Being a biologist myself, Titanus giganteus is definitely on my bucket list of species that I'd love to see at least once in my life! (They also get bonus points for having one of the coolest Latin names out there, on par with Dynastes satanas, Attacus atlas and Varroa destructor).

These beetles belong to the family Prioninae, which are notoriously difficult to breed, as these insects require very specific conditions that are often hard to replicate in a terrarium. That's why they haven't been bred in captivity.

It would probably have been done by now by hobbyist beetle keepers, if you could just buy them from an online store without any trouble. But they are illegal to buy or own in many countries.

You could theoretically travel to the South American forests to find male and female beetles, but the female titan beetles are really elusive and may take a lot of time and effort to find, and not many people are willing to commit to such an expedition, because knowing what the larvae of these insects look like isn't exactly a scientific priority.