Novel Carbon Nanotube-Based Scaffolds for Cartilage Tissue Engineering
Creators: name: ELIDOTTIR, KATRIN
Publisher: name: University of Surrey
Year: 2021

description: "Cartilage tissue engineering has become one of the most attractive solutions to tackling osteoarthritis, improving understanding of this disease and providing a platform for potential therapeutic testing. Carbon nanotubes (CNTs) have prompted interest as tissue engineering scaffolding material to support the growth of cartilage in vitro, owing to their unique mechanical and electrical properties, as well as their innate nanoscale, fibrous structure mimicking cartilage components such as collagen.
description: In this work, traditional material science approaches were used to design and fabricate CNT-based substrates and determine their suitability as cell culture scaffolds. Consideration was given primarily to the physical, mechanical and electrical properties of scaffolds. The physical structure of hyaline cartilage is particularly unique, where it is divided into zones that vary by fibre and cell orientation. The mechanical properties of cartilage are vital to its function yet are not accurately mimicked by existing tissue engineering techniques. Moreover, it has been shown that electrical stimulation of chondrocytes can be beneficial to their growth. Additionally, Raman spectroscopy was used as a tool to determine and monitor the production of cartilage components and to confirm chondrocyte phenotype, a method that is still being developed for this use.
description: This work concluded that significant alterations to scaffold design at a nano-, micro-, and macro-scale alters cell growth and behaviour; a substantial increase in nano- and micro-level roughness by the addition of spray deposited CNTs led to an improvement in cell proliferation; the introduction of anisotropic micro-sized features by the use of textured PDMS scaffolds controlled the directional growth of chondrocytes. The addition of randomly deposited CNTs negated this alignment, showing that chondrocytes take preferential cues at the nanoscale. Raman spectroscopy was successfully used to identify the deposition of key cartilage components such as collagen and glycosaminoglycans, indicating that chondrocyte culture on the produced scaffolds facilitates the production of cartilage. Raman spectra also provided evidence of the presence of aggrecan, suggesting the preservation of an appropriate chondrocyte phenotype. The alignment of collagen fibres was detected using polarised Raman spectroscopy, showing that textured PDMS scaffolds allow control of collagen fibre alignment, as well as chondrocyte alignment, providing more complete biomimicry of the superficial zone of cartilage.
description: Outlined is the successful design and fabrication of smart synthetic scaffolds with highly tunable physical, mechanical and electrical cues, aiding in the understanding and control of cell proliferation and phenotype preservation. Utilising CNTs as tools allowed control of physical parameters at different length scales. The results presented here help gain an improved understanding of chondrocyte behaviour, providing fundamental knowledge to the field of cartilage tissue engineering."