Characterization and optimization of silk blend microstructure for use in tissue engineering applications

 

Abby W. Morgan, Matthew L. Becker, Carl G. Simon, Jr

Biomaterials Group, Polymers Division, National Institute of Standards and Technology, Gaithersburg , MD

 

Natural and synthetic silks are attractive materials for tissue engineering purposes due to their unique mechanical properties. Their elasticity and strength make them ideal candidates for use in synthetic bone, ligament, and cartilage applications. This work investigated different blends of silks to determine the optimal composition to support cell attachment and tissue in-growth. Two silks were studied: Bombyx mori derived silk (natural) and an engineered spider silk (synthetic). The synthetic silk includes an Arg-Gly-Asp (RGD) sequence known to encourage cell attachment. Blend compositions used were: 70:30, 50:50, and 30:70 natural: synthetic. Pure silks of each type served as controls. The silks were annealed at 70 ēC overnight in a humidified atmosphere to induce beta sheet formation. The blending of the natural and synthetic silks alters the extent of beta sheet formation, which in turn affects the crystallinity within the material.

The films were characterized through differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and contact angle for each blend and pure polymer. Results were compared to the unannealed silk to confirm beta sheet formation. Cellular response to the pure and blended (both annealed and unannealed) silks was then investigated through cell attachment, proliferation, and spreading.

 

 

 

Name:              Abby W. Morgan

Mentor:            Carl G. Simon, Jr

Division:           Polymers Division (854)

Laboratory:      Materials Science and Engineering Laboratory (MSEL)

Location:          Room B114, Bldg 224, MS 8543

Phone:              (301) 975-4954

Fax:                  (301) 975-4977

Email:               abby.morgan@nist.gov

Sigma Xi:          Not a member

Category:         Biology