Polymersomes degradable

Hammer and coworkers prepared PEG-h-PCL polymersomes entrapping DXR (Fig. 11a). The release of DXR from the polymersomes was in a sustained manner over 14 days at 37 °C in PBS via drug permeation through the PCL membrane, and hydrolytic degradation of the PCL membrane [228]. The release rate of encapsulated molecules from polymersomes can be tuned by blending with another type of block copolymer [229]. Indeed, the release rate of encapsulated DXR from polymersomes prepared from mixtures of PEG- -PLA with PEG- -PBD copolymers increased linearly with the molar ratio of PEG- -PLA in acidic media (Fig. lib). Under acidic conditions, the PLA first underwent hydrolysis and, hours later, pores formed in the membrane followed by final membrane... 

Hydrophobic blocks that are used for polymersome fabrication are inert polyethylethylene, polybutadiene, polystyrene, polydimethylsiloxane, degradable poly(lactic acid) (PLA), and poly(e-caprolactone) (PCL). Hydrophilic blocks include negatively charged poly(acrylic acid) and cross-linkable poly-methyloxazoline. Neutral PEG is more common for bioapplications. Among block copolymers, PEO-PLA and PEO-PCL are becoming widely adopted [26]. 

Ahmed F, Pakunlu RI, Srinivas G, et al. Shrinkage of a rapidly growing tumor by drug-loaded polymersomes pH-triggered release through copolymer degradation. Mol Pharm 2006 3 340-350. 

Chen W, Meng F, Cheng R, Zhong Z. pH-Sensitive degradable polymersomes for triggered release of anticancer drugs A comparative study with micelles. Journal of Controlled Release. 2010 142(l) 40-46. 

Du, Y., et al. 2012. pH-sensitive degradable chimaeric polymersomes for the intracellular release of doxorubicin hydrochloride. Biomaterials 33(29) 7291-7299. 

Liposomes (with a bilayer resembling that of the cell membrane) are considered to be the first example of inspired dmg carriers together with the vims-inspired vesicles such as virosomes and polymersomes (Alvarez-Lorenzo et al., 2012). Recently, pharmaceutical research has extended its focus to degradable polymeric matrices... 

Ahmed, E, Pakunlu, R. L, Srinivas, G., Brannan, A., Bates, E, Klein, M. L., Minko, T. and Discher, D. E. (2006) Shrinkage of a rapidly growing tumor by drug-loaded polymersomes pH-triggered release through copolymer degradation. Mol Pharm, 3,340-350. 

Chen, W., Meng, F.H., Cheng, R., Zhong, Z.Y. pH-sensitive degradable polymersomes for triggered release of anticancer drugs a comparative study with micelles. J. Controlled Release 142, 40 6 (2010)... 

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