What this is
Adhesion in wet environments is hard: bulk water breaks non-covalent bonds and forms boundary layers that stop synthetic glues (cyanoacrylates, epoxies) from reaching the substrate. When catecholamines like dopamine are oxidised in alkaline, aqueous conditions, they polymerise into polydopamine, which co-deposits into a strong wet-setting adhesive.
Why it is worth looking at
Polydopamine has mostly been used as a nanometre-thin dip-coating, which is useless for structural bonding. The low-CapEx opportunity here is building it in situ as a load-bearing underwater adhesive.
Buying research, not a business plan
Nobody has built this venture. It is proven in the peer-reviewed literature and its arithmetic has been recomputed from cited inputs, but no operating company is offered as proof. You are buying research, not a business plan, and not a promise of return. Every figure and regulatory requirement should be verified independently before committing capital.