Fabrication of Carboxylated Cellulose Microspheres Via Fe2+/H2o2  Oxidation Method and Their Application in Vitamin B12 Efficient Loading And Controlled Release

Abstract

Vitamin B12 deficiency with great dangers of neuropathy, neurological complications, myocardial infarction , and stroke. However, the acidic environment of the stomach prevents oral absorption of vitamin B12 and injection pain greatly reduces patient compliance. In this work, a facile and efficient method was used to prepare carboxylated cellulose microspheres (CCMs) for oral delivery of Vitamin B12. The hydroxyl group of cellulose microspheres (CMs) was oxidized to the carboxyl group by Fe2+/H2O2 oxidation, making it pH responsive. The micro-nanopore structure of CCMs was represented in SEM images, which provided many binding sites for Vitamin B12 loading and delivery. Vitamin B12 was multilayered in CCMs by electrostatic action, and the release was controlled by the ionization equilibrium of the carboxyl group. Vitamin B12 was released by the Fickian diffusion. Cytotoxicity experiments showed that CCMs were non-toxic. CCMs were suggested to be a potential drug carrier for clinical therapy.

Keywords: pH-responsive, Carboxylated cellulose microspheres, oral delivery, Controlled Release