An endoscope with integrated transparent bioelectronics and theranostic nanoparticles for colon cancer treatment

The gastrointestinal tract is a challenging anatomical target for diagnostic and therapeutic procedures for bleeding, polyps and cancerous growths. Advanced endoscopes that combine imaging and therapies within the gastrointestinal tract provide an advantage over stand-alone diagnostic or therapeutic devices. However, current multimodal endoscopes lack the spatial resolution necessary to detect and treat small cancers and other abnormalities. Here we present a multifunctional endoscope-based interventional system that integrates transparent bioelectronics with theranostic nanoparticles, which are photoactivated within highly localized space near tumours or benign growths. These advanced electronics and nanoparticles collectively enable optical fluorescence-based mapping, electrical impedance and pH sensing, contact/temperature monitoring, radio frequency ablation and localized photo/chemotherapy, as the basis of a closed-loop solution for colon cancer treatment. In vitro, ex vivo and in vivo experiments highlight the utility of this technology for accurate detection, delineation and rapid targeted therapy of colon cancer or precancerous lesions.

Chemical design of biocompatible iron oxide nanoparticles for medical applications

Iron oxide nanoparticles are one of the most versatile and safe nanomaterials used in medicine. Recent progress in nanochemistry enables fine control of the size, crystallinity, uniformity, and surface properties of iron oxide nanoparticles. In this review, the synthesis of chemically designed biocompatible iron oxide nanoparticles with improved quality and reduced toxicity is discussed for use in diverse biomedical applications.

Chemical Design of Biocompatible Iron Oxide Nanoparticles for Medical Applications

Iron oxide nanoparticles are one of the most versatile and safe nanomaterials used in medicine. Recent progress in nanochemistry enables fine control of the size, crystallinity, uniformity, and surface properties of iron oxide nanoparticles. In this review, the synthesis of chemically designed biocompatible iron oxide nanoparticles with improved quality and reduced toxicity is discussed for use in diverse biomedical applications.11801881sciescopu

Chemical synthesis and assembly of uniformly sized Iron oxide nanoparticles for medical applications

Magnetic iron oxide nanoparticles have been extensively investigated for their various biomedical applications including diagnostic imaging, biological sensing, drug, cell, and gene delivery, and cell tracking. Recent advances in the designed synthesis and assembly of uniformly Sited iron oxide nanoparticles have brought innovation in the field of nanomedicine. This Account provides a review on the recent progresses in the controlled synthesis and assembly of uniformly sized iron oxide nanoparticles for medical applications. In particular, it focuses on three topics: stringent control of particle size during synthesis via the "heat-up" process, surface modification for the high stability and biocompatibility of the nanoparticles for diagnostic purposes, and assembly of the nanoparticles within polymers or mesoporous silica matrices for theranostic applications. Using extremely small 3 nm sized iron oxide nanoparticles (ESION), a new nontoxic T1 MRI contrast agent was realized for high-resolution MRI of blood vessels down to 0.2 trim. Ferrimagnetic iron oxide nanoparticles (FION) that are larger than 20 nm exhibit extremely large magnetization and coercivity values. The cells labeled with FIONs showed very high T2 Contrast effect so that even a single cell can be readily imaged. Designed assembly of iron oxide nanoparticles with mesoporous silica and polymers was conducted to fabricate multifunctional nanoparticles for theranostic applications. Mesoporous silica nanoparticles are excellent scaffolds for iron oxide nanoparticles, providing magnetic resonance and fluorescence imaging modalities as well as the functionality of the drug delivery vehicle. Polymeric ligands could be designed to respond to various biological stimuli such as pH, temperature, and enzymatic activity. For example, we fabricated tumor pH-sensitive magnetic nanogrenades (termed PMNs) composed of self-assembled iron oxide nanoparticles and pH-responsive ligands. They were utilized to visualize small tumors (<3 mm) via pH-responsive T1 MRI and fluorescence imaging. Also, superior photodynamic therapeutic efficacy in highly drug-resistant heterogeneous tumors was observed. We expect that these multifunctional and bioresponsive nanoplatforms based on uniformly sized iron oxide nanoparticles will provide more unique theranostic approaches in clinical uses.

Chemical synthesis and assembly of uniformly sized iron oxide nanoparticles for medical applications

ConspectusMagnetic iron oxide nanoparticles have been extensively investigated for their various biomedical applications including diagnostic imaging, biological sensing, drug, cell, and gene delivery, and cell tracking. Recent advances in the designed synthesis and assembly of uniformly sized iron oxide nanoparticles have brought innovation in the field of nanomedicine. This Account provides a review on the recent progresses in the controlled synthesis and assembly of uniformly sized iron oxide nanoparticles for medical applications. In particular, it focuses on three topics: stringent control of particle size during synthesis via the heat-up process, surface modification for the high stability and biocompatibility of the nanoparticles for diagnostic purposes, and assembly of the nanoparticles within polymers or mesoporous silica matrices for theranostic applications.Using extremely small 3 nm sized iron oxide nanoparticles (ESION), a new nontoxic T1 MRI contrast agent was realized for high-resolution MRI of blood vessels down to 0.2 mm. Ferrimagnetic iron oxide nanoparticles (FION) that are larger than 20 nm exhibit extremely large magnetization and coercivity values. The cells labeled with FIONs showed very high T2 contrast effect so that even a single cell can be readily imaged.Designed assembly of iron oxide nanoparticles with mesoporous silica and polymers was conducted to fabricate multifunctional nanoparticles for theranostic applications. Mesoporous silica nanoparticles are excellent scaffolds for iron oxide nanoparticles, providing magnetic resonance and fluorescence imaging modalities as well as the functionality of the drug delivery vehicle. Polymeric ligands could be designed to respond to various biological stimuli such as pH, temperature, and enzymatic activity. For example, we fabricated tumor pH-sensitive magnetic nanogrenades (termed PMNs) composed of self-assembled iron oxide nanoparticles and pH-responsive ligands. They were utilized to visualize small tumors (<3 mm) via pH-responsive T1 MRI and fluorescence imaging. Also, superior photodynamic therapeutic efficacy in highly drug-resistant heterogeneous tumors was observed. We expect that these multifunctional and bioresponsive nanoplatforms based on uniformly sized iron oxide nanoparticles will provide more unique theranostic approaches in clinical uses. © 2015 American Chemical Society11511631sciescopu

Surface ligands in synthesis, modification, assembly and biomedical applications of nanoparticles

Nanotechnology hasreceivedextraordinaryattentionrecentlyduetoitsburgeon- ing roleinbiomedicalscience.Thematerialscomposingthenanoparticlesproducefascinating and diversefunctionalitiesasaresultoftheirexceptionallysmallsize.Infact,evenseemingly insignificant changesinparticlesizecanhaveprofoundeffectsontheseproperties.Thussize control, bothduringsynthesisandinparticlesuspensions,isa sine quanon for functionality. This canbeaccomplishedbymaskingtheparticlesurfacewithamultitudeofdifferentlig- ands. Notonlycansurfaceligandsconstrainthegrowthofnucleation,theycanalsodirectthe shape ofcrystallization.Howevernosingleligandcandoeverything.Fortunatelyligandsare essentially fungibleandcanbeexchangedatvarioustimestoconferthedesiredproperties to theparticle.Thiscanincludeprotectingtheparticlefromharshaqueousconditions,such as pHextremes,maximizingopticalpropertiesfordiagnosticsorshieldingtheparticlefrom potentially hostileconditionsfoundinthebody.Becausethesemoietiesinteractubiquitously with variousbiologicalmaterials,particularlyproteins,thereneedstobearationalizeddesign of surfaceligands.Thedesignoftheligandcanhavecrucialeffectsonbiodistributionaswell as evasionofbiologicaldefenses.Ligandscanevenbedesignedtoprovidenewfunctionality in responsetovariousenvironmentalstimulitoimprovetheirtherapeuticordiagnosticcapa- bilities. Consideringtheimportanceofligandsthenonthisemergingfield,thisreviewwill thoroughly considertheliganddesignforthevariousstepsofnanodevelopment,fromsynthesis and assemblythroughbiomedicaltranslation. © 2014ElsevierLtd.Allrightsreserved.171761sciescopu

Nature‐inspired K+‐sensitive imaging probes for biomedical applications

Abstract In living systems, potassium ion (K+) plays a vital role in a variety of physiological functions, whose dyshomeostasis has been seen as a biomarker of many diseases. Consequently, real‐time monitoring of K+ dynamics would benefit disease diagnosis and offer insight into the pathogenic mechanisms as well as the progression of diseases. By learning from K+‐specific substances in nature, such as ionophores, ion channels and DNA G‐quadruplex, this perspective introduces the ingenious designs, imaging functionalities, and response principles of K+‐sensitive probes. Furthermore, the recent advances in K+ probes for disease diagnosis, especially for brain disorders and tumors, are briefly summarized. Finally, we highlight the current challenges and future perspectives of K+‐sensitive probes for biomedical applications

Cancer imaging: Lighting up tumours

Gao and colleagues have developed a polymeric, micelle-based nanoprobe that is highly responsive to both the angiogenic tumor vasculature and the extracellular pH. First, Gao and colleagues introduced tertiary amines with controlled hydrophobic substituents as ionizable hydrophobic blocks for the pH-sensitive core. Nanoprobes with different transition pH values can thus be achieved by using tertiary amino groups that protonate at a different pH. Subsequently the polymers were derivatized with hydrophobic fluorophores. At physiological pH, the monomers spontaneously assemble with the fluorophores oriented into the centre of the particle and in close proximity with each other. As a result of this, the fluorophores tend to silence each other by a process called fluorescence resonance energy transfer. As the particle navigates the body and enters the tumor site, the drop in pH begins to protonate the amines. The extremely high sensitivity makes these nanoprobes promising candidates for clinical tumor diagnosis.117181sciescopu

The surface science of nanocrystals

All nanomaterials share a common feature of large surface-to-volume ratio, making their surfaces the dominant player in many physical and chemical processes. Surface ligands-molecules that bind to the surface-are an essential component of nanomaterial synthesis, processing and application. Understanding the structure and properties of nanoscale interfaces requires an intricate mix of concepts and techniques borrowed from surface science and coordination chemistry. Our Review elaborates these connections and discusses the bonding, electronic structure and chemical transformations at nanomaterial surfaces. We specifically focus on the role of surface ligands in tuning and rationally designing properties of functional nanomaterials. Given their importance for biomedical (imaging, diagnostics and therapeutics) and optoelectronic (light-emitting devices, transistors, solar cells) applications, we end with an assessment of application-targeted surface engineering. © 2016 Macmillan Publishers Limited. All rights reserved32233