Fabrication of poly(L-lactic acid) tissue engineering scaffolds with precisely controlled gradient structure

• PLLA tissue engineering scaffolds with gradient pore structures were fabricated.
• A thermally induced phase separation combining a precisely regulated sugar sphere template technique were used.
• The gradient scales may meet different requirements for different cells in multiple tissues.

To mimic the gradients across a spatial volume of native tissue, poly(L-lactic acid) (PLLA) scaffolds with physical gradient at the macroscale were designed and precisely fabricated for tissue engineering via a thermally induced phase separation (TIPS) method combining a modified sugar sphere template leaching technique. The gradient structure was investigated by scanning electron microscopy (SEM). The resulting scaffolds have a gradient macropore size (from 300 µm to 600 µm), porosity, as well as interconnectivity. The internal architectures can be well controlled by the gradient sugar sphere templates. The gradient scales in the scaffold may meet different requirements for different cells in multiple tissues.