Mechanism of Mesoporous Silica Nanoparticle Interaction with Hairy Root Cultures during Nanoharvesting of Biomolecules

• Published in: Advanced biology 2021-03, Vol.5 (3), p.e2000173-n/a
• Main Authors: Khan, Md Arif, Fugate, Madeleine, Rogers, Dennis T., Sambi, Jatinder, Littleton, John M., Rankin, Stephen E., Knutson, Barbara L.
• Format: Article
• Language: English
• Subjects: cell penetration; hairy root culture; nanoharvesting; Nanoparticles; Plant Cells; Plants; silica nanoparticles; Silicon Dioxide
• ISSN: 2701-0198; 2701-0198
• DOI: 10.1002/adbi.202000173

Cellular uptake and expulsion mechanisms of engineered mesoporous silica nanoparticles (MSNPs) are important in their design for novel biomolecule isolation and delivery applications such as nanoharvesting, defined as using nanocarriers to transport and isolate valuable therapeutics (secondary metabolites) out of living plant organ cultures (e.g., hairy roots). Here, temperature‐dependent MSNP uptake and recovery processes in hairy roots are examined as a function of surface chemistry. MSNP uptake into hairy roots and time‐dependent expulsion are quantified using Ti content (present for biomolecule binding) and fluorescence spectroscopy of fluorescently tagged MSNPs, respectively. The results suggest that functionalization and surface charge (regulated by amine group attachment) play the biggest role in the effectiveness of uptake and recovery. Comparison of MSNP interactions with hairy roots at 4 and 23 °C shows that weakly charged MSNPs functionalized only with Ti are taken up and expelled by thermally activated mechanisms, while amine‐modified positively charged particles are taken up and expelled mainly by direct penetration of cell walls. Amine‐functionalized MSNPs move spontaneously in and out of plant cells by dynamic exchange with a residence time of 20 ± 5 min, suggesting promise as a biomolecule nanoharvesting platform for plant organ cultures. Charge‐dependent cellular internalization, transport, and expulsion mechanism of functionalized mesoporous silica nanoparticles are investigated to elucidate their intracellular pathways during nanoharvesting and delivery applications. Uptake and expulsion of weakly charged particles in plant cells are regulated by activated processes (endo‐ and exocytosis), whereas strongly charged particles mostly penetrate the cell‐membrane directly via a charge mediated process, which gives them the ability to access intracellular compounds.