25992
The new micromotors consist of biodegradable and environmentally friendly magnesium microparticles and a nickel - gold bilayer patch for magnetic guidance and surface modification .
 Chemical: magnesium; Chemical: nickel
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: magnesium; Chemical: nickel