The invention provides articles of manufacture comprising biocompatible nanostructures comprising nanotubes and nanopores for, e.g., organ, tissue and/or cell growth, e.g., for bone, kidney or liver growth, and uses thereof, e.g., for in vitro testing, in vivo implants, including their use in making and using artificial organs, and related therapeutics. The invention provides lock-in nanostructures comprising a plurality of nanopores or nanotubes, wherein the nanopore or nanotube entrance has a smaller diameter or size than the rest (the interior) of the nanopore or nanotube. The invention also provides dual structured biomaterial comprising micro- or macro-pores and nanopores. The invention provides biomaterials having a surface comprising a plurality of enlarged diameter nanopores and/or nanotubes.