Dissertation
Collagen nanoyarns: hierarchical three-dimensional biomaterial constructs for tendon fiber reconstruction
Doctor of Philosophy (Ph.D.), Drexel University
Dec 2022
DOI:
https://doi.org/10.17918/00001424
Abstract
Rotator cuff tendon (RCT) disorders are noteworthy because of their preponderance in the elderly, and the high surgical failure rates in cases presenting with massive tears. Surgical strategies include the augmentation of the repair site mechanically by various graft materials. However, challenges such as immune rejection, donor site morbidity, poor cell adhesion and induced chronic inflammation among others still exist, hence the need for biomaterial-based scaffold replacements which mimic the extracellular matrix (ECM) architecture. Hierarchical fibrous scaffolds (HFS) consist of nanoscale fibers arranged in larger macroscale structures, much in the same pattern as in native tissue such as tendon and bone. Creation of continuous macroscale nanofiber yarns has been made possible using modified electrospinning set-ups that combine electrospinning with techniques such as twisting, drawing, and winding. In this work, a modified electrospinning set-up was used to successfully create continuous type I collagen nanofiber yarns (CNY). Structural denaturation assessment of native collagen using circular dichroism (CD) spectroscopy showed that 60% of the triple-helical collagen content in CNYs was preserved. Crosslinking of CNYs significantly improved their mechanical properties as well as stability in buffered saline with no sign of degradation for 14 days. To tune the porosity of CNY scaffolds, a sacrificial nanofiber removal process was executed by spinning PEO-CNY composites from which PEO nanofiber component was dissolved out to create pores. HeLa cells and 3T3 fibroblasts cultured on porosity-tuned CNY (PT-CNY) showed improved cell adhesion, infiltration, and viability, with cells displaying the characteristic spindle-like morphology of cells grown on surfaces with aligned topography. Collectively, the results demonstrate the promising potential of collagen nanoyarns as a new class of shapable biomaterial scaffold and building block for generating macroscale fiber-based tissues.
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Details
- Title
- Collagen nanoyarns
- Creators
- Chukwuemeka Wisdom Chikelu
- Contributors
- Caroline L. Schauer (Advisor)Lin Han (Advisor)
- Awarding Institution
- Drexel University
- Degree Awarded
- Doctor of Philosophy (Ph.D.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- xv, 106 pages
- Resource Type
- Dissertation
- Language
- English
- Academic Unit
- School of Biomedical Engineering, Science, and Health Systems (1997-2026); Drexel University
- Other Identifier
- 991020041414504721