Development of bio-specific adsorbent films for biotechnological applications based on sustainable polymer

TOMÁS GREPPI; LAURA DANIELA PILATO; MARÍA FERNANDA BAIELI; FEDERICO JAVIER WOLMAN

CABA

Congreso; WCCE11-11 World Congress on Chemical Engineering; 2023

World Chemical Engineering Council, Asociación Argentina de Ingenieros Químicos

Objectives. Chitosan is a polysaccharide derived from the deacetylation of chitin. Chitosan can be easily handled, formatted and chemically modified to be used in material fields applications. The aim of this work was to develop biospecific adsorptive chitosan films to be used in the coating of plastic surfaces for the selective binding of target proteins with technological interest. Materials and methods. Films preparation. Chitosan (1-2%) without and with polyethylene glycol addition (0-5% w/v; PEG 20000 g/mol), were dissolved in 2% acetic acid and different volumes were dispersed on plastic materials to generate coatings of different thicknesses. Chemical functionalization. The films were crosslinked with epiclorhydrin (150 mM) and employed without further modification as well as after iminodiacetic acid immobilization and Cu2+ loading. Support characterization. The structural and morphological parameters were evaluated by SEM. Adsorptive characterization. Adsorption of commercial proteins such as glycomacropeptide (GMP), wheat germ agglutinin (WGA) and lysozyme (Lz) were evaluated to explore different interaction modes (ionic exchange, affinity and IMAC respectively). Results. The SEM images allowed us to validate the procedure to obtain different films with meso/macroporous internal structure (Fig. 1). Smooth structures or porous structures could be identified in conditions without PEG and with PEG, respectively. Also, the further chemical modification of films did not affect its structure. Fig 1. SEM images of chitosan films without PEG (A) and with 1 or 5% PEG (B and C, respectively). The coatings with an internal porous structure showed higher adsorption capacities than non-porous films. For GMP, adsorption capacities varied from 8.1 ± 0.1 mg/g (1mL chitosan 2% without PEG films) to 83.8 ± 2.0 mg/g (0.25mL chitosan 1% with PEG 5% films). For Lz, values varied from 2.7 ± 1.3 mg/g (1mL chitosan 2% without PEG films) to 51.8 ± 4.6 mg/g (1mL chitosan 1% with PEG 5% films) and for WGA, from 24.8 ± 6.1 mg/g (0.25mL chitosan 2% without PEG films) to 52.2 ± 8.9 mg/g (0.25mL chitosan 1% with PEG 5% films). Conclusions. The use of chitosan as coating films for binding of proteins was showed by exploring different adsorptive mechanisms. The addition of PEG, as porogen, improved the performance for all the studied cases and interestingly, the correlation between the chitosan mass dispensed per well and the adsorptive capacity did not show a linear behavior.