Magnetic black phosphorus microbubbles for targeted tumor theranostics

In this work by Zhu et al, the authors develop black phosphorus magnetic microbubbles (MBBPM) for contrast enhanced ultrasound and therapeutic imaging. The surface properties of MBBPM were optimized to improve stability, responsiveness, and echogenicity. MBBPM provided excellent ultrasound contrast in vivo and inhibited tumor growth when combined with laser irradiation.

Key Points/Summary:

  • Gas filled microbubbles (MB) are FDA approved imaging agents that provide excellent ultrasound contrast
  • However, MBs alone have low vascular binding ability, short retention time, and limited specificity and sensitivity
    • Multifunctional MBs with the ability to target, treat, and monitor therapeutic response in tissues are therefore highly desirable
  • Black phosphorous is a biocompatible compound with unique thermal, electrical and mechanical properties that can be exploited for biomedical applications
  • In this work, the authors hypothesize that combining MBs with black phosphorous (MBBPM) can enable tumor detection and treatment
  • MBBPM were generated by linking MB with black phosphorous nanoparticles using polyethylene glycol (PEG)
  • US and NLC was performed on a Vevo 2100 system using the MS250 probe
    • For in vitro experiments, samples were suspended in agar plates
    • For in vivo experiments, MCF tumors grown in nude mice were imaged before and after a destructive pulse sequence. Tumors were then treated with laser irradiation.
  • MBBPM provided excellent US contrast in vitro and in vivo
  • Applying a magnetic field enabled concentration of MBBPM levels in vitro and in tumors
  • Tumor bearing animals injected with MBBPM and treated with laser irradiation showed significant growth reduction compared to black phosphorous nanoparticles

Conclusion: MBBPM are multifunctional agents for tumor diagnostic imaging, treatment, and treatment monitoring.

Zhu, Y. et al. Magnetic black phosphorus microbubbles for targeted tumor theranostics. Nanophotonics (2021).