DEVELOPMENT AND CHARACTERISATION OF PEPTIDE-BASED HYDROGELS AS BIOINKS FOR 3D BIOPRINTING APPLICATIONS

Abstract

With an increasing demand for effective regenerative medicine therapies, more sophisticated bone tissue-engineered in vitro models are required to better understand the fundamental biological processes underlying regeneration. The state-of-the-art technology of three-dimensional (3D) bioprinting aims to achieve well-defined biological structures by depositing cell-encapsulated hydrogels or bioinks in a layer-by-layer manner. A main challenge of 3D bioprinting is the lack of suitable bioinks with a wide printability window that offer adequate biofabrication properties and a cell-friendly extracellular matrix (ECM)-like microenvironment. This lack hinders the encapsulation and culture of cells in complex in-vitro 3D tissue models. Self-assembling peptide hydrogels (SAPHs) are fully defined, semi-synthetic hydrogels that are biocompatible and possess tuneable mechanical properties. Therefore, SAPHs are believed to be a powerful option with unique properties that make them perfect candidates for designing and exploring novel bioinks for the purpose of creating tissue-engineered bone constructs. In this research, we aimed to design and explore SAPHs as novel bioinks for bone biofabrication and, more specifically, with incorporated bone morphogenic protein (BMP)-2 growth factor to promoting osteogenic differentiation of human mesenchymal stem cells (hMSCs). To date, we have successfully developed peptide-based bioinks and assessed their mechanical properties, printability, and cell viability in fibroblast and hMSC- encapsulated 3D bioprinted constructs. Additionally, we conducted preliminary studies on the efficient induction of bone differentiation by incorporating BMP-2 enriched polyhedrin crystals (PODS), into our bioinks, which enabled sustained release of growth factors. Our overall aim was to print SAPHs with adequate shape fidelity, biocompatibility, and the ability to differentiate into a physiologic bone phenotype. In practical terms, the biofabrication of bone models through 3D bioprinting holds promise as a powerful tool for in vitro disease modelling and for the treatment of bone conditions such as osteoarthritis in the early stages of the disease.

Date of Award	28 Feb 2024
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Alberto Saiani (Main Supervisor), Judith Hoyland (Co Supervisor) & Suelen Barg (Co Supervisor)