A general strategy for creating self-defending surfaces for controlled drug production for long periods of time

Compartmentalization – A Prerequisite for Maintaining and Changing an Identity

“…Low stability of these artificially produced liposomes triggered, among other things, the development of polymer molecules mimicking a lipid membrane. Such polymersomes have been used to encapsulate active enzymes and integrate membrane proteins in the polymer shell and they exhibit, in general, higher stability compared to liposomes and are therefore of particular interest for drug delivery, [3] see the article by Palivan and coworkers in this issue. [4] Another important application for artificially-produced compartments is the creation of miniaturized reaction chambers for a directed evolution process to endow whole organisms [5] or single enzymes [6] with new properties such as novel substrate specificity or improved yield on starting material.…”

'Active Surfaces' as Possible Functional Systems in Detection and Chemical (Bio) Reactivity

“…[32] A first example of such active surfaces based on immobilization of nanoreactors served for controlled production and release of antibiotics for long periods of time. [27,33] The immobilization method preserved the vesicular structure of the nanoreactors, and did not influence the enzymatic activity of the encapsulated catalyst for up to 7 days. Such self-defending surfaces allow a control of drug production at a specific rate for long periods of time by adding the required amounts of substrate to the outer medium.…”

“…[32] In collaboration with the group of W. Meier (University of Basel) we developed a versatile and efficient method for compartment immobilization via an aldehyde-amino reaction: aldehyde groups exposed at the compartment external surface react with amino groups of chemically modified glass surfaces. [27] This immobilization method enables stable immobilization of compartments on solid supports. In addition, the mild conditions of enzymes/proteins encapsulation/insertion and immobilization of the nanoreactors do not affect the activ- molecular understanding of both materials and natural products, driven by analytical and computational techniques, more sophisticated strategies were developed for surface functionalization.…”

“…lipid or polymers) to embed the biomolecules and avoid denaturation on contact with the support [25,26] and ii) encapsulate the biomolecules in lipid or polymer compartments that are immobilized on the support. [27] Synthetic membranes are the preferred template when combining with biomolecules for technologic applications because of the higher stability in time and robustness compared to lipid bilayers, in addition to the possibility in fine-tuning their properties (flexibility, architectures and responsiveness). [28] Asymmetric ABC triblock copolymers represent ideal candidates for performing a directional membrane protein insertion/ attachment or to generate membranes with a different specificity at each surface.…”

“…In this context, we performed successive deposition/transfer of two layers of PEG 45 -b-PMCL 101 -b-PDMAEMA 27 . The first layer of the triblock copolymer was transferred on solid support by emersion of silica slides from the water subphase (up movement), whilst the second layer was transferred either by emersion followed by immersion transfer (resulting in an 'up-down' bilayer) or by two consecutive emersion transfers (resulting in an 'up-up' bilayer).…”