Efficient delivery of fucoxanthin using metal–polyphenol network-coated magnetic mesoporous silica

Fucoxanthin (FX) is a natural carotenoid pigment that exhibits antitumor activity and is found primarily in brown seaweed. However, its effectiveness as a therapeutic agent varies owing to low bioavailability, poor water solubility, and poor physicochemical stability. The acidic nature of the tumor microenvironment may be utilized to design and construct a targeted magnetic, acid-labile nano-carrier (FX@Fe 3 O 4 -mSiO 2 -TA) with improved FX bioactivity. A nano-drug delivery system composed of magnetic mesoporous silica coated with a tannic acid–iron network (TA/Fe 3+ ) was designed and constructed to improve FX bioactivity based on pH and magnetic targeting in a tumor microenvironment. The external magnetic field guided the carrier to the tumor site. TA/Fe 3+ in the outer coating of the carrier was decomposed, resulting in FX release, which was attributed to the low pH of the tumor microenvironment. Drug release was sustained and pH-dependent in vitro , which significantly improved the stability and bioavailability of FX. The simplicity of its preparation and efficacy of the targeted therapeutic suggest the potential of this nano-carrier for application in tumor therapy.