Martínez Ávila Héctor, Schwarz Silke, Feldmann Eva-Maria, Mantas Athanasios, von Bomhard Achim, Gatenholm Paul, Rotter Nicole
Biopolymer Technology, Department of Chemical and Biological Engineering, Chalmers University of Technology, Kemivägen 4, 41346, Gothenburg, Sweden,
Appl Microbiol Biotechnol. 2014 Sep;98(17):7423-35. doi: 10.1007/s00253-014-5819-z. Epub 2014 May 28.
Bacterial nanocellulose (BNC), synthesized by the bacterium Gluconacetobacter xylinus, is composed of highly hydrated fibrils (99 % water) with high mechanical strength. These exceptional material properties make BNC a novel biomaterial for many potential medical and tissue engineering applications. Recently, BNC with cellulose content of 15 % has been proposed as an implant material for auricular cartilage replacement, since it matches the mechanical requirements of human auricular cartilage. This study investigates the biocompatibility of BNC with increased cellulose content (17 %) to evaluate its response in vitro and in vivo. Cylindrical BNC structures (Ø48 × 20 mm) were produced, purified in a built-in house perfusion system, and compressed to increase the cellulose content in BNC hydrogels. The reduction of endotoxicity of the material was quantified by bacterial endotoxin analysis throughout the purification process. Afterward, the biocompatibility of the purified BNC hydrogels with cellulose content of 17 % was assessed in vitro and in vivo, according to standards set forth in ISO 10993. The endotoxin content in non-purified BNC (2,390 endotoxin units (EU)/ml) was reduced to 0.10 EU/ml after the purification process, level well below the endotoxin threshold set for medical devices. Furthermore, the biocompatibility tests demonstrated that densified BNC hydrogels are non-cytotoxic and cause a minimal foreign body response. In support with our previous findings, this study concludes that BNC with increased cellulose content of 17 % is a promising non-resorbable biomaterial for auricular cartilage tissue engineering, due to its similarity with auricular cartilage in terms of mechanical strength and host tissue response.
由木醋杆菌合成的细菌纳米纤维素（BNC）由具有高机械强度的高度水合纤维（99%为水）组成。这些优异的材料特性使BNC成为一种适用于许多潜在医学和组织工程应用的新型生物材料。最近，纤维素含量为15%的BNC已被提议作为耳软骨置换的植入材料，因为它符合人体耳软骨的力学要求。本研究调查了纤维素含量增加（17%）的BNC的生物相容性，以评估其在体外和体内的反应。制备了圆柱形BNC结构（Ø48×20 mm），在内置的室内灌注系统中进行纯化，并进行压缩以增加BNC水凝胶中的纤维素含量。在整个纯化过程中，通过细菌内毒素分析对材料内毒素毒性的降低进行了量化。之后，根据ISO 10993规定的标准，在体外和体内评估了纤维素含量为17%的纯化BNC水凝胶的生物相容性。纯化后，未纯化的BNC中的内毒素含量（2390内毒素单位（EU）/ml）降至0.10 EU/ml，远低于医疗器械设定的内毒素阈值。此外，生物相容性测试表明，致密化的BNC水凝胶无细胞毒性，引起的异物反应最小。与我们之前的研究结果一致，本研究得出结论，纤维素含量增加至17%的BNC因其在机械强度和宿主组织反应方面与耳软骨相似，是一种有前景的用于耳软骨组织工程的不可吸收生物材料。
