Figure 4.

Biomanufacturing: incorporation of growth factor. To demonstrate further applicability for biofabrication, the incorporation and release of growth factors such as insulin-like growth factor 1 (IGF-1) is evaluated in green vs. traditional electrospinning. (a) No significant difference in fiber morphology, diameter (n = 50 fibers/group) or surface energy (n = 5) is seen between methods. (b) Significantly greater IGF-1 incorporation is found with green electrospinning (n = 5, ^p < 0.05). After an initially higher IGF-1 burst release, a comparable amount of the factor release was measured over 3 weeks (n = 5, ^p < 0.05 between groups, *p < 0.05 over time). (c) Circular dichroism (CD) analysis reveals that the secondary structure of BSA, which protects IGF-1 during the electrospinning process, is better preserved with green electrospinning. Compared to acetic acid or deionized water, harsh solvents such as DMF/DCM deteriorate the α helical content of BSA (222 nm, n = 3, ^p < 0.05).