I want to make my kids tires on their big wheels more durable?

Question:what can i do?
My husband mentioned spray on rubber?
the big wheel is 17 inches and the back wheels are like 8 inches.
is there another tire i can replace the plastic ones with?
Any ideas are appreciated.

Answers:
If the wheels are hollow drill some small holes it them and fill with a low expansion spray foam then over the exterior of the tires coat with plasti dip or similar rubberized coating, get from major hardware stores for re-coating handles of old tools