MSc.Thesis Defense:Mahdiyeh Zahrabi
HYBRID BIOPRINTING OF FUNCTIONALIZED SCAFFOLDS FOR TISSUE ENGINEERING APPLICATIONS
Mahdiyeh Zahrabi
Materials Science and Nanoengineering, MSc. Thesis, 2024
Thesis Jury:
Prof. Dr. Bahattin Koç (Thesis Supervisor)
Prof. Dr. Nur Mustafaoğlu
Prof. Dr. Pınar Yılgör Huri
Date & Time: July 22th, 2024 – 13:30
Place: FENS L027
Zoom Link: https://sabanciuniv.zoom.us/j/7850411386?omn=93575783403
Keywords: Hybrid Bioprinting, Melt Electro-Spinning Writing, Tissue Engineering, Hair Follicle Development, Functionalized Scaffolds, Bone Tissue Engineering, MXene
Abstract
Tissue engineering (TE) is an interdisciplinary field that focuses on developing materials and methods for regenerating damaged tissues. This field utilizes a combination of biomaterials, cells, and bioactive molecules to mimic the human body microenvironment and stimulate tissue growth. To develop successful tissue replacements, it is necessary to consider various factors, including the biochemical and biophysical properties of the host tissue. Despite on-going efforts, development of functionalized scaffolds with desirable bioactivity capable of regenerating full-thickness tissue substitutes with improved vascularization are the main challenges yet to be addressed.
Three-dimensional (3D) bioprinting is a novel technique that allows for the controlled deposition of biomaterials in the desired geometry using computer-aided design (CAD) models. The use of this method allows fabrication of fine-tuned fibers that mimic the natural extracellular matrix (ECM), as well as selection of functional materials with desirable properties for various applications and incorporation of bioactive molecules to enhance functionality. Owing to its power in fabricating structures with desirable architecture and use of functionalized biomaterials, 3D printing is a promising technology that paves the way for regeneration of functionalized tissues.
In this work, a hybrid methodology of melt-electrospinning writing (MEW) combined with bioprinting methods is proposed for fabricating bioactive hybrid scaffolds. For this, functionalized bioactive glass (BG)/polycaprolactone (PCL) composite is first fabricated with MEW process and then gelatin hydrogel reinforced with carboxymethylcellulose-tyramine (CMC-Tyr) conjugates were combined with human primary hair follicle dermal papilla (HFDPCs) spheroids. The developed method was applied for skin tissue engineering (STE) by bioprinting epidermis and dermis sections. The development of HFDPC spheroids was carried out using non-adhesive polydimethylsiloxane (PDMS) well plates with special geometry and the hanging drop model. Spheroid size, functionality and cell viability were assessed, contributing to incorporation of more complex and biologically relevant skin models including complex adnexal structure, such as hair follicle development using a novel microcapillary bioprinting technology.
Moreover, the developed MEW process was investigated for printing composite scaffolds composed of Ti3C2Tx MXene and PCL, as a first attempt in literature. Various concentrations of MXene were incorporated into PCL for Bone Tissue Engineering (BTE). The resulting scaffolds demonstrated desirable cell adhesion, proliferation, and cell viability, as evidenced by cytocompatibility with pre-osteoblasts (MC3T3-E1), mechanical characterizations, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM).
This comprehensive approach, which combines development of advanced and novel nanocomposites, 3D cell culture techniques, and 3D bioprinting technology, has led to the development of scaffolds with enhanced properties, offering promising solutions for TE applications. The findings emphasize the potential of the proposed scaffolds to advance regenerative medicine and develop functional tissue substitutes.