Abstract
Polycaprolactone (PCL) scaffolds have been widely investigated for tissue engineering applications, however, they exhibit poor cell adhesion and mechanical properties. Subsequently, PCL composites have been produced to improve the material properties. This study utilises a natural material, Bombyx mori silk microparticles (SMP) prepared by milling silk fibre, to produce a composite to enhance the scaffolds properties. Silk is biocompatible and biodegradable with excellent mechanical properties. However, there are no studies using SMPs as a reinforcing agent in a 3D printed thermoplastic polymer scaffold. PCL/SMP (10, 20, 30wt%) composites were prepared by melt blending. Rheological analysis showed that SMP loading increased the shear thinning and storage modulus of the material. Scaffolds were fabricated using a screw-assisted extrusion-based additive manufacturing system. Scanning electron microscopy and X-ray microtomography was used to determine scaffold morphology. The scaffolds had high interconnectivity with regular printed fibres and pore morphologies within the designed parameters. Compressive mechanical testing showed that the addition of SMP significantly improved the compressive Young's modulus of the scaffolds. The scaffolds were more hydrophobic with the inclusion of SMP which was linked to a decrease in total protein adsorption. Cell behaviour was assessed using human adipose derived mesenchymal stem cells. A cytotoxic effect was observed at higher particle loading (30wt%) after 7days of culture. By day 21, 10wt% loading showed significantly higher cell metabolic activity and proliferation, high cell viability, and cell migration throughout the scaffold. Calcium mineral deposition was observed on the scaffolds during cell culture. Large calcium mineral deposits were observed at 30wt% and smaller calcium deposits were observed at 10wt%. This study demonstrates that SMPs incorporated into a PCL scaffold provided effective mechanical reinforcement, improved the rate of degradation, and increased cell proliferation, demonstrating potential suitability for bone tissue engineering applications.
Highlights
A widely investigated biomaterial is the synthetic polymer, polycaprolactone (PCL), which has been used for bone tissue engineering applications and in vivo is degradable, bioresorbable, and biocompatible [9,10]
The particle volume distribution is relatively narrow with only a single peak, which demonstrates that the silk microparticles (SMP) fabrication process produces uniform particles
This study demonstrates the development and characterisation of a new composite material, a PCL blended with SMPs
Summary
A widely investigated biomaterial is the synthetic polymer, polycaprolactone (PCL), which has been used for bone tissue engineering applications and in vivo is degradable, bioresorbable, and biocompatible [9,10] These properties can be readily exploited in tissue engineering applications because PCL can be processed as it has a low melting temperature (~60 °C), soluble in a range of solvents (e.g. chloroform, dichloromethane, toluene, and acetone), excellent blending compatibility, and suitable rheological and viscoelastic properties enabling the fabrication of a variety of scaffolds using both conventional and additive manufacturing techniques [9,10,11]. The development of a composite scaffold containing poly(L-lactic-co-ε-caprolactone), bovine bone matrix, and gelatin promoted faster and mature bone regeneration in human patients [23,24] This demonstrates that the biological properties of PCL can be improved through the incorporation of the appropriate biological motifs
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
