Performances of a Pristine Graphene–Microbubble Hybrid Construct as Dual Imaging Contrast Agent and Assessment of Its Biodistribution by Photoacoustic Imaging. (29th May 2018)

• Record Type: Journal Article
• Authors: Toumia, Yosra; Cerroni, Barbara; Trochet, Philippe; Lacerenza, Savino; Oddo, Letizia; Domenici, Fabio; Paradossi, Gaio
• Is Part Of: Particle and particle systems characterization. Volume 35:Number 7(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-05-29
• Subjects: biodistribution -- graphene -- microbubbles -- photoacoustics -- ultrasounds; Particles -- Periodicals; 620.43
• DOI: 10.1002/ppsc.201800066
• Languages: English
• ISSNs: 0934-0866

Abstract

Abstract: Coupling near‐infrared (NIR) nanoscale absorbing materials with microbubbles (MBs) can generate a multifunctional dual imaging contrast agent. A new approach is presented for a hybrid photoacoustic/ultrasound contrast enhancer where pristine graphene is stably tethered to poly(vinyl alcohol) (PVA)‐based MBs. The main advantages of this approach are i) the preservation of optical and mechanical properties of intact graphene for an efficient photoacoustic (PA) enhancement and ii) the echogenicity and biocompatibility due to the robust anchoring of graphene to the bioinert PVA shell. PVA MBs provide ideal platforms for drug loading and ligand tethering for specific tumor targeting. One of the crucial goals toward this direction is optimizing this system in terms of balance between favorable acoustic/photoacoustic properties, immune shielding, and cytotoxicity. Such a combination strongly depends on the bridging moieties between graphene and the microbubble surface and can be easily tuned by PEGylation. The optimized graphene PVA MBs as contrast agent provide an efficient enhancement in vivo both in ultrasound and photoacoustic modes. The spectrally separable absorbance profile allows to a first demonstration of performing real‐time in vivo multiplexed photoacoustic imaging of graphene PVA MBs, and assessment of their full body biodistribution using a Vevo LAZR‐X photoacoustic imaging system. Abstract : Graphene is stably tethered on biocompatible microbubbles via molecular spacers. Such a construct is a potential contrast agent supporting both ultrasound and photoacoustic imaging due to the graphene strong near‐infrared absorbance. The work describes the role of spacers in optimizing colloidal stability, photoacoustic efficiency, echogenicity, and biocompatibility of the graphene–microbubbles and assessing the biodistribution of the system by photoacoustic imaging.