system
Given the following post, respond as if you're commenting on Reddit:
human
[Spider-Man 3] Is The Sandman immortal?

When Spidey and Sandman fight in the back of the money truck, Spidey punches straight thru Sandman's torso with no adverse affects to him. He was also able to manipulate sand that was not in the accident with him when he was mutated into Sandman. 

This leads me to think that as long as he's got access to fresh* sand,  he can regenerate himself to the point of replacing aging inner organs. 

Is this true? Am I way off?

*obviously, no sand is "new" but there is plenty he's never used and is new to him.
gpt
In the Spider-Man comics, Sandman's consciousness is preserved within a single grain of sand. As long as that grain remains intact, Sandman will not die. Spider-Man 3 seems to operate on the same logic as the comics.