Progress of Tumor Targeted Therapy Based on Magnetic Nanomaterials br

Magnetic nanomaterials exhibit multiple magnetic-responsive behaviors under different externalmagnetic fields to produce various physicochemical effects(e.g.,force and heat),which possess a broad range ofapplications in cancer therapy.To realize the precise deliveryin vivo,magnetic nanomaterials induced magneticactuation under static magnetic field has been the focus of biomedicine research.For instance,magnetic drugdelivery systems such as nano-trajectory,nano-drugs have shown promise in efficient intratumoral accumulationof drugs.Inspired by a natural physiologic phenomenon in the tumor microenvironment and multiplephysicochemical effects by external stimulation,a variety of endogenous-responsive and magnetic field-stimulated drug delivery systems were constructed.Magnetic nanomaterials loaded with drugs can activelypenetrate into tumors under low-frequency alternating magnetic fields,resulting in their uniform distributionthrough the entire tumor tissue.Under a medium-frequency alternating magnetic field,magnetic nanomaterialsproduce heat and reactive oxygen species,which can facilitate the active drug release on-demand for cancertreatment.All those effects depend on size,composition,morphology,surface functionalization of magneticnanomaterials.Owing to their easy surface functionalization,it presents an exciting opportunity in themodularized design and operation of an all-in-one system(imaging,targeted drug delivery,magnetothermaleffect,nano-enzyme catalysis,etc.),which can achieve image-guided precise cancer theranostics.In this review,we focused on how to improve the magnetic nano-targeted drug delivery efficiency for tumor treatment,includingthe potential applications of magnetic targeted drug therapy,passive targeted magnetic hyperthermia and activetargeted magnetic hyperthermia in enhancing the efficacy of cancer therapy.We highlighted the mechanismsunderlying magnetically-actuated delivery and controlled release of drug.We also considered perspectives andchallenges in tumor targeted therapy based on magnetic nanomaterials.Although the biomedical research basedon magnetic nanomaterials has made great progress,most of the research is still in the stage of animal testing,andthere is a long way to go to realize its clinical application in diagnosis and treatment.There is a series ofchallenges need to be overcome.(1)Designing safer and more efficient magnetic nanomaterials is needed.Forexample,improving magnetic properties of magnetic nanomaterials to achieve efficient magnetic targeted drugdelivery;optimizing magnetic nanomaterials to avoid its penetration into the normal tissue.(2)Clarifying theregulation mechanism of magnetic nanomaterial-mediated effects on cell fate and disease treatment.(3)Understanding the interaction between magnetic field and living body,such as the effect of magnetic field onliving body metabolism and clearance.(4)Developing safe and controllable magnetic field-generating equipment,control system and analysis software,etc.With the in-depth understanding of the biological effects of magneticnanomaterials,a new discipline"magnetobiology"will be established soo