Biohybrid devices. Biohybrid devices are implantable medical contraptions that undergo vascularization inside the body before the normal human cells (such as islet cells of Langerhans) can be placed inside them. They provide local immunosuppression that ensures that the normal human cells are not rejected by the host’s immune system or the graft versus host disease (Dorian). Biohybrid devices can be used to prevent diseases such as liver failure and diabetes. For persons at risk of developing type I diabetes mellitus (such as genetically predisposed individuals) or pre-diabetic individuals, their islets cells of Langerhans can be protected by biohybrid devices (Ricchie). These biohybrid devices are designed using nanoencapsulation technology into conformal polymer biomaterials that form a scaffold over the population of islet cells of Langerhans in the endocrine pancreas; thereby preventing the auto-antibodies from accessing the islets cells, and, causing irreversible injury to the cells by auto-immune reactions that ultimately lead to cell death, and, absolute lack of insulin production (Lucy et al). For the pre-diabetic individuals on immunomodulatory medications, the biohybrid scaffold locally concentrates the drug thus increasing its pharmacologic efficiency and reducing its systemic toxicity. The biohybrid scaffold also improves nutrient distribution across the islet cells and reduces stress encountered by the islet cells of Langerhans (Nazek). Liver failure caused by autoimmune hepatitis can be prevented by biohybrid devices, which form an, intricate conformal scaffold on the hepatocytes surface thereby blocking the auto-antibodies from interacting with the hepatocytes, and, causing immune-mediated liver necrosis (Nazek). Oxygen diffusion is critical for hybrid artificial organs because the normal human cells within them require oxygen for aerobic oxidative respiration...