Facile preparation of succinylated-zein-ZIF-8 hybrid for enhanced stability and pH-responsive drug delivery

Zein nanoparticles have good prospects as a pharmaceutical carrier but limited in further application by its poor stability and re-dispersibility. To obtain high stability and pH-responsive drug delivery, succinylated-zein (Suc-zein) was synthesized by nucleophilic substitution reaction, the material obtained was used to prepare Suc-zein nanoparticles (SZs). The SZs prepared not only had good dispersibility but showed better stability than zein particles on pH, storage and salinity. After loading indomethacin (Indo) into zeolitic imidazolate framework-8 (ZIF-8), the core-shelled Indo-Suc-zein-ZIF-8 (Indo-SZZs) were fabricated by coating Suc-zein onto the surface of ZIF-8 with better stability and high drug loading. Indo-SZZs were pH-responsive and sustained a drug release profile in a simulated environment. Also SZZs presented as being non-toxic, having good biocompatibility and good cellular up-take performance, and the cytotoxicity of Indo-SZZs was significantly higher than that of Indo. This provides a new insight into the preparation of a zein-based oral drug delivery system.