Pereira Sara, Costa-Ribeiro Ana, Teixeira Pilar, Rodríguez-Lorenzo Laura, Prado Marta, Cerqueira Miguel A, Garrido-Maestu Alejandro
International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal.
CEB-Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal.
Polymers (Basel). 2023 Sep 14;15(18):3759. doi: 10.3390/polym15183759.
Chitosan is obtained from the deacetylation of chitin, and it is known to possess antimicrobial activity. It has attracted attention as it may be used for treating infections caused by different types of microorganisms due to its broad spectrum. Its application in the form of micro- or nanoparticles (CM/CN) has expanded its usage, as in this form, it retains its activity, and remain stable in aqueous solutions. However, inconsistencies in the results reported by different authors have been identified. In this communication, the antimicrobial activity of CN produced from different starting materials was tested against . It was observed that, even though all the starting materials were reported to have a molecular weight (MW) below 200 kDa and degree of deacetylation (DD) > 75%, the size of the CNs were significantly different (263 nm vs. 607 nm). Furthermore, these differences in sizes exerted a direct effect on the antimicrobial properties of the particles, as when testing the ones with the smallest size, i.e., 263 nm, a lower Minimum Inhibitory Concentration (MIC) was achieved, i.e., 0.04 mg/mL. Even though the largest particles, i.e., 607 nm, in individual experiments were able to achieve an MIC of 0.03 mg/mL, the results with CN presented great variation among replicates and up to 0.2 mg/mL were needed in other replicates. The starting material has a critical impact on the properties of the CN, and it must be carefully characterized and selected for the intended application, and MW and DD solely do not fully account for these properties.
壳聚糖是由甲壳素脱乙酰化得到的，已知其具有抗菌活性。由于其广谱性，它可用于治疗由不同类型微生物引起的感染，因此受到关注。其以微颗粒或纳米颗粒（CM/CN）形式的应用扩大了其用途，因为以这种形式它能保持活性，并在水溶液中保持稳定。然而，已发现不同作者报道的结果存在不一致性。在本通讯中，测试了由不同起始原料制备的CN对……的抗菌活性。据观察，尽管所有起始原料的分子量（MW）均低于200 kDa且脱乙酰度（DD）>75%，但CN的尺寸却有显著差异（263 nm对607 nm）。此外，这些尺寸差异对颗粒的抗菌性能产生了直接影响，例如在测试最小尺寸（即263 nm）的颗粒时，最低抑菌浓度（MIC）较低，为0.04 mg/mL。尽管在个别实验中最大尺寸（即607 nm）的颗粒能够达到0.03 mg/mL的MIC，但CN的结果在重复实验中差异很大，在其他重复实验中需要高达0.2 mg/mL的浓度。起始原料对CN的性能有至关重要的影响，必须针对预期应用对其进行仔细表征和选择，仅分子量和脱乙酰度并不能完全说明这些性能。
