ABSTRACT
The sensitivity of bioluminescence imaging in animals is primarily dependent on the amount of photons emitted by the luciferase enzyme at wavelengths greater than 620 nm where tissue penetration is high. This area of work has been dominated by firefly luciferase and its substrate, D-luciferin, due to the system's peak emission (~ 600 nm), high signal to noise ratio, and generally favorable biodistribution of D-luciferin in mice. Here we report on the development of a codon optimized mutant of click beetle red luciferase that produces substantially more light output than firefly luciferase when the two enzymes are compared in transplanted cells within the skin of black fur mice or in deep brain. The mutant enzyme utilizes two new naphthyl-luciferin substrates to produce near infrared emission (730 nm and 743 nm). The stable luminescence signal and near infrared emission enable unprecedented sensitivity and accuracy for performing deep tissue multispectral tomography in mice.
Subject(s)
Benzothiazoles/metabolism , Coleoptera/enzymology , Insect Proteins/metabolism , Luciferases/metabolism , Animals , Benzothiazoles/chemistry , HEK293 Cells , Humans , Insect Proteins/genetics , Luciferases/genetics , Luminescence , Luminescent Measurements/methods , MCF-7 Cells , Mice, Inbred C57BL , Mice, Nude , Microscopy, Fluorescence , Mutation , Spectroscopy, Near-InfraredABSTRACT
Targeting nanomedicine to brain tumors is hampered by the heterogeneity of brain tumors and the blood brain barrier. These represent the main reasons of unsuccessful treatments. Nanomedicine based approaches hold promise for improved brain tissue distribution of drugs and delivery of combination therapies. In this review, we describe the recent advancements and latest achievements in the use of nanocarriers, virus and cell-derived nanoparticles for targeted therapy of brain tumors. We provide successful examples of nanomedicine based approaches for direct targeting of receptors expressed in brain tumor cells or modulation of pathways involved in cell survival as well as approaches for indirect targeting of cells in the tumor stroma and immunotherapies. Although the field is at its infancy, clinical trials involving nanomedicine based approaches for brain tumors are ongoing and many others will start in the near future.
Subject(s)
Brain Neoplasms/drug therapy , Nanomedicine , Nanoparticles/chemistry , Animals , Blood-Brain Barrier/drug effects , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/pathology , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Cell Survival/drug effects , Drug Carriers/chemistry , Humans , ImmunotherapyABSTRACT
in vivo bioluminescence imaging (BLi) is an optical molecular imaging technique used to visualize molecular and cellular processes in health and diseases and to follow the fate of cells with high sensitivity using luciferase-based gene reporters. The high sensitivity of this technique arises from efficient photon production, followed by the reaction between luciferase enzymes and luciferin substrates. Novel discoveries and developments of luciferase reporters, substrates, and gene-editing techniques, and emerging fields of applications, promise a new era of deeper and more sensitive molecular imaging.