Polyortho ester

No.22, Nov.2002, p.4397-404 DEVELOPMENT AND APPLICATIONS OF INJECTABLE POLYORTHO ESTERS FOR PAIN CONTROL AND PERIODONTAL TREATMENT Heller J Barr J Ng S Y Shen H-R Schwach-Abdellaoui K Gumy R Vivien-Castioni N Loup P J Baehni P Mombelli A AP Pharma Geneva,University... 

There are many polymers that are suitable for the production of nanoparticles employed for drug delivery, which can generally be divided into two groups natural polymers, e.g., polysaccharides (chitosan), proteins (albumin, gelatin), as well as synthetic polymers, e.g., polyesters (poly(lactic add), poly(glycolic add), poly(hydroxy butyrate), poly-e-caprolactone, poly-p-malic add, poly(dioxanones)) polyanhydrides (poly(adipic add)) polyamides (poly(amino acids)) phosphorous-based polymers (polyphosphate) poly(cyano acrylates) polyurethanes polyortho esters and polyacetals. Extreme attention has to be paid to the biodegradability and biocompatibility of the polymers. It is essential that polymers used for medical applications are not detrimental for the tissue or cells and that they can be easily decomposed into simple harmless molecules and eliminated by the human body [ 18-22]. 

Intracellular pH gradients can be exploited in the cellular delivery of macromolecules [129]. Polyortho esters (POEs) are relatively stable under physiological pH, but rapidly hydrolyze at the endosomal/lysosomal pH of 5. This characteristic has been exploited for enhanced dehvery of DNA vaccines by... 

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