Biodistribution and preliminary toxicity studies of nanoparticles made of Biotransesterified ß-cyclodextrins and PEGylated phospholipids.

BACKGROUND: The modification of ß-cyclodextrins (ßCDs) by grafting alkyl chains on the primary and/or secondary face yields derivatives (ßCD-C10) able to self-organize under nanoprecipitating conditions into nanoparticles (ßCD-C10-NP) potentially useful for drug delivery. The co-nanoprecipitation of ßCD-C10 with polyethylene glycol (PEG) chains yields PEGylated NPs (ßCD-C10-PEG-NP) with potentially improved stealthiness. The objectives of the present study were to characterize the in vivo biodistribution of ßCD-C10-PEG-NP with PEG chain length of 2000 and 5000Da using nuclear imaging, and to preliminarily evaluate the in vivo acute and extended acute toxicity of the most suitable system. RESEARCH DESIGN AND METHODS: The in vivo and ex vivo biodistribution features of naked and decorated nanoparticles were investigated over time following intravenous injection of 125I-radiolabeled nanoparticles to mice. The potential toxicity of PEGylated ßCD-C10 nanosuspensions was evaluated in a preliminary in vivo toxicity study involving blood assays and tissue histology following repeated intraperitoneal injections of nanoparticles to healthy mice. RESULTS: The results indicated that ßCD-C10-PEG5000-NP presented increased stealthiness with decreased in vivo elimination and increased blood kinetics without inducing blood, kidney, spleen, and liver acute and extended acute toxicity. CONCLUSIONS: ßCD-C10-PEG5000-NPs are stealth and safe systems with potential for drug delivery.

In vitro tests aiding ecological risk assessment of ciprofloxacin, tamoxifen and cyclophosphamide in range of concentrations released in hospital wastewater and surface water.

Ciprofloxacin (CIP), tamoxifen (TAM) and cyclophosphamide (CP) which are often used in anticancer treatment are released in hospital effluent and into the environment. Although the concentrations are low (from ng/L to µg/L), no data exist concerning their ecotoxicological impact. In this study two biomarkers of early effect were performed on hepatic cells (HepG2): cell viability and genotoxicity (DNA breaks) using cell proliferative assay and comet assay, respectively. These data were compared with two standardized ecotoxicological tests: algaltoxkit F™ and microtox®. Cells were exposed to an increasing amount of an individual drug or in a mixture for 24, 48 or 72h. The time-exposure of bacteria and algae ranged between 5 and 30min and 72h, respectively. A non-monotonic dose-response on cell viability was observed when HepG2 cells were exposed to TAM alone or in the presence of CIP. The same scheme was observed with microtox® when the bacteria were exposed to the mixtures. On the other side, an individual drug does not induce any DNA breaks on hepatic cells, whereas a mixture leads to a dose dependent increase of DNA breaks. Similarly a positive response was observed with algaltoxkit F™ only with mixtures. Synergistic effects observed when drugs are in a mixture highlight the importance of investigating the ecotoxicological effects of contaminants at low concentrations and in mixtures.

Cyclophosphamide removal from water by nanofiltration and reverse osmosis membrane.

The rejection of cyclophosphamide (CP) by nanofiltration (NF) and reverse osmosis (RO) membranes from ultrapure (Milli-Q) water and membrane bioreactor (MBR) effluent was investigated. Lyophilization-extraction and detection methods were first developed for CP analysis in different water matrices. Experimental results showed that the RO membrane provided excellent rejection (>90%) under all operating conditions. Conversely, efficiency of CP rejection by NF membrane was poor: in the range of 20-40% from Milli-Q water and around 60% from MBR effluent. Trans-membrane pressure, initial CP concentration and ionic strength of the feed solution had almost no effect on CP retention by NF. On the other hand, the water matrix proved to have a great influence: CP rejection rate by NF was clearly enhanced when MBR effluent was used as the background solution. Membrane fouling and interactions between the CP and water matrix appeared to contribute to the higher rejection of CP.

Molecular effects of Eya1 domain mutations causing organ defects in BOR syndrome.

Eya1 is a critical gene for mammalian organogenesis. Mutations in human EYA1 cause branchio-oto-renal (BOR) syndrome, an autosomal dominant disorder characterized by varying combinations of branchial, otic and renal anomalies, whereas deletion of mouse Eya1 results in the absence of multiple organ formation. Eya1 and other Eya gene products share a highly conserved 271 amino acid Eya domain that is required for protein-protein interaction. Recently, several point mutations that result in single amino acid substitutions in the conserved Eya domain region of EYA1 have been identified in BOR patients; however, the molecular and developmental basis of organ defects that occurred in BOR syndrome is unclear. To understand how these point mutations cause disease, we have analyzed the functional importance of these Eya domain missense mutations with respect to protein complex formation and cellular localization. We have demonstrated that these point mutations do not alter protein localization. However, four mutations are crucial for protein-protein interactions in both yeast and mammalian cells. Our results provide insights into the molecular mechanisms of organ defects detected in human syndromes.

A pharmacological analysis of the responses of the gastrointestinal smooth muscle of the bat to transmural and periarterial nerve stimulation.

A comparative study of the responses of the gastrointestinal tract of the guinea-pig and of the fruit-eating bat Eidolon helvum to transmural nerve stimulation (TNS) was made. The stomach and rectum of the guinea-pig, the bat and the guinea-pig ileum contracted in response to TNS. These contractions were cholinergic in nature because atropine blocked and physostigmine potentiated them. Tetrodotoxin reversibly abolished these contractions suggesting that they were nerve-mediated. The bat isolated ileum usually responded to TNS with mixed motor and inhibitory components. In some cases, there were only motor or inhibitory components. The motor component was abolished by atropine and potentiated by physostigmine. However, the inhibitory component was non-adrenergic and non-cholinergic (NANC). Tetrodotoxin abolished the motor component without influencing the inhibitory components. Periarterial nerve stimulation of the bat ileum produced a relaxation that was blocked by bretylium, propranolol, phentolamine, reserpine and tetrodotoxin. It is concluded that the bat gastrointestinal smooth muscle, like the guinea-pig, has cholinergic excitatory innervation; however, the bat ileum has both a cholinergic excitatory innervation and a nonadrenergic and non-cholinergic inhibitory component.

Actions of chloroquine and its N-oxidation metabolites on the rectus abdominis muscle of the toad (Bufo regularis).

Using the isolate rectus abdominis muscle preparation of the toad (Bufo regularis) the pharmacological actions of chloroquine, chloroquine-N-oxide and chloroquine N-di-oxide were investigated. On their own at concentrations ranging from 7.5 x 10(-5) -5 x 10(-3)M, the compounds induced contractures, chloroquine being the most active. At lower concentrations (5 x 10(-7) - 5 x 10(-5) M), chloroquine and its N-oxides enhanced acetylcholine-induced contractures whereas they depressed the carbachol-evoked contractures. At higher concentrations (5 x 10(-4) - 5 x 10(-3)M), chloroquine and its N-oxides inhibited both ACh- and carbachol-induced contractures. Analysis of the results obtained showed that the antagonism between ACh (or carbachol) and chloroquine (or its N-oxides) is non-competitive. At low concentrations chloroquine and its N-oxides (5 x 10(-7) - 5 x 10(-5)M) inhibited the potentiating action of neostigimine on ACh-induced contractures. From the results obtained in the study presented here, it is suggested that the antagonism of acetylcholine (or carbachol) by chloroquine and its N-oxidation metabolites on this muscle preparation may be at the cellular level. It is also suggested that the compounds examined may be acting as anticholinesterases (with chloroquine being the most active).

Some pharmacological effects of the nematocide, morantel.

1. In isolated nerve-muscle preparations as well as in nerve-muscle preparations in intact anaesthetized animals, morantel exhibited neuromuscular blocking properties similar to those of depolarizing blockers. The drug also caused spastic paralysis of 3 day-old chicks and contracture of the isolated toad rectus abdominis muscle.2. Morantel caused contraction of the guinea-pig and rabbit isolated small intestine. This effect was antagonized by atropine and hexamethonium.3. Morantel caused an increase in the blood pressure of the anaesthetized rat and cat and contraction of the nictitating membrane of the anaesthetized cat. These effects were antagonized by hexamethonium.4. It was concluded that morantel (like the related compound pyrantel) has acetylcholine-like action and that its structure is consistent with such action.