Evaluation of antibacterial and anticancer properties of poly(3-hydroxybutyrate) functionalized with different amino compounds

The chemical modification of biodegradable poly(3-hydroxybutyrate) (PHB) is useful for biomedical applications. In this study, the transesterification reaction of PHB was carried out under reflux conditions in the presence of 1,4-butanediol to form telechelic PHB-diol. Further modification of PHB-diol into PHB-diacrylate was carried out by the reaction of PHB-diol with acryloyl chloride. PHB-diacrylate was grafted with amino compounds such as 1,4-butanediamine, 1,3-propanediamine, 1,2-ethylenediamine, piperazine, cyclohexylamine, 2,2'-(ethane-1,2-diylbis(oxy)) diethanamine (jeffamine EDR 148) and morpholine via Michael-type addition reaction. The functionalized amino-PHB polymers were characterized by using FTIR and 1H NMR techniques. XRD showed that amino-PHB polymers have different crystallinity compared with neat PHB. Some biological activities of amino-PHB polymers were determined such as antibacterial, antioxidant and anticancer activities. In this regard, the results showed that PHB-ethylenediamine revealed a potent antibacterial activity against Staphlococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. All amino-PHB polymers under the study showed reasonable antioxidant activity. Among these polymers, PHB-piperazine showed a potent anticancer effect against in vivo Ehrlich ascetic carcinoma bearing mice.