disregarding vs no matter

disregarding and no matter both are adverbs.

Word	Noun	Adjective	Verb	Adverb
disregarding	No	No	No	Yes
no matter	No	No	No	Yes

As adverbs, disregarding and no matter are synonyms defined as:

disregarding and no matter: in spite of everything; without regard to drawbacks

Other synonyms of disregarding include disregardless, irrespective, regardless.

disregarding (adverb)	no matter (adverb)
in spite of everything; without regard to drawbacks	in spite of everything; without regard to drawbacks