Citations

AbstractEmbolization is a catheter‐based minimally invasive procedure that deliberately occludes diseased blood vessels for treatment purposes. A novel silk‐based embolic material (SEM) that is developed and optimized to provide tandem integration of both embolization and the delivery of therapeutics is reported. Natural silk is processed into fibroin proteins of varying lengths and is combined with charged nanoclay particles to allow visibility and injectability using clinical catheters as small as 600 μm in diameter at lengths >100 cm. SEMs loaded with fluorochrome labeled bovine albumin and Nivolumab, which is among the most used immunotherapy drugs worldwide, demonstrate a sustained release profile in vitro over 28 days. In a porcine renal survival model, SEMs with labeled albumin and Nivolumab successfully embolize porcine arteries without recanalization and lead to the delivery of both albumin and Nivolumab into the interstitial space of the renal cortex. Mechanistically, it is shown that tissue delivery is most optimal when the internal elastic membrane of the embolized artery is disrupted. SEM is a potential next‐generation multifunctional embolic agent that can achieve embolization and deliver a wide range of therapeutics to treat vascular diseases including tumors.

AbstractHepatocellular carcinoma (HCC) is the fastest-growing cancer worldwide, causing significant morbidity and mortality. Surgical resection, ablation, or transplantation is the best treatment option for patients with HCC. However, only about one-fifth of patients are suitable for such primary curative treatments due to underlying liver disease or rapid extension of the tumor. Image-guided locoregional therapies may prove an important alternative in this scenario, particularly transarterial radioembolization (TARE) with yttrium-90 (Y-90). Based on many studies, TARE can be considered a curative treatment option for patients with early-stage HCC, a bridge to transplantation, and a method for downstaging tumors to give patients with unresectable HCC a chance to potentially receive a curative treatment. TARE can be also combined with other treatment modalities to provide a better quality of life in patients when compared with systemic therapy in patients with unresectable HCC. Here, we discuss the use of TARE in the approach to HCC patients who are in early, intermediate, or advanced stages.

Minimally invasive endovascular interventions have become the cornerstone of medical practice in the treatment of a variety of vascular diseases. Tools developed for these interventions have also opened new avenues for targeted delivery of therapeutics, such as chemotherapy or radiation therapy, using the vessels as highways into remote lesions. A more ambitious move toward an all‐endovascular approach to acute or chronic conditions, however, is fundamentally hindered by a variety of challenges, such as the complexity of the vascular anatomy, access to smaller vessels, the fragility of diseased vessels, emergency procedure requirements, prolonged exposure to ionizing X‐ray radiation, and patient‐specific factors including coagulopathy. These shortcomings necessitate new advances to the current practice. Smart soft‐body robots that fit the smallest vessels with high‐precision wireless control and autonomous capabilities have the potential to set the future standards of minimally invasive endovascular therapies. Herein, the current state of the small‐scale robotics from the viewpoint of endovascular applications is discussed, and their potential advantages to the existing tethered clinical devices are compared. Then, technical challenges and the clinical requirements toward realistic applications of small‐scale untethered robots inside the vasculature are discussed.