subject(s)
Microarray Analysis/methods , Platelet-Derived Growth Factor/chemistry , Polysaccharides/chemistry , Becaplermin , Cell Proliferation/drug effects , Dextrans/chemistry , Fibroblasts/drug effects , Humans , Microarray Analysis/instrumentation , Molecular Weight , Peptide Library , Platelet-Derived Growth Factor/pharmacology , Proto-Oncogene Proteins c-sis , Surface Properties
7.
Bioconjug Chem ; 15(2): 317-25, 2004.
Article in English | MEDLINE | ID: mdl-15025527

ABSTRACT

We have described in the accompanying article the preparation of peptide-protein semicarbazide microarrays and their use for the simultaneous serodetection of antibodies directed against different pathogens. Here, we present a comparative study between semicarbazide and amine glass slides in an immunofluorescent serodetection assay using HIV (Gp120, Gp41), HCV (mix-HCV, core, NS3, and NS4), and HBV (HBs) recombinant antigens. Amine and semicarbazide surfaces displayed the same sensitivity for antibodies detection just after printing. However, the reactivity of protein antigens changed rapidly upon aging on amine slides but not on semicarbazide slides. Peptide or protein semicarbazide microarrays were found to be remarkably stable for months. Additional data concerning the characterization of the semicarbazide surface (homogeneity of the slides, chemical stability, contact angle measurements, atomic force microscopy studies, reproducibility of serodetection results) are also presented and discussed.


Subject(s)
Amines/chemistry , Peptides/chemistry , Protein Array Analysis/methods , Semicarbazides/chemistry , Serologic Tests/methods , Adsorption , Drug Stability , Glass/chemistry , Humans , Microscopy, Atomic Force , Protein Array Analysis/instrumentation , Serologic Tests/instrumentation
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