College
College of Engineering
Mentor Information
Neda Latifi Alavijeh
Description
Cardiovascular disease remains a major cause of morbidity and mortality, often requiring surgical repair or replacement of damaged tissues. Current cardiovascular substitutes, including synthetic grafts, mechanical valve replacements, and biologically derived tissues, have improved patient outcomes but still face limitations such as thrombosis risk, limited remodeling capacity, mechanical mismatch, and durability concerns. Cardiovascular tissue engineering seeks to address these challenges by developing biomimetic scaffolds that support cell attachment, extracellular matrix synthesis, tissue integration, and in vivo adaptation. Silk fibroin is a promising natural biomaterial because of its biocompatibility, tunable degradation, favorable mechanical properties, and anti-inflammatory potential; however, its low solution viscosity makes electrospinning difficult without an electrospinning-inducing polymer. This study investigates silk fibroin–polyethylene oxide (PEO) blend ratios for fabricating electrospun nanofibrous scaffolds. We first evaluated electrospinning parameters using an 8% aqueous silk solution. To improve jet stability and fiber homogeneity, silk was then blended with PEO at Silk:PEO ratios of 1:1, 2:1, 3:1, 4:1, and 5:1. We found that temperature, mixing speed, and mixing duration strongly affected solution homogeneity. Mixing for less than one hour produced nonhomogeneous solutions and frequent nozzle clogging, while higher temperature, faster mixing, or prolonged mixing promoted beta-sheet formation and impaired fiber formation. Scanning electron microscopy showed that Silk:PEO ratios of 1:1, 2:1, and 3:1 produced smooth, homogeneous nanofibers, whereas higher silk content resulted in beads and fibers due to reduced viscosity and insufficient chain entanglement. Ongoing work focuses on crosslinking strategies to stabilize silk fibers in water and further characterize scaffold morphology and mechanics.
Optimizing Silk Fibroin–Polyethylene Oxide Polymer Blends for Electrospun Nanofibrous Scaffold Fabrication
Cardiovascular disease remains a major cause of morbidity and mortality, often requiring surgical repair or replacement of damaged tissues. Current cardiovascular substitutes, including synthetic grafts, mechanical valve replacements, and biologically derived tissues, have improved patient outcomes but still face limitations such as thrombosis risk, limited remodeling capacity, mechanical mismatch, and durability concerns. Cardiovascular tissue engineering seeks to address these challenges by developing biomimetic scaffolds that support cell attachment, extracellular matrix synthesis, tissue integration, and in vivo adaptation. Silk fibroin is a promising natural biomaterial because of its biocompatibility, tunable degradation, favorable mechanical properties, and anti-inflammatory potential; however, its low solution viscosity makes electrospinning difficult without an electrospinning-inducing polymer. This study investigates silk fibroin–polyethylene oxide (PEO) blend ratios for fabricating electrospun nanofibrous scaffolds. We first evaluated electrospinning parameters using an 8% aqueous silk solution. To improve jet stability and fiber homogeneity, silk was then blended with PEO at Silk:PEO ratios of 1:1, 2:1, 3:1, 4:1, and 5:1. We found that temperature, mixing speed, and mixing duration strongly affected solution homogeneity. Mixing for less than one hour produced nonhomogeneous solutions and frequent nozzle clogging, while higher temperature, faster mixing, or prolonged mixing promoted beta-sheet formation and impaired fiber formation. Scanning electron microscopy showed that Silk:PEO ratios of 1:1, 2:1, and 3:1 produced smooth, homogeneous nanofibers, whereas higher silk content resulted in beads and fibers due to reduced viscosity and insufficient chain entanglement. Ongoing work focuses on crosslinking strategies to stabilize silk fibers in water and further characterize scaffold morphology and mechanics.
