Scientific Context of the Project

Bioactive glasses are conventionally used for hard tissue applications. Recent research showed promising application of bioactive glasses also for soft tissue engineering applications. Borate glasses could heal wounds untreatable with conventional methods. In addition to this, they are also promising for other applications such as muscle and nerve tissue regeneration. In this study, first boron doped bioactive glasses will be prepared by sol-gel technique. Then, prior to 3D printing, a design of experiments analysis will be conducted utilizing custom codes and available softwares, e.g., Design-Expert®software (DX7), to determine the printing parameters. With these results, the polymeric phase of the 3D printing model will be determined by the student. Then, rheological studies will be carried out to determine accuracy of the determined variables from the DOE analysis. The scaffolds will be 3D printed. Then, they will be characterized by techniques including XRD, SEM, mechanical tests, contact angle measurements, DLS, FTIR, and cell culture studies. Finally, in vivo studies will be carried out with zebra fish to study effect of the produced scaffold for the healing of a damaged tissue. Histochemical studies will be conducted to study the effect of scaffolds on wound healing. The zebrafish has a pronounced ability to regenerate its tissues and organs. To unravel the potential contribution of boron doped bioactive glasses in tissue regeneration in vivo, we will exploit stab wound injury of the adult zebrafish brain, which is a well-established approach to investigate vertebrate brain neurogenesis and regeneration. Following stab injury, fluorescently labeled boron doped bioactive glasses will be delivered into the brain using cerebroventricular microinjection (CVMI). Afterwards, the tissue will be analyzed with respect to expression of glial and neuronal markers that are indicative of reactive regeneration. Here, immunoflurescent staining of tissue sections and/or quantitative real-time PCR on RNA isolated from the brain tissue will be performed.

Innovative Aspects of the Project

This study is very novel as application of boron-doped bioactive glasses for wound healing is a recent growing and very promising field. Boron doped bioactive glasses are capable of healing wounds of diabetes patients. Therefore, this showed great promise of use of boron doped bioactive glasses also for soft tissue engineering applications. Another important aspect is use of statistical tools for optimization of 3D printing parameters. This is a very key aspect of the study as this would reduce work labour (studying many parameters for optimization) and also reduce cost of 3D printing. Another important aspect is application of zebra fish models for in vivo studies as there is very limited amount of in vivo study for evaluation of boron doped bioactive glass-based 3D printing scaffolds for soft tissue engineering applications.

Research Environment and Infrastructure

In our Institute of Biomedical Engineering, we have required facilities for production and in depth- characterization of the bioactive glasses and 3D printed scaffolds (http://web.boun.edu.tr/duygu.ege/ ). There is a 3D extrusion based bioprinter (Axolotl Biosystems) in our laboratory. A mechanical testing device (Lloyd Instrument, LF Plus) is present which is capable of measuring compression and tension of soft biomaterials. At Boğaziçi University, there is a rheological testing machine (Anton Paar), Fourier Infra-red Spectroscopy (FTIR) (Perkin Elmer), X-Ray Diffraction Spectroscopy (XRD) (Rikagu), X-ray Photoelectron Spectroscopy (XPS) (Thermoscientific), Scanning Electron Microscopy (SEM) (Phillips-FEI XL-30), dynamic light scattering (DLS), and contact angle measurement device. There is a cell culture laboratory present in our laboratory. We are capable of measuring cell viability and analysing cell morphology and differentiation via staining. We have a cell culture incubator, laminar flow cabinet, flourescence microscope (Zeiss) and centrifuge in an isolated room with a Hepa filter to carry out the cell culture studies in a sterile environment. Izmir Institute of Technology has the required know-how for the computational and statistical analysis aspect of the study. This part of the study will be purely computer based with use of commercially available design of experiments (DOE) tools and open 3D printing databases (such as https://cect.umd.edu/3d-printing-database). İzmir Biomedicine and Genome Center has the required facilities for in vivo studies with zebra fish. In the zebrafish facility at the Vivarium center, there is anesthetic apparatus, class2A Biosafety Cabin, Operation equipment, procedure room, stereo microscope, surgery set and technical support. Additionally, for studying gene expressions, there is a real-time PCR detection system is present in the center.

Required GRE Score

GRE Quantitative 156.00