Turkish Scientist Rahmi Oklu Attracted Attention with the Biomaterial He Developed

From the Department of Vascular and Interventional Radiology at Mayo Clinic in the United States, Prof. Dr. Rahmi Okluis one of the two co-founders of the medical materials startup Obsidio, which had developed a biomaterial with significant advantages over existing products for intravascular embolization, controlling bleeding, blocking the vessels that feed tumors, and being used to treat aneurysms (bulges in blood vessels). Obsidio announced that its gelatin and silicate nanoparticle embolization (vessel-blocking) material completed a financing round on 21 August 2019 with Infinite Corridor Fund, a unit of venture capital firm Good Growth Capital. Shear-thinning is the name of this biomaterial, which has a very high degree of effectiveness in permanently blocking blood vessels. Over time, Obsidio's material is replaced by natural tissue, leaving no inflammatory foreign material behind.

Science Translational Medicine was the journal in which, in 2016, their paper presented preclinical evidence showing that the shear-thinning biomaterial developed by Obsidio can be injected through catheters in a minimally invasive manner, has hemostatic activity, withstands the physiological pressures of blood vessels, and creates safe and strong occlusions. Dr. Rahmi Oklu, also Obsidio's Chief Medical Officer, "The biomaterial was designed and optimized with the physician user in mind. It had to be easy to use. It has much greater effectiveness than the devices used today and is simple to inject. I believe we have achieved all these goals. This material will change the way we perform therapeutic (for treatment purposes) vessel occlusion today." said.

Obsido's other partner and CEO, Ehsan Jabbarzadeh: "We see tremendous potential for Obsidio to offer a single, one-size-fits-all technology across many markets, including peripheral, neurovascular and tumor embolization applications" said. Obsidio's shear-thinning biomaterial can be injected through a wide variety of catheters, is compatible with all imaging techniques, and will be ready to use. It also eliminates the need for inventory costs associated with embolic devices of different sizes and accessories. Founded in December 2018, the company's vision is to optimally balance the "Iron Triangle" of embolization (Quality, Access and Cost).

Note: Obsidio Inc. is a medical device company dedicated to the research, development and commercialization of groundbreaking embolotherapy products.

Who is Rahmi Oklu? (brief academic CV)

Rahmi Oklu is Professor and Chair of the Department of Vascular and Interventional Radiology at Mayo Clinic in the United States and Director of the Minimally Invasive Therapeutics Laboratory. He graduated from medical school at Northwestern University, earned a master's degree at Yale University and a doctorate in biochemistry at Cambridge University. He completed his surgical and radiology training at Columbia University NY Presbyterian Hospital. He worked in vascular and interventional radiology at Massachusetts General Hospital, Harvard Medical School. He is known for his work focusing on patient-inspired engineering to develop medical devices. He is one of the world's leading figures in interventional radiology.

What is the current state of interventional radiology and vascular embolization?

Today, interventional radiology makes important contributions in different fields of medicine. Its techniques have achieved significant success in cancer treatment by stopping bleeding caused by vascular injuries, occluding the vascular bulges in the brain that we call aneurysms and that put patients at risk of bleeding, and embolizing the arteries that nourish cancerous tissue. However, the vessel-occluding agents used in this treatment method to date have brought certain problems and limitations. Therefore, medicine has a serious need for more stable and cost-effective embolization procedures. At precisely this point, the work of Prof. Dr. Rahmi Oklu and his team targets a major unmet need in interventional radiology.

What is embolization? Advances in biomaterials and technologies for vascular embolization

Minimally invasive procedures, are one of the cornerstones of modern medicine. Over the past few decades, there has been a gradual transition from complex open surgery to image-guided minimally invasive interventions with fewer complications, generally better outcomes and lower costs. Blood vessels provide a common entry route into the body for many minimally invasive procedures, and almost any organ can be reached through an intravascular approach. With an intravascular approach, for example by targeting a tumor, embolization is the name given to the procedure that can reduce blood flow to that part of the body. Embolization means occluding blood vessels by depositing embolic (blocking) agents inside them through catheters for therapeutic purposes. This allows treatment of acute, potentially fatal bleeding, aneurysms and vascular malformations, or targeted oncological applications such as embolizing the blood vessels feeding a tumor.

A brief history of embolization and interventional radiology: The first documented embolization was performed in 1904 by Robert Dawbain, who injected melted paraffin-petrolatum into the external carotid artery before surgery to reduce tumor blood flow in a patient with a head and neck tumor. In 1930, Barney Brooks said that the only satisfactory method of treating an arteriovenous malformation (AVM) was to close the vessels by embolization. Later, a thin strip of muscle was used to successfully embolize a carotid-cavernous fistula. These and other pioneering studies created innovative directions using both natural and synthetic agents for embolization. In 1964, Charles Dotter, a radiologist at Oregon Health and Science University, performed the first percutaneous transluminal angioplasty, known today as "angio", to treat atherosclerotic arterial narrowing (due to fatty plaques), marking a breakthrough in new catheter-based interventions for diagnosis and treatment. He also pioneered balloon catheterization, coronary angiography (X-ray imaging to visualize vessels) and percutaneous arterial stenting, and an entirely new medical specialty, interventional radiology developed.

Biomaterials and technologies used in vascular embolization

In the early years, pieces of muscle, blood clots and stainless steel pellets were used as embolic agents. However, since the 1970s, advances in imaging and catheter technology have significantly improved embolization methods. In response to the failure of natural substances in embolization, researchers and physicians used advances in materials science to create new embolic agents for specific clinical applications. Examples of these materials include metallic coils, calibrated microspheres and bioadhesives. All existing embolic materials have advantages and shortcomings. Although there is no "one size fit all" (a single solution suitable for every situation) material for embolization, the general characteristics of an ideal embolic material are 1) biocompatibility; 2) ease of delivery; 3) resistance to fragmentation / migration; 4) biodegradability (depending on the application); 5) visibility and traceability with common imaging methods such as fluoroscopy, magnetic resonance imaging (MRI), computed tomography (CT) or ultrasound; and 6) the ability to serve as a vehicle for therapeutic delivery (for example, an anticancer drug). The main challenge in developing embolic agents, is the versatility of embolization as an intervention. Clinical scenarios may require occlusion of blood vessels from arteries (1-2 cm in diameter) to capillaries (down to 5-10 micrometers in diameter) as a temporary or permanent intervention. Being deliverable through a catheter also requires maintaining structural integrity to withstand arterial blood pressure. Therefore, an embolic agent's effectiveness depends on its ability to adapt to the unique clinical scenarios presented by each patient and to provide effective treatment while minimizing injury to adjacent structures. 

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