ABSTRACT
The ability to conduct highly localized delivery of contrast agents, viral vectors, therapeutic or pharmacological agents, and signaling molecules or dyes to live mammalian embryos is greatly desired to enable a variety of studies in the field of developmental biology, such as investigating the molecular regulation of cardiovascular morphogenesis. To meet such a demand, we introduce, for the first time, the concept of employing optical coherence tomography (OCT)-guide microinjections in live mouse embryos, which provides precisely targeted manipulation with spatial resolution at the micrometer scale. The feasibility demonstration is performed with experimental studies on cultured live mouse embryos at E8.5 and E9.5. Additionally, we investigate the OCT-guided microinjection of goldsilica nanoshells to the yolk sac vasculature of live cultured mouse embryos at the stage when the heart just starts to beat, as a potential approach for dynamic assessment of cardiovascular form and function before the onset of blood cell circulation. Also, the capability of OCT to quantitatively monitor and measure injection volume is presented. Our results indicate that OCT-guided microinjection could be a useful tool for mouse embryonic research.
Subject(s)
Embryo, Mammalian/pathology , Tomography, Optical Coherence/instrumentation , Tomography, Optical Coherence/methods , Animals , Dextrans/administration & dosage , Equipment Design , Gold/chemistry , Heart/embryology , Imaging, Three-Dimensional , Metal Nanoparticles/chemistry , Mice , Microinjections , Nanomedicine , Silicon Dioxide/chemistry , Sodium Chloride/administration & dosage , Time Factors , Yolk Sac/pathologyABSTRACT
Multimodal imaging offers the potential to improve diagnosis and enhance the specificity of photothermal cancer therapy. Toward this goal, gadolinium-conjugated gold nanoshells are engineered and it is demonstrated that they enhance contrast for magnetic resonance imaging, X-ray, optical coherence tomography, reflectance confocal microscopy, and two-photon luminescence. Additionally, these particles effectively convert near-infrared light to heat, which can be used to ablate cancer cells. Ultimately, these studies demonstrate the potential of gadolinium-nanoshells for image-guided photothermal ablation.
Subject(s)
Gadolinium/chemistry , Gold/chemistry , Hyperthermia, Induced , Multimodal Imaging , Nanoshells/chemistry , Neoplasms/therapy , Phototherapy , Animals , Disulfides/chemistry , Luminescence , Melanoma, Experimental/diagnosis , Melanoma, Experimental/pathology , Mice , Nanoshells/ultrastructure , Neoplasms/diagnosis , Phantoms, Imaging , Photons , Polyethylene Glycols/chemistry , Spectroscopy, Near-Infrared , Subcutaneous Tissue/pathology , Tomography, Optical CoherenceABSTRACT
Nanotechnology-based cancer treatment approaches potentially provide localized, targeted therapies that aim to enhance efficacy, reduce side effects, and improve patient quality of life. Gold-nanoparticle-mediated hyperthermia shows particular promise in animal studies, and early clinical testing is currently underway. In this article, the rapidly evolving field of gold nanoparticle thermal therapy is reviewed, highlighting recent literature and describing current challenges to clinical translation of the technology.
Subject(s)
Gold/chemistry , Hyperthermia, Induced/methods , Metal Nanoparticles/chemistry , Nanotechnology/methods , Neoplasms/therapy , HumansABSTRACT
Chitosan-based, defect-free nanofibers with average diameters ranging from 62 +/- 9 nm to 129 +/- 16 nm were fabricated via electrospinning blended solutions of chitosan and polyethylene oxide (PEO). Several solution parameters such as acetic acid concentration, polymer concentration, and polymer molecular weight were investigated to optimize fiber consistency and diameter. These parameters were evaluated using the rheological properties of the solutions as well as images produced by scanning electron microscopy (SEM) of the electrospun nanofibers. Generally, SEM imaging demonstrated that as total polymer concentration (chitosan + PEO) increased, the number of beads decreased, and as chitosan concentration increased, fiber diameter decreased. Chitosan-PEO solutions phase separate over time; as a result, blended solutions were able to be electrospun with the weakest electric field and the least amount of complications when solutions were electrospun within 24 h of initially being blended. The addition of NaCl stabilized these solutions and increased the time the blended solutions could be stored before electrospinning. Pure chitosan nanofibers with high degrees of deacetylation (about 80%) were unable to be produced. When attempting to electrospin highly deacetylated chitosan from aqueous acetic acid at concentrations above the entanglement concentration, the electric field was insufficient to overcome the combined effect of the surface tension and viscosity of the solution. Therefore, the degree of deacetylation is an extremely important parameter to consider when attempting to electrospin chitosan.
