Adsorption of Arginine on Cellulose Nanofibers: Implications for Biomedical Applications

Adsorption of Arginine on Cellulose Nanofibers: Implications for Biomedical Applications

• Autor
• Rafael Giovanini de Lima
• Co-autores
• Diego Magalhães do Nascimento , Juliana da Silva Bernardes
• Resumo

• Effective immobilization of biomolecules is a crucial technology to give materials appropriate functions for biomedical applications. Arginine (Arg) is an amino acid with healing properties. Its incorporation into polymers can lead to innovative materials to treat wounds. Here, we evaluated the adsorption of arginine to TEMPO-oxidized cellulose nanofibers (o-CNF) by force spectroscopy by atomic force microscopy (AFM-FS) and quartz crystal microbalance with dissipation monitoring (QCM-D). The conversion of hydroxyl to carboxylate groups on the o-CNF surface prompts a high surface density of negative charges to promote arginine absorption through the guanidinium group at pH 7. To analyze the electrostatic interaction, spherical AFM probes were functionalized with o-CNF with two degrees of oxidation (160 and 1160 µmol of carboxylate groups per g of cellulose) and their interaction with mica substrate in an aqueous medium was measured before and after the incubation in an Arg solution (0.1% m/m). During the tip approaching, the repulsion between the mica surface and o-CNFs tips becomes evident at approximately 200 nm and reaches a maximum between 15 and 35 nm. For lower (higher) charged nanofibers, a force of 0.10 nN and 0.04 nN (0.23 nN and 0.11 nN) was measured before and after arginine adsorption, corresponding to a decrease of 60% (52%) in the repulsion force and confirming the interaction between -COO^_ and guanidinium groups. Furthermore, the repulsive profile of the force-distance curves after ARG incubation suggests that the ARG molecules shield not all carboxylates.  In situ adsorption of Arg onto o-CNFs was analyzed by QCM-D. The mass increment of the o-CNF sensor was measured after 10 minutes of an Arg solution (0.1% m/m) flow, preliminary results indicate that the ARG adsorbs on o-CNF. This study suggests that the incorporation of Arg molecules into o-CNFs has the potential to create materials with sustained release of ARG to promote healing.

• Palavras-chave
• TEMPO-oxidized cellulose nanofibers, Arginine
• Modalidade
• Comunicação oral
• Área Temática
• Materiais Funcionais Avançados