Biomedical multi-materials bone scaffolds with tuneable properties using additive manufacturing

Mohammed, Abdullah ORCID: 0000-0002-5264-8824 (2024). Biomedical multi-materials bone scaffolds with tuneable properties using additive manufacturing. University of Birmingham. Ph.D.

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Abstract

Bone tissue engineering is a promising field that focuses on developing new techniques and materials for repairing or replacing damaged bones with bone scaffolds. Recently, 3D printing technologies have emerged as a feasible alternative to conventional manufacturing techniques, enabling the customization of bone scaffolds to meet individual patient needs. This technology has the potential to overcome the shortcomings of traditional approaches and provide better solutions for bone injuries by allowing for customized geometries, materials, and pore structures.
The structural properties of bone scaffolds, such as pore size and porosity, play a crucial role in their functionality in both in vitro and in vivo environments. In general, interconnected porous bone scaffolds that promote cell migration and proliferation are highly desirable. Polylactic acid (PLA) is a widely used biodegradable polymer in tissue engineering applications due to its favourable biocompatibility and mechanical properties. Calcium peroxide (CPO), which can release oxygen upon contact with water, is a valuable component in bone tissue engineering as increased oxygen levels can aid in promoting bone growth and healing.
In this thesis, a novel Fused Deposition Modelling (FDM) PLA/CPO composite filament was created through wet solution mixing and hot melt extrusion. The filaments were produced with different CPO ratios ranging from 1.5% to 24% and subjected to various physical analyses, including X-ray diffraction, surface morphology assessment, evaluation of filament extrudability and printability, microstructural analysis, and examination of rheological and mechanical properties.
The findings of the study indicated that increasing the CPO content resulted in changes in viscosity and microstructure, thereby influencing the mechanical strength and ductility of the composite filaments. However, it was found that the filament with 6% CPO content exhibited promising properties, including acceptable surface morphology and strength, making it suitable for 3D printing applications.
Additionally, the release of oxygen and calcium ions, generated porosity, antibacterial activities and cell culturing of the PLA/CPO composite filaments were assessed. The results revealed that among all the CPO ratios investigated, the 6% CPO content exhibited optimal outcomes, including higher oxygen and calcium ions release, effective bacterial inhibition and exhibited differentiation to bone. These findings suggest that the PLA/CPO composite filament with 6% CPO content holds significant potential for enhancing bone generation by improving oxygenation of bone cells and providing resistance against bacterial infections.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):