13828
Few nanocarriers have been proposed to address the challenge of ATP / AZT - TP cellular delivery , but the loading efficiency , preparation complexity , and efficient cellular delivery remain important barriers to their development .
 Chemical: ATP; Chemical: AZT - TP
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: ATP, AZT - TP 
Answer:
 Chemical: ATP; Chemical: AZT - TP