I don't know the difference between Neosporin and Polysporin, but Neosporin is fine to use. Just keep him on towel (cloth or paper) until the injuries heal - otherwise the substrate will stick to the wounds. I hope you have separate housing for them now. It doesn't sound like they will ever be able to live together. 
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Torey
Eugene, Oregon, USA
1.1 Uromastyx Geyri (Joe and Arthur)
2.0.1 Uromastyx Dispar Maliensis (Tank, Turtle, and Spike)
1.2 Anolis Carolinensis (Bowser, Leeloo, and Sprocket)
1.1 African Dwarf Frogs (Bruce and Sheila)
1.0 Betta Splendens (Mr. Miagi)
1.1 Felis Domesticus (Roscolux and Jenny)
And several miscellaneous community fish
