“…Amongst the commonly used polymers for colloidal drug delivery approved for human use are poly(lactic acid) (Guiziou et al, 1996), poly(lactic-coglycolic acid) (Aguiar et al, 2004;Bilati et al, 2005) and poly(-caprolactone) (Kim et al, 2005;Le Ray et al, 2003). There is also a growing list of novel synthetic biodegradable polymers that are being investigated for their potential in drug delivery systems, including polycarbonates, polyanhydrides, polymalic acid, polyphosphazenes, polyaminoacids (Davis et al, 1996), polyesters (Breitenbach et al, 2000;De Jesús et al, 2002) and poly-N-isopropylacrylamide and other responsive polymers (Alexander and Shakesheff, 2006).…”