Porous gradient scaffold for bone repair and preparation method

The invention provides a porous gradient scaffold for bone repair and a preparation method. The porous gradient scaffold comprises an inner-layer scaffold structure and at least one outer-layer scaffold structure, and the inner-layer scaffold structure and the outer-layer scaffold structure are respectively formed by arraying a plurality of structural units along a length dimension, a width dimension and a height dimension; the inner-layer scaffold structure is of a columnar porous structure, the outer-layer scaffold structure is of a hollow columnar porous structure, the inner-layer scaffoldstructure is arranged at the hollow position of the middle of the outer-layer scaffold structure, and the relative density of the porous gradient scaffold changes in a gradient mode from the inner-layer scaffold structure to the outer-layer scaffold structure; and the structure units in the inner-layer scaffold structure and the structure units in the outer-layer scaffold structure are the same inconnecting structure and different in relative density. According to the porous gradient scaffold, the relative density is designed to change in a gradient manner, so that a gradient structure with dense outside and sparse inside is formed, and the porous gradient scaffold has target mechanical properties and biological properties.