Multiscale regeneration scaffold in vitro and in vivo.

Biocompatible scaffolds play an important role in modulating tissue growth. A gelatin and sodium alginate scaffold with a unique structure produced by a combination of 3-D printing, electrospinning, and vacuum freeze-drying has been developed for tissue engineering. The scaffold is composed of a macrostructure, a honeycomb microporous surface morphology, and nanofibers. This structure meets the design criteria for an ideal tissue engineering scaffold. The scaffold degrades and has low cytotoxicity. The biocompatibility of the scaffold is improved by the favorable cell-matrix interaction; cells attach to the scaffold well and secrete large amounts of extracellular matrix in vitro. Rats with the scaffold implanted survived without signs of complications and the host cells infiltrated the interior of the scaffold. After 2 months in vivo, the scaffold was vascularized and contained collagen fibers. This multiscale regeneration scaffold may be suitable for tissue engineering because of its unique structure, degradation, mechanical properties, and lower cytotoxicity, which support cell infiltration and growth, and promote vascularization and generation of granulation tissue in vivo. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1218-1225, 2018.