Master thesis defense

On Tuesday 14. June, Wegdan Hamed Nasser successfully defended her Master thesis entitled: "Development of 3-D printed scaffolds for bone regeneration".

Wegdan was awarded an 'A' grade by the examiners for work, which was considered to be of high scientific quality and relevance to the field. 

The following is a summary of the work:

3-D printing process is capable of producing 3-D scaffolds layer-by-layer with 100% interconnected porous structure with the help of computer-aided design. In this study we utilized 3-D bio plotter system to fabricate 3-D interconnected porous scaffolds for bone tissue engineering. Poly(L-lactide-co-caprolactone (PLCL)) was selected to fabricate the scaffold due to its biocompatibility and printability. Two scaffolds were produced with a layer rotation of 45° and 90° and a distance of 1000 µm and 1200 µm between the printed fibers. Micro computed tomography (µ-CT) was utilized to study the interconnected porous structure of the scaffolds. The protein adsorption on the surface of the scaffolds was performed using a protein assay kit. Cellular activities in terms of attachment, morphology, and proliferation of human osteoblast-like cells (HOB) seeded onto the two different designed PLCL scaffold were investigated by scanning electron microscopy (SEM), live/dead stain, lactate dehydrogenase enzyme (LDH), and methylthiazol tetrazolium (MTT). Gene expression of apoptotic (Bax and Bcl2) and osteogenic markers (ALP and OC) were investigated by qRT-PCR.  The µ-CT results confirmed the open porous structure of the two printed scaffolds and no significant difference was found in the protein adsorption between the two designs. SEM, LDH and MTT analysis disclosed that HOB cells adhered, spread and proliferated well on all tested copolymer scaffolds. The qRT-PCR analysis showed that cells seeded on 1200 µm scaffold expressed higher mRNA levels of Bcl2 (day 1, 3, 7 and 14), ALP and OC than cells seeded on1000 µm scaffold (day 14). In conclusion, the new designed 3D printed scaffolds are cytocompatible with HOBs, and do not have an adverse effect on cell attachment and proliferation. Enhanced osteoblast proliferation and differentiation were revealed. Therefore, 1200 3-D printed poly(L-lactide-co-caprolactone scaffolds might be suitable candidates as scaffolds for bone regeneration. Designing copolymer scaffolds with a distance of 1200 µm between the printed fibers promoted cellular differentiation.

Congratulations!