Waqar Hira, Riaz Ramish, Ahmed Nasir M, Majeed Ayesha Isani, Abbas Shah Rukh
Department of Industrial Biotechnology, ASAB-NUST Pakistan
Biosensors and Therapeutics Lab, School of Interdisciplinary Engineering and Sciences (SINES)-NUST Pakistan.
RSC Adv. 2022 Apr 5;12(17):10504-10513. doi: 10.1039/d2ra01542k. eCollection 2022 Mar 31.
Multimodal imaging is a recent idea of combining two or more imaging methods synergistically to overcome the weakness of individual imaging modalities and utilizing complementary benefits. Ultrasound (US) and magnetic resonance imaging (MRI) are widely used imaging techniques in healthcare and to fully utilize the potential of fusion imaging, dual-modal contrast agents are necessary to improve disease diagnosis by enhancing contrast resolution and reducing health risks associated with the dual dosage of contrast agents. In this study, magnetic microbubbles were synthesized by incorporating oleic acid stabilized superparamagnetic iron oxide nanoparticles (OA-SPIONs) into lecithin microbubbles, encapsulating the perfluoropentane (PFP) core. The magnetic microbubbles were characterized by FTIR, SEM, MFM, zeta potential, MRI, and ultrasound. Upon MRI, magnetic microbubbles showed a negative contrast effect by producing darker T2 weighted images. Magnetic microbubbles showed concentration-dependent response with a decrease in signal intensity with an increase in the concentration of OA-IONP in microbubbles. However, a decrease in acoustic enhancement was also observed with an increase in OA-IONP concentration, therefore concentration was optimized to achieve the best effect on both modalities. The magnetic lecithin microbubble with 10 mg SPIONs provided the best contrast on both US and MR imaging. The hemocompatibility testing resulted in hemolysis less than 7% with plasma recalcification time and thrombin time of 240 s and 6 s corresponding to excellent hemocompatibility. Thus the magnetic microbubbles with a phase convertible PFP core encapsulated by a lecithin shell loaded with OA-SPIONs can serve as a potential bimodal contrast agent for both US and MRI imaging.
多模态成像（Multimodal imaging）是一种近期出现的理念，即协同结合两种或更多成像方法，以克服单一成像方式的弱点并利用其互补优势。超声（US）和磁共振成像（MRI）是医疗保健领域广泛使用的成像技术，为充分发挥融合成像的潜力，需要双模态造影剂来提高疾病诊断水平，通过增强对比分辨率并降低与双倍剂量造影剂相关的健康风险。在本研究中，通过将油酸稳定的超顺磁性氧化铁纳米颗粒（OA-SPIONs）掺入卵磷脂微泡中，包裹全氟戊烷（PFP）核心，合成了磁性微泡。通过傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、磁力显微镜（MFM）、zeta电位、磁共振成像（MRI）和超声对磁性微泡进行了表征。在MRI检查中，磁性微泡通过产生更暗的T2加权图像显示出负性对比效果。磁性微泡呈现浓度依赖性反应，随着微泡中OA-IONP浓度的增加，信号强度降低。然而，随着OA-IONP浓度的增加，也观察到声学增强作用减弱，因此对浓度进行了优化，以在两种模态上均实现最佳效果。含有10mg SPIONs的磁性卵磷脂微泡在超声和磁共振成像上均提供了最佳对比效果。血液相容性测试结果显示溶血率低于7%，血浆再钙化时间和凝血酶时间分别为240秒和6秒，表明具有优异的血液相容性。因此，由负载OA-SPIONs的卵磷脂壳包裹的具有相转换PFP核心的磁性微泡可作为超声和MRI成像的潜在双模态造影剂。
