Synthesis And Characterization Of Multifunctional Biocompatible Nanofibrous Membranes Based On Sodium Carboxymethyl Cellulose And Chitosan

Multifunctional nanofibrous membranes have drawn tremendous attention in many fileds such as tumor therapy, drug delivery and releasing, cell imaging et al because of their superparamagnetic, fluorescence, and nano-scale properties. In this paper, through an electrospinning process, we fabricated multifunctional nanofibrous membranes, using chitosan and sodium carboxymethylcellulose seperately as substrate, with some magnetic nanoparticles（NPs） or fluorescent NPs or anbacterial Ag NPs added. The results showed as follows:1) Superparamagnetic and fluorescence bifunctional nanofibrous membranesSuperparamagnetic nanofibrous membranes（NFMs） and fluorescent NFMs were fabricated by electrospinning by adding superparamagnetic Fe₃O₄ NPs and fluorescent CDs NPs into the CS/PEO blend solution separately and together. We found that: 1) for the superparamagnetic NFMs, the saturation magnetization of the membranes increased linearly with increasing the content of Fe₃O₄ NPs. The max saturation magnification（8.63emu/g） was obtained when the content of Fe₃O₄ was 16%. The absorbing test indicated that this kind of NFMs had a certain wave absorption performance; 2) but for the fluorescent membranes, the fluorescence intensity decreased as CDs content increased; 3) we studied the mutual effect of magnetic and fluorescent property and found that addition of CDs almost had no effect on magnetic properties, but the addition of Fe₃O₄ decreased fluorescence intensity. NFMs with optimum magnetic and fluorescent properties was obtained when Fe₃O₄ and CDs contents were 8% and 8%（w/w） separately. The antibacterial tests showed that the sterilization rate of this as-prepared CS/PEO/Fe₃O₄/CDs NFMs was22.7%.2) CMC/Ag Fluorescent antibacterial nanofibrous membranesWe fabricated nanofibrous membranes containing Ag NPs by two different methods. In the first method, AgNO3 was dissolved in the blend solution of CMC and PEO, and then Ag+were reduced to Ag NPs by natural light when CMC/PEO/Ag NO3 solution was electrospun, with CMC served as reductant and stabilizer here. It’s found that fluorescence of as-prepared NFMs was 50 and the sterilization rate was 27.4%, with Ag NPs of an average size of 4.5 nm evenly distributed on the nanofibers.In the second method, electrospinning was carried out on CMC/PEO solution, thenCMC/PEO fibers were immersed into the AgNO3 sulution to substitute Na+ with Ag+,followed by exposing the membranes to the UV-light for a certain time to obtain the membranes with Ag NPs on the surface. This kind of membranes has three characteristics:1) Ag NPs was distributed on the surface and in the network of the fibers; 2) the diameter of Ag NPs increases with the extension of exposure time; 3) PEO was dissolved in the emersing process, and NFMs composed of pure natural organics and Ag NPs was obtained.Fluorescence intensity of as-prepared NFMs was 20 and sterilization rate was 97.1%.