The potential of cashew gum functionalization as building blocks for layer-by-layer films

Álvaro J Leite; Rui R Costa; Ana M S Costa; Jeanny S Maciel; José F G Costa; Regina C M de Paula; João F Mano

doi:10.1016/j.carbpol.2017.06.055

The potential of cashew gum functionalization as building blocks for layer-by-layer films

Carbohydr Polym. 2017 Oct 15:174:849-857. doi: 10.1016/j.carbpol.2017.06.055. Epub 2017 Jun 28.

Authors

Álvaro J Leite¹, Rui R Costa², Ana M S Costa³, Jeanny S Maciel⁴, José F G Costa⁵, Regina C M de Paula⁶, João F Mano⁷

Affiliations

¹ 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark - Parque de Ciência e Tecnologia, 4805-017 Barco, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal. Electronic address: alvaro.leite@dep.uminho.pt.
² 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark - Parque de Ciência e Tecnologia, 4805-017 Barco, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal. Electronic address: rui.costa@dep.uminho.pt.
³ 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark - Parque de Ciência e Tecnologia, 4805-017 Barco, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal; Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: amargaridasc@ua.pt.
⁴ Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, CP 12200, 60455-760 Fortaleza-CE, Brazil. Electronic address: jeanny@dqoi.ufc.br.
⁵ Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, CP 12200, 60455-760 Fortaleza-CE, Brazil. Electronic address: josecosta@alu.ufc.br.
⁶ Departamento de Química Orgânica e Inorgânica, Universidade Federal do Ceará, CP 12200, 60455-760 Fortaleza-CE, Brazil. Electronic address: rpaula@dqoi.ufc.br.
⁷ 3B's Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark - Parque de Ciência e Tecnologia, 4805-017 Barco, Guimarães, Portugal; ICVS/3B's - PT Government Associate Laboratory, Braga/Guimarães, Portugal; Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address: jmano@ua.pt.

PMID: 28821140
DOI: 10.1016/j.carbpol.2017.06.055

Abstract

Cashew gum (CG), an exudate polysaccharide from Anacardium occidentale trees, was carboxymethylated (CGCm) and oxidized (CGO). These derivatives were characterized by FTIR and zeta potential measurements confirming the success of carboxymethylation and oxidation reactions. Nanostructured multilayered films were then produced through layer-by-layer (LbL) assembly in conjugation with chitosan via electrostatic interactions or Schiff bases covalent bonds. The films were analyzed by QCM-D and AFM. CG functionalization increased the film thickness, with the highest thickness being achieved for the lowest oxidation degree. The roughest surface was obtained for the CGO with the highest oxidation degree due to the predominance of covalent Schiff bases. This work shows that nanostructured films can be assembled and stabilized by covalent bonds in alternative to the conventional electrostatic ones. Moreover, the functionalization of CG can increase its feasibility in multilayers films, widening its potential in biomedical, food industry, or environmental applications.

Keywords: Biomimetics; Cashew gum; Chitosan; Layer-by-layer; Natural biomaterials.