Preparation of Porous Biodegradable Polymer and Its Nanocomposites by Supercritical CO₂ Foaming for Tissue Engineering

Figure 3

SEM microphotographs of CO₂-foamed PLLA samples saturated at 25^oC and 5.5 MPa for 5 min and foamed at (a₁) 70^oC, ×50; (a₂) 70^oC, skin ×2000; (a₃) 70^oC, skin ×20000; (b₁) 80^oC, ×50; (b₂) 80^oC, skin ×2000; (b₃) 80^oC, skin ×20000; (c₁) 90^oC, ×50; (c₂) 90^oC, skin ×2000; (c₃) 90^oC, skin ×20000. (From [17]. Copyright (2006) with permission from American Chemical Society.)

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