Facile and Efficient Preparation of Ph-Responsive Carboxylated Cellulose Microspheres as Carrier for Simple Loading and Controlled Release Of Vitamin B12

Abstract

Vitamin B12 deficiency with great dangers of neuropathy, neurological complications, myocardial infarction, and stroke. While the absorption of direct oral Vitamin B12 is low and variable, injections can cause pain and anxiety. In this work, a facile and efficient method was used to prepare carboxylated cellulose microspheres (CCMs) for oral delivery of oral delivery of Vitamin B12. The hydroxyl group of cellulose microspheres (CMs) was oxidized to the carboxyl group by Fe2+/H2O2 oxidation, which endowed CCMs with pH responsiveness. The micropore and nanopore structures of CCMs were represented in SEM images, which provided many binding sites for Vitamin B12 loading and delivery. Vitamin B12 was simply multiple-loaded into the CCMs by electrostatic interactions, and controlled release through protonation and ionization of carboxyl groups. Vitamin B12 was released by the Fickian diffusion. Cytotoxicity and blood compatibility experiments showed that CCMs were non-toxic and had low hemolytic activity. CCMs were suggested to be a potential drug carrier for clinical therapy.

Keywords: pH-responsive, Carboxylated cellulose microspheres, Controlled drug delivery