Assessing the material biocompatibility of the product (including the material of construction and final device) is critical for successful commercialization. The tests should follow ISO 10993 and type of tests will depend on application and exposure. For example, for an implant device in contact with tissue/bone it will require cytotoxicity, sensitization, genotoxicity, implantation, chronic toxicity, and carcinogenicity. Additional tests may be applicable such as irritation or intracutaneous reactivity, systemic toxicity (acute), and sub-chronic (sub-acute) toxicity. ISO 10993 is endorsed by FDA which has published guidance with their thinking on how to comply with it (link below).
https://www.fda.gov/downloads/medicaldevices/deviceregulationandguidance/guidancedocuments/ucm348890.pdf