title: Cross-linked chitosan improves the mechanical properties of calcium phosphate-chitosan cement.
abstract: Calcium phosphate (CaP) cements are highly applicable and valuable materials for filling bone defects by minimally invasive procedures. The chitosan (CS) biopolymer is also considered as one of the promising biomaterial candidates in bone tissue engineering. In the present study, some key features of CaP-CS were significantly improved by developing a novel CaP-CS composite. For this purpose, CS was the first cross-linked with tripolyphosphate (TPP) and then mixed with CaP matrix. A group of CaP-CS samples without cross-linking was also prepared. Samples were fabricated and tested based on the known standards. Additionally, the effect of different powder (P) to liquid (L) ratios was also investigated. Both cross-linked and uncross-linked CaP-CS samples showed excellent washout resistance. The most significant effects were observed on Young's modulus and compressive strength in wet condition as well as surface hardness. In dry conditions, the Young's modulus of cross-linked samples was slightly improved. Based on the presented results, cross-linking does not have a significant effect on porosity. As expected, by increasing the P/L ratio of a sample, ductility and injectability were decreased. However, in the most cases, mechanical properties were enhanced. The results have shown that cross-linking can improve the mechanical properties of CaP-CS and hence it can be used for bone tissue engineering applications.
authors.affiliation: Department of Mechanical Engineering, University of Toledo, Toledo, OH 43606, USA.
authors.forename: Ashkan
authors.initials: A
authors.lastname: Aryaei
authors.affiliation: School of Medicine, University of Toledo, OH 43614, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, University of Toledo, Toledo, OH 43606, USA.
authors.forename: Ahalapitiya H
authors.initials: AH
authors.lastname: Jayatissa
authors.affiliation: Department of Orthopaedic Surgery, University of Toledo, Toledo, OH 43614, USA. Electronic address: a.jayasuriya@utoledo.edu.
authors.forename: A Champa
authors.initials: AC
authors.lastname: Jayasuriya
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001843:Bone Cements / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D019245:Compressive Strength; D055119:Elastic Modulus; D006244:Hardness; D008422:Materials Testing; D016062:Porosity; D023822:Tissue Engineering; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D002130:Calcium Phosphates; D048271:Chitosan; C020243:calcium phosphate
keywords: Calcium phosphate cement; Chitosan; Cross-linking; Mechanical properties; Porosity