You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Synthesis and physicochemical properties of new tripodal amphiphiles bearing fatty acids as a hydrophobic group. Saturated fatty acids (FA) were grafted using tyrosine as a spacer group to the cyclotriphosphazene ring along with equimolar hydrophilic methoxy poly(ethylene glycol) (MPEG) in cis-nongeminal way. Seven new cyclotriphosphazene amphiphiles were prepared from combinations of hydrophilic MPEGs with different molecular weights of 350, 550, 750 and 1000 and four different fatty acids of different hydrophobicity including lauric, myristic, palmitic and stearic acids. These steric amphiphiles bearing fatty acids as a hydrophobic group were found to form more stable micelles with very low critical micelle concentrations (CMC) (2.95-7.80mg/L) compared with oligopeptide analogues, and their highly hydrophobic core environment is unique and potentially useful for various biomedical applications.
{"Chemical": ["cyclotriphosphazene", "lauric, myristic, palmitic and stearic acids", "fatty acids", "methoxy poly(ethylene glycol)", "tyrosine", "MPEG", "MPEGs", "Saturated fatty acids"]}