Novel electrospun silk biomaterial systems: An alternative approach to wound dressings using resorbable biomaterials for potential delivery of antibiotics, immuno-peptides, and tissue regeneration biotherapies.

摘要

Exploring medical device engineering, biomaterial characterization and biological assays, unique electrospun silk materials were evaluated for potential utility as an ideal skin substitute for patients with full-thickness burn wounds.;Innovative electrospinning techniques were investigated to facilitate the production of large research grade electrospun silk materials for experimental applications related to wound dressings. Electrostatic field gradients generated at alternative equipotential node points on a modified potential plate were shown to stably displace and orient a spinning fiber beyond the field of liquid polymer spray inherent in the electrospinning process. Placing a rotating fiber collection ground plate directly in the path of the displaced fiber established the ability to create large experimental grade non-woven silk materials for wound dressing bio-functional assessments. Additionally, the symmetrical fiber displacement signature around the modified potential plate enabled concurrent multi-spinning with one commercial apparatus.;Six distinct electrospun silk material groups were evaluated to assess the conformational and bio-functional properties related to wound dressings. In a hydrated state, all six materials groups exhibited absorption, water vapor transmission, oxygen permeation and enzymatic biodegradation traits suitable for full-thickness wound sites. Employing constrained drying techniques, silk concentration was a determinate factor influencing the material structural properties related to the storage and distribution of such wound dressing systems. Exhibiting an affinity for cell implantation, adhesion, and proliferation, three electrospun silk models demonstrated ideal biomaterial properties for resorbable bandage applications with potential to deliver antibiotic, immuno-peptide, and tissue regeneration biotherapies.;Effect of hydration on silk fibroin was explored with water-annealed and MeOH treated silk films. After hydration, MeOH immersed films displayed a 2-fold increase in absorption compared with water-annealed samples. 02 permeability for water-annealed films were stable and linear with transmission rates averaging 4096 +/- 47 cm3·m-2·day -1 while MeOH treated films exhibited rising permeation rates from of 3701 cm3·m-2·day-1 over 2 h to over 8000 cm3·m-2·day -1 over 7 h. FTIR analysis revealed that -prior to and after hydrated oxygen permeation analysis, water-annealed samples had an increased beta-sheet content with water vapor exposure while MeOH immersed films remained unchanged. Through hydration and O2 permeation analysis, it was determined that highly crystalline MeOH treated silk films exhibit a less ordered secondary structure arrangement compared to a less crystalline, yet more densely packed water-annealed films.