Study On Aloe Emodin Grafted On PP Nonwoven Fabrics And Papain Immobiliztion

Polypropylene non-woven fabric was an unknitted material, polymerized by propylene through melt spinning, with a large surface area, little resistance for the reactants or products, good mechanical strength and other characteristics and it showed a great prospect in the field of enzyme immobilization. The aloe emodin was an anthraquinone compounds, widely found in plants such as aloe and rhubarb and it could be applied to the restructuring of antibacterial materials due to its anti-bacterial and anti-viral effects. In this paper, aloe emodin was grafted on the surface of polypropylene non-woven fabric, which detected its surface structure and determined of its antibacterial properties and conditions of immobilized papain.In this study, polypropylene non-woven fabric was as a carrier for reaction of glutaraldehyde and Polyethylenimine by the way of adsorption-covalent, which formed structure of Schiff base through the Maillard reaction and aloe emodin effectively grafted on polypropylene non-woven fabric. Aloe emodin grafted on polypropylene nonwoven fabric effectively made its surface cover with the carbonyl group. Characterized by FTIR and SEM, the results showed that aloe emodin effectively grafted on the surface of non-woven polypropylene. And it was analysed for the concentration and reaction time of glutaraldehyde and polyethyleneimine through response surface analysis. The best grafting conditions was that:concentration of glutaraldehy and Polyethylenimine was 24.35 mg/mL and 7.67 mg/mL and treating time of that was 122.52 min and 40 min, respectively. The grafting degree of that was 67.2634%.Taking polypropylene nonwoven fabric grafted aloe emodin for antibacterial test through inhibition zone method, turbidity method and colony counting method, the results showed that polypropylene nonwoven fabric grafted aloe emodin was a non-release type of antibacterial material, the antimicrobial rate of which against Staphylococcus aureus, Escherichia coli and Candida albicans was 61.49%,34.40% and 58.46%, respectively. So the activity of antibacterial effect of polypropylene nonwoven fabric grafted aloe emodin was Staphylococcus aureus> Candida albicans> Escherichia coli. The results of SEM showed that polypropylene nonwoven fabric grafted aloe emodin had the effect on adsorption of bacteria, which had terrific prospects as an antibacterial material in the future.As a biological protein molecules, papain was immobilized on a carrier of aloe emodin grafted polypropylene nonwoven fabric through covalently bound, which was characterized by FTIR and SEM. It was investigated the best condition of papain immobilization on polypropylene nonwoven fabric and comparision on the different property of free papain and immobilized papain. The result showed that immobilized rate of papain was 19.28%; under the conditions that 1.66 mg/mL papain,16 h immobilized time and pH 7.2, the activity of immobilized papain was 10.78 U/mg and enzymatic activity recovery was 37.32% which showed that catalytic center of papain immobilization on polypropylene nonwoven fabric had not changed; under optimal conditions immobilizing papain, the immobilized papain with respect to the free papain, its optimum pH deviated to acidic direction of 0.4 units and the optimum reaction temperature was raised up 20 ℃; immobilized papain had more alkali resistance in the environment and more resistant to the impact of temperature on the activity, and remained 61% relative activity for storage after 30 d and still active after using of four times. Thus it was indicated that the AE-PP nonwoven fabric was a perfect carrier for papain immobilized.