1107
Hydroxyapatite ( HA ) coatings have been used to improve biological and mechanical fixation of metallic prosthesis .
 Chemical: Hydroxyapatite
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: Hydroxyapatite 
Answer:
 Chemical: Hydroxyapatite