Reinvestigation of the mechanism of polymerization of β-butyrolactone from 1,5,7-triazabicyclo[4.4.0]dec-5-ene

The questionable mechanism initially proposed to explain how 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) allows us to ring-open β-lactones, such as β-butyrolactone (BL), is reinvestigated here.

Archaeosomes based on synthetic tetraether-like lipids as novel versatile gene delivery systems

Novel cationic liposomes, termed "archaeosomes", based on mixtures of neutral/cationic bilayer-forming lipids and archaeobacterial synthetic tetraether-type bipolar lipids show efficient in vitro gene transfection properties and represent a new approach for modulating the lipidic membrane fluidity of the complexes they form with DNA.

Bioactive functionalized polymer of malic acid for bone repair and muscle regeneration

A bioactive poly(beta-hydroxyalkanoate) derived from malic acid was prepared and tested on bone repair and muscle regeneration. This functionalized and hydrolyzable polymer was obtained after several steps, the first one being the anionic copolymerization of three malolactonic acid esters. Chemical modifications were carried out on the terpolymer to turn benzyl-protecting groups into carboxyl groups and allyl groups into sulfonate groups. The resulting polymer bore carboxylate, sulfonate, and sec-butyl pendent groups in 65/25/10 molar proportions and were aimed at interacting with heparan binding growth factors. This polymer did not present any toxic effect in cell viability of HepG2 cells, over a large range of concentrations (0.01-0.25 mgl(-1)). Its ability to improve wound healing was tested in vivo and positive results are reported. Furthermore, the bioactivity of this polymer was evaluated using the regeneration model of Extensor digitorum longus (EDL) rat muscle. The study displayed a significant increase in the muscle regeneration and maturation.