Chiral-functionalized Natural Polymers And Their Antimicrobial Applications

Bacterial adhesion, colonization or proliferation and the subsequent formation of biofilms are hold responsible for numerous human healthcare and industrial problems. Usually, the antibacterial strategies were immobilization or release of bactericidal substances. However, those methods still have some limitations in applications. Based on the knowledge that cells could distinguish stereochemical signals of external surfaces, we make a design to grafte borneol via covalent bond onto the surface of natural polymer (cellulose and chitosan). These synthesized materials will produce antibacterial effects at preliminary stage of microbial adhesion mainly based on the polymer surface stereochemistry. These materials are evaluated to be biocompatible and environment-friendly, demonstrating great potential for biomedical applications.Here, we present a borneol-grafted cellulose (BGC) by tethering L-borneol to cellulose. The attained BGC was characterized by a series of analytical techniques. The BGC material was subsequently challenged with microorganism, and exhibited a remarkable performance in antifungal adhesion and fungal growth inhibition, suggesting grafted borneol molecules were curial on influencing tactile sense of fungal cells and subsequently selective inadhesion. The main results are as follows:1. BGC has broad-spectrum antifungal properties, such as Mucor racemosus, Aspergillus Niger and Yeast.2. The efficiency of BGC bacteriostasis reaches to more than 8 days. The microcosmic morphological study indicated a growth inhibition of spores on the BGC surface.3. Microorganisms recognized the caged bicyclic borneol molecules and subsequently tended to inadhesion on the BGC surface, where borneol stereochemisty plays the key role for the antimicrobial effect on the BGC product.4. The BGC was evaluated as a non-cytotoxic material, demonstrating great potential for biomedical and sanitary applications.In addition, this paper present a borneol-functionalized chitosan (BFC) by schiff based binding L-borneol to glycol chitosan. The BFC was challenged with microorganisms, and exhibited a remarkable performance on antibacterial activity. The BFC show growth inhibition of microorganism when small amount of bacteria’attack’ it. But it will present germicidal qualities when the amount of bacteria increased. The main results are as follows:1. BFC has broad-spectrum antibacterial properties on microorganisms, such as A. Niger and Escherichia coli.2. BFC showed powerful performance on inhibiting mocur cells adhesion. The morphological study indicated a growth inhibition of spores on the BFC surface.3. The growth inhibitory effect of E. coli can reach 67 cell/cm2.4. The BFC show growth inhibition of microorganism when small amount of bacteria ’attack’ it. But when there are amount of bacteria, the schiff base bond broke, parts of borneol released and a certain amount of glycol chitosan dissolved, suggesting the material not only stop the growth of the microbial adhesion but also has a good potential of sterilization of microorganisms.