Quantitative characterization of the electrospun gelatin–chitosan nanofibers by coupling scanning electron microscopy and atomic force microscopy

Abstract

Nanofibers&nbsp;were&nbsp;electrospun&nbsp;from&nbsp;gelatin&nbsp;and&nbsp;chitosan&nbsp;at&nbsp;different&nbsp;mass&nbsp;ratios<br /> &nbsp;(gelatin/chitosan:&nbsp;0/100,&nbsp;25/75,&nbsp;50/<br /> 50,&nbsp;75/25,&nbsp;100/0).&nbsp;Atomic&nbsp;forcemicroscopy&nbsp;(AFM)&nbsp;combined&nbsp;with&nbsp;scanning<br /> &nbsp;electronmicroscopy&nbsp;(SEM)was&nbsp;utilized<br /> in&nbsp;this&nbsp;study&nbsp;to&nbsp;evaluate&nbsp;the&nbsp;morphological&nbsp;and&nbsp;mechanical&nbsp;properties&nbsp;of&nbsp;the&nbsp;gelatin&ndash;chitosan&nbsp;nanofibers.&nbsp;The&nbsp;SEM<br /> images&nbsp;showed&nbsp;that&nbsp;the&nbsp;electrospun&nbsp;gelatin&ndash;chitosan&nbsp;nanofibers&nbsp;possessed&nbsp;more&nbsp;uniform&nbsp;morphologies&nbsp;than&nbsp;the<br /> pure&nbsp;gelatin&nbsp;or&nbsp;chitosan&nbsp;nanofibers.&nbsp;Moreover,&nbsp;AFM-HarmoniX&nbsp;mode&nbsp;was&nbsp;used&nbsp;to&nbsp;quantitatively&nbsp;assess&nbsp;the&nbsp;Derjaguin&ndash;<br /> M&uuml;ller&ndash;Toporov&nbsp;(DMT)&nbsp;modulus&nbsp;of&nbsp;gelatin&ndash;chitosan&nbsp;nanofibers.&nbsp;After&nbsp;modified&nbsp;by&nbsp;two&nbsp;correction&nbsp;factors,<br /> the&nbsp;DMTmodulus&nbsp;of&nbsp;gelatin&ndash;chitosan&nbsp;nanofibers&nbsp;showed&nbsp;higher&nbsp;values&nbsp;than&nbsp;the&nbsp;pure&nbsp;gelatin&nbsp;or&nbsp;chitosan&nbsp;nanofibers,<br /> which&nbsp;indicated&nbsp;the&nbsp;existence&nbsp;of&nbsp;intermolecular&nbsp;interaction&nbsp;within&nbsp;the&nbsp;electrospun&nbsp;gelatin&ndash;chitosan&nbsp;nanofibers.<br /