CTAB-assisted fabrication of well-shaped PDA-based colloidosomes

Colloidosomes have gained intensive attention in the past years due to their substantial applications in wide scopes involving encapsulation, catalysis, and drug delivery, etc. In this study, we depicted the templated fabrication of well-shaped colloidosomes with tunable shell thickness by Pickering emulsion at a mild condition. To this end, toluene-in-water Pickering emulsion stabilized by cetyltrimethylammonium bromide (CTAB)–modified polydopamine (PDA) nanoparticles (PDA@CTAB) was prepared. After the covalent cross-linking of PDA nanoparticles assembled on the surface of an oil droplet through chemical reactions occurring in toluene phase, exclusive intra-colloidosomes were afforded. The shell thickness of colloidsomes could be roughly tuned by the adjustment of the amount of the reactive monomers in the oil phase. Our investigations revealed that CTAB was critical for the successful fabrication of well-shaped colloidosomes. Otherwise, only irregular structures were obtained if pristine PDA–stabilized Pickering emulsion was applied. The current strategy could enable hydrophobic cargo, such as 10-hydroxycamptothecin to be encapsulated while colloidosomes were created. The release behavior of the encapsulated cargoes was also investigated. CTAB was necessary for the templated fabrication of well-shaped colloidosomes by PDA-stabilized oil-in-water Pickering emulsion