Hydrogel-integrated 3D-printed poly(lactic acid) scaffolds for bone tissue engineering

There is currently a high demand for synthetic biodegradable scaffolds with enhanced osteogenic and angiogenic performance for the regeneration of large-size bone defects. Here, hybrid scaffolds were prepared by integrating either alginate or alginate-bioglass composite hydrogels with a 3D-printed poly(lactic acid) (PLA) porous structure. The as-deposited PLA scaffolds were surface treated with polyacrylic acid (PAA), which significantly enhanced the PLA scaffold's wettability. The surface-modified PLA scaffolds integrated well with hydrogels and provided shape and mechanical rigidity to the hydrogel. In phosphate-buffered saline, the lowest weight loss during 21-days immersion was measured for the PLA scaffold, while alginate-bioglass scaffolds lost similar to 1.9% weight during the first 7 days of immersion. In vitro cytocompatibility tests indicated good cell viability and cell proliferation on the scaffolds. The bioglass-containing hybrid scaffold promoted osteogenic differentiation and calcium mineralization. The excellent biocompatibility, good mechanical stability of the hydrogel, and shape retention of the novel hybrid scaffolds with cell-laden alginate could make them attractive for large bone regeneration