ApoE-modified solid lipid nanoparticles: A feasible strategy to cross the blood-brain barrier.

Solid lipid nanoparticles (SLN) are colloidal drug delivery systems characterized by higher entrapment efficiency, good scalability of the preparation process and increased sustained prolonged release of the payload compared to other nanocarriers. The possibility to functionalize the surface of SLN with ligands to achieve a site specific targeting makes them attractive to overcome the limited blood-brain barrier (BBB) penetration of therapeutic compounds. SLN are prepared for brain targeting by exploiting the adaptability of warm microemulsion process for the covalent surface modification with an Apolipoprotein E-derived peptide (SLN-mApoE). Furthermore, the influence of the administration route on SLN-mApoE brain bioavailability is here evaluated. SLN-mApoE are able to cross intact a BBB in vitro model. The pulmonary administration of SLN-mApoE is related to a higher confinement in the brain of Balb/c mice compared to the intravenous and intraperitoneal administration routes, without inducing any acute inflammatory reaction in the lungs. These results promote the pulmonary administration of brain-targeted SLN as a feasible strategy for improving brain delivery of therapeutics.

Influence of intermediate and uninterrupted FMR1 CGG expansions in premature ovarian failure manifestation.

BACKGROUND: Studies attempting to precisely define the range of fragile mental retardation 1 (FMR1) expansions and its inf luence in premature ovarian failure (POF) manifestation are partially lacking. To this aim, we evaluated a large cohort of POF patients for the size and, in selected cases, for the sequence of the CGG expansion. Furthermore, the correlation between POF and X-inactivation was investigated in FRAXA families. METHODS: By fluorescent PCR, 190 POF and 200 control women were sized for the CGG tract; some subjects were also characterized by sequencing and for the FMR1 activation ratio. RESULTS AND CONCLUSION: We found a significant association (19/190, 10%, P < 1 x 10(-6)) between POF and FMR1 premutation (range 63-163 repeats) and a significant enrichment (9/190, 4.7%, P = 0.021) of POF carriers of intermediate expansions (range 41-58 repeats). Interestingly, intermediate alleles were entirely composed of CGG repeats. Furthermore, the analysis of three pairs of siblings with similar FMR1 expansions and discordant for the POF phenotype showed a direct correlation between the expression of the intermediate/premutated allele and POF manifestation. The results obtained strengthen the correlation between FMR1 expansion and POF and suggest that the manifestation of the ovarian dysfunction could be influenced both by the pattern of interruption of the CGG repeat and by X-inactivation.

The protective effects of N-acetyl-L-cysteine against methyl mercury embryotoxicity in mice.

N-Acetyl-L-cysteine (NAC) has been widely used in the protection against the toxic effects produced by several chemicals because of its radical scavenger properties and because NAC is a precursor of glutathione, one of the most important intracellular defenses against oxidants. The aim of this investigation was to verify the potential protective activity of NAC against the well-known embryotoxicity induced by methyl mercuric chloride (MMC) in mice. Three experimental approaches were carried out. In the first investigation, acute treatment of MMC (25 mg/kg po) was given in CD female mice on Day 10 of pregnancy, and was followed immediately and/or after 24, 48, and 72 hr by administrations of NAC (800 mg/kg i.v.). The embryolethal effects caused by MMC poisoning were completely antagonized by just a single administration of NAC, while the incidence of palatoschisis was reduced in relation to the number of NAC administrations. In the second experiment MMC was chronically gavaged (3 mg/kg/day po) during the period of organogenesis on Days 5 to 14 of gestation. During the same period of time some of these females were also exposed to 1% NAC dissolved in drinking water. MMC poisoning reduced the body weight of viable fetuses and induced many cases of palatoschisis. The body weight of fetuses from MMC-poisoned mothers treated with NAC was improved and the incidence of palatoschisis was in the normal range. In the last experiment the treatment with NAC (400 mg/kg i.v., during the period of organogenesis) drastically reduced the severe embryolethality induced by MMC (6 mg/kg/day po) administered during the same period of time.(ABSTRACT TRUNCATED AT 250 WORDS)

Induction of micronuclei in pre-implantation rat embryos in vivo.

To test the capability of different chemicals to induce clastogenic effects in pre-implantation embryos in vivo, rat blastocysts were collected on the afternoon of the 4th day of gestation from the uterus of females treated on the morning of the 3rd day. Cyclophosphamide (40 mg/kg) and daunomycin (10 mg/kg) did induce micronuclei, but methotrexate (10 mg/kg) and CuSO4 (8 mg/kg) did not. The micronucleus frequency was dose-related when 3, 9, or 18 mg/kg of mitomycin C were administered. These results confirm the sensitivity of the rat pre-implantation embryo to clastogenic chemicals also after in vivo exposure.

A rapid electrochemical assay of lecithin in amniotic fluid using a fluoride ion-sensitive electrode.

An electrochemical method is described for the determination of lecithin in rat and human amniotic fluid. Choline is released from lecithin enzymatically by phospholipase D and the hydrogen peroxide released by the action of choline oxidase is quantitatively determined by peroxidase-catalyzed rupture of the covalent C-F bond of 4-fluorophenol. The concentration of F- ions in solutions is determined by a fluoride sensitive electrode from the resulting cell potential difference recorded before and 10 min after addition of a solution containing phospholipase D, choline oxidase and horseradish peroxidase. Lecithin levels in rat amniotic fluid increased from about 10 mumol/l on the 20th day of gestation to 80 mumol/l on day 21, which corresponds to the time of spontaneous delivery. In human amniotic fluid the lecithin concentrations determined with this new method parallel those already reported. They were approximately 10 to 50 mumol/l between the 15th and 18th weeks of gestation and increased from 5- to 7-fold between the 37th and 41st weeks of pregnancy. This method was only slightly influenced by the presence of blood or meconium contamination in the amniotic fluid.

Determination of fetal lung maturity in rats by fluorescence polarization.

The fluorescence polarization technique was utilized to determine fetal lung maturity in rats. The study confirmed that changes in fluorescence polarization values with gestational age follow the pattern already seen in human beings. A sharp drop was observed on the afternoon of the 20th day of gestation which corresponds in the rat to the beginning of surfactant synthesis. This was confirmed by determination of phosphatidylglycerol. In order to verify the effectiveness of this animal model, a group of pregnant rats was treated with 100 micrograms/kg betametasone twice 48 and 24 hr before the 20th or 21st days of gestation. As expected, this significantly reduced fluorescence polarization on day 20 (4-6 p.m.) and day 21 of gestation, indicating increased surfactant synthesis in betametasone-treated rats. Another group of female rats was pretreated before mating with streptozotocin (40 mg/kd), inducing diabetes. Fluorescence polarization values in the amniotic fluid of the diabetic rats at the above intervals were significantly higher than controls, indicating reduced lung maturation.

Developmental toxicity during the preimplantation period: embryotoxicity and clastogenic effects of chlorambucil in the rat.

To evaluate the toxicological effects of chemicals on preimplantation mammalian embryos, pregnant rats were treated with chlorambucil (0, 3, 6, and 12 mg/kg IP) on day 1, 2, or 3 of gestation (positive vaginal smear = day 0). Blastocysts were collected on day 4 and evaluated for gross morphology, cell number, and mitotic index. Some females treated on day 3 post coitum were sacrificed on day 20 and fetuses were evaluated for teratogenic effects. On day 4 of gestation a dose-related reduction of cell number/embryo was recorded; this effect was most manifest with treatment on day 3 post coitum. The mitotic index was significantly higher in all treated groups. A dose-related increase in "micronucleus-like bodies" has been observed in treated embryos. A comparison with the micronucleus test in the bone marrow revealed a major sensitivity of the embryonic material. No malformations have been observed in fetuses at term, but their weights were significantly reduced and a dose-related increase of postimplantation loss was recorded in treated females.