具有可调疏水性的侧链可降解阳离子两亲聚合物具有体内活性。
Side Chain Degradable Cationic-Amphiphilic Polymers with Tunable Hydrophobicity Show in Vivo Activity.
机构信息
Chemical Biology & Medicinal Chemistry Laboratory, New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) , Jakkur, Bangalore 560064, India.
ICAR-National Institute of Veterinary Epidemiology and Disease Informatics (NIVEDI) , Ramagondanahalli, Yelahanka, Bengaluru 560064, India.
出版信息
Biomacromolecules. 2016 Sep 12;17(9):3094-102. doi: 10.1021/acs.biomac.6b01057. Epub 2016 Aug 2.
Cationic-amphiphilic antibacterial polymers with optimal amphiphilicity generally target the bacterial membranes instead of mammalian membranes. To date, this balance has been achieved by varying the cationic charge or side chain hydrophobicity in a variety of cationic-amphiphilic polymers. Optimal hydrophobicity of cationic-amphiphilic polymers has been considered as the governing factor for potent antibacterial activity yet minimal mammalian cell toxicity. However, the concomitant role of hydrogen bonding and hydrophobicity with constant cationic charge in the interactions of antibacterial polymers with bacterial membranes is not understood. Also, degradable polymers that result in nontoxic degradation byproducts offer promise as safe antibacterial agents. Here we show that amide- and ester (degradable)-bearing cationic-amphiphilic polymers with tunable side chain hydrophobicity can modulate antibacterial activity and cytotoxicity. Our results suggest that an amide polymer can be a potent antibacterial agent with lower hydrophobicity whereas the corresponding ester polymer needs a relatively higher hydrophobicity to be as effective as its amide counterpart. Our studies reveal that at higher hydrophobicities both amide and ester polymers have similar profiles of membrane-active antibacterial activity and mammalian cell toxicity. On the contrary, at lower hydrophobicities, amide and ester polymers are less cytotoxic, but the former have potent antibacterial and membrane activity compared to the latter. Incorporation of amide and ester moieties made these polymers side chain degradable, with amide polymers being more stable than the ester polymers. Further, the polymers are less toxic, and their degradation byproducts are nontoxic to mice. More importantly, the optimized amide polymer reduces the bacterial burden of burn wound infections in mice models. Our design introduces a new strategy of interplay between the hydrophobic and hydrogen bonding interactions keeping constant cationic charge density for developing potent membrane-active antibacterial polymers with minimal toxicity to mammalian cells.
具有最佳两亲性的阳离子抗菌聚合物通常靶向细菌膜而不是哺乳动物膜。迄今为止,通过改变各种阳离子两亲聚合物中的阳离子电荷或侧链疏水性来实现这种平衡。阳离子两亲聚合物的最佳疏水性被认为是具有强大抗菌活性和最小哺乳动物细胞毒性的控制因素。然而,阳离子电荷恒定的情况下,氢键和疏水性与抗菌聚合物与细菌膜相互作用的伴随作用尚不清楚。此外,可导致无毒降解副产物的可降解聚合物作为安全的抗菌剂具有很大的应用前景。在这里,我们展示了具有可调侧链疏水性的酰胺和酯(可降解)支链阳离子两亲聚合物可以调节抗菌活性和细胞毒性。我们的结果表明,具有较低疏水性的酰胺聚合物可以作为有效的抗菌剂,而相应的酯聚合物需要相对较高的疏水性才能与其酰胺对应物一样有效。我们的研究表明,在较高的疏水性下,酰胺和酯聚合物都具有相似的膜活性抗菌活性和哺乳动物细胞毒性特征。相反,在较低的疏水性下,酰胺和酯聚合物的细胞毒性较低,但前者与后者相比具有更强的抗菌和膜活性。酰胺和酯部分的掺入使这些聚合物具有侧链可降解性,其中酰胺聚合物比酯聚合物更稳定。此外,这些聚合物的毒性较小,其降解副产物对小鼠无毒。更重要的是,优化后的酰胺聚合物可减少小鼠烧伤感染模型中的细菌负荷。我们的设计引入了一种新的策略,即在保持阳离子电荷密度恒定的情况下,利用疏水性和氢键相互作用之间的相互作用,开发出具有最小细胞毒性的强大膜活性抗菌聚合物。