[alvarezbjm-hn]

They didn't print brain tissue, they kinda printed scaffolds for it to grow.

"The researchers aimed to construct layered neural tissue in which neural progenitor cells (NPCs) mature ..."

Don't trust this kind of source for titles.

About cartilage. That is a very specific configuration of materials in not a random shape. Also, it must want to attach to the bone by itself, and source its nutrients from synovial liquid. Sounds too complicated for what I know we can do.

About human cells growing in a petri dish. Thats pretty much cancer right there. In such an alien environment, healthy cells expect something to kill them, and if enough changes happen without that, they will suicide.

Growing hearts in pigs is much closer to something viable.