Point Biomedical, a San Carlos, Calif., biotechnology company developing a new medical-imaging and drug-delivery technology, raised $4.3 million toward an expected seventh funding round of up to $25.7 million, VentureWire reports (subscription required), citing an SEC filing last month (no link available).
Point Biomedical's focus is a tiny collapsible particle it calls the biSphere, which it is currently studying in clinical trials to aid in the imaging of blood flow within vessels and tissues. The company's biSpheres consist of a pair of nested spheres that are designed to collapse when subjected to a pulse of ultrasound. When filled with a gas such as nitrogen, which provides a strong ultrasound "echo," the spheres can make it possible to image the flow of blood in various organs. Crushed by ultrasound, the spheres release the highly visible nitrogen, which is then swept away and replaced by new spheres. The spheres could also be used to deliver drugs to a specific area.
Point Biomedical is currently studying the spheres in late-stage human trials as a non-invasive way to image blood flow in the heart and an alternative to assays that rely on radioactive particles.