Methoxyl poly (ethylene glycol) (mPEG-OH) was successfully grafted onto branched polyethyleneimine (hy-PEI) to yield a water soluble graft copolymer mPEG-g-PEI.
The young mother looked down at her son.He was dying of illness.Like any parent she wanted her son to grow up.Now it was no longer possible.But she still wanted