State Of The Art, Cutting Edge
noun, の adjective
最新 is, as you can probably guess, "the newest." So, the newest sharp thing, is the cutting edge. It is state of the art.
さいしんえい
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
かつて、少し前までは、3Dプリンタは最新鋭の機械でした。
Once, a little while ago, 3D printers were cutting edge machines.