title: Superparamagnetic iron oxide nanoparticle-based delivery systems for biotherapeutics.
abstract: BACKGROUND
  Superparamagnetic iron oxide nanoparticle (SPION)-based carrier systems have many advantages over other nanoparticle-based systems. They are biocompatible, biodegradable, facilely tunable and superparamagnetic and thus controllable by an external magnetic field. These attributes enable their broad biomedical applications. In particular, magnetically driven carriers are drawing considerable interest as an emerging therapeutic delivery system because of their superior delivery efficiency.
  
  
  METHODS
  This article reviews the recent advances in use of SPION-based carrier systems to improve the delivery efficiency and target specificity of biotherapeutics. The authors examine various formulations of SPION-based delivery systems, including SPION micelles, clusters, hydrogels, liposomes and micro/nanospheres, as well as their specific applications in delivery of biotherapeutics.
  
  
  CONCLUSIONS
  Recently, biotherapeutics including therapeutic cells, proteins and genes have been studied as alternative treatments to various diseases. Despite the advantages of high target specificity and low adverse effects, clinical translation of biotherapeutics has been hindered by the poor stability and low delivery efficiency compared with chemical drugs. Accordingly, biotherapeutic delivery systems that can overcome these limitations are actively pursued. SPION-based materials can be ideal candidates for developing such delivery systems because of their excellent biocompatibility and superparamagnetism that enables long-term accumulation/retention at target sites by utilization of a suitable magnet. In addition, synthesis technologies for production of finely tuned, homogeneous SPIONs have been well developed, which may promise their rapid clinical translation.
authors.affiliation: Konkuk University, Department of Bioscience and Biotechnology, Seoul 143-701, Republic of Korea.
authors.forename: Hyejung
authors.initials: H
authors.lastname: Mok
authors.forename: Miqin
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001691:Biological Therapy; D002626:Chemistry, Pharmaceutical; D004337:Drug Carriers; D005290:Ferric Compounds / Q000008:administration & dosage*; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D060526:Magnetic Fields; D008823:Micelles; D053758:Nanoparticles / Q000008:administration & dosage*; D004364:Pharmaceutical Preparations / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D005290:Ferric Compounds; D008055:Lipids; D008081:Liposomes; D008823:Micelles; D004364:Pharmaceutical Preparations; C000499:ferric oxide