Silica micro/nanospheres for theranostics: from bimodal MRI and fluorescent imaging probes to cancer therapy

Abstract

SummaryNano-theranostics offer remarkable potential for future biomedical technology with simultaneous applications for diagnosis and therapy of disease sites. Through smart and careful chemical modifications of the nanoparticle surface, these can be converted to multifunctional tiny objects which in turn can be used as vehicle for delivering multimodal imaging agents and therapeutic material to specific target sites in vivo. In this sense, bimodal imaging probes that simultaneously enable magnetic resonance imaging and fluorescence imaging have gained tremendous attention because disease sites can be characterized quick and precisely through synergistic multimodal imaging. But such hybrid nanocomposite materials have limitations such as low chemical stability (magnetic component) and harsh cytotoxic effects (fluorescent component) and, hence, require a biocompatible protecting agent. Silica micro/nanospheres have shown promise as protecting agent due to the high stability and low toxicity. This review will cover a full description of MRI-active and fluorescent multifunctional silica micro/nanospheres including the design of the probe, different characterization methods and their application in imaging and treatment in cancer.

Drug and gene delivery across the blood–brain barrier with focused ultrasound

“…Combined, these properties can reduce drug doses and drug-associated toxicity while improving therapeutic efficacy [181–186]. Polymer NPs can be loaded with a variety of payloads including soluble or non-soluble drugs[166,183,187,188], imaging or theranostic agents[189–191], or nucleic acids[154,180,192,193]. …”

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“…[9][10][11] The combination of multimodal imaging and theranostics will lead to cuttingedge technologies in which the potential of the NPs can be maximized. [12] However, the sensitivity at cellular/molecular imaging level is obviously lower than positron emission tomography and fluorescence imaging. MRI CAs, such as superparamagnetic iron oxide NPs (SPIONs), are emerging as one of the most promising probes for improving contrast at cellular or even molecular levels.…”

The role of surface functionalization of silica nanoparticles for bioimaging

“…[1][2][3][4][5][6][7][8][9] Currently, mesoporous and amorphous SNP have been extensively used in the biomedical eld. 9,10 While mesoporous SNP are normally used as drug delivery systems through physical or chemical adsorption, colloidal SNP have been often employed to encapsulate or to graft at the surface active agents.…”