Chitosan is cancer cytotoxic. It induces apoptosis/necrosis/autophagy and immuno-responses, and mitigates angiogenic and metastasis tendency of cancer cells. The lower molecular weight chitosan induces apoptosis, whereas the higher molecular weight chitosan exerts apoptosis and necrosis. Transforming chitosan into nanoparticles raises its anti-cancer efficacy with mode of cancer cell death governed by particle size to a greater extent than chitosan molecular weight. The larger nanoparticles tend to exert apoptosis. The smaller nanoparticles mediate necrosis. “Drug-free” small nanoparticles constituted of lower molecular weight chitosan are more cytotoxic than those of larger chitosan molecules/particles in vitro and in vivo, with no clear relationship between the deacetylation degree and zeta potential of nanoparticulate chitosan with anti-cancer activity. “Drug-free” chitosan nanoparticles are potentially as viable as the drug-loaded chitosan nanoparticles but with reduced systemic adverse effects. Their anti-cancer efficacy can be modulated through particle dose adjustment with lower risks of harmful effects than drugs and without processing hurdles faced in the development of drug-loaded chitosan nanoparticles such as low aqueous drug solubility, poor drug encapsulation, premature drug release and drug absorption, and drug instability with toxic metabolite formation.

中文翻译：

---

“无药”壳聚糖纳米粒子作为癌症治疗药物


壳聚糖具有癌症细胞毒性。它诱导细胞凋亡/坏死/自噬和免疫反应，并减轻癌细胞的血管生成和转移倾向。较低分子量的壳聚糖诱导细胞凋亡，而较高分子量的壳聚糖则引起细胞凋亡和坏死。将壳聚糖转化为纳米颗粒可提高其抗癌功效，与壳聚糖分子量相比，颗粒尺寸对癌细胞死亡模式的影响更大。较大的纳米粒子往往会引起细胞凋亡。较小的纳米粒子介导坏死。由较低分子量的壳聚糖构成的“无药”小纳米颗粒在体外和体内比较大的壳聚糖分子/颗粒具有更强的细胞毒性，具有抗癌活性的纳米颗粒壳聚糖的脱乙酰度和zeta电位之间没有明确的关系。 “无药”壳聚糖纳米颗粒可能与载药壳聚糖纳米颗粒一样可行，但全身不良反应减少。其抗癌功效可以通过颗粒剂量调节来调节，与药物相比，有害作用的风险更低，并且不存在载药壳聚糖纳米颗粒开发中面临的加工障碍，例如药物水溶性低、药物封装性差、药物过早释放和药物过早释放等。吸收和药物不稳定并形成有毒代谢物。