Disulfide cross-linked nanospheres from sodium alginate derivative for inflammatory bowel disease: Preparation, characterization, and in vitro drug release behavior

► Disulfide crosslinked nanospheres based on thiolated sodium alginate were synthesized. ► The nanospheres had a 170 nm diameter, negative surface charge and pH-sensitivity. ► The nanospheres were stable in buffer solutions without GSH and with 10 μM GSH. ► While the particle size obviously increased in a buffer containing millimolar GSH. ► The drug release in a mimic colonic pH and reducing fluid showed a marked increase.