Protein adsorptive materials prepared by radiografting of acrylates onto mercerized cellulose

ACHILLI, ESTEFANIA; MIRNA LORENA SANCHEZ; MARIA LAURA CARBAJAL; MARCELO FERNANDEZ LAHORE; MARIANO GRASSELLI

Jeju Island

Simposio; 11th Meeting of the Ionizing Radiation and Polymers Symposium IRaP; 2014

IRaP IAEA

The downstream processing of biopharmaceuticals is generally more cost intensive than corresponding fermentation processes in the biotech industry and can account for up to 80% of production costs. Novel process integration and intensification based on the utilization of non-traditional chromatographic or extractive methods are highly required in order to reduce these costs. Cellulose and other natural polymers have been traditionally used in the recovery and purification of proteins; through industrially processed materials into specific shapes, such as spherical adsorptive microparticles and thin ultra/microfiltration membranes, among others. However, the natural arrangement of cellulose into fibers allows the development of non-woven structures, which could be useful for adsorptive process using non-clarified biological samples. Radiation-induced grafting polymerization is a powerful technique to modify cellulose fibers. In addition, different grafting techniques has been applied for preparation of adsorptive materials of water pollutants and proteins [1,2]. However, these materials show low capacity for protein adsorption. In order to improve the adsorptive property, mercerized cellulose fibers were cografted with a hydrophilic monomer, dimethyl acrylamide (DMAAm), in addition to glycidyl methacrylate (GMA) to further fiber functionalization. Simultaneous radiation-induced polymerization in an oxygen-free atmosphere was performed by 60Co irradiation at 10 kGy dose and 1 kGy/h dose rate. Initial monomer solution was prepared using 5-10% DMAAm and 1.6-3.2 % GMA in ethanol/water (1/1 v/v), reaching grafting yields in the order of 10 to 50 % and variable amount of homopolymer. Pendant epoxy groups from grafted GMA were converting into sulfonic and iminodiacetic moieties by reaction with sodium sulfite and iminodiacetic acid respectively. Polymer modifications were followed by FT-IR and EDAX-SEM microscopy. SEM pictures and fluorescent microscopy analysis showed an internal (bulk) grafting modification of the fibers. Functionalized materials were tested for protein recovery from protein solutions. Lysozyme adsorption was run onto sulfonic fibers reaching a maximum 280 mg/g for the best material. Based onto these results, we can conclude optimized grafting modification of mercerized cellulose fibers has a great potential for development of novel low-cost high-capacity protein adsorbents.