One-step fabrication of silica colloidosomes with in situ drug encapsulation

Abstract

Colloidosome is an important field of microencapsulation with various applications in catalysis, the food industry and pharmacy. Owing to its outstanding biocompatibility, silica colloidosomes are promising for biomedical applications. Nevertheless, silica modification as well as drug encapsulation are separated in some reported fabrication methods. In this article, bio-friendly materials SiO₂ nanoparticles and chitosan are used in fabrication as dispersants. Pickering emulsion formed under the shear force of continuous phase n-octanol was further solidified and freeze-dried to obtain silica colloidosomes. In situ covalent modification of SiO₂ nanoparticles' hydrophobicity by chitosan is the key to the formation of hollow silica colloidosomes and drug encapsulation can also be achieved during emulsion formation. By tuning the size of SiO₂ nanoparticles and the solidification time of chitosan the size of interstices on the surface can be easily controlled to realize different release profiles of encapsulated drugs.