Customizing porosity and mechanical strength in chitosan-based scaffolds for enhanced bone tissue regeneration

abstract

Chitosan is increasingly employed in bone tissue engineering due to its biocompatibility, biodegradability, and chemical versatility. This study focuses on the design and optimization of chitosan-based scaffolds, emphasizing the influence of key preparation parameters on their structural and mechanical performance. Formulations were prepared using chitosan concentrations from 1.0 % to 2.5 % (w/v), freezing temperatures of -20 degrees C and -196 degrees C, genipin crosslinker from 1.5 % to 10 % (w/v), and magnetite nanoparticle addition at 10 % and 20 % (w/w relative to chitosan). For CS solution frozen at -20 degrees C, the increase of CS concentration, genipin cross-linking (10 %), and incorporation of magnetite nanoparticles resulted in enhanced compressive strength and modulus of scaffolds, reaching values of 0.40 MPa and 3.57 MPa, respectively. This scaffold offers a combination of porosity (above 80 %) and mechanical strength suitable for trabecular bone regeneration. Freezing the CS solution at -196 degrees C also enhanced the compressive strength and modulus (0.25 MPa and 1.6 MPa, respectively, versus 0.13 MPa and 1.2 MPa at -20 degrees C), while resulting in lower porosity (31 %), making it suitable for applications where higher mechanical integrity is required. These findings underscore the tunability of chitosan scaffolds through parameter control, offering a robust approach for developing chitosan-based biomaterials tailored to distinct bone tissue environments.

keywords

COMPOSITE SCAFFOLDS; MAGNETIC-FIELD; PORE; CARTILAGE; CHITIN; NANOCOMPOSITES; DEACETYLATION; NANOPARTICLES; BIOCOMPOSITE; FUCOIDAN

subject category

Chemistry; Polymer Science

authors

Gonçalves, J; Pinto, ML; Ferreira, P; Nunes, C

Groups

G2 - Photonic, Electronic and Magnetic Materials
G4 - Renewable Materials and Circular Economy

Projects

Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

Biorrefinaria de microalgas Coccolithophore: uma abordagem para biomateriais sustentaveis (Coccolitho4BioMat)

Projeto de Investigação Exploratória: Paula Ferreira (IF_Paula Ferreira)

acknowledgements

This work was developed within the scope of the project CICECO - Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50011/2020) & LA/P/0006/2020 (DOI 10.54499/LA/P/0006/2020), financed by national funds through the FCT/MEC (PIDDAC). MLP gratefully acknowledge the support of the CERENA (FCT-UIDB/04028/2025 and FCT-UIDP/04028/2025). The authors acknowledge to FCT/MEC for the financial support of the project "Coccolitho4BioMat" (POCI-01-0145-FEDER-031032). JG and PF thank FCT for the grants 2020.06654.BD and IF/00300/2015, respectively. CN is grateful to Portuguese national funds (OE), through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.