Treated with care (6)
I believe the answer is:
nursed
'treated' is the definition.
(nursing is a kind of treating)
'care' is the wordplay.
I cannot really understand how this works, but
'care' could be 'nurse' (I've seen this before) and 'nurse' is present in the answer.
A single letter 'd' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'with' is the link.
Can you help me to learn more?
(Other definitions for nursed that I've seen before include "Tended to the sick, cared for" , "26dn the ill" , "Cherished" , "Took care of while ill" , "Cared for a patient" .)