Priming the body to receive the therapeutic agent to redefine treatment benefit/risk profile.

Many therapeutic agents offer a low useful dose (dose responsible for efficacy)/useless dose (dose eliminated or responsible for toxicity) ratio, mainly due to the fact that therapeutic agents must ensure in one single object all the functions required to deliver the treatment, which leads to compromises in their physico-chemical design. Here we introduce the concept of priming the body to receive the treatment by uncorrelating these functions into two distinct objects sequentially administered: a nanoprimer occupying transiently the main pathway responsible for therapeutic agent limited benefit/risk ratio followed by the therapeutic agent. The concept was evaluated for different nature of therapeutic agents: For nanomedicines we designed a liposomal nanoprimer presenting preferential hepatic accumulation without sign of acute toxicity.

In vitro localized release of thermosensitive liposomes with ultrasound-induced hyperthermia.

Localized drug delivery with ultrasound-induced hyperthermia can enhance the therapeutic index of chemotherapeutic drugs by improving efficacy and reducing systemic toxicity. A novel in vitro method for the activation of drug-loaded thermosensitive liposomes is described. In particular, a dual-compartment, acoustically transparent container is used in which thermosensitive liposomes suspended in cell culture medium are immersed in a thermally absorptive medium, glycerol.

MRI contrast variation of thermosensitive magnetoliposomes triggered by focused ultrasound: a tool for image-guided local drug delivery.

Improved drug delivery control during chemotherapy has the potential to increase the therapeutic index. MRI contrast agent such as iron oxide nanoparticles can be co-encapsulated with drugs in nanocarrier liposomes allowing their tracking and/or visualization by MRI. Furthermore, the combination of a thermosensitive liposomal formulation with an external source of heat such as high intensity focused ultrasound guided by MR temperature mapping allows the controlled local release of the content of the liposome.

Production of magnetic multilamellar liposomes as highly T2-efficient MRI contrast agents.

Unlabelled: Lipid-based multilamellar vesicles loaded with aminosilane-modified maghemite nanoparticles (a-MNPs), also called magnetonions (MO), were analyzed for their magnetic resonance imaging (MRI) contrast agent properties. They were shown to be better T(2)-MRI contrast agents than commercial contrast agents and other reported liposome-based contrast agents as shown by their higher value of relaxivity ratio (r(2)/r(1) = 17), although a lower magnetic field intensity was used (0.2 T).

Multilamellar liposomes entrapping aminosilane-modified maghemite nanoparticles: "magnetonions".

4.6 nm-sized aminosilane-modified maghemite (γ-Fe(2)O(3)) nanoparticles (aMNPs) were synthesized and encapsulated into onion-type multilamellar vesicles of soybean phosphatidylcholine (90%mol) and monoolein (10%mol). The magnetic multilamellar vesicles were obtained by shearing lipids with an aqueous dispersion of the preformed aMNPs (ferrofluid).

Magnetic multilamellar liposomes produced by in situ synthesis of iron oxide nanoparticles: "magnetonions".

We report the formation of magnetic onion-type multilamellar vesicles. Iron oxide nanoparticles (np's) were synthesized inside lipidic multilamellar vesicles by coprecipitation of vesicle-encapsulated Fe(2+) and Fe(3+) ions induced by HO(-) diffusion through vesicle lamellae. The iron ion encapsulation efficiency of onions was measured by potentiometry and UV-vis absorbance spectroscopy.

A new bio-inspired route to metal-nanoparticle-based heterogeneous catalysts.

Onion-type multilamellar vesicles are made of concentric bilayers of organic surfactant and are mainly known for their potential applications in biotechnology. They can be used as microreactors for the spontaneous and controlled production of metal nanoparticles. This process does not require any thermal treatment and, hence, it is also attractive for material sciences such as heterogeneous catalysis.

Radiation-induced synthesis of gold nanoparticles within lamellar phases. Formation of aligned colloidal gold by radiolysis.

A sheared lamellar phase has been used as a nanoreactor for the synthesis of gold nanoparticles by radiolysis and by a photochemical approach. A gold salt solution (KAuCl4, 10(-2) M) is introduced into the aqueous compartments between the lipid-based bilayers. Gold nanoparticles grow within the lamellar phase as shown by TEM analysis and X-ray diffraction, limiting the particle size.