Tissue engineering involves fabrication of three-dimensional scaffolds to support cellular in-growth and proliferation. The goal: generation of 'neotissues' that the body can adapt to carry out physiological function. To achieve this generation of scaffolds having tailored, biomimetic (across multiple scales) geometries has become important. The functional complexity of electrospun scaffolds provides significant advantages over other techniques; however, improvements are required before optimal utilization in vivo becomes routine. Cells on such surfaces are sensitive to topography. Electrospinning can be altered to influence either (1) the surface topography of the fibers themselves or (2) the larger topography of the 'web' of spun fibers. Improved deposition efficiencies are a necessary advance needed to maintain the attractiveness of this technique. While the role of residual solvent in the electrospun polymer remains unclear, high pressure CO, can be used to enhance chemical functionality while maintaining polymer morphology. Electrospun pore sizes, as spun, are typically too small for cells to pass through. Post-processing of these scaffolds to improve internal proliferation is expected to yield considerable benefits as tissue engineering matures as a subdiscipline and the limits of the basic electrospinning process are more widely realized. (c) 2006 Elsevier B.V. All rights reserved.