Nanomaterials are at the leading edge of the rapidly developing field of nanotechnology. Their unique size-dependent properties make these materials superior and indispensable in many areas of human activity. This brief review tries to summarise the most recent developments in the field of applied nanomaterials, in particular their application in biology and medicine, and discusses their commercialisation prospects. For the treatment of brain illnesses, nanotechnology has opened up a whole new universe of possibilities. Nanosystems can encapsulate, transport, and administer a wide range of therapeutic substances, including medicines and nucleic acids. Nanoparticles can also be manufactured to include photosensitizers or act as photothermal conversion agents in phototherapy on their own. Nano-delivery agents can also improve the efficacy of contrast agents, allowing for better brain imaging and diagnosis. The blood–brain barrier, on the other hand, makes effective nano-delivery to the brain difficult (BBB). Advances in understanding natural transport channels through the BBB have led to the possibility of using receptor-mediated transcytosis as a method of nanoparticle absorption. As a targeted ligand, the oligopeptide Angiopep-2, which has a high BBB transcytosis potential, has been used. Angiopep-2 has been functionalized on a variety of organic and inorganic nanostructures to route medicinal and diagnostic substances to the brain. These have showed considerable promise not just in the treatment and diagnosis of brain cancer, but also in the treatment of brain damage, stroke, epilepsy, Parkinson's disease, and Alzheimer's disease. This review focuses on studies using Angiopep-2-modified nanoparticles for the treatment and diagnostics of brain diseases done between 2010 and 2021. "BBB-crossing nanotechnology is predicted to have a transformative influence on traditional brain cancer management," Tang and colleagues. Angiopep-2-mediated transport techniques are becoming increasingly significant in this area. Most Angiopep-2-functionalized nanomedicines are currently being used to treat brain tumours, particularly glioblastoma, which is very aggressive and resistant to current treatment. As it stands now, the majority of commercial nanoparticle applications in medicine are geared towards drug delivery. In biosciences, nanoparticles are replacing organic dyes in the applications that require high photo-stability as well as high multiplexing capabilities. There are some developments in directing and remotely controlling the functions of nano-probes, for example driving magnetic nanoparticles to the tumour and then making them either to release the drug load or just heating them in order to destroy the surrounding tissue. The major trend in further development of nanomaterials is to make them multifunctional and controllable by external signals or by local environment thus essentially turning them into nano-devices.