The use of linear polyethylenimine nano-fibers in chemical warfare protective clothing and wound dressing applications

Linear polyethylenimine (L-PEI) nano-fibers were produced by electrospinning the polymer from a 25% (by weight (wt/wt)) ethanol solution. The fibers were small and uniform in diameter (<1μm), white, and insoluble in water. The strain and the tensile stress of the fiber mat were 86% ± 9 and 2.7 ± 0.2 MPa, respectively. The fibers of L-PEI were also cross-linked with 1,4-butanediol diglycidyl ether. The cross-linked fibers were achieved by adding (1 to 30% wt/wt) of the cross-linking agent to the spinning solution. Partially cross-linked fibers formed within twenty to thirty minutes. The cross-linked fibers were insoluble in all solvents. L-PEI fibers were further improved for use in two different areas, protective clothing and wound dressing applications.; To enhance the fiber's activity as protective clothing materials, L-PEI was spun with Cu(II) and/or branched polyethylenimine (B-PEI) with the cross-linking agent in ethanol solutions. In addition to the known competence of amines and Cu(II) in available nerve gas decontaminants, these fibers also possess high surface area making them more effective materials in detoxifying nerve gases.; Moreover, partial acidic hydrolysis of poly(ethyl-oxazoline) (PEOZ) was performed to produce a water soluble poly(ethyl-oxazoline-ethylenimine) (PEOZ-EI). A successful spinning of PEOZ-EI with fluorescent albumin was produced from a water/ethanol solvent and confirmed by optical micrographs. It was the first time for a protein to be tested in fibers. Furthermore, the positive spinning of albumin with PEOZ-EI proves the possibility of incorporating organophosphorus hydrolase (OPH) in the same fibers. Adding the most effective nerve gases-hydrolyzing enzyme (OPH) to an active material, such as cross-linked PEOZ-El fibers, will boost the detoxification activity. These fibers can be spun directly on cloth fabric, embedded, or sandwiched between two layers of fabric to be used in protective clothing.; Composite hydrogel wound dressings were accomplished by electrospinning polycaprolactone (PCL) with L-PEI. Both polymers were spun together from an acetone/ethanol solvent and produced one single fiber. When labeled L-PEI was mixed with unlabeled PCL in acetone/ethanol spinning mixture, all the fibers became fluorescent. The fibers were white, ∼1 μm in size, insoluble in water, and formed a fairly strong mat (tensile stress of 2.9 ± 0.25 MPa and strain of 85% ±7).; The water uptake (WU) and the equilibrium water content (EWC) of PCL, L-PEI, and two ratios of PCL/L-PEI composite fibers were measured in deionized water and saline (buffered at pH 7) for different periods of time (1 min to several days) with or without absorbents, alginic acid or polyacrylic acid (carbopol®). The WU and EWC of the two ratios of PCL/L-PEI composite fibers in water after one day were 1,200% and 92% for 80/20, and 1,750% and 95% for 67/33, respectively. The fibers, when saturated with water, formed a three-dimensional gel with high absorbance capacity. Moreover, supplementing alginic acid or polyacrylic acid (2.9% (wt/wt)) to these fibers enhanced their absorbance capacity. Alginic acid lowered the fiber's pH to neutral, while polyacrylic acid had no significant effect on the pH.; These composite fibers can be used for most dermal treatment applications, especially burns and wounds. They can be perfectly designed according to the wound type and to the amount of wound exudates by varying the ratio of polymers and supplements or by spinning them directly to the affected area.