Degenerative osteoarthritis poses considerable economic burden to the global healthcare system, attributed largely to challenges in biofabrication of human articular cartilage. Current musculoskeletal tissue engineering techniques, though more effective than self-repair induction techniques, comprise overly complex multi-stage procedures. One of the most feasible options for the delivery of bioscaffolds is through mesenchymal stem cells by the application of 3D bioprinting. However, effective translation of the biofabrication process to surgical settings is replete with challenges. A team of researchers that include surgeons from numerous institutes in Australia claimed to have overcome this problem by developing a handheld extrusion device called Biopen that can be successfully used for the biofabrication of human neocartilage.
The device is based on in situ additive manufacturing technique and was demonstrated to deposit cells that are embedded in a hydrogel material to generate bioscaffolds made of human adipose derived mesenchymal stem cells (hADSCs). Hydrogels used are gelatin methacrylate (GelMa) and hyaluronic acid methacrylate (HAMa) and were generated from an already established protocol in 2017.The researchers consider in situ biofabrication approach a breakthrough for potential clinical applications in cartilage repair in patients with cartilage injuries and osteoarthritis.
Formation of Hyaline-Like Cartilage Validated using Comprehensive Characterization
The handheld device could successfully reproduce human hyaline-like cartilage formation by coaxial extrusion of hADSC via hydrogels. The formation was validated using the cellular response to the chondrogenic stimuli by using an elaborate characterization, notably with the help of gene and protein expression analyses. They found that handheld co-axial bioprinting could preserve potential of the hADSC to proliferate adequately. The proof-of-principle pilot animal study was performed in vivo in a sheep model
Future Work to focus on expanding Delivery Potential of Hydrogels
The researchers are considering the viability of delivering osteogenic and chondrogenic growth factors by hydrogel injection. Studies will also aim at enhancing the biomechanical properties of chondrogenic bioscaffolds to resemble native articular cartilage. This will also call for understanding the property of architectured gelatin hydrogels.
The detailed of the biofabrication approach was published online in the journal Biofabrication on August 21, 2018.