Nanocellulose is an excellent carrier to deliver drugs, as the material is biocompatible and has a desirable non-spherical shape. However, nanocellulose displays low solubility in aqueous solution and needs to be modified with water-soluble polymers in order to achieve high colloidal stability. In this study, (2,2,6,6-tetramethylpiperidin-1-yl)oxyl or (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl (TEMPO)-oxidized cellulose nanofibers bearing carboxylic acid moieties (TOCNs) are modified by nitrile imine-mediated tetrazole/carboxylic acid ligation. The advantage of this reaction is that TOCNs do not need to be modified further and the polymer with tetrazole end-functionalities can be directly clicked onto the TOCNs forming fluorescent functional groups. Poly(2-hydroxyethyl acrylate) with a tetrazole end-functionality is prepared using RAFT polymerization. The polymer is mixed with TOCNs and after irradiation at λ = 326 nm for 10 h, fluorescent pHEA-g-TOCNs are obtained. The polymer-grafted nanocellulose is found to disperse well in water and has only limited albumin binding. The uptake of these nanoparticles by MCF-7 breast cancer cell lines can now be monitored by fluorescent microscopy without further modification. Excess negatively charged carboxylic groups of TOCNs allow doxorubicin loading by electrostatic interactions at various drug-loading capacities. Higher drug loading is more efficient in inhibiting the cell proliferation, highlighting the effect of drug loading on toxicity.

中文翻译：

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光诱导的纳米纤维素修饰：自发光药物载体的设计。

纳米纤维素是传递药物的出色载体，因为该材料具有生物相容性并具有理想的非球形形状。然而，纳米纤维素在水溶液中显示出低溶解度，并且需要用水溶性聚合物进行改性以实现高的胶体稳定性。在这项研究中，（2,2,6,6-四甲基哌啶-1-基）氧基或（2,2,6,6-四甲基哌啶-1-基）氧烷基（TEMPO）氧化的纤维素纳米纤维带有羧酸部分（TOCNs） ）被腈亚胺介导的四唑/羧酸连接修饰。该反应的优点在于不需要进一步修饰TOCN，并且可以将具有四唑末端官能团的聚合物直接点击到形成荧光官能团的TOCN上。使用RAFT聚合制备具有四唑末端官能度的聚（丙烯酸2-羟乙酯）。将该聚合物与TOCN混合，并在λ= 326 nm照射10小时后，获得荧光pHEA-g-TOCN。发现该聚合物接枝的纳米纤维素很好地分散在水中并且仅具有有限的白蛋白结合。现在可以通过荧光显微镜监测MCF-7乳腺癌细胞系对这些纳米颗粒的摄取，而无需进一步修改。TOCN的带负电荷的羧基过多，会通过在各种药物负载量下的静电相互作用而使阿霉素负载。较高的载药量在抑制细胞增殖方面更有效，突出了载药量对毒性的影响。获得荧光pHEA-g-TOCN。发现该聚合物接枝的纳米纤维素很好地分散在水中并且仅具有有限的白蛋白结合。现在可以通过荧光显微镜监测MCF-7乳腺癌细胞系对这些纳米颗粒的摄取，而无需进一步修改。TOCN的带负电荷的羧基过多，会在各种载药量下通过静电相互作用使阿霉素载药。较高的载药量在抑制细胞增殖方面更有效，突出了载药量对毒性的影响。获得荧光pHEA-g-TOCN。发现该聚合物接枝的纳米纤维素很好地分散在水中并且仅具有有限的白蛋白结合。现在可以通过荧光显微镜监测MCF-7乳腺癌细胞系对这些纳米颗粒的摄取，而无需进一步修改。TOCN的带负电荷的羧基过多，会通过在各种药物负载量下的静电相互作用而使阿霉素负载。较高的载药量在抑制细胞增殖方面更有效，突出了载药量对毒性的影响。TOCN的带负电荷的羧基过多，会通过在各种药物负载量下的静电相互作用而使阿霉素负载。较高的载药量在抑制细胞增殖方面更有效，突出了载药量对毒性的影响。TOCN的带负电荷的羧基过多，会通过在各种药物负载量下的静电相互作用而使阿霉素负载。较高的载药量在抑制细胞增殖方面更有效，突出了载药量对毒性的影响。