Atomic force microscopy mechanical properties determination of three dimensional rapid-prototyped tissue engineering scaffolds Adrian Chlanda 1), Michal J. Wozniak 3), Krzysztof J. Kurzydlowski 1) 1) Warsaw University of Technology, Faculty of Material Science and Engineering, 141 Woloska str., 02-507, Warsaw, Poland 2) Institute of Technical Physics, Military University of Technology, 2 Sylwestra Kaliskiego str., 00-908 Warsaw, Poland 3) Warsaw University of Technology, University Research Centre - Functional Materials, 141 Woloska str., 02-507, Warsaw, Poland
Introduction This work is concerned with atomic force microscopy (AFM) mechanical properties determination of rapid-prototyped three dimensional (3D) tissue engineering scaffolds made of polycaprolactone (PCL), with and without small portions of hydroxyapatite (HAp) inclusions. 3D scaffolds serve as a temporary extracellular matrix (ECM) that can provide an environment with desirable mechanical support for cell growth and tissue regeneration. The mechanical properties of scaffolds play important role in regulating cellular functions and tissue maturation. This is due to the fact that tissues in the body are characterized by different mechanical properties with elastic modulus ranging from tens, up to hundreds of MPa. To engineer these tissues it is required to design scaffolds with biomimetic mechanical properties, which possess similar elastic modulus, or elasticity to that of native tissues. To study the mechanical properties of 3D scaffolds at the nanoscale AFM can be used. It is a powerful tool for the visualization, and probing of selected mechanical properties of materials in broadly defined life sciences.
Materials and methods a
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Fig 1. a) scaffold CAD model, b) BioScaffolfer, c) scaffold printing scheme, d) tomograph image of ready scaffold, e) AFM measurements scheme, f) AFM.
System-Solution for manufacturing of customised 3D tissue scaffolds with defined external shape and internal architecture (three dimensional distribution of interconnective porosity and material) from polymer/ceramic biomaterials (polycaprolactone/hydroxyapatite) based on 3D-dispensing (Bioscaffolder) was used for scaffold fabrication. Mechanical properties in nanoscale were tested using atomic force microscopy technique. All AFM measurements were made in air, under ambient conditions with Bruker NanoScope Multimode 8 using APP NANO scanning probes.
Results 2a
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Fig 2,3. AFM topography and mechanical properties maps of 3D rapid-prototypedtissue engineering scaffolds. 5μm scan size area: 1a) topography, 1b) reduced Young`s modulus, 1c) adhesion, 1d) deformation, 1μm scan size area: 1a) topography, 1b) reduced Young`s modulus, 1c) adhesion, 1d) deformation.
Conclusions
• Atomic force microscopy proven to be a suitable method for • Dependence between topography and mechanical proeperties probing of selected mechanical properties of 3D scaffolds for can be observed. tissue engineering application that produces data for both • Average reduced Young`s modulus value is about 150 MPa. qualiative and quantitative analysis.
Acknowledgement The work was supported by: National Science Center of Poland (NCN) under grant: UMO-2011/01/B/ST8/07559
Contact E-mail address: adrian.chlanda@inmat.pw.edu.pl Website: www.bio.materials.pl