Fabrication of polymeric scaffolds with a controlled distribution of pores

The design of tissue engineering scaffolds must take into account many factors including successful vascularisation and the growth of cells. Research has looked at refining scaffold architecture to promote more directed growth of tissues through well-defined anisotropy in the pore structure. In many cases it is also desirable to incorporate therapeutic ingredients, such as growth factors, into the scaffold so that their release occurs as the scaffold degrades. Therefore, scaffold fabrication techniques must be found to precisely control, not only the overall porosity of scaffolds, but also the pore size, shape and spatial distribution. This work describes the use of a regularly shaped porogen, sugar spheres, to manufacture polymeric scaffolds. Results show that pre-assembling the spheres created scaffolds with a constant porosity of 60%, but with varying pores sizes from 200-800 mu m, leading to a variation in the surface area and likely degradation rate of the scaffolds. Employing different polymer impregnation techniques tailored the number of pores present with a diameter of less than 100 mu m to suit different functions, and altering the packing structure of the sugar spheres created scaffolds with novel layered porosity. Replacing sugar spheres with sugar strands formed scaffolds with pores aligned in one direction. (C) 2005 Springer Science + Business Media, Inc.