Thermosensitive Cyclotriphosphazenes

Effect of Inorganic and Organic Salts on the Thermogelling Behavior of Poly(organophosphazenes)

“…[7] Of those polymers, the last two in the above list show immense potential in terms of an injectable in situ depot-forming system, because they are both biocompatible and biodegradable. [1,2,[7][8][9][10] Our group has reported a series of thermosensitive poly(organophosphazenes) [7][8][9][10] and cyclotriphosphazenes [11,12] which bear MPEG and amino acid esters as side groups. Aqueous solutions of poly(organophosphazenes) undergo the sol-to-gel transition under increased temperatures.…”

Thermoresponsive Micelles from Oligopeptide‐Grafted Cyclotriphosphazenes

“…We have shown in our previous work that nucleophilic substitution of hexachlorocyclotriphosphazene (I) with the sodium salt of MPEG at low temperature (T < À60 8C) gives rise to the half-substituted intermediate (II) with cis nongeminal conformation as a major product. [4] Further substitution of the intermediate with an oligopeptide ethyl ester (H 2 NR') produced a final amphiphilic product (III), which was purified twice by precipitation at the lower critical solution temperature (LCST) in aqueous solution. The LCST is the temperature at which the polymer solution undergoes phase transition from a soluble to an insoluble state.…”

Poly‐ and Cyclophosphazenes as Drug Carriers for Anticancer Therapy

“…In this regard, cyclotri(organophosphazene)s are in a much better position, because the phosphazene trimer backbone is monodisperse and it is much easier to control the purity and molecular weight of the side groups. As a matter of fact, Lee et al (2000) have succeeded in the synthesis of pure amphiphilic cyclotriphosphazenes by stepwise substitutions of hexachlorocyclotriphosphazene with equimolar hydrophilic PEG and hydrophobic amino acid. A few typical compounds among the products were analyzed to be highly pure (W99%) using MALDI mass spectrometry and high-performance liquid chromatography.…”