Figure 1.

A scheme representing two systems which is promising in improving the solubility of poorly water soluble molecules. B,D show a combined therapy drug delivery system for improved solubility, in such a system, two different drugs are loaded into the dendrimer separately, then the two nanosystems are combined together to have one system with two different drugs. The two drugs are both delivered to cell F. C,E represent a combined drug delivery system, in such a system, two different nanoparticles are prepared separately loaded or unloaded with drugs. Then, the two systems are combined together and drug is released. Conjugation with polyethylene glycol PEG and/or special ligands such as antibody to polyamidoamine (PAMAM) dendrimer nanohybrid not only improves solubility and sustains release of drugs but also enhances targeted drug delivery. Red, black, and blue balls represent drugs entrapped or conjugated into the nanohybrid system.