Yin Na, Stilwell Matthew D, Santos Thiago M A, Wang Huaping, Weibel Douglas B
Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; College of Materials Science and Engineering, Donghua University, Shanghai 201620, People's Republic of China.
Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Acta Biomater. 2015 Jan;12:129-138. doi: 10.1016/j.actbio.2014.10.019. Epub 2014 Oct 27.
Bacterial cellulose (BC) is a biocompatible hydrogel with a three-dimensional (3-D) structure formed by a dense network of cellulose nanofibers. A limitation of using BC for applications in tissue engineering is that the pore size of the material (∼0.02-10μm) is smaller than the dimensions of mammalian cells and prevents cells from penetrating into the material and growing into 3-D structures that mimic tissues. This paper describes a new route to porous bacterial cellulose (pBC) scaffolds by cultivating Acetobacter xylinum in the presence of agarose microparticles deposited on the surface of a growing BC pellicle. Monodisperse agarose microparticles with a diameter of 300-500μm were created using a microfluidic technique, layered on growing BC pellicles and incorporated into the polymer as A. xylinum cells moved upward through the growing pellicle. Removing the agarose microparticles by autoclaving produced BC gels containing a continuous, interconnected network of pores with diameters ranging from 300 to 500μm. Human P1 chondrocytes seeded on the scaffolds, replicated, invaded the 3-D porous network and distributed evenly throughout the substrate. Chondrocytes grown on pBC substrates displayed a higher viability compared to growth on the surface of unmodified BC substrates. The approach described in this paper introduces a new method for creating pBC substrates with user-defined control over the physical dimensions of the pore network, and demonstrates the application of these materials for tissue engineering.
细菌纤维素（BC）是一种具有三维（3-D）结构的生物相容性水凝胶，由纤维素纳米纤维的致密网络形成。将BC用于组织工程应用的一个限制是材料的孔径（约0.02 - 10μm）小于哺乳动物细胞的尺寸，这会阻止细胞穿透材料并生长成模拟组织的三维结构。本文描述了一种制备多孔细菌纤维素（pBC）支架的新方法，即在生长的BC菌膜表面存在琼脂糖微粒的情况下培养木醋杆菌。使用微流控技术制备了直径为300 - 500μm的单分散琼脂糖微粒，将其分层放置在生长的BC菌膜上，并随着木醋杆菌细胞向上穿过生长的菌膜而掺入聚合物中。通过高压灭菌去除琼脂糖微粒后，得到了含有直径范围为300至500μm的连续、相互连接的孔网络的BC凝胶。接种在支架上的人P1软骨细胞进行复制，侵入三维多孔网络并均匀分布在整个基质中。与在未改性BC基质表面生长相比，在pBC基质上生长的软骨细胞具有更高的活力。本文所述方法引入了一种新的方法来制备对孔网络物理尺寸具有用户定义控制的pBC基质，并展示了这些材料在组织工程中的应用。
