Simple application of adipose-derived stem cell-derived extracellular vesicles coating enhances cytocompatibility and osteoinductivity of titanium implant.

Surface modification using bioactive molecules is frequently performed to improve the biological properties of medical metal biomaterial titanium (Ti) implants. Developmental evidence suggests that mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) served as potent bioactive component. As a subset of MSC-EV, adipose-derived stem cell-derived extracellular vesicles (ADSC-EVs) could be obtained from abundant adipose tissue. Meanwhile, it possesses multiple regenerative properties and might be used to endow biological activities to medical Ti implant. Here, we present a simple ADSC-EV coating strategy based on physisorption of fibronectin. This ADSC-EV functionalized Ti implants (EV-Ti) revealed enhanced osteoblast compatibility and osteoinductive activity. Cell spreading area of EV-Ti group was 1.62- and 1.48-fold larger than that of Ti group after 6 and 12 h of cell seeding, respectively. Moreover, EV-Ti promoted alkaline phosphatase, collagen 1 and osteocalcin gene expression in osteoblast by 1.51-, 1.68- and 1.82-fold compared with pristine Ti, respectively. Thus, the MSC-EVs modification method reported here provide a clinically translatable strategy to promote the bioactivity of Ti implants.