Journal of Bioprocessing & Biotechniques

Despite the drawbacks of using conventional organic fluorescence probes, such as the weak fluorescent signal against the strong cellular autofluorescence background coupled with a fast-photobleaching rate, single-particle tracking (SPT) is a powerful method for exploring singlemolecule dynamics in living cells or tissues. Quantum dots (QDs), which enable tracking targets in multiple colours, have been suggested as an alternative to conventional organic fluorescence dyes. However, due to their hydrophobicity, cytotoxicity, and blinking issues, QDs are not ideal for applying SPT. The silica-coated QD-embedded silica nanoparticles (QD2) used in this study's improved SPT method have brighter fluorescence and are less toxic than single QDs. The label was kept after treatment with QD2 in 10 g/mL for 96 hours with impaired cell function, such as impaired angiogenesis, labelling efficiency was 83.76 percent. QD2's increased stability makes it easier to observe in situ endothelial vessel formation without needing to stain in real time. For 15 days at 4 °C, a cell maintain their QD2 fluorescence signal without experiencing significant photobleaching, proving that QD2 has overcome the limitations of SPT and is now capable of long-term intracellular tracking. With its superior brightness, photostability, and biocompatibility, QD2 was shown to be a viable alternative to single quantum dots or conventional organic fluorophores for SPT.

A crucial tactic for reducing pollution and climate change is the use of renewable energy, which has led to an increase in the demand for new sources. Studies are currently being conducted on proprietary, rapidly growing cyanobacterial strains of Fremyella diplosiphon with a 7–10 day life cycle on average and a demonstrated ability to produce lipids for biofuel production. The growth and photosynthetic pigmentation of a cyanobacterial strain (SF33) were examined in this study, as well as the production of biocrude through hydrothermal liquefaction. Under less-thanideal conditions, including in outdoor bioreactors with growth differences of less than 0.04 (p = 0.035) between different batches, the cultivation of F. diplosiphon did not significantly differ (0.05). The components of the biocrude were examined, and fatty acids were found.