Facile fabrication of cellulose membrane containing polyiodides and its antibacterial properties

Iodine exhibits a broad antibacterial spectrum, low toxicity, high efficiency and no drug resistance. However, free iodine is unstable and has strong irritation on wounds if applied directly. Hence, a carrier improving the stability of iodine is required. In this study, a branched polyethylenimine (PEI) was employed as an iodine carrier. It was firstly fixed to dialdehyde cellulose membrane (DCM) via Schiff-base reaction. Then the PEI-DCM was immersed in an I-2-KI aqueous solution to prepare a novel antibacterial cellulose membrane containing polyiodides (I-PEI-DCM). Its structure and properties were characterized by SEM, EDX, XPS, Raman, ATR-FTIR, XRD and antibacterial activity. Results demonstrated that the iodine loaded on the I-PEI-DCM was the mixture of I-3(-) and I-5(-), whose distribution on the membrane was uniform. During the iodination treatment, the amino groups of PEI molecular chains participated in the complex reaction with polyiodide ions. The microbiological tests showed that the I-PEI-DCM had excellent antibacterial activity against both E. coli and S. aureus. It can completely inactivate all of two bacteria within 0.5 min even after 30-day storage. Meanwhile, the antibacterial membrane exhibited good stability and reusability. Based on the characteristic features, the I-PEI-DCM can be regarded as a promising wound dressing.