First multi-reactive polysaccharide-based transurf to produce potentially biocompatible dextran-covered nanocapsules.

•Multi-reactive Dextran-based transurfs (RAFT agent and surfactant) are designed.•Dithiobenzoate groups of transurf confine RAFT polymerization at o/w interface.•RAFT miniemulsion polymerization of MMA from transurf is controlled.•Dextran-covered nanocapsules with PMMA shell and oily core are produced.•Nanocapsules seem to be cytocompatible with vascular smooth muscle cells.