BMEBT Seminar & Thesis Proposal Defense by Abdulrahman Kehail
When: Thursday,
September 24, 2015
12:00 PM
-
1:00 PM
Where: Textiles Building 101E
Description: TOPIC:Production and degradation of microbial synthesized poly (hydroxybutyrate-co- hydroxyhexanoate) polymer: impact on mechanical stability and medical applications
ABSCRACT: The copolymer poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(HB-co-HHx)], is produced by engineered Ralstonia eutropha strains using lipids and fatty acids as carbon feedstocks. The presence of the 3-hydroxyhexanoate (HHx) monomer disrupts the packing of polymer chains, resulting in less numerous polymer crystals and producing a polymer with favorable thermal and mechanical properties. In this study, copolymers varying in HHx content will be recovered from different R. eutropha strains. Tensile constitutive response of solvent-cast samples of PHB and P(HB-co-17mol%HHx), P(HB-co-23mol%HHx), and P(HB-co-30mol%HHx) will be investigated using a custom-built micro-tensile tester. Our preliminary results show that presence and quantity of HHx monomer has a noticeable impact on P(HB-co-HHx) mechanical properties, such as tensile strength, elongation at break, toughness and thermal properties. It was found that with higher content of HHx in the material, the more flexible and tougher the polymer is, and the greater the reduction of Tm and crystallinity.
The challenges associated with using biodegradable, bio-based polymers in resorbable medical devices are; the monitoring of mechanical properties over the course of degradation, and correlation of mechanical properties with application, therefore, the degradation kinetics and crystallization dynamics of the P(HB-co-HHx) polymer in vivo (zebra fish) and in vitro will be investigated by applying tensile testing, indentation, and scanning electron microscopy.
A biodegradable PHA-based anti-biofilm material will be designed by preparing the sheets via solvent-casting and electro-spinning, and immobilizing the antibiotic lysozyme on the membrane, then evaluate its properties against a gram-positive bacteria, such as Rhodococcus, Bacillus, and Clostridium.
By this work, four copolymers will be prepared with different HHx content in order to test its mechanical and thermal properties to have a better understanding between the medical device material and the HHx content. Also, the correlation between the mechanical properties and in vivo and in vitro degradation will be found by implanting PHA in zebrafish and placing it on cell culture plates, and then perform mechanical testing. Moreover, PHA sheets will be prepared to act as an anti-biofilm and load them with antibiotics to prevent and/or cure biofilms that develops in a wounded area.
ABSCRACT: The copolymer poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(HB-co-HHx)], is produced by engineered Ralstonia eutropha strains using lipids and fatty acids as carbon feedstocks. The presence of the 3-hydroxyhexanoate (HHx) monomer disrupts the packing of polymer chains, resulting in less numerous polymer crystals and producing a polymer with favorable thermal and mechanical properties. In this study, copolymers varying in HHx content will be recovered from different R. eutropha strains. Tensile constitutive response of solvent-cast samples of PHB and P(HB-co-17mol%HHx), P(HB-co-23mol%HHx), and P(HB-co-30mol%HHx) will be investigated using a custom-built micro-tensile tester. Our preliminary results show that presence and quantity of HHx monomer has a noticeable impact on P(HB-co-HHx) mechanical properties, such as tensile strength, elongation at break, toughness and thermal properties. It was found that with higher content of HHx in the material, the more flexible and tougher the polymer is, and the greater the reduction of Tm and crystallinity.
The challenges associated with using biodegradable, bio-based polymers in resorbable medical devices are; the monitoring of mechanical properties over the course of degradation, and correlation of mechanical properties with application, therefore, the degradation kinetics and crystallization dynamics of the P(HB-co-HHx) polymer in vivo (zebra fish) and in vitro will be investigated by applying tensile testing, indentation, and scanning electron microscopy.
A biodegradable PHA-based anti-biofilm material will be designed by preparing the sheets via solvent-casting and electro-spinning, and immobilizing the antibiotic lysozyme on the membrane, then evaluate its properties against a gram-positive bacteria, such as Rhodococcus, Bacillus, and Clostridium.
By this work, four copolymers will be prepared with different HHx content in order to test its mechanical and thermal properties to have a better understanding between the medical device material and the HHx content. Also, the correlation between the mechanical properties and in vivo and in vitro degradation will be found by implanting PHA in zebrafish and placing it on cell culture plates, and then perform mechanical testing. Moreover, PHA sheets will be prepared to act as an anti-biofilm and load them with antibiotics to prevent and/or cure biofilms that develops in a wounded area.
Contact: BMEBT Seminar Series
Topical Areas: University Community, Biology, Bioengineering, College of Engineering