Nanomaterials are diverse in size, shape, and charge and these differences likely alter their physicochemical properties in biological systems. We have investigated how these properties alter the initial and long-term dynamics of endocytosis, cell viability, cell division, exocytosis, and interaction with a collagen extracellular matrix using silica-based fluorescent nanoparticles and the murine pre-osteoblast cell line, MC3T3-E1. Three surface modified nanoparticles were analyzed: positively charged (PTMA), negatively charged (OH), and neutrally charged polyethylene glycol (PEG). Positively charged PTMA-modified nanoparticles demonstrated the most rapid uptake, within 2 hours, while PEG modified and negatively charged OH nanoparticles demonstrated slower uptake. Cell viability was >80% irrespective of nanoparticle surface charge suggesting a general lack of toxicity. Long-term monitoring of fluorescent intensity revealed that nanoparticles were passed to daughter cells during mitotic cell division with a corresponding decrease in fluorescent intensity. These data suggest that irrespective of surface charge silica nanoparticles have the potential to internalize into pre-osteoblasts, albeit with different kinetics. Furthermore, long lived nanoparticles have the potential to be transferred to daughter cells during mitosis and can be maintained for weeks intracellularly or within a collagen matrix without toxicity and limited exocytosis.

纳米材料的大小、形状和电荷各不相同，这些差异可能会改变它们在生物系统中的物理化学特性。我们已经使用基于二氧化硅的荧光纳米粒子和鼠前成骨细胞系 MC3T3-E1 研究了这些特性如何改变内吞作用的初始和长期动态、细胞活力、细胞分裂、胞吐作用以及与胶原细胞外基质的相互作用. 分析了三种表面改性纳米粒子：带正电荷 (PTMA)、带负电荷 (OH) 和带中性电荷的聚乙二醇 (PEG)。带正电的 PTMA 修饰的纳米颗粒表现出最快的吸收，在 2 小时内，而 PEG 修饰的和带负电的 OH 纳米颗粒表现出较慢的吸收。细胞活力是 > 80% 与纳米颗粒表面电荷无关，表明普遍缺乏毒性。荧光强度的长期监测表明，纳米粒子在有丝分裂细胞分裂过程中传递给子细胞，荧光强度相应降低。这些数据表明，无论表面电荷如何，二氧化硅纳米粒子都有可能内化为前成骨细胞，尽管动力学不同。此外，长寿命纳米粒子有可能在有丝分裂期间转移到子细胞中，并且可以在细胞内或胶原基质内维持数周，而没有毒性和有限的胞吐作用。荧光强度的长期监测表明，纳米粒子在有丝分裂细胞分裂过程中传递给子细胞，荧光强度相应降低。这些数据表明，无论表面电荷如何，二氧化硅纳米粒子都有可能内化为前成骨细胞，尽管动力学不同。此外，长寿命纳米粒子有可能在有丝分裂期间转移到子细胞中，并且可以在细胞内或胶原基质内维持数周，而没有毒性和有限的胞吐作用。荧光强度的长期监测表明，纳米颗粒在有丝分裂细胞分裂期间传递给子细胞，荧光强度相应降低。这些数据表明，无论表面电荷如何，二氧化硅纳米粒子都有可能内化为前成骨细胞，尽管动力学不同。此外，长寿命纳米粒子有可能在有丝分裂期间转移到子细胞中，并且可以在细胞内或胶原基质内维持数周，而没有毒性和有限的胞吐作用。