Self-hardening polycaprolactone/calcium phosphate inks for 3D printing of bone scaffolds: rheology, mechanical properties and shelf-life

The development of 3D-printed calcium phosphate bone grafts represents a breakthrough for personalized bone tissue engineering. However, their high brittleness is a limiting factor for clinical applications. The present work aims to overcome this drawback by developing a composite ink for direct ink...

Descripción completa

Detalles Bibliográficos
Autores: Mazo Barbara, Laura del|||0000-0001-9482-8244, Ginebra Molins, Maria Pau|||0000-0002-4700-5621
Tipo de recurso: artículo
Fecha de publicación:2024
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/419908
Acceso en línea:https://hdl.handle.net/2117/419908
https://dx.doi.org/10.1016/j.matdes.2024.113035
Access Level:acceso abierto
Palabra clave:3D printing
Bone scaffold
Calcium phosphates
Polycaprolactone
Mechanical properties
Àrees temàtiques de la UPC::Enginyeria biomèdica::Biomaterials
Descripción
Sumario:The development of 3D-printed calcium phosphate bone grafts represents a breakthrough for personalized bone tissue engineering. However, their high brittleness is a limiting factor for clinical applications. The present work aims to overcome this drawback by developing a composite ink for direct ink writing using a polycaprolactone solution (20 wt% in pyridine) as binder for a self-hardening a-tricalcium phosphate powder. The ink consolidation results from a two-step process. First, evaporation of the solvent gives rise to a flexible green body, in which the polymer matrix retains the loose ceramic particles. Subsequently, upon contact with water, the hydrolysis of these particles creates a continuous network of biomimetic hydroxyapatite nanocrystals, with the consequent hardening of the ink. The presence of the polymer improves the mechanical properties, increasing the flexural strength from 2 to 4 MPa and the strain energy density from 0.2 to 1.1 kJ/m3. Unlike the inks based on hydrogel binders, where the hardening reaction starts as soon as the liquid and solid components are mixed, the ink prepared with the non-aqueous binder is stable, with over 5 months shelf life, and allows the hardening reaction to be triggered at will by contact with water.