Wei Zhao, Liu Lu, Yang Jingjing, Dunn Carmen B, Zhang Tikai, Hong Feng F, Qiang Zhe, Ren Jie
Institute of Nano and Biopolymeric Materials, School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
College of Biological Science and Medical Engineering, Donghua University, No.2999 North Ren Min Road, Shanghai 201620, China.
Carbohydr Polym. 2025 Nov 15;368(Pt 1):124091. doi: 10.1016/j.carbpol.2025.124091. Epub 2025 Jul 21.
This work reports an ethanol-mediated freeze-drying (EMFD) strategy that enables the scalable production of high-performance bacterial cellulose aerogels (BCAs), effectively addressing key limitations of conventional methods such as supercritical drying and standard freeze-drying, including fragility, low mechanical strength, and high cost. Specifically, by replacing water in bacterial cellulose hydrogels (BCHs) with ethanol-water solution (EWs) prior to freeze-drying, the process limits ice crystal formation and reduces capillary forces and adhesion, thereby preserving structural integrity and enhancing mechanical properties. The effects of EWs concentration on BCA morphology, volume shrinkage, mechanical strength, and pore structure were systematically investigated. The BCA derived from 10 % EWs exhibits optimal performance, with improved tensile strength (0.75 MPa) and specific surface area (228.7 m/g), exceeding that of conventionally freeze-dried aerogel (0.05 MPa; 98.1 m/g). Our method enables retaining a robust 3D nanofiber network, ultra-low density (7.44 mg/cm), and very high porosity (~99 %). When applied as drug carriers and hemostatic materials, these BCAs demonstrate rapid drug loading (2 min), a 4.4-fold increase in loading capacity, and sustained release, along with superior hemostatic performance in both in vitro and in vivo models. Overall, this EMFD approach offers a simple, cost-effective, and scalable method for fabricating high-performance BCAs for biomedical applications.
这项工作报道了一种乙醇介导的冷冻干燥（EMFD）策略，该策略能够实现高性能细菌纤维素气凝胶（BCA）的规模化生产，有效解决了传统方法（如超临界干燥和标准冷冻干燥）的关键局限性，包括易碎性、低机械强度和高成本。具体而言，通过在冷冻干燥前用乙醇 - 水溶液（EWs）替代细菌纤维素水凝胶（BCHs）中的水，该过程限制了冰晶形成并降低了毛细管力和附着力，从而保持了结构完整性并增强了机械性能。系统研究了EWs浓度对BCA形态、体积收缩、机械强度和孔结构的影响。源自10% EWs的BCA表现出最佳性能，其拉伸强度（0.75MPa）和比表面积（228.7m/g）得到改善，超过了传统冷冻干燥气凝胶（0.05MPa；98.1m/g）。我们的方法能够保留坚固的三维纳米纤维网络、超低密度（7.44mg/cm）和非常高的孔隙率（约99%）。当用作药物载体和止血材料时，这些BCA表现出快速药物负载（2分钟）、负载能力提高4.4倍和持续释放，以及在体外和体内模型中均具有优异的止血性能。总体而言，这种EMFD方法为制造用于生物医学应用的高性能BCA提供了一种简单、经济高效且可扩展的方法。
