Fabrication and Characterization of PCL/HA Filament as a 3D Printing Material Using Thermal Extrusion Technology for Bone Tissue Engineering.

Fengze Wang,Michaela Maintz,Francesco Santarella,Neha Sharma,Mirja Michalscheck,Shuaishuai Cao,Esma Bahar Tankus,Sabrina Märtin,Florian M Thieringer,Nadja Rohr

doi:10.3390/polym14040669

Abstract

The most common three-dimensional (3D) printing method is material extrusion, where a pre-made filament is deposited layer-by-layer. In recent years, low-cost polycaprolactone (PCL) material has increasingly been used in 3D printing, exhibiting a sufficiently high quality for consideration in cranio-maxillofacial reconstructions. To increase osteoconductivity, prefabricated filaments for bone repair based on PCL can be supplemented with hydroxyapatite (HA). However, few reports on PCL/HA composite filaments for material extrusion applications have been documented. In this study, solvent-free fabrication for PCL/HA composite filaments (HA 0%, 5%, 10%, 15%, 20%, and 25% weight/weight PCL) was addressed, and parameters for scaffold fabrication in a desktop 3D printer were confirmed. Filaments and scaffold fabrication temperatures rose with increased HA content. The pore size and porosity of the six groups’ scaffolds were similar to each other, and all had highly interconnected structures. Six groups’ scaffolds were evaluated by measuring the compressive strength, elastic modulus, water contact angle, and morphology. A higher amount of HA increased surface roughness and hydrophilicity compared to PCL scaffolds. The increase in HA content improved the compressive strength and elastic modulus. The obtained data provide the basis for the biological evaluation and future clinical applications of PCL/HA material.

Highlights

Oral and maxillofacial tumors and trauma often lead to different degrees of jaw defects, and their reconstruction remains a challenging task [1]
The PCL melting temperature was gradually increased by increasing the amount of HA
The first melting point (T4) allowed a pre-melting of the PCL powder; this PCL temperature plus 10% variation was set when supplemented with HA powder

Summary

Introduction

Oral and maxillofacial tumors and trauma often lead to different degrees of jaw defects, and their reconstruction remains a challenging task [1]. Due to the limited availability of bone material, various biomaterials have been applied to generate scaffolds using three-dimensional (3D) printing [5]. Polycaprolactone (PCL) has attracted much in bone tissue engineering and is widely used in 3D printing, enabling the fabrication of complex patient-specific and biomimetic structures [6]. Composites comprise two or more materials, and the goal is to create more efficient scaffolds by combining the regenerative properties of more than one biomaterial [10]. Composites containing HA and polymers combine good mechanical properties with good biocompatibility, yielding a 3D substitute that mimics the heterogeneity and hierarchical structure of the native extracellular bone matrix [11,12]

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