Restricted oxygen diffusion can result in central cell necrosis in engineered tissue, a problem
that is exacerbated when engineering large tissue constructs for clinical application.
Here we show that pre-treating human mesenchymal stem cells (hMSCs) with synthetic
membrane-active myoglobin-polymer–surfactant complexes can provide a reservoir of
oxygen capable of alleviating necrosis at the centre of hyaline cartilage. This is achieved
through the development of a new cell functionalization methodology based on
polymer–surfactant conjugation, which allows the delivery of functional proteins to the hMSC
membrane. This new approach circumvents the need for cell surface engineering using
protein chimerization or genetic transfection, and we demonstrate that the surface-modified
hMSCs retain their ability to proliferate and to undergo multilineage differentiation. The
functionalization technology is facile, versatile and non-disruptive, and in addition to tissue
oxygenation, it should have far-reaching application in a host of tissue engineering and
cell-based therapies.