Department of Chemistry, College of Science, Qassim University, Buraidah 51452, Saudi Arabia; Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt.
Int J Biol Macromol. 2024 Sep;276(Pt 2):133810. doi: 10.1016/j.ijbiomac.2024.133810. Epub 2024 Jul 14.
The phenomenon of microbial resistance and its resulting biofilms to traditional antibiotics is worsening over time. Therefore, the discovery of alternative substances that inhibit microbial activities through mechanisms different from those of known antibiotics requires attention. So, chitosan was crosslinked using different amounts of oxalyl dihydrazide yielding four novel hydrogels; ODHCs-I, ODHCs-II, ODHCs-III, and ODHCs-IV of crosslinking degree 12.17, 20.67, 31.67, and 43.17, respectively. Different amounts of CuO nanoparticles were impregnated into ODHCs-IV, obtaining ODHCs-IV/CuONPs-1 %, ODHCs-IV/CuONPs-3 % and ODHCs-IV/CuONPs-5 % composites. Their structure was emphasized using FTIR, SEM, XRD, TEM, EDX and elemental analysis. Their in vitro antimicrobial and anti-biofilm activities improved with increasing ODH and CuONPs content. ODHCs-IV exhibited minimal inhibition concentration (2 μg/mL) against S. pyogenes that was much lower than Vancomycin (3.9 μg/mL). ODHCs-IV/CuONPs-5 % displayed better inhibition performance than Vancomycin and Amphotericin B against Gram-positive-bacteria and fungi, respectively, and comparable one to that of Vancomycin against Gram-negative-bacteria. ODHCs-IV/CuONPs-5 % displayed much lower minimal biofilm inhibition concentrations (1.95 to 3.9 μg/mL) as compared with those of ODHCs-IV (7.81 and 15.63 μg/mL), against C. albicans, S. pyogenes, and K. pneumonia. ODHCs-IV/CuONPs-5 % composite is safe on normal human cells. Oxalyl dihydrazide and CuONPs amalgamated into chitosan in one formulation promoted its antimicrobial efficiency.
微生物耐药性及其导致的生物膜对传统抗生素的影响随着时间的推移而日益加剧。因此，需要关注发现通过与已知抗生素不同的机制抑制微生物活性的替代物质。为此，使用不同量的乙二酰二腙使壳聚糖交联，得到四种新型水凝胶；ODHCs-I、ODHCs-II、ODHCs-III 和 ODHCs-IV 的交联度分别为 12.17、20.67、31.67 和 43.17。将不同量的 CuO 纳米粒子浸渍到 ODHCs-IV 中，得到 ODHCs-IV/CuONPs-1%、ODHCs-IV/CuONPs-3%和 ODHCs-IV/CuONPs-5%复合材料。通过 FTIR、SEM、XRD、TEM、EDX 和元素分析强调了它们的结构。它们的体外抗菌和抗生物膜活性随着 ODH 和 CuONPs 含量的增加而提高。ODHCs-IV 对酿脓链球菌的最小抑制浓度（2μg/mL）比万古霉素（3.9μg/mL）低得多。ODHCs-IV/CuONPs-5%对革兰氏阳性菌和真菌的抑制性能优于万古霉素和两性霉素 B，与万古霉素对革兰氏阴性菌的抑制性能相当。与 ODHCs-IV（7.81 和 15.63μg/mL）相比，ODHCs-IV/CuONPs-5%对白色念珠菌、酿脓链球菌和肺炎克雷伯菌的最低生物膜抑制浓度（1.95 至 3.9μg/mL）要低得多。ODHCs-IV/CuONPs-5% 复合材料对正常人体细胞是安全的。乙二酰二腙和 CuONPs 在一个配方中与壳聚糖结合，提高了其抗菌效率。
