Date of Completion


Embargo Period



Skeletal muscle regeneration, Electroconductive matrices, rotator cuff injury, muscle atrophy

Major Advisor

Cato T. Laurencin

Associate Advisor

Yusuf Khan

Associate Advisor

Lakshmi Nair

Associate Advisor

Tai-His Fan

Associate Advisor

Harold Brody

Field of Study

Materials Science and Engineering


Doctor of Philosophy

Open Access

Open Access


The treatment of rotator cuff tears of the shoulder is one the most common and challenging orthopedic problems. Tendon tears not only lead to pain but can also cause tendon thinning and retraction, fatty expansion and muscle atrophy. This subsequently can result in loss of shoulder stability and function. Clinically, surgical repair of tendons is performed to restore the connection between bone, tendon, and muscle. However, even after surgical repair, compromised tendon healing can be observed mainly due to fatty expansion into adjacent muscles. Preventing adjacent muscle degeneration and addressing fatty expansion is therefore critical to achieving favorable clinical outcomes after tendon repair.

Among different approaches, the application of electrical cues has shown to promote muscle functional regeneration. The goal of this study was to engineer novel electrically conducting polymer matrices, which could help to retain muscle quality and enhance muscle regeneration after rotator cuff repair. Matrices were prepared by coating different concentrations of poly (3,4ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT: PSS) (1%, 10%, 33%, 100%) on polycaprolactone (PCL) electrospun nanofiber matrices. The electrical conductivity, biocompatibility and the ability of the matrices to support muscle cell adhesion, proliferation and differentiation were studied using in vitro techniques. In vivo studies using rat rotator cuff acute and chronic repair models found that aligned electroconductive muscle matrices could guide and stimulate muscle regeneration, thereby suppressing fatty expansion.

In summary, the study examined the feasibility of novel electroconducitve matrices to achieve high levels of muscle regeneration in the setting of rotator cuff tears.