Nanodevices made of surfactant-like lipids for controlled drug delivery

Some surfactant-like lipids (such as fitantriol and monoolein) can self-assemble into lyotropic liquid crystalline phases in aqueous medium. This process is driven by hydrophobic effect, hydrogen bonding, and van der Waals interactions. The dispersion of the bulk liquid crystal to the nanometer range gives rise to nanoparticles with liquid crystalline inner structure, such as cubosomes (reverse cubic phases) and hexosomes (reverse hexagonal phase). They can be kinetically stabilized by hydrophilic polymers, or anionic/non-ionic surfactants. Additives can induce phase transitions or the nanoparticle targeting to particular organs and tissues. We are interested in nanoparticles containing additives designed to promote phase transitions triggered by an external stimulus, such as pH, natural enzymes, and redox environment for controlled drug delivery. We also decorate cubosomes, hexosomes, and lipid-based nanoparticles with disordered bicontinuous inner structure for drug targeting to the central nervous system and specific cell types and organelles. Interactions between the surfactant-like lipids and polymers or host-guest assemblies are also explored to obtaining smart nanodevices.

Cerium-based nanozymes confined in non-lamellar lyotropic liquid crystals
Functional mimics of enzymes are synthetic catalysts for biologically relevant reactions. Usually, they are inorganic nanoparticles, which are called nanozymes. They are more robust against degradation during storage or after in vivo administration than their natural counterparts. Despite this, nanozymes do not act only in diseased tissues, which might cause undesirable and harmful effects. We propose new ways to synthesize cerium-based nanozymes in confined environments from biocompatible systems in order to circumvent this drawback. Cerium-based nanozymes can mimic superoxide dismutase and catalase enzymes, scavenging superoxide anion radicals and degrading hydrogen peroxide. The biocompatible systems used in our investigations are composed of lipid lyotropic liquid crystals, particularly reverse bicontinuous cubic phases. We recently described the first proof-of-concept of a cerium-based “pronanozyme” confined in liquid crystal inspired by Nature´s zymogen strategy.
Synthesis and self-assembly of stimuli-responsive surfactants
We use classical synthetic chemistry to get innovative surfactants designed to respond to external stimuli, such as light, metal cations, and redox environment. They can form nanodevices by stimuli-triggered self-assembly or can be used as additives in lyotropic liquid crystalline nanoparticles. Most of the current investigations focus on the potential of these assemblies to be the next generation of antibiotics to treat resistant bacteria infections.