Synthesis of E-caprolactone based antimicrobial biodegradable scaffolds

• Main Author: Mamba, Feziwe Bathabile
• Other Authors: Gule, Nonjabulo Prudence, Klumperman, Bert, Pfukwa, Rueben, Stellenbosch University. Faculty of Science. Dept. of Chemistry and Polymer Science.
• Format: Thesis
• Language: English
• Published: Stellenbosch : Stellenbosch University 2019
• Subjects: UCTD; Polycaprolactone; Nanofibers > Membranes (Biology); Antarc*; Antarctica
• Online Access: http://hdl.handle.net/10019.1/107090

Thesis (MSc)--Stellenbosch University, 2019. ENGLISH ABSTRACT: Antimicrobial and biodegradable fibers are essential in medical applications, especially those in direct contact with the skin like wound dressings. It is ideal to have wound dressings that can eliminate microbes from the wound bed and be biodegradable. The use of biocompatible and biodegradable polymers in production of wound dressings will lead to a novel approach. Some biodegradable and biocompatible polymers such as polycaprolactone, poly (lactic acid), poly (lactic-co-glycolic acid) have been approved by the Food and Drug Administration for wound dressings, tissue engineering, drug delivery, etc. In this study, polycaprolactone was synthesized and antimicrobial agents were attached to the polymer backbone. The polymerization of caprolactone was first optimized via ring opening polymerization using tin(II) 2-ethylhexanoate (Sn(Oct2)) or Candida antarctica lipase. After the optimization, poly(ε-caprolactone-co-γ-amino-ε-caprolactone) (poly(CL-co-ACL)) was successfully synthesized. This was achieved in three steps: synthesis of γ-(carbamic acid benzyl ester)-ε-caprolactone (γ-CABεCL); copolymerisation of the γ-CABεCL and ε-caprolactone, via ring-opening polymerization (ROP) using Sn(Oct2) as a catalyst and water as initiator; and finally, deprotection via acidolysis. The structures of the monomers and polymers/copolymers were confirmed by 1H-NMR, 13C-NMR, and ATR-FTIR spectroscopy. The molecular weight and molar mass dispersity of the polymer was determined using GPC. To induce antimicrobial properties to poly(CL-co-ACL), it was modified by grafting polylysine or quaternization of the pendant amine functional groups. Caprolactone-based scaffolds were fabricated by electrospinning and they were characterized by SEM. The antimicrobial nanofibers were further characterized by zone inhibition assay. The polymers showed antimicrobial activity against both Staphylococcus aureus and Pseudomonas aeruginosa after 24 h of incubation. Biodegradation studies ...