7484
In this review , various approaches for the design and preparation of PVP - modified surfaces are summarized and potential biomedical applications of these PVP - modified materials are indicated .
 Chemical: PVP; Chemical: PVP
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: PVP, PVP 
Answer:
 Chemical: PVP; Chemical: PVP