Amine Functionalization of Bacterial Cellulose for Targeted Delivery Applications

Bacterial cellulose (BC), produced by acetic acid bacteria Gluconacetobacter xylinus, is ideal for delivery and related biomedical functions. It is FDA approved for wound dressings and internal applications, non-toxic to endothelial cells and has little effect on blood profiles. Conjugation of therapeutics to BC can be accomplished through the available alcohol groups of the anhydroglucose units (AGU), making targeted delivery possible. Amine was introduced to BC through a reaction involving epichlorohydrin and ammonium hydroxide. The chemical structure was analyzed using infrared spectroscopy and quantified through pH titration. Conjugation of amine to BC was demonstrated through fluorescein-5’-isothiocyanate (FITC) and bromocresol green (BCG) attachment. Due the its large molecular size, the protein horseradish peroxidise (HRP) was conjugated to aminated-BC through a bis(sulfosuccinimidyl)suberate (BS3) linker to reduce steric congestion on the BC surface. Hydrogen peroxide was used to hydrolyze BC to create nanocrystalline cellulose (NCC-BC) with dimensions capable of intracellular delivery. Amine was introduced to NCC-BC and the chemical structure was analyzed using infrared spectroscopy and quantified through pH titration. HRP was optimized to demonstrate protein attachment, while avidin-HRP was used to demonstrate the ability of maximizing protein loading. An avidin-biotin glucose oxidase and avidin-biotin β-galactosidase complex was conjugated to aminated NCC-BC to demonstrate the application of a drug carrier of therapeutic proteins.