Discovery Sciences, RTI International, 3040 Cornwallis Drive, Research Triangle Park, NC, 27709, USA.
Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, 2907 East Gate City Blvd, Greensboro, NC, 27401, USA.
Food Chem Toxicol. 2022 Aug;166:113204. doi: 10.1016/j.fct.2022.113204. Epub 2022 Jun 6.
The potential applications of cellulose nanomaterials (CNMs) as food additives or in food packaging, present a possible source of human ingestion. While micron- and macro-scale cellulose products are classified as Generally Regarded As Safe, the safety of ingested nano-scale cellulose is largely unknown. Using fully differentiated Caco-2 cells, the perturbation of intestinal barrier function and cytotoxicity was investigated for four nanocellulose crystals (CNCs) and four nanocellulose fibrils (CNFs) following 24 h of exposure at 50 μg/mL. Scanning electron microscope showed some aggregation of both CNCs and CNFs. X-ray photoelectron spectroscopy analyses showed that carbon and oxygen were the main elements. The zeta-potential for CNMs formulated in cell culture medium showed a negative surface charge. Two CNMs increased cell membrane permeability and three CNMs decreased the cell metabolic activity. While three CNMs lead to cytotoxic responses, no changes in apparent permeability coefficient (P) for dextran or tight junction integrity were found. Our results show that three CNMs induce cytotoxicity in differentiated Caco-2 cells, demonstrating the need to understand the role of size and shape. The interaction between CNMs and the intestinal epithelium needs to be evaluated to understand potential intestinal barrier dysfunction and resulting health implications following CNM ingestion.
纤维素纳米材料（CNMs）作为食品添加剂或在食品包装中的潜在应用，可能成为人类摄入的来源。虽然微米和宏观尺度的纤维素产品被归类为一般认为是安全的，但摄入的纳米尺度纤维素的安全性在很大程度上是未知的。使用完全分化的 Caco-2 细胞，在 50μg/mL 下暴露 24 小时后，研究了四种纳米纤维素晶体（CNCs）和四种纳米纤维素纤维（CNFs）对肠道屏障功能的干扰和细胞毒性。扫描电子显微镜显示 CNCs 和 CNFs 都有一些聚集。X 射线光电子能谱分析表明，碳和氧是主要元素。在细胞培养基中配制的 CNM 的动电位显示出负表面电荷。两种 CNM 增加了细胞膜通透性，三种 CNM 降低了细胞代谢活性。虽然三种 CNM 导致细胞毒性反应，但发现葡聚糖的表观渗透系数（P）或紧密连接完整性没有变化。我们的结果表明，三种 CNM 在分化的 Caco-2 细胞中诱导细胞毒性，这表明需要了解尺寸和形状的作用。需要评估 CNM 与肠上皮的相互作用，以了解摄入 CNM 后潜在的肠道屏障功能障碍和由此产生的健康影响。
