Targeted drug delivery to macrophages.

INTRODUCTION: Targeted drug delivery to the macrophages appears to be an attractive proposition to improve therapeutic efficacy of enclosed drug. Thus, macrophages can be exploited as Trojan horses for targeted drug delivery. Nanocarriers can migrate across the different membrane barriers and release their drug cargo at sites of infection. AREAS COVERED: This review discusses the current status and utilization of various micro- as well as nanocarriers like microspheres/microparticles, liposomes, nanoparticles, dendrimers, niosomes, and carbon nanotubes for targeted delivery of bioactives to the macrophages. EXPERT OPINION: The design of nanocarriers for cell-mediated drug delivery may differ from those used for conventional drug delivery systems. The literature review shows that nanocarriers could supplement sustained drug delivery to the macrophages, extended duration of action, reduced therapeutic dose, improved patient compliance, and reduced adverse effects of highly toxic, potent drugs. There is still a need to identify more specific receptors that are responsible for macrophage targeting. The identification of such receptors may also facilitate drug targeting to further specific parts of the body containing different types of macrophages.