Effect of chemistry and morphology on the biofunctionality of self-assembling diblock copolypeptide hydrogels.
Amphiphilic, diblock copolypeptides of hydrophilic lysine or glutamic acid and hydrophobic leucine or valine have been observed to self-assemble into rigid hydrogels in aqueous solution at neutral pH and very low volume fraction of polymer, > or =0.5 wt % polypeptide. Laser scanning confocal microscopy and ultra small angle neutron scattering revealed a heterogeneous microstructure with distinct domains of hydrogel matrix and pure water pores. In situ nanoscale characterization, using cryogenic transmission electron microscopy, revealed a porous, interconnected membranous network of assembled polypeptides. At concentrations of polypeptide below gelation, diblocks containing lysine were cytotoxic to cells, whereas those containing glutamic acid were noncytotoxic. At higher polypeptide concentrations, within rigid gel scaffolds, both lysine and glutamic acid based diblocks were noncytotoxic but did not support cell attachment/proliferation. The cationic chemistry observed as cytotoxic in the fluid state was essentially inert in the intact, rigid hydrogel state.
Department of Materials Science, Delaware Biotechnology Institute, University of Delaware, Newark, Delaware 19716, USA.
Lisa M
LM
Pakstis
Bulent
B
Ozbas
Kelly D
KD
Hales
Andrew P
AP
Nowak
Timothy J
TJ
Deming
Darrin
D
Pochan
D000818:Animals; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects / Q000648:ultrastructure; D020100:Hydrogels / Q000737:chemistry* / Q000494:pharmacology; D051379:Mice; D041681:NIH 3T3 Cells; D009502:Neutrons; D010455:Peptides / Q000737:chemistry* / Q000494:pharmacology; D012542:Scattering, Radiation
D020100:Hydrogels; D010455:Peptides