ADO09, a co-formulation of the amylin analogue pramlintide and the insulin analogue A21G, lowers postprandial blood glucose versus insulin lispro in type 1 diabetes

AIM

To compare the safety, pharmacokinetics and pharmacodynamics of ADO09 with insulin lispro (Lispro) and separate subcutaneous injections of human insulin and pramlintide (Ins&Pram) in 24 subjects with type 1 diabetes.

METHODS

At three dosing visits, participants received single doses of ADO09, Ins&Pram or Lispro immediately before eating a standardized mixed meal together with 1 g of acetaminophen, which was used as a surrogate marker to evaluate the kinetics of gastric emptying. Premeal blood glucose was adjusted to 126 mg/dL ± 10% by means of insulin and glucose infusions. The insulin dose was 7.5 U and the pramlintide dose was 45 μg. Blood glucose, glucagon and acetaminophen concentrations were assessed as pharmacodynamic endpoints; insulin and pramlintide concentrations were analysed as pharmacokinetic endpoints, and safety and tolerability were assessed.

RESULTS

Compared with Lispro, ADO09 reduced postprandial blood glucose (ppBG) excursions by more than 95% in the first hour postmeal (mean ± SD ∆AUC BG 0-1 h: 1.4 ± 9.9 mg*h/dL vs. 43.5 ± 15.3 mg*h/dL; p < .0001). Maximum ppBG was significantly improved with ADO09 (∆BGmax 87.0 ± 35.5 mg/dL) versus both Lispro (109.2 ± 31.1 mg/dL; p = .0133) and Ins&Pram (109.4 ± 44.3 mg/dL; p = .0357). Gastric emptying with ADO09 was similar to Ins&Pram and significantly slower than with Lispro. All treatments were well tolerated and both adverse events and hypoglycaemic events were rare during the meal test procedure.

CONCLUSION

ADO09 was well tolerated and markedly reduced ppBG compared with Lispro. ADO09 formulation was generally similar to the separate administration of insulin and pramlintide, except for a better BG level in the 4-8 h interval postmeal. These positive results warrant further investigations with ADO09.

Chiroselective assembly of a chiral porphyrin-fullerene dyad: photoconductive nanofiber with a top-class ambipolar charge-carrier mobility

Upon slow admission of MeOH, the enantiomerically pure form of chiral amphiphilic porphyrin-fullerene dyad 1 in CH(2)Cl(2) self-assembles at 25 degrees C into nanofibers with a built-in donor/acceptor heterojunction, while its racemic form, under identical conditions, self-assembles into submicrometer-sized spheres with a donor/acceptor arrangement essentially different from that in the nanofiber assembly. Although a cast film of the latter hardly shows a photoconducting profile on micrometer-gap electrodes, the former sample clearly displays photoconduction with an ambipolar charge-transporting character. The electron and hole mobilities under zero electric field, as estimated from time-of-flight profiles, are 0.14 and 0.10 cm(2) V(-1) s(-1), respectively, which are comparable to or even better than those reported for top-class organic materials with a donor/acceptor heterojunction.

Challenges and breakthroughs in recent research on self-assembly

The controlled fabrication of nanometer-scale objects is without doubt one of the central issues in current science and technology. However, existing fabrication techniques suffer from several disadvantages including size-restrictions and a general paucity of applicable materials. Because of this, the development of alternative approaches based on supramolecular self-assembly processes is anticipated as a breakthrough methodology. This review article aims to comprehensively summarize the salient aspects of self-assembly through the introduction of the recent challenges and breakthroughs in three categories: (i) types of self-assembly in bulk media; (ii) types of components for self-assembly in bulk media; and (iii) self-assembly at interfaces.

Porphyrin colorimetric indicators in molecular and nano-architectures

One of the most important outcomes of organic nanotechnologies could be development of well-integrated systems for sensing of particular chemical species. Use of color indicators is an attractive approach to guest reporting. Of the known chromophores, porphyrin and its derivatives are the most widely studied functional chromophores in a diverse range of research fields. In this review, recent developments in colorimetric indicator functions of porphyrin derivatives and related compounds in their molecular and nano-architectures are reviewed according to the classification: (i) rather simple porphyrin derivatives, (ii) porphyrin conjugates, (iii) porphyrins embedded in bulk materials, and (iv) porphyrins in organized films. Porphyrin derivatives with unusual structures, such as expanded and N-confused ones have been used for color indicators in specific cases. Electron and energy transfers in porphyrins conjugated with other functional moieties resulted in dynamic sensing systems including switch-on and switch-off actions. Immobilization of porphyrin color indicators in appropriate matrices is important for practical applications. Use of supramolecular films such as self-assembled monolayers, Langmuir-Blodgett films, and layer-by-layer assemblies as porphyrin nanoarchitectures often offers opportunities for colorimetric outputs based on control of their aggregate structures.

Quantification of imidacloprid uptake in maize crops

The systemic imidacloprid is one of the most used insecticides in the world for field and horticultural crops. This neurotoxicant is often used as seed-dressing, especially for maize, sunflower, and rape. Using a LC/MS/MS technique (LOQ = 1 microg/kg and LOD = 0.1 microg/kg), the presence of imidacloprid has been measured in maize from field samples at the time of pollen shed, from less than 0.1 microg/kg up to 33.6 microg/kg. Numerous random samples were collected throughout France from 2000 to 2003. The average levels of imidacloprid measured are 4.1 microg/kg in stems and leaves, 6.6 microg/kg in male flowers (panicles), and 2.1 microg/kg in pollen. These values are similar to those found previously in sunflower and rape. These results permit evaluation of the risk to honeybees by using the PEC/PNEC ratios (probable exposition concentrations/predicted no effect concentration). PEC/PNEC risk ratios were determined and ranged between 500 and 600 for honeybees foraging on maize treated with imidacloprid by seed dressing. Such a high risk factor can be related to one of the main causes of honeybee colony losses.

Insecticides systémiques : de nouveaux risques pour les insectes pollinisateurs

Imidacloprid, a new systemic insecticide used as seed-dressing, has been widely used in France since 1994. Its application mode and its efficiency allow a significant reduction in comparison with the usual quantity of chemicals used during pulverising treatment. But the insecticide imidacloprid is suspected to have harmful effects on the pollinators as many bees have died since its introduction. Recent studies have shown that imidacloprid has chronic and sub-lethal toxicities at levels of micro g/kg or less. It was therefore necessary to detect imidacloprid at these levels in soils, plants, flowers, and pollens. With this aim, we characterised the bio-availability of imidacloprid in the environment using a new quantitative analytical method, as a basis for the evaluation of the risk for bees.

Self-assembly of a π-electronic amphiphile consisting of a zinc porphyrin–fullerene dyad: formation of micro-vesicles with a high stability

An amphiphilic zinc porphyrin-fullerene dyad appended with triethyleneglycol chains in aqueous media forms uniformly-sized multilamellar vesicles with a mean diameter of 100 nm that are thermally stable and robust against membrane lysis with surfactants.

A LC/APCI-MS/MS method for analysis of imidacloprid in soils, in plants, and in pollens

Imidacloprid, the most used systemic insecticide, is suspected of having harmful effects on honeybees at nanogram per bee or at microgram per kilogram levels. However, there is a lack of methodology to detect imidacloprid and its metabolites at such low levels. We developed a method for the determination of low amounts of imidacloprid in soils, plants (leaves and flowers), and pollens by using HPLC coupled to tandem mass spectrometry (APCI-MS/MS). Extraction, separation, and detection were performed according to quality assurance criteria, to Good Laboratory Practice, and to criteria from the directive 96/23/EC, which is designed for banned substances. The linear range of application is 0.5-20 microg/kg imidacloprid in soils, in plants, and in pollens, with a relative standard deviation of 2.9% at 1 microg/kg. The limits of detection and of quantification are LOD = 0.1 microg/kg and LOQ = 1 microg/kg, respectively. For the first time, this study permitted us to follow the fate of imidacloprid in the environment. When treated, flowers of sunflower and maize contain average values of approximately 10 microg/kg imidacloprid. This explains that pollens from these crops are contaminated at levels of a few micrograms per kilogram, suggesting probable deleterious effects on honeybees.