2/18/2011
Synthesis and self-assembly behavior of novel polyaspartamide derivatives for anti-tumor drug delivery
(63-71) Colloid and Polymer Science 289 #1 (2011)
Moon et al of South Korea synthesized a series of amphiphilic graft copolymers based on polyaspartamide by a successive aminolysis reaction of polysuccinimide using 2-diisopropylaminoethyl (DIP) and laurylamine as a pH sensitive and hydrophobic group, respectively.  Nano-aggregation occurred at a pH in the vicinity of the pKa of the DIP group, which was induced by a hydrophilic–hydrophobic shift of the DIP group in solution. The mean diameter of the nano-aggregate could be modulated by changing the composition of both pendants. The mean diameter of the nanoparticles increased with increasing solution pH from 6.5 to 8. At pH 8, the mean diameter of the nanoparticles increased rapidly at the temperature above 45 °C, probably due to the change in hydrophilic–hydrophobic balance of the pH-sensitive DIP moiety.  The results showed significantly faster release of PTX at pH 6.5, which is a tumoral acidic pH, than in a neutral physiological pH.  These thermo- and pH-sensitive polyaspartamide derivatives have potential use as a tumor-targeting delivery.  (RDC 2/14/2011)

2/4/2011
Development of PEGylated doxorubicin-E-[c(RGDfK)2] conjugate for integrin-targeted cancer therapy
(103–113)Polymers for Advanced Technologies 22 #1 (2011)
Polyak et al of Israel and Germany  synthesized a delivery system for doxorubicin that enables the conjugation of Arg-Gly-Asp (RGD) peptidomimetic, on one end of a linear poly(ethylene glycol) (PEG) chain, and DOX on the other end. The drug was bound to the polymer through an acid-sensitive (6-maleimidocaproyl)hydrazone linker. The resulting PEG-DOX-E-[c(RGDfK)2] conjugate actively and selectively targets endothelial and tumor cells overexpressing αvβ3 integrin.  Doxorubicin (DOX) is extensively used in cancer therapy; however, it is cardiotoxic in cumulative doses and chemoresistance can evolve with prolonged use. Conjugation of a chemotherapeutic agent to a water-soluble polymeric carrier prolongs the circulation life of the drug, promotes its accumulation at the tumor site due to the enhanced permeability and retention (EPR) effect and prevents the drug from extravasating into healthy tissues. (RDC 2/4/2011)

10/26/2010
7,820,759
Micellar preparation containing sparingly water-soluble anticancer agent and novel block copolymer
Shimizu of Nippon Kayaku and Nanocarrier Kabushiki, Japan  has developed a micellar preparation in which the solubility of a sparingly water-soluble anticancer agent has been increased and facilitates the maintenance of a high blood concentration.  The solubilizing element is s block copolymer of a polyether and a polypeptide. (RDC 2/18/2011)