Preparation of Immobilized ε-Polylysine PET Nonwoven Fabrics and Antibacterial Activity Evaluation

A novel antibacterial material （L-PET） was prepared by immobilizing ε-polylysine on polyethylene terephthalate （PET） nonwoven fabrics. Surface modifications of the fabric were performed by using a chemical modification procedure where carboxyl groups were prepared on the PET surface, a coupling agent was grafted, and the ε-polylysine was immobilized. Scanning electron microscopy （SEM） was used to analyze the surface morphology of the fabrics, while the toluidine blue method and X-ray photoelectron spectroscopy （XPS） were used to evaluate the grafting densities. The antibacterial activities of the L-PET were investigated by using the shaking-flask method. The electron micrographs showed that the surface of the blank PET and the modified fabrics did not change. The results of XPS analysis confirmed that ε-polylysine was successfully grafted onto the surface of PET. The results of the antibacterial experiments showed that L-PET fabrics had excellent antibacterial activity against Escherichia coli and Staphylococcus aureus, and that L-PET fabrics were stable in storage for at least two years.

Enhanced production of cytidine 5'-monophosphate using biocatalysis of di-enzymes immobilized on amino-functionalized sepharose

Cytidine 5'-monophosphate(5'-CMP)is an essential nucleotide for additives.In this study,enhanced production of 5'-CMP was realized by the transformation of cytidine using co-immobilized di-enzymes,uridine-cytidine kinase(UCK)and acetate kinase(AcK).The immobilization yield of the enzyme had a clear correlation with the surface charges as zeta potential(ξ).Among them,ε-polylysinefunctionalized sepharose(SA-EPL,ξ=9.31 m V)showed high immobilization yield(78.8%),which was4.9-fold than that of nitrilotriacetic acid functionalized sepharose(SA-NTA,ξ=-12.6 m V).The residual activity of affinity co-immobilized enzyme(EPL-Ni/EPL@Ac K-UCK)was higher than 70.6%after recycled 10 times.Thus,this study provides an effective approach for the production of 5'-CMP with the advantages of low adenosine 5'-triphosphate(ATP)consumption,reduced side reactions,and improved reusability by co-immobilized UCK and Ac K on the functionalized Sepharose.

A targeted nanoplatform co-delivery of pooled siRNA and doxorubicin for reversing of multidrug resistance in breast cancer

Multi-drug resistance(MDR)has become the largest obstacle to the success of cancer patients receiving traditional chemotherapeutics or novel targeted drugs.Here,we developed a targeted nanoplatform based on biodegradable boronic acid modifiedε-polylysine to co-deliver P-gp siRNA,Bcl-2 siRNA,and doxorubicin for overcoming the challenge.The targeted nanoplatform showed a robust suppressing efficiency for the invasion,proliferation,and colony formation of adriamycin(ADR)resistant breast cancer cell line(MCF-7/ADR)cells in vitro.The ATP responsiveness of the nanoplatform was also proved in the research.In the in vivo antitumor experiment,the targeted nanoplatform showed a significant inhibition of tumor growth with good biocompatibility.The goal of this study is to develop a novel and facile strategy to prepare a highly efficient and safe gene and drug delivery system for MDR breast cancer based on biocompatibleε-polylysine polymers.