Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an, Shaanxi 710021, PR China.
Department of Polymer and Process Engineering, IIT Roorkee Saharanpur Campus, Saharanpur 247001, Uttar Pradesh, India.
ACS Appl Mater Interfaces. 2021 Feb 3;13(4):4874-4885. doi: 10.1021/acsami.0c20258. Epub 2021 Jan 19.
This work is strategically premeditated to study the potential of a herbal medicinal product as a natural bioactive ingredient to generate nanocellulose-based antibacterial architectures. In situ fibrillation of purified cellulose was done in cinnamon extract (E) to obtain microfibrillated cellulose (MFC). To this MFC suspension, carboxylated cellulose nanocrystals (cCNCs) were homogeneously mixed and the viscous gel thus obtained was freeze-dried to obtain lightweight and flexible composite aerogel architectures impregnated with E, namely, MFC/cCNCs. At an optimal concentration of 0.3 wt % cCNCs (i.e., for MFC/cCNCs_0.3), an improvement of around 106% in compressive strength and 175% increment in modulus were achieved as compared to pristine MFC architecture. The efficient loading and interaction of E components, specifically cinnamaldehyde, with MFC and cCNCs resulted in developing competent antibacterial surfaces with dense and uniform microstructures. Excellent and long-term antimicrobial activity of the optimized architectures (MFC/cCNCs_0.3) was confirmed through various antibacterial assays like the zone inhibition method, bacterial growth observation at OD, minimum inhibitory concentration (MIC, here 1 mg/mL), minimum bactericidal concentration (MBC, here 3-5 mg/mL), and Live/Dead BacLight viability tests. The changes in the bacterial morphology with a disrupted membrane were further confirmed through various imaging techniques like confocal laser scanning microscopy, FESEM, AFM, and 3D digital microscopy. The dry composite architecture showed the persuasive capability of suppressing the growth of airborne bacteria, which in combination with antibacterial efficiency in the wet state is considered as an imperative aspect for a material to act as the novel biomaterial. Furthermore, these architectures demonstrated excellent antibacterial performance under real "in use" contamination prone conditions. Hence, this work provides avenues for the application of crude natural extracts in developing novel forms of advanced functional biomaterials that can be used for assorted biological/healthcare applications such as wound care and antimicrobial filtering units.
这项工作是有策略地预先计划的，旨在研究一种草药药物作为天然生物活性成分的潜力，以生成基于纳米纤维素的抗菌结构。在肉桂提取物 (E) 中进行了纯化纤维素的原位原纤化，以获得微原纤化纤维素 (MFC)。将这种 MFC 悬浮液与羧基化纤维素纳米晶体 (cCNC) 均匀混合，所得粘性凝胶经冷冻干燥得到轻质柔韧的复合气凝胶结构，其中浸渍有 E，即 MFC/cCNC。在 cCNC 的最佳浓度 0.3wt%（即 MFC/cCNC_0.3）下，与原始 MFC 结构相比，抗压强度提高了约 106%，模量提高了 175%。E 成分（特别是肉桂醛）与 MFC 和 cCNC 的有效负载和相互作用导致形成具有致密均匀微观结构的有竞争力的抗菌表面。通过各种抗菌试验（如抑菌圈法、OD 处细菌生长观察、最低抑菌浓度 (MIC，这里为 1mg/mL)、最低杀菌浓度 (MBC，这里为 3-5mg/mL) 和 Live/Dead BacLight 活力测试），证实了优化结构（MFC/cCNC_0.3）具有优异且持久的抗菌活性。通过各种成像技术（如共聚焦激光扫描显微镜、FESEM、AFM 和 3D 数字显微镜）进一步证实了细菌形态的变化与破坏的膜有关。干燥的复合结构表现出抑制空气中细菌生长的令人信服的能力，结合其在湿态下的抗菌效率，这被认为是该材料作为新型生物材料的一个重要方面。此外，这些结构在实际“使用中”易受污染的条件下表现出优异的抗菌性能。因此，这项工作为在开发新型先进功能生物材料方面应用粗天然提取物提供了途径，这些生物材料可用于各种生物/医疗保健应用，如伤口护理和抗菌过滤单元。
