My 2 week old hamster has an injury....help!?

OK, 2 weeks ago my hamster had 4 babies. Everything I read said to leave them alone...don't even look at them... Now that they are two weeks old and starting to move around the cage, I noticed that the little brown one (the other 3 are white) had it's foot caught in the nesting material (that was given to me by the pet store). It didn't look distressed...but while "mamma" was in another side of the cage, I picked up the baby with a spoon and clipped off the "fluff" (careful not to touch the baby with my hand so mamma wouldn't reject it). It's poor foot is no longer even there! It is just a bloody stump! Can I put anything on it to prevent infection? I have no idea how long it has been like that (since they have been hidden in the nest). I feel so bad for it....but it now seems to be getting around and even is using it to prop up food to eat (they just started eating real food today...that I have noticed).