Abstract
An osteoblast-laden nanocomposite hydrogel construct, based on polyethylene glycol diacrylate (PEGDA)/laponite XLG nanoclay ([Mg(5.34)Li(0.66)Si(8)O(20)(OH)(4)]Na(0.66, clay))/hyaluronic acid sodium salt (HA) bio-inks, is developed by a two-channel 3D bioprinting method. The novel biodegradable bio-ink A, comprised of a poly(ethylene glycol) (PEG)-clay nanocomposite crosslinked hydrogel, is used to facilitate 3D-bioprinting and enables the efficient delivery of oxygen and nutrients to growing cells. HA with encapsulated primary rat osteoblasts (ROBs) is applied as bio-ink B with a view to improving cell viability, distribution uniformity, and deposition efficiency. The cell-laden PEG-clay constructs not only encapsulated osteoblasts with more than 95% viability in the short term but also exhibited excellent osteogenic ability in the long term, due to the release of bioactive ions (magnesium ions, Mg(2+) and silicon ions, Si(4+)), which induces the suitable microenvironment to promote the differentiation of the loaded exogenous ROBs, both in vitro and in vivo. This 3D-bioprinting method holds much promise for bone tissue regeneration in terms of cell engraftment, survival, and ultimately long-term function.