There is a significant need to understand the complexity and heterogeneity of articular cartilage to develop more effective therapeutic strategies for diseases such as osteoarthritis. Designing an appropriate scaffold for cartilage tissue engineering will allow insights into cartilage growth, studying the influence of external stimuli on cellular response and provide a platform for potential therapies. Here we show that carbon nanotubes (CNTs) are excellent candidates as a material for fully synthetic scaffolds to support the growth of chondrocytes – the cells that produce and maintain articular cartilage. Cartilage is made up of chondrocytes and their extra-cellular matrix (ECM), which is comprised of proteins and polysaccharides of a very distinctive nanoscale structure. The structure of articular cartilage is further complicated at the macroscale, as the organisation of cells and biomolecules varies throughout cartilage. Its structure is therefore described by different zones, where each zone has a different arrangement of cells and proteins. These complexities are rarely considered when designing scaffolds for cartilage. Chondrocyte morphology, proliferation and alignment were investigated as nanoscale CNT networks were applied to macroscopically textured polydimethylsiloxane (PDMS) scaffolds. The application of CNTs to the surface of PDMS-based scaffolds resulted in a significant increase in cell adherence and proliferation. The introduction of macroscale features to PDMS induced alignment of chondrocytes, successfully mimicking the superficial layer of cartilage. Raman spectroscopy was used as a non-invasive, label-free method to monitor extra-cellular matrix production and chondrocyte phenotype. Chondrocytes on these scaffolds successfully produced collagen, glycosaminoglycan and aggrecan. This study demonstrates that the introduction of physical features at different length scales allows for high level of control over tissue scaffold design and, as a result, cell behaviour. Ultimately, these textured scaffolds can serve as platforms to improve understanding of osteoarthritis and for potential therapeutic testing. Having more reliable early-stage testing will reduce late-stage attrition of drug candidates and therapies.

Nano- to macroscale biomimicry of articular cartilage using carbon nanotube-coated and textured polydimethylsiloxane tissue scaffolds

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.