Taking Advantage of Tailored Electrostatics and Complementary Hydrogen Bonding in the Design of Nanostructures for Biomedical Applications

Four-armed, star-shaped poly(D,L-lactide) (PDLLA) was synthesized and terminally-functionalized with either adenine or thymine complementary hydrogen bonding groups (PDLLA-A and PDLLA-T, respectively). The strong hydrogen bonding led to increased viscosity below the dissociation temperature of the hydrogen bonds. Rheology confirmed that these bonds were thermally reversible, with a sharp reduction in viscosity near 100 °C. PDLLA, PDLLA-A, and PDLLA-T were melt electro-spun with no significant change in fiber diameter (all between 3.6 and 4.0μm). However, a blend of PDLLA-A and PDLLA-T formed fibers with an average diameter of 9.8 ± 2.0 μm, resulting from the hydrogen bond associations. Also, the phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) was melt electro-spun at 200°C and formed uniform fibers with average fiber diameter of 6.5 ±2.0 μm.