Gene delivery has become an essential method for neuroscience research and offers promises for therapeutic applications. Adeno-associated viruses (AAVs) have been among the most preferred gene delivery vehicles (vectors) due to their low toxicity and high engineering potential. However, their poor efficacy and target specificity remain critical limitations, often raising serious safety concerns in clinical trials. My research has focused on engineering these viral vectors, enabling efficient and targeted gene delivery to the central and peripheral nervous systems through minimally invasive routes. To achieve this goal, we have developed several high-throughput platforms for engineering and screening the genetic variant libraries of AAV capsids (protein shell) and genomes by adapting cutting-edge technologies such as directed evolution and spatial omics. Through these technical innovations, we have identified a series of synthetic AAV variants that are, for instance, capable of penetrating the protective blood-brain barrier, preferentially transducing specific brain cell types, or avoiding the liver when intravenously administered. Our platform technologies have successfully been translated across species, including rodents and non-human primates, offering the great potential of advancing therapeutic gene delivery tools. In my new lab at UIUC Bioengineering, we aim to advance the precision of gene delivery by better understanding the genetic and epigenetic basis of brain functions and disorders and utilizing the obtained knowledge to develop targeted gene delivery vectors for specific brain cell types and states. We tackle this challenge at the intersection of synthetic biology, single-cell/spatial omics, and machine learning, ultimately hoping to deliver precision gene therapy for complex neurological and mental disorders.