Establishing a cell-affinitive interface and spreading space in a 3D hydrogel by introduction of microcarriers and an...

Hydrogels hold great promise for tissue engineering and as cell delivery vehicles, but their application is greatly limited by the mass depletion of cells after encapsulation due to their low cell affinity and high cell constraints. In this study, using human osteoblast-like cells (MG63) as a model for anchorage-dependent cells (ADCs), alginate hydrogels incorporated with collagen microcarriers (MCs) and collagenase (GCE) were constructed to promote the cellular functional establishment. In this system, the cell-laden microcarriers as cellular 'anchors' provided a cell-affinitive interface between cells and hydrogels, while the collagenase promoted the degradation of collagen microspheres and thus provided adequate room for cell spreading and migration. Compared to the pure alginate hydrogel (Gel), the alginate hydrogel/microcarrier composite (GC) improved initial cell spreading by supplying a cell adhesive interface, while GCE with both microcarriers and collagenase exhibited much better cell spreading, proliferation and differentiation, which is attributed to the sustainable supply of both a cell adhesive interface and cell spreading room. The composites showed potential as an injectable vehicle for the conveyance of ADCs and tissue engineering.