20310
This study proposes a multimaterial system to sustain the release by covering the hydrogel with a poly ( alkyl - 2 - cyanoacrylate ) [ PACA ] - based film , which should be formed by an in situ polymerization on the hydrogel surface initiated upon contact with water .
 Chemical: poly ( alkyl - 2 - cyanoacrylate ); Chemical: PACA
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: poly ( alkyl - 2 - cyanoacrylate ); Chemical: PACA