Significance: Nanotechnology-based drug delivery is expected to bring new hope for cancer treatment by enhancing anticancer drug efficacy, overcoming drug resistance, and reducing drug toxicity. In this respect, we developed an innovative drug delivery system based on a self-assembling amphiphilic dendrimer, which can generate supramolecular nanomicelles with large void space in their core to encapsulate anticancer drugs with high loading capacity. The resulting drug-encapsulated nanomicelles can effectively enhance drug potency and combat drug resistance by promoting cellular uptake and decreasing efflux of the anticancer drug. Moreover, this drug delivery system can significantly reduce the systemic toxicity of the free drug. The present study illustrates a successful example of how advances in dendrimer nanotechnology can be advantageously implemented to foster therapeutic perspectives.
12 September 2014 in Angewandte Chemie International Edition
Stable oil/water emulsions are usually obtained by using mixtures of different surfactants. Such systems display synergistic interface stabilizing effects, which have not been fully elucidated yet. Moreover, in many applications surfactants are added at concentrations well above their critical micellar concentration (CMC), and this regime has not been thoroughly explored in the literature as well. Here, we investigate oil/water emulsions through oil/water interfacial tension using two common non-ionic surfactants, Tween 80 and Span 20, in the concentration range C (0.3–1 wt%) well above their respective CMCs. Mesoscale molecular simulations coupled interfacial tensiometry experiments to characterise these interfaces at a molecular level. Interfacial tension γ was measured by a pendant drop technique. Coarse-grained calculations provided a microscopic view of the interface at the molecular level (i.e. surfactant arrangement, interface thickness), and were employed to extend the study to those surfactant concentrations where experiments could hardly provide reliable data, if any. We found a significant synergistic effect between Tween 80 and Span 20, with low molecular weight Span molecules occupying free spaces between the much larger, bulky Tween compounds. The surfactant intermolecular interactions could be associated to a striking decrease of interfacial tension in going from pure surfactants to a mixture at the same total weight concentration. Furthermore, the interface was found to exhibit a spatial inhomogeneity with a “patch-like” organisation, reminiscent of microphase separation. Our results show that the proposed, combined experimental/in silico approach provides relevant insights for several industrial applications, such as emulsion stability and oil spill remediation.
10 February 2007 in The Journal of Physical Chemistry B