094 Electrospun Collagen in Dermal Regeneration

Electrospinning is a nonmechanical processing strategy that is used to fabricate tissue‐engineering scaffolds composed of submicron diameter, banded fibrils of collagen. In biocompatibility tests these fibers are nonimmunogenic. Fiber diameter can be manipulated over a wide range by regulating the concentration of collagen present in the starting electrospinning solutions. Table 1 illustrates average fiber diameters and pore dimensions achieved under different conditions.Collagen Concentration Fiber Diameter Pore Area40 mgs/ml TFE    113 ± 51 nm     184 ± 87.6 nm 260 mgs/ml TFE    304 ± 120 nm  1,311 ± 384 nm 280 mgs/ml TFE    761 ± 276 nm  4,913 ± 3978 nm 2100 mgs/ml TFE    745 ± 314 nm  5,039 ± 2947 nm 2120 mgs/ml TFE 1,534 ± 448 nm 19,154 ± 20809 nm 2We prepared four 1 cm 2 full thickness dermal injuries on the dorsum of the guinea pig. Electrospun scaffolds composed of different fiber diameters were cut to fit the defects, sutured in place and then recovered at 7 and 14 days. Injuries treated with scaffolds composed of electrospun collagen fibers greater than 300 nm in diameter exhibited extensive tongue formation, dense dermal cell infiltration and functional capillary beds. Dermal regeneration was substantially complete by 14 days. Scaffolds prepared with individual fiber diameters of less than 300 nm were well epithelialized but, less densely "populated by dermal fibroblasts and capillaries. Fibrils of electrospun gelatin, a collagen isolate that is heat denatured prior to electrospinning, lack the banded appearance of electrospun collagen. Scaffolds of electrospun gelatin were less densely infiltrated than electrospun collagen at all fiber diameters and pore dimensions, and induced inflammation. We conclude that banded fibrils of electrospun collagen have unique biological activity. Funded in part NIH R01 EB003087. US & International Patents Issued and Pending .