The end of aging, maybe. But that still leaves a plethora of diseases, accidents, etc.
Let's assume this artificial blood actually repairs organs hours after death. That's not immortality, merely an extension of current resuscitation techniques. If you get crushed by a car, you're still crushed. If you splatter your head on the pavement, you're still splattered.
Immortality would mean no death through aging (and to make it worthwhile, an end to aging), and no death from disease, and no death from accidents, at a minimum, and that'd still leave death by deliberate violence.
The closest thing would likely be cyborgification - replacing limbs and organs with more easily serviced or exchanged metal parts. Leave the brain, and then you just need a cure for alzheimers/dementia and you're more or less there. A couple artificial organs already exist, too.