13319
In order to better understand the relationship between type I collagen self - assembly and D - spacing distribution , we investigated surface - mediated collagen self - assembly as a function of substrate and incubation concentration .
 None
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:  
Answer:
 None