54 research outputs found
Reproductive consequences of electrolyte disturbances in domestic animals
Electrolyte balance is essential to maintain homeostasis in the body. The most crucial
electrolytes are sodium (Na+), potassium (K+), magnesium (Mg2+), chloride (Cl?), and calcium (Ca2+).
These ions maintain the volume of body fluids, and blood pressure, participate in muscle
contractions, and nerve conduction, and are important in enzymatic reactions. The balance is mainly
ensured by the kidneys, which are an important organ that regulates the volume and composition
of urine, together with which excess electrolytes are excreted. They are also important in the
reproductive system, where they play a key role. In the male reproductive system, electrolytes are
important in acrosomal reaction and sperm motility. Sodium, calcium, magnesium, and chloride
are related to sperm capacitation. Moreover, Mg2+, Ca2+, and Na+ play a key role in spermatogenesis
and the maintenance of morphologically normal spermatozoa. Infertility problems are becoming
more common. It is known that disturbances in the electrolyte balance lead to reproductive
dysfunction. In men, there is a decrease in sperm motility, loss of sperm capacitation, and male
infertility. In the female reproductive system, sodium is associated with estrogen synthesis. In the
contraction and relaxation of the uterus, there is sodium, potassium, and calcium. Calcium is
associated with oocyte activation. In turn, in women, changes in the composition of the follicular
fluid are observed, leading to a restriction of follicular growth. Imbalance of oocyte electrolytes,
resulting in a lack of oocyte activation and, consequently, infertility.FE1B-06B2-126F | Jos? Pedro Pinto de Ara?joN/
Site-specific Forest-assembly of Single-Wall Carbon Nanotubes on Electron-beam Patterned SiOx/Si Substrates
Based on electron-beam direct writing on the SiOx/Si substrates, favorable
absorption sites for ferric cations (Fe3+ ions) were created on the surface
oxide layer. This allowed Fe3+-assisted self-assembled arrays of single-wall
carbon nanotube (SWNT) probes to be produced. Auger investigation indicated
that the incident energetic electrons depleted oxygen, creating more dangling
bonds around Si atoms at the surface of the SiOx layer. This resulted in a
distinct difference in the friction forces from unexposed regions as measured
by lateral force microscopy (LFM). Atomic force microscopy (AFM) affirmed that
the irradiated domains absorbed considerably more Fe3+ ions upon immersion into
pH 2.2 aqueous FeCl3 solution. This rendered a greater yield of FeO(OH)/FeOCl
precipitates, primarily FeO(OH), upon subsequent washing with lightly basic
dimethylformamide (DMF) solution. Such selective metalfunctionalization
established the basis for the subsequent patterned forest-assembly of SWNTs as
demonstrated by resonance Raman spectroscopy
Clinical application of bioextracts in supporting the reproductive system of animals and humans: potential and Limitations
There is an increasing demand of spices and herbs in developing countries due to the beneficial effects of plants and herbal
preparations as medicines. The basic technological process of obtaining extracts from natural raw materials is extraction,
consisting in etching with solvents. Plant extracts are extremely complex, multicomponent mixtures obtained from flowers, fruits,
leaves, stems, twigs, or seeds of various plant materials. They are a rich source of polyphenols, flavonoids, phytosterols, carotenoids, and vitamins. The search for alternative methods of treatment is increasingly replacing the scientists? excessive focus on
the healing properties of bioextracts. Recent research offers great hope for the development of alternative methods to improve the
reproductive system. The use of animal models in experimental research has increased knowledge regarding the beneficial effects
of bioextracts on both male and female reproductive systems and reproductive cells. Demonstrating the positive effect of plant
extracts creates new opportunities for the use of biowaste, which is a by-product in various production sectors. The aim of this
review is to present the functional properties of extracts of natural origin, a cross section of modern methods of their preparation,
and a discussion of the possibilities of their use in the auxiliary reproductive system.FE1B-06B2-126F | Jos? Pedro Pinto de Ara?joN/
Fertility rate and assessment of the cytoprotective capacity of Vvrious types of Holothuroidea extracts on spermatozoa
For years, compounds of natural origin have been the subject of extensive biomedical
research due to very interesting, new ingredients potentially useful for various pharmaceutical,
medical and industrial applications. The therapeutic properties and healing benefits of sea cucumbers
may result from the presence of numerous, biologically active ingredients. Sperm subjected to
processing and subsequent storage at low temperatures experience a number of damage, including
the loss of the integrity of the cytoplasmic membrane, DNA and acrosome defragmentation. Therefore,
the aim of this experiment was to investigate the cytoprotective potential of sea cucumber extract
against cryopreserved sperm and semen fertility rate. Commercially available sea cucumber extract
was taken from the cellulose shell, then 790 mg of powder was weighed out and placed in 3 glass
tubes containing, respectively: 10 mL of water-glycerin solution (WG), water-ethanol (EC), glycerinethanol (GE), glycerin-DMSO (DG). Tubes were mixed with vortex for 3 min, then placed in a water
bath and incubated for 16 h at 40 ?C. Six simmental bulls, 3 years old, of known health status were
used for the experiment. Semen was collected from each male once a week (for 18 weeks) using an
artificial vagina. After an initial assessment of semen quality, the ejaculates were pooled to eliminate
individual differences between males, then diluted to a final concentration of 80 ? 106
sperm/mL
with a commercial extender (Optixcell, IMV, L?Aigle, France) and divided into 16 equal samples.
Control (C) without additive, the test samples contained 2, 4, 6, 8 and 10 ?L WG, 2, 4, 6, 8 and 10 ?L
WE, 2, 4, 6, 8 and 10 ?L GE, 2, 4, 6, 8 and 10 ?L DG. Semen was frozen/thawed and assessed for
motility, viability, DNA defragmentation, mitochondrial membrane potential and acrosome integrity.
It was shown a positive effect of water-glycerin (WG) and glycerine-ethanol (GE) extracts on the
efficiency of sperm preservation at low temperatures. Established that, depending on the type of
prepared extract, the sea cucumber can have both cytoprotective (WG, GE, WE) and cytotoxic (DG)
effects. Moreover, too high concentrations of the extract can adversely affect the sperm in terms of
parameters such as viability, motility, mitochondrial potential, and the integrity of the acrosome or
DNA of cells. The present study, thanks to the use of model animals to study the cytoprotective
potential of the sea cucumber extract, proves that it can be a potential candidate for use in semen
cryopreservation technology to improve the efficiency of storage at low temperatures. Further
research is needed to optimize the composition of individual types of extracts and their effect on
sperm. The highest effectiveness of female fertilization was observed when doses from GE groups (2
and 4) were used for insemination. The results of this analysis prove that the addition of the tested
extract may improve the fertilization efficiency.FE1B-06B2-126F | Jos? Pedro Pinto de Ara?joN/
Mikrosfere ropinirol hidroklorida za polagano oslobađanje: Utjecaj procesnih parametara
An emulsion solvent evaporation method was employed to prepare microspheres of ropinirole hydrochloride, a highly water soluble drug, by using ethylcellulose and PEG with the help of 32 full factorial design. The microspheres were made by incorporating the drug in a polar organic solvent, which was emulsified using liquid paraffin as an external oil phase. Effects of various process parameters such as viscosity of the external phase, selection of the internal phase, surfactant selection and selection of stirring speed were studied. Microspheres were evaluated for product yield, encapsulation efficiency and particle size. Various drug/ethylcellulose ratios and PEG concentrations were assayed. In vitro dissolution profiles showed that ethylcellulose microspheres were able to control release of the drug for a period of 12 h.Mikrosfere ropinirol hidroklorida, ljekovite tvari vrlo dobro topljive u vodi, pripravljene su metodom isparavanja otapala, koristeći etilcelulozu i PEG te 32 potpuno faktorijalno dizajniranje. Mikrosfere su pripravljene na sljedeći način: otopina ljekovite tvari u polarnom organskom otapalu emulgirana je s tekućim parafinom kao vanjskom uljnom fazom. Ispitivan je utjecaj različitih procesnih parametara poput viskoznosti vanjske faze, vrste interne faze i površinski aktivne tvari te brzine miješanja. Za pripravljene mikrosfere određeno je iskorištenje, učinkovitost inkapsuliranja i veličina čestica. Isprobavani su različiti odnosi ljekovite tvari i etilceluloze te koncentracija PEG-a. In vitro pokusi su pokazali da je oslobađanje ljekovite tvari kontrolirano tijekom 12 h
Preparation and characterization of starch-poly-epsilon-caprolactone microparticles incorporating bioactive agents for drug delivery and tissue engineering applications
One limitation associated with the delivery of bioactive agents concerns the short half-life of these molecules when administered intravenously,
which results in their loss from the desired site. Incorporation of bioactive agents into depot vehicles provides a means to
increase their persistence at the disease site. Major issues are involved in the development of a proper carrier system able to deliver
the correct drug, at the desired dose, place and time. In this work, starch-poly-e-caprolactone (SPCL) microparticles were developed
for use in drug delivery and tissue engineering (TE) applications. SPCL microparticles were prepared by using an emulsion solvent
extraction/evaporation technique, which was demonstrated to be a successful procedure to obtain particles with a spherical shape (particle
size between 5 and 900 lm) and exhibiting different surface morphologies. Their chemical structure was confirmed by Fourier transform
infrared spectroscopy. To evaluate the potential of the developed microparticles as a drug delivery system, dexamethasone (DEX)
was used as model drug. DEX, a well-known component of osteogenic differentiation media, was entrapped into SPCL microparticles at
different percentages up to 93%. The encapsulation efficiency was found to be dependent on the polymer concentration and drug-to-polymer
ratio. The initial DEX release seems to be governed mainly by diffusion, and it is expected that the remaining DEX will be released
when the polymeric matrix starts to degrade. In this work it was demonstrated that SPCL microparticles containing DEX can be successfully
prepared and that these microparticular systems seem to be quite promising for controlled release applications, namely as carriers
of important differentiation agents in TE.E.R.B. thanks the Marie Curie Host Fellowships for Early Stage Research Training (EST) "Alea Jacta EST" (MEST-CT-2004-008104) for providing her with a PhD Fellowship. This work was partially supported by the European NoE EXPERTISSUES (NMP3-CT-2004-500283)
Bioacceptable and calcification-resistant membranes and interfaces for implantable sensors and devices
The rational design and characterization of biocompatible, semipermeable and calcification resistant materials to serve as an outer membrane for implantable glucose biosensors, was the primary focus of this research. Multilayered films of polyanions (i.e. Nafion™, a perfluorinated ionomer, and Humic Acids (HAs), naturally occurring biopolymers), fabricated by layer-by-layer self-assembly with oppositely charged ferric ions were investigated as potential membranes. Spectroscopic ellipsometry and quartz crystal microbalance studies point towards a stepwise film growth, with growth rates of 47 and 24.3 nm per layer (for Nafion and HAs respectively) that can be altered depending on the pH and ionic strength of the polyanion solution. Nafion/Fe3+ assembled films exhibited an order of magnitude lower calcification as compared to dip-coated Nafion films and did not require annealing to impart insolubility. Similarly the HAs/Fe3+ films were also devoid of calcification, even after four-week immersion in DMEM cell culture media. Significantly, in vivo studies on the HAs/Fe3 films point to their biocompatibility as demonstrated by mild tissue reaction. These results, along with controllable glucose permeability, could prove vital in prolonging the lifetime of implantable biosensors. ^ Additionally in effort to minimize tissue trauma upon implantation, novel poly(lactic-co-glycolic acid) (PLGA) microsphere/poly(vinyl alcohol) (PVA) hydrogel composites were investigated for dexamethasone delivery. A release rate of 25 to 40% over one month, following a zero order profile, was achieved by preferential adsorption of surface active polyacids (poly(acrylic acid), Nafion and HAs) on the hydrogel dispersed microspheres. Environmental scanning electron microscopy investigation on the degradation mechanism of the microspheres pointed towards their slow homogeneous degradation in the PVA hydrogels that was significantly surface-accelerated in the presence of polyacids. The physico-mechanical properties (fluid uptake and Young\u27s modulus) and release of unencapsulated dexamethasone (80 to 100%) from the hydrogels were related to their crystallinity. Significantly, with Young\u27s modulus in the range of 0.1 to 4 MPa, comparable to human sub-dermal tissue, the hydrated gels provide soft and flexible tissue/sensor interface.
A Route for Bulk Separation of Semiconducting from Metallic Single-Wall Carbon Nanotubes
Metal-Assisted Organization of Shortened Carbon Nanotubes in Monolayer and Multilayer Forest Assemblies
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