In preclinical studies, successful BBB opening can be verified various established approaches (e.g., dyes such as Evans blue, imaging contrast agents, biomarkers such as S100β biomarker). Most commonly used approach to assess the successful BBB opening in preclinical studies performed at InnoSer is by utilizing Evans blue staining. Evans blue is a dye that binds to albumin (60 kDa molecular complex) and does not cross the BBB under normal circumstances, therefore, the presence of Evans blue dye in post-mortem rodent brains following sonication indicates the successful opening of the BBB.  

Moreover, this technique is also commonly utilized in literature, with animal studies consistently showing enhanced Evans blue staining in sonicated murine brain hemispheres compared to control hemispheres (Ahmed et al., 2023; Sabbagh et al., 2021; Géraudie et al., 2023), in turn confirming the reproducibility and efficiency of BBB disruption by LIPU.  

SonoCloud® opens the BBB safely and reversibly for a few hours. In rodents, permeability increases within minutes and begins to close within ~30 minutes and can remain partially open for up to 2 hours. In preclinical studies, compound dosing (typically via IV) is usually performed before microbubble injection and sonication to maximize the delivery of the compound across the brain parenchyma.  

Preclinical studies have shown that for large molecules/therapeutics, the BBB begins closing immediately after sonication, with a theoretical half-closure time of less than 1 hour for molecules larger than 5 nm (Marty et al., 2012). 

In clinical studies, BBB opening with SonoCloud® has been demonstrated to occur immediately after ultrasound activation, with gadolinium-enhanced MRI showing a rapid increase in permeability that gradually declines over several hours (see Figure 3 in a study performed by Carpentier et al., 2024). 

A wide range of molecules from small molecules to larger biologics such as antibodies, antisense oligonucleotides, viral vectors, and lipid nanoparticles can be delivered to the brain using ultrasound-mediated BBB drug delivery.  

SonoCloud® has been shown to enhance delivery of a wide range of molecules, from small drugs (~1 kDa) to large biologics (~150 kDa). Preclinical data demonstrate up to 4-fold concentrations of small molecule therapeutics in murine brains (Arrieta et al., 2024), up to 4-fold concentrations for antibodies with single treatment (Sabbah et al, 2021; Arrieta et al, 2024), and up to 7-fold with antibodies with double treatment (Sabbah et al, 2021). Ongoing studies are exploring the enhanced brain delivery of advanced modalities such as antisense oligonucleotides (ASOs), adeno-associated viral vectors (AAVs), and lipid nanoparticles (LNPs).  

Contact our team to learn how we can help maximize your CNS-targeted therapeutic’s brain concentration and efficacy.

No, you do not need to change the formulation of your drug prior to delivering your compound via ultrasound. This is the advantage of choosing to work with ultrasound-mediated BBB delivery system, as this works by temporarily opening the BBB, meaning that compounds do not require formulation or chemical modification. This makes it applicable across many therapeutic modalities. However, the resultant fold-increase in your compounds’ concentration in the brain is still dependent on the chemistry and physical properties of your compound.  

Reach out to our team to discuss whether your CNS-targeted drug pipeline would benefit from ultrasound-mediated BBB drug delivery.  

In preclinical studies, SonoCloud® uses an externally applied ultrasound system adapted for rodents, allowing BBB opening through the skin and skull without the need for surgical implantation (as further explained in Figure 1 in a study performed by Sabbagh and colleagues, 2021). Briefly, the low-intensity pulsed ultrasound (LIPU) platform used in preclinical rodent studies consists of an ultrasound transducer placed in a small cylinder surrounded by a compartment of degassed water to ensure acoustic coupling. Anesthetized mice are placed on the platform in contact with the degassed water and stabilized, allowing for motionless sonication to the CNS. Microbubbles are injected through the tail vein prior to start of sonication. In preclinical studies, compound dosing (via IV) is usually performed before microbubble injection and sonication to maximize the delivery of the compound across the brain parenchyma. For technical details of the preclinical set-up, see Figure 1 of Sabbagh et al., 2021. 

In contrast, the clinical system for patients requires a surgical implantation of a small implant in the skull (SonoCloud®-9, used for e.g., in study by Carpentier et al., 2024). The SonoCloud-9 is an implantable device containing nine ultrasound emitters that are powered by a transdermal needle used to connect the device at each activation to an external generator.  During activation, patients receive an intravenous injection of microbubbles, and the device delivers pulsed ultrasound to transiently and reversibly open the BBB. Compound dosing is performed either immediately before or after sonication. For further technical details, see Figure 6 of Carpentier et al., 2024.  

However, both the preclinical SonoCloud LIPU and SonoCloud-9 systems use the same underlying LIPU technology combined with intravenously injected microbubbles, ensuring translational relevance from animal models to human applications. Therefore, data generated in preclinical studies with SonoCloud® can help inform dosing strategies and optimize therapeutic delivery in future clinical trials.  

Reach out to our team to learn more about how preclinical ultrasound-mediated BBB drug delivery using the SonoCloud® platform can help guide your clinical strategy.