Characterization of mechanical properties of hybrid contrast agents by combining atomic force microscopy with acoustic/optic assessments

Guo, Gepu; Tu, Juan; Guo, Xiaojun; Huang, Pintong; Wu, Junru; Zhang, Dong

doi:10.1016/j.jbiomech.2015.12.018

Cited by 12 publications

(12 citation statements)

References 28 publications

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“…As can be seen in Figure , the estimation result fits well toward the tail of the spectrum and deviates by 0.3 to 0.4 dB/cm around the peak. Such a degree of deviation has been reported in various articles and could be the result of bubble rupture, fusion, or cleavage. Although independent oscillations were assumed, it has been pointed out by Stride and Saffari that the application of Equation might lead to discrepancies between calculated attenuation and experimental data around resonance frequencies, indicating that multiple scattering and secondary Bjerknes forces are not neglectable for concentrations higher than 1 × 10 6 bubbles mL.…”

Section: Resultsmentioning

confidence: 68%

Acoustic Characterization and Enhanced Ultrasound Imaging of Long‐Circulating Lipid‐Coated Microbubbles

Yang

Zhang

et al. 2017

J of Ultrasound Medicine

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Section: Resultsmentioning

confidence: 68%

Acoustic Characterization and Enhanced Ultrasound Imaging of Long‐Circulating Lipid‐Coated Microbubbles

Yang

Zhang

et al. 2017

J of Ultrasound Medicine

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“…Since its introduction over thirty years ago (21), atomic force microscopy (AFM) has become a versatile and highly quantitative experimental technique capable of capturing lateral resolution of the order of nanometres, vertical resolution of the order of Angstroms and force resolution as accurate as 10 piconewtons (22)(23)(24). It is fast becoming one of the most important tools in the biomedical setting.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Probing phospholipid microbubbles by atomic force microscopy to quantify bubble mechanics and nanostructural shell properties

Shafi

McClements

Albaijan

et al. 2019

Colloids and Surfaces B: Biointerfaces

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Highlights  Using tapping mode imaging, the thickness of microbubble shells can be quantified  Quantifying shell thickness has significant impact on Young's Modulus values  Atomic force microscopy can be used to quantify thickness of the PEG brush layer ABSTRACT: Microbubbles (MBs), which are used as ultrasonic contrast agents, have distinct acoustic signatures which enable them to significantly enhance visualisation of the vasculature. Research is progressing to develop MBs which act as drug/gene delivery vehicles for site-specific therapeutics. In order to manufacture effective theranostic vehicles, it is imperative to understand the mechanical and nanostructural properties of these agents; this will enrich the understanding of how the structural, biophysical and chemical properties of these bubbles impact their functionality. We produced microfluidic phospholipid-based MBs due to their favourable properties, such as biocompatibility and echogenicity, as well as the ability to modify the shell for targeting applications. We have drawn upon atomic force microscopy to conduct force-spectroscopy and tapping-mode imaging investigations. We have, for the first time to our knowledge, been able to accurately quantify the thickness and lipid configuration of phospholipid-shelled MBs-showing a trilayer as opposed to the conventional monolayer structure. Furthermore, we have measured MB stiffness and employed different mechanical theories to quantify the Young s Modulus. We show that the Reissner theory is inappropriate for mechanical characterisation of phospholipid MBs, however, the Hertz model does offer biologically relevant comparisons. Analysis using the Alexander-de Gennes polymer brush theory has allowed us to provide new information regarding how the thickness of the polyethylene glycol brushes, end-grafted to our phospholipid microbubbles, changes with diameter.

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“…protect the genetic material inside [1], which can sustain the megapascal-range inwards and outwards osmotic pressure [2]. UCAs, composed of a thin biocompatible shell that encapsulates an inert gas, are widely used and researched as carriers for target drug and gene delivery [3,4]. The study on pressured buckling and rupture of the capsid is of particular interest as they determine the resistance to osmotic shocks and the maximum ejection pressure of DNA in the host cell [2], which is relevant in understanding their biological functions such as protecting genetic materials, maturation, and infection of cells [5].…”

Section: Introductionmentioning

confidence: 99%

Post-buckling of a pressured biopolymer spherical shell with the mode interaction

Zhang

2018

Proc. R. Soc. A.

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Imperfection sensitivity is essential for mechanical behaviour of biopolymer shells characterized by high geometric heterogeneity. The present work studies initial post-buckling and imperfection sensitivity of a pressured biopolymer spherical shell based on non-axisymmetric buckling modes and associated mode interaction. Our results indicate that for biopolymer spherical shells with moderate radius-to-thickness ratio (say, less than 30) and smaller effective bending thickness (say, less than 0.2 times average shell thickness), the imperfection sensitivity predicted based on the axisymmetric mode without the mode interaction is close to the present results based on non-axisymmetric modes with the mode interaction with a small (typically, less than 10%) relative errors. However, for biopolymer spherical shells with larger effective bending thickness, the maximum load an imperfect shell can sustain predicted by the present non-axisymmetric analysis can be significantly (typically, around 30%) lower than those predicted based on the axisymmetric mode without the mode interaction. In such cases, a more accurate non-axisymmetric analysis with the mode interaction, as given in the present work, is required for imperfection sensitivity of pressured buckling of biopolymer spherical shells. Finally, the implications of the present study to two specific types of biopolymer spherical shells (viral capsids and ultrasound contrast agents) are discussed.

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Characterization of mechanical properties of hybrid contrast agents by combining atomic force microscopy with acoustic/optic assessments

Cited by 12 publications

References 28 publications

Acoustic Characterization and Enhanced Ultrasound Imaging of Long‐Circulating Lipid‐Coated Microbubbles

Acoustic Characterization and Enhanced Ultrasound Imaging of Long‐Circulating Lipid‐Coated Microbubbles

Probing phospholipid microbubbles by atomic force microscopy to quantify bubble mechanics and nanostructural shell properties

Post-buckling of a pressured biopolymer spherical shell with the mode interaction

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