Macromolecule nanotherapeutics: approaches and challenges.

With the advent of technology, newer forms of drugs, such as proteins, DNA, and RNA, have entered mainstream product development. However, systemic delivery of macromolecules is limited by rapid blood clearance, poor stability in vivo, and inadequate uptake by cells. Nanoparticle (NP)-based delivery systems have emerged as suitable carriers for overcoming such pharmacokinetic limitations of macromolecule delivery. Nanocarriers, such as liposomes, provide protection for sensitive drug materials and also enhance the circulation half-life of therapeutics. Nanocarriers have also been shown to promote cellular uptake and the release of intact macromolecules in the cell. Besides liposomes, other nanocarriers, such as gold and iron oxide NPs, are also now being tested in clinical trials.