Biocompatible fluorescent nanoparticles for pH-sensoring

Alkynyl Ethers of Glucans: Substituent Distribution in Propargyl‐, Pentynyl‐ and Hexynyldextrans and ‐amyloses and Support for Silver Nanoparticle Formation

“…Since it is known from the literature that amphiphilic dextran derivatives with an appropriate hydrophilic/lipophilic balance form nanoparticles by dialysis of diluted DMAc or DMSO solutions against water, [9][10][11][12][13] SEM images were recorded from the products, obtained by dialysis from DMSO during work-up and subsequent freeze-drying. Pentynyl-and hexynyldextrans gave a mixture of geometries: spheres, long cylindrical structures with a diameter in the range up to 1 mm diameter, and laminary sheet like structures ( Figure 11).…”

“…[10][11][12] pH-Sensitive fluorescent dyes could be included and used as pH probes in cells. [13] Mainly average substitution data obtained by NMR spectroscopy and elemental analysis (EA) have been reported in the literature and often a random distribution is hypothesised. [14] To the best of our knowledge, there are only few papers dealing with differentiated analysis of the substituent distribution in the glucosyl units.…”

Polymeric nanoparticles for optical sensing

“…Unfortunately, no long-term cytotoxicity and photostability studies have been performed to show whether these particular nanosystems might be employed to investigate pH changes related to cellular aging and molecular alteration in cancer. In contrast, FITC-based NPs were coated with dextran to increase their long-term cytocompatibility with the result that no cytotoxic effects were observed over a 22 day period (Hornig et al, 2008).…”

“…However, these dyes cannot be targeted to individual organelles and often aggregate, invalidating pH measurements (Clark et al, 1999). By incorporating the indicator dyes in silica NPs these drawbacks can be overcome, since NPs can minimize organelle sequestration and avoid cytotoxic effects due to direct contact with organic fluorophores (Hornig, Biskup, 2008). In another example, Xu and colleagues developed core-shell silica nanoparticles (60 nm) containing two dyes (FITC and Ru(phen) 3 2+ ) which were employed as a ratiometric intracellular pH indicator (Xu et al, 2011).…”

Optical Chemical Sensors:Design and Applications

“…In the field of biology and medicine, sensors able to monitor pH in real time are in great demand, as they can be used for the general understanding of biological processes and for biomedical diagnostics (Doussineau et al, 2009). Recently, a lot of work has been done on optical pH-sensitive micro- (Borisov et al, 2008a;Doussineau et al, 2009;Schulz et al, 2009 ;Hornig et al, 2008) and nano-sensors (Allard & Larpent, 2008;Burns et al, 2006;Gao et al, 2005;Gao et al, 2007;Kim et al, 2006;Peng et al, 2007;Sun et al, 2006;). Here, the latter will be discussed, since they are less than 100 nm in size.…”