I intend to apply for PhD in US ..I have bachelor’s degree in zoology and master’s degree in industrial biotechnology with thesis based on nanosciences and application in drug delivery. Most of the unis are offering same type of research in chem engg dept, chemistry or biomedical engg dept and offer admission to the students having the very same bachelor’s degree. Now as i have different background how can i tackle the problem of prerequisite courses ? Is there any university offering phd with research focus on nanosciences but takes students from diverse background.