We reported crosslinking of electrospun nanofibers of three representative pectins
(high-methoxylated, low-methoxylated, low-methoxylated and amidated pectin) and
characterization of the crosslinked nanofibers. One mono-crosslinking strategy and two dualcrosslinking
strategies were developed. Mono-crosslinking is achieved using calcium ions (Ca2+)
3
to crosslink carboxylate ions in galacturonic acid residues. Dual-crosslinking is achieved using
covalent crosslinking reagents glutaraldehyde (GLU) or adipic acid dihydrazide (ADH) to
further crosslink hydroxyl groups or carboxylate ions after Ca2+ crosslinking. Mechanical tests
and degradation experiments indicated pectin structure affected mechanical and degradation
properties of Ca2+
-crosslinked nanofibers remarkably. Subsequent GLU crosslinking improved
their mechanical strength moderately but did not inhibit their degradation, while subsequent
ADH crosslinking improved their mechanical strength and slowed down their degradation
dramatically. Cell studies demonstrated that most crosslinked pectin nanofibers were of no
obvious cytotoxicity, and both ADH crosslinking and high degree of methoxylation facilitated
cell adhesion and proliferation on pectin nanofiber mats.