How to pass parameter with regex query

Question

I am trying to query using regular expression in py2neo. However, I ran this query, but It did not work. I tried running the same query directly in Cypher and it worked. I do not know what I am missing.

            propertyNode = tx.run("MATCH (n) WHERE n.name=~(?i)$x(s?) RETURN n.id, labels(n)", x=word).data()

I appreciate any help.

Thanks.