Papers by Author: Ding Ding Guo

Abstract: The objective of this study is to investigate whether the PEGylated conjugated linoleic acid (PCLA) as an anti-cancer prodrug can have favorable stability, biological activity, and prevention of proliferation in MCF-7 breast cancer cells for anti-cancer when compared with conjugated linoleic acid (CLA) itself. The CLA was simply coupled to poly(ethylene glycol) (PEG) at melting state without solvent or catalyst through ester linkage between carboxylic group of CLA and hydroxyl one of PEG. The results showed that the half life of PCLA was 55h in cell culture medium at pH 7.4 and 37°C. Apoptosis of MCF-7 breast cancer cells were induced by not only CLA- but PCLA-treatment with increasing concentrations whereas PCLA increased cell viability when compared with CLA itself. These results indicate that the PCLA is a more stable and valuable prodrug in that it has good stability and inhibition of cancer cell proliferation.

Abstract: The objective of this study is to develop a new type of cationic nanoparticles for the intracellular drug delivery to breast cancer. Poly(ester amine) (PEA) based on polyethylenimine and polycaprolactone was synthesized to make cationic PEA nanoparticles for all-trans retinoic acid (RA). In the 1H-NMR study, the proton signals of RA appeared in the spectrum of RA-loaded PEA nanoparticles in CDCL3, whereas they disappeared in D2O, suggesting that hydrophobic inner-core with hydrophilic outer-shell formed in water. RA release was faster at lower drug content and RA was released over a period of 20 days. RA-loaded PEA nanoparticles showed enhanced cytotoxicity compared with RA itself, whereas nanoparticles of PEA themselves did not show it. These results indicated that the cationic PEA provided an efficient intracellular delivery of RA.