Fabrication and characterization of bionylon-56 nanofiber membranes for antibacterial activity

Abstract

The continuous development of biomaterial polyamide 56 (PA56) and 512 (PA512) nanofiber membranes via electrospinning is synthesized by a green bioprocess in this study At first cadaverine was bioconversion from lysine through lysine decarboxylase (LdcC) in E coli The LdcC can achieve nearly 90% conversion to produce 92 g/L cadaverine from 1 M lysine and showed enzyme activity with wide pH range Then bio-polyamide 56 (i e PA56) and bio-polyamide 512 (i e PA512) were polymerized from cadaverine with adipic acid The bio-nylon 56 and 512 was further synthesized via melt polymerization The melting point and crystallization point for PA56 were 250oC and 220oC which were determined by differential scanning calorimetry (DSC) For PA512 the melting point and crystallization point were 206oC and 186oC respectively Whereas the thermogravimetric analysis (TGA) analyzes for degradation temperature were 421°C and 469oC for PA56 and PA512 respectively Afterwards PA56 and PA512 nanofiber membrane was prepared by electrospinning with polyethylene terephthalate (PET) acted as a supporting layer and further characterized by scanning electron microscopy (SEM) The Reactive Red 141 was directly reacted with amino group of PA56 and PA512 to form dyed membranes (P-Dye) and enhanced poly-(hexamethylene biguanide) (PHMB) grafting on PAM and achieved PHMB modified membranes (P-Dye-PHMB) The modified membranes were examined for the antibacterial activity against pathogens which showed the excellent activity against Escherichia coli and Pseudomonas putida for PA56 nanofiber membrane but no antibacterial effect for PA512 nanofiber membrane The results indicate that P-Dye-PHMB is a potential material for biomedical applications and functional textiles

Date of Award	2020
Original language	English
Supervisor	I-Son Ng (Supervisor)