Understanding the physical and mechanical properties of hybrid keratin hydrogels

• Main Author: Seah, Adelene Wei Hui
• Other Authors: School of Materials Science and Engineering
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Materials::Biomaterials
• Online Access: http://hdl.handle.net/10356/59759
• Institution: Nanyang Technological University

Keratin, a fibrous structural protein, is a bioactive and readily available material that is gaining popularity for biomedical applications. Hence, thriving on the advantages, keratin in the form of hydrogels was investigated in this study. Specifically, keratin was blended with gellan gum and chitosan to produce novel hybrid gels and characterized. Keratin-gellan gum hydrogels were found to possess higher stiffness with higher concentration of keratin up to a maximum weight percentage of 10mg in 1.5% gellan gum sample. This was probably attributed to spontaneous physical crosslinking by hydrogen bonding between keratin and gellan gum. Degradation temperature of keratin-gellan gum hydrogels were found from TGA results to be at the range of around 70-94oC. For FTIR spectra of all samples with the exception of 1.5% gellan gum with 20mg of keratin, two significant distinct peaks with one ranged 3430-3448cm-1 corresponding to O-H bond and another at approximately 1634cm-1 corresponding to COO- bonds characteristic of gellan gum was observed. From the SEM images, it was observed that as the concentration of keratin increased in 1.5% gellan gum samples, the pores in the microstructure became smaller. Similarly, as the concentration of keratin was increased in the mixture, the density of the fibers was increased as well. Chitosan was a cationic polysaccharide and it was mixed with anionic keratin to form a polyelectrolyte complex through electrostatic interaction. Upon sample preparation and incubation at 37oC, it was found that those with 75% and higher weight percentage of keratin did not gel after several hours and was omitted from the rheological tests. For the rest of the keratin-chitosan samples, it was found that the higher the weight percentage of keratin relative to chitosan, the higher the storage and loss modulus. Further studies for both the keratin-gellan gum and keratin-chitosan hydrogels should be made to validate the findings in this study.