Chiral stereochemistry is a unique and fundamental strategy that determines the interaction of bacteria cells with chiral biomolecules and stereochemical surfaces. The interaction between bacteria and material surface (molecular chirality or supramolecular chirality) plays a significant role in modulating antibacterial performance. Herein, we developed inherent chiral antibacterial hydrogels by modifying the carboxyl groups of our previously reported supramolecular gelator (LPF-left handed phenylalanine gelator and DPF- right handed phenylalanine gelator) with 2-amino-5-methylthiazole (MTZ) and 5-amino-1,3,4-thiadiazole-2- thiol (TDZ). The new L/D-gelator molecules initiate self-assembly to form hydrogels through non-covalent interactions (Hydrogen bonding and π-π interactions) verified by FTIR and CD spectroscopy. Morphological studies of the xerogels revealed left and right-handed chiral nanofibers for the gelators' L-form and D-form, respectively. The resulting hydrogels exhibited inherent antibacterial activity against Gram-positive (Bacillus subtilis, Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria, with TDZ hydrogels showing more significant antibacterial activity than MTZ hydrogels. Interestingly, the D-form (having right-handed nanofibers) of both hydrogels (MTZ and TDZ) exhibited higher antibacterial activities compared with the left-handed nanofibrous hydrogels (L-form) attributed to the stereoselective interaction of the chiral helical nanofiber. Moreover, the amplification of chirality moving from a molecular to a supramolecular level essentially improved the antibacterial action. Our results provide deep insight into the development of unique supramolecular chiral antimicrobial agents and hint at the potentiality of right-handed nanofibers (D-form) having enhanced antibacterial activity.

Statement of significance

Chiral stereochemistry plays a significant role in many biological processes, which determines the interaction of bacteria cells with chiral biomolecules. The interaction between bacteria and material surface (molecular chirality or supramolecular chirality) plays a significant role in modulating antibacterial performance. Here, we deigned and synthesized unique inherent biocompatible supramolecular chiral hydrogel. From this study we concluded that the D-form (having right-handed nanofibers) of hydrogels exhibited higher antibacterial activities compared with the left-handed nanofibrous hydrogels (L-form) attributed to the stereoselective interaction of the chiral helical nanofiber. Additionally, this study also explored the amplification of chirality moving from a molecular to a supramolecular level essentially improved the antibacterial action.

中文翻译：

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甲基噻唑和噻二唑基超分子生物相容性水凝胶的手性影响抗菌活性

手性立体化学是一种独特的基本策略，它决定了细菌细胞与手性生物分子和立体化学表面的相互作用。细菌与材料表面（分子手性或超分子手性）之间的相互作用在调节抗菌性能方面起着重要作用。在此，我们通过用 2-氨基-5-甲基噻唑 (MTZ) 和 5-氨基-修饰我们之前报道的超分子凝胶剂（LPF-左手苯丙氨酸凝胶剂和 DPF-右手苯丙氨酸凝胶剂）的羧基开发了固有的手性抗菌水凝胶。 1,3,4-噻二唑-2-硫醇 (TDZ)。新的 L/D-凝胶分子通过 FTIR 和 CD 光谱验证的非共价相互作用（氢键和 π-π 相互作用）启动自组装形成水凝胶。干凝胶的形态学研究揭示了左手和右手手性纳米纤维分别用于凝胶剂的 L 型和 D 型。由此产生的水凝胶对革兰氏阳性菌表现出固有的抗菌活性（枯草芽孢杆菌、金黄色葡萄球菌）和革兰氏阴性（铜绿假单胞菌）细菌，TDZ 水凝胶比 MTZ 水凝胶显示出更显着的抗菌活性。有趣的是，由于手性螺旋纳米纤维的立体选择性相互作用，与左手纳米纤维水凝胶（L 型）相比，两种水凝胶（MTZ 和 TDZ）的 D 型（具有右手型纳米纤维）表现出更高的抗菌活性。此外，从分子水平到超分子水平的手性放大从本质上提高了抗菌作用。我们的研究结果为独特的超分子手性抗菌剂的开发提供了深刻的见解，并暗示了具有增强抗菌活性的右手纳米纤维（D 型）的潜力。

重要性声明

手性立体化学在许多生物过程中发挥着重要作用，它决定了细菌细胞与手性生物分子的相互作用。细菌与材料表面（分子手性或超分子手性）之间的相互作用在调节抗菌性能方面起着重要作用。在这里，我们设计并合成了独特的固有生物相容性超分子手性水凝胶。从这项研究中，我们得出结论，与左手纳米纤维水凝胶（L 型）相比，水凝胶的 D 型（具有右手纳米纤维）表现出更高的抗菌活性，这归因于手性螺旋纳米纤维的立体选择性相互作用。此外，本研究还探索了从分子水平到超分子水平的手性放大，从根本上改善了抗菌作用。