Thermally induced micelles

The utility of FTIR spectroscopy in studies of phase transitions involving micellar surfactant solutions has been increasingly demonstrated in recent years (1-7). The familiar concentration-dependent monomer to micelle transition (cmc), the thermally induced hydrated solid to micelle transition (cmt), and the micelle to coagel transition achieved at high pressure (ccp) have all been investigated (Figure 1). These transitions can be monitored by shifts in frequency (= 5 cm"1) of the CH2 stretching bands which appear in the spectra. 

In vitro cytotoxicity studies with drug-loaded micelles have also shown greater cytotoxicity above the LCST, resulting from thermally induced drug release. These results suggest that combination therapy can be implemented, using both thermosensitive systems and local hyperthermic treatment of tumors, primarily at 42°C. The coupled treatment may prove to be more... 

The suggested mechanism of the thermally induced pore closure process is illustrated in Scheme 11.1. The starting point of the synthesis is the formation of an ordered silica-copolymer (or organosilica-copolymer) composite, in which the copolymer micelles are embedded in the silica (or organosilica) framework. More specifically, the hydrophilic blocks (i.e., poly(ethylene oxide), PEO, blocks) of the copolymer are occluded in the silica (or organosilica) framework, while the hydro-phobic blocks (i.e., poly(propylene oxide), PPO, blocks) form separate domains. Such a structure of silica/copolymer composites emerged from NMR studies and provided the basis of the explanation of the pore connectivity in the structure of SBA-... 

Amphiphilic block copolymers have attracted great interest in biomaterials apphcalions. Erom micelle formation to thermally induced gelation, these amphiphilic block copolymers find interesting applications in drug delivery and tissue engineering. Poly(ethylene... 

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