National Institute for Research and Development in Chemistry and Petrochemistry, 202 Spl. Independentei, 060021 Bucharest, Romania.
Faculty of Chemical Engineering and Biotechnology, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania.
Int J Mol Sci. 2023 Jul 24;24(14):11871. doi: 10.3390/ijms241411871.
Nanocellulose (NC) is a valuable material in tissue engineering, wound dressing, and drug delivery, but its lack of antimicrobial activity is a major drawback for these applications. In this work, basil ethanolic extract (BE) and basil seed mucilage (BSM) were used to endow nanocellulose with antibacterial activity. NC/BE and NC/BE/BSM sponges were obtained from nanocellulose suspensions and different amounts of BE and BSM after freeze-drying. Regardless of the BE or BSM content, the sponges started to decompose at a lower temperature due to the presence of highly volatile active compounds in BE. A SEM investigation revealed an opened-cell structure and nanofibrillar morphology for all the sponges, while highly impregnated nanofibers were observed by SEM in NC/BE sponges with higher amounts of BE. A quantitative evaluation of the porous morphology by microcomputer tomography showed that the open porosity of the sponges varied between 70% and 82%, being lower in the sponges with higher BE/BSM content due to the impregnation of cellulose nanofibers with BE/BSM, which led to smaller pores. The addition of BE increased the specific compression strength of the NC/BE sponges, with a higher amount of BE having a stronger effect. A slight inhibition of growth was observed in the NC/BE sponges with a higher amount of BE, and no effect was observed in the unmodified NC. In addition, the NC/BE sponge with the highest amount of BE and the best antibacterial effect in the series showed no cytotoxic effect and did not interfere with the normal development of the L929 cell line, similar to the unmodified NC. This work uses a simple, straightforward method to obtain highly porous nanocellulose structures containing antibacterial basil extract for use in biomedical applications.
纳米纤维素（NC）在组织工程、伤口敷料和药物输送方面具有重要价值，但缺乏抗菌活性是这些应用的主要缺点。在这项工作中，罗勒醇提物（BE）和罗勒籽胶（BSM）被用于赋予纳米纤维素抗菌活性。通过冷冻干燥从纳米纤维素悬浮液中获得 NC/BE 和 NC/BE/BSM 海绵，并加入不同量的 BE 和 BSM。无论 BE 或 BSM 的含量如何，由于 BE 中存在高度挥发性的活性化合物，海绵开始在较低的温度下分解。扫描电镜（SEM）研究表明，所有海绵都具有开孔细胞结构和纳米纤维形态，而在含有较高 BE 量的 NC/BE 海绵中，通过 SEM 观察到高度浸渍的纳米纤维。通过微计算机断层扫描（microcomputer tomography，micro-CT）对多孔形态进行定量评估表明，海绵的开孔率在 70%至 82%之间变化，在含有较高 BE/BSM 含量的海绵中较低，这是由于 BE/BSM 浸渍纤维素纳米纤维导致较小的孔。BE 的加入增加了 NC/BE 海绵的比压缩强度，且 BE 含量越高，效果越强。在含有较高 BE 量的 NC/BE 海绵中观察到对 生长的轻微抑制，但未改性的 NC 则没有这种效果。此外，在含有最高量 BE 且具有最佳抗菌效果的 NC/BE 海绵中，未观察到细胞毒性作用，也未干扰 L929 细胞系的正常发育，与未改性的 NC 相似。本工作使用简单直接的方法获得了含有抗菌罗勒提取物的高多孔纳米纤维素结构，可用于生物医学应用。
