Effect of thiol-functionalisation on chitosan antibacterial activity: Interaction with a bacterial membrane model
Effect of thiol-functionalisation on chitosan antibacterial activity: Interaction with a bacterial membrane model
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DOI：
10.1016/j.reactfunctpolym.2013.01.004
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发表时间：
2013-10-01
影响因子：
5.1
通讯作者：
Tzanov, Tzanko
中科院分区：
文献类型：
--
作者：
Fernandes, Margarida M.;Francesko, Antonio;Tzanov, Tzanko
采用Langmuir膜平衡技术，采用双棕榈酰基磷脂酰甘油（DPPG）单层细菌膜模型，研究了含巯基亚氨基硫烷HCl （TC-IMI）和n -乙酰- l-半胱氨酸（TC-NAC）改性壳聚糖的抑菌活性。通过监测在亚相中不存在壳聚糖和硫代缀合物时记录的压缩等温线形状的差异，评估生物聚合物与膜模型的相互作用。低分子量壳聚糖（15 kDa）使DPPG单层膜的压缩等温线向更大的区域移动(A(0，CS) = 145埃(2))，证实了其膜扰动能力。进一步的硫基化诱导了更高的膨胀率，在TC-IMI的情况下更为明显。在TC-IMI的存在下，单层膜的膨胀率显著增加(A(0,TC-NAC) = 150埃(2)vs A(0,TC-IMI) = 175埃(2))，在30 mN/m的表面压力下，生物膜典型的弹性降低程度更大(C-s,30TC-NAC（-1) = 120 mN/m vs C-s,30 TC-IMI(-1) = 87 mN/m）。对革兰氏阴性大肠杆菌和革兰氏阳性金黄色葡萄球菌的抗菌试验与这些发现很好地一致，表明与2-亚氨基硫烷HCl硫化的壳聚糖作为一种杀菌剂破坏了细菌细胞膜的完整性。(C) 2013 Elsevier Ltd.版权所有。
The antibacterial activity of chitosan modified with the thiol-containing 2-iminothiolane HCl (TC-IMI) and N-acetyl-L-cysteine (TC-NAC) was studied by Langmuir film balance technique using a dipalmitoylphosphatidylglycerol (DPPG) monolayer bacterial membrane model. The interactions of the biopolymer with the membrane model were assessed by monitoring the differences in the shape of the compression isotherms recorded in the absence and presence of chitosan and thiolated conjugates in the subphase. A low molecular weight chitosan (15 kDa) shifted the compression isotherms of DPPG monolayers towards larger areas (A(0,CS) = 145 angstrom(2)), confirming its membrane disturbance capacity. Further thiolation induced higher yield of expansion, more pronounced in the case of TC-IMI. The expansion of the monolayer increased significantly (A(0,TC-NAC) = 150 angstrom(2) vs A(0,TC-IMI) = 175 angstrom(2)) and the elasticity at a surface pressure of 30 mN/m, typical for bio-membranes decreased to a greater extent (C-s,30TC-NAC(-1) = 120 mN/m vs C-s,30 TC-IMI(-1) = 87 mN/m) in presence of TC-IMI. Antibacterial tests against a Gram-negative Escherichia coli and a Gram-positive Staphylococcus aureus were in good agreement with these findings, suggesting that chitosan thiolated with 2-iminothiolane HCl acts as a bactericide disrupting the integrity of the bacterial cell membrane. (C) 2013 Elsevier Ltd. All rights reserved.