Sample Solution

There is considerable interest in recent years in developing biodegradable nanoparticles as a drug/gene delivery system [25, 38-41]. An ideal drug-delivery system possesses two elements: the ability to target and to control the drug release. Targeting will ensure high efficiency of the drug and minimize the side effects, especially when dealing with drugs that are supposed to kill cancer cells but can also kill healthy cells when delivered to them. Controlled drug release can decrease or even prevent its side effects.
The advantages of using nanoparticles for drug delivery applications rise from their three main basic properties. First, nanoparticles, because of their small size, can penetrate through smaller capillaries, which could allow efficient drug accumulation at the target sites [42, 43]. Second, the use of biodegradable materials for nanoparticle preparation can allow sustained drug release within the target site over a period of days or even weeks [44-46]. Third, the nanoparticle surface can be adapted to modify biodistribution of drugs or can be conjugated to a ligand to attain target-specific drug delivery [47, 48].

The advantages of using nanoparticles as drug delivery system include: (1) stable dosage forms of drugs which are either unstable [49, 50] or have unacceptably low bioavailability in non-nanoparticulate dosage forms[51, 52] ; (2) they control and sustain release of