Bacterial cellulose (BC) membranes display special properties and structures, thus attracting much attention in application in the biomedical areas, for example, as implants for bone or cartilage tissue engineering, as substitutes for skin repairing, and as supports for controlled drug delivery. However, native BC lacks the activity to inhibit bacteria growth on its surface, which limits its applications in biomedical fields. There have been reports on chemical modification of BC membranes to endow them with antimicrobial properties needed for some special biomedical applications. In the present study, aminoalkyl‐grafted BC membranes were prepared by alkoxysilane polycondensation using 3‐aminopropyltriethoxysilane (APTES). The characterization for morphology and chemical composition showed that BC membranes were successfully grafted with aminoalkylsilane groups through covalent bonding. The surface morphology and roughness of the membranes changed after chemical grafting. Furthermore, after grafting with APTES, the membranes got less hydrophilic than native BC. The aminoalkyl‐grafted BC membranes showed strong antibacterial properties against Staphylococcus aureus and Escherichia coli and moreover, they were nontoxic to normal human dermal fibroblasts. These results indicate that aminoalkyl‐grafted BC membranes are potential to be used for biomedical applications.

Bat algorithm is an effective swarm intelligence optimization algorithm which is widely used to solve continuous optimization problems. But it still has some limitations in search process and can’t solve discrete optimization problems directly. Therefore, this paper introduces an unordered pair and proposes an unordered pair bat algorithm (UPBA) to make it more suitable for solving symmetric discrete traveling salesman problems. To verify the effectiveness of this method, the algorithm has been tested on 23 symmetric benchmarks and compared its performance with other algorithms. The results have shown that the proposed UPBA outperforms all the other alternatives significantly in most cases.