Poly(amidoamine)s carrying TEMPO residues for NMR imaging applications

Interaction of an Endosomolytic Polyamidoamine ISA23 with Vesicles Mimicking Intracellular Membranes: A SANS/EPR Study

“…Our previous studies with model micelles [17] demonstrated ISA23 mediated pH-dependent interaction with micelle surfaces having a small head group (e.g., SDS), but not with the more bulky, physiological head groups like lyso-PC. Those results are consistent with the findings this study.…”

“…Phospholipid composition of the different biological membranes (for structures, see Scheme 1; values adapted from Quinn, [10] Robinson, [11] Gallegos et al, [12] Bergstrand et al, [13] Evans and Hardison, [14] and Urade et al [15] conjugate (M w ¼ 10 600 g Á mol À1 ; M w =M n 1.6) were synthesized and characterized as previously described. [17] Hydrogenous and tail deuterated analogues of the phospholipids DPPC, DPPS sodium salt and DPPE were from Avanti Polar Lipids Inc. (USA). All the phospholipids contained saturated fatty acid chains with 16 carbons in each chain, they were supplied in powder form, and were used without further purification.…”

A pH dependent thermo-sensitive copolymer drug carrier incorporating 4-amino-2,2,6,6-tetramethylpiperidin-1-oxyl (4-NH2-TEMPO) residues for electron spin resonance (ESR) labeling

“…6. The spectra exhibited the typical three-line hyperfine splitting pattern due to coupling of the electron spin of the nitroxyl group with the nuclear spin (I = 1) of the 14 N nucleus [25,44]. In Fig.…”

“…Nitroxyl radicals possess the properties of chemical flexibility, easy preparation and excellent stability at both physiological pH and temperature. As occurs generally for paramagnetic ions, when attached to a macromolecule, TEMPO exhibits an increased relaxation rate [25]. ESR frequencies usually used are in the microwave range at 10 GHz (X-band) or 1 GHz (L-band).…”

Synthesis of Novel Nitroxide Radical Polymer Materials for Imaging and Energy Storage Applications

“…Several similar studies followed from various groups, reporting on preliminary in vitro and in vivo MRI studies as well as toxicity tests of prepared macromolecular nitroxide-based contrast agents. 228,251,262,277,282,294,304,323 Rajca et al further developed the dendrimer-type contrast agents to a more advanced stage and, in doing so, coined the term "organic radical contrast agent" (ORCA).…”