Biocomposites containing poly(lactic acid) and chitosan for 3D printing - Assessment of mechanical, antibacterial and in vitro biodegradability properties

Isabel Hui; Eva Pasquier; Amalie Solberg; Karin Agrenius; Joakim Håkansson; Gary Chinga-Carrasco

doi:10.1016/j.jmbbm.2023.106136

Biocomposites containing poly(lactic acid) and chitosan for 3D printing - Assessment of mechanical, antibacterial and in vitro biodegradability properties

J Mech Behav Biomed Mater. 2023 Nov:147:106136. doi: 10.1016/j.jmbbm.2023.106136. Epub 2023 Sep 21.

Authors

Isabel Hui¹, Eva Pasquier², Amalie Solberg², Karin Agrenius³, Joakim Håkansson⁴, Gary Chinga-Carrasco⁵

Affiliations

¹ Swiss Federal Institute of Technology Zurich, Switzerland.
² RISE PFI, Høgskoleringen 6b, Trondheim, Norway.
³ Unit of Biological Function, Division Materials and Production, RISE Research Institutes of Sweden, Box 857, SE-50115, Borås, Sweden.
⁴ Unit of Biological Function, Division Materials and Production, RISE Research Institutes of Sweden, Box 857, SE-50115, Borås, Sweden; Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, P.O. Box 440, SE-40530, Gothenburg, Sweden; Department of Chemistry and Molecular Biology, University of Gothenburg, 405 30, Gothenburg, Sweden.
⁵ RISE PFI, Høgskoleringen 6b, Trondheim, Norway. Electronic address: gary.chinga.carrasco@rise-pfi.no.

PMID: 37774439
DOI: 10.1016/j.jmbbm.2023.106136

Abstract

New bone repair materials are needed for treatment of trauma- and disease-related skeletal defects as they still represent a major challenge in clinical practice. Additionally, new strategies are required to combat orthopedic device-related infections (ODRI), given the rising incidence of total joint replacement and fracture fixation surgeries in increasingly elderly populations. Recently, the convergence of additive manufacturing (AM) and bone tissue engineering (BTE) has facilitated the development of bone healthcare to achieve personalized three-dimensional (3D) scaffolds. This study focused on the development of a 3D printable bone repair material, based on the biopolymers poly(lactic acid) (PLA) and chitosan. Two different types of PLA and chitosan differing in their molecular weight (MW) were explored. The novel feature of this research was the successful 3D printing using biocomposite filaments composed of PLA and 10 wt% chitosan, with clear chitosan entrapment within the PLA matrix confirmed by Scanning Electron Microscopy (SEM) images. Tensile testing of injection molded samples indicated an increase in stiffness, compared to pure PLA scaffolds, suggesting potential for improved load-bearing characteristics in bone scaffolds. However, the potential benefit of chitosan on the biocomposite stiffness could not be reproduced in compression testing of 3D printed cylinders. The antibacterial assays confirmed antibacterial activity of chitosan when dissolved in acetic acid. The study also verified the biodegradability of the scaffolds, with a process producing an acidic environment that could potentially be neutralized by chitosan. In conclusion, the study indicated the feasibility of the proposed PLA/chitosan biocomposite for 3D printing, demonstrating adequate mechanical strength, antibacterial properties and biodegradability, which could serve as a new material for bone repair.

Keywords: 3D printing; Antibacterial; Biocomposites; Biodegradability; Chitosan; Poly(lactic acid).