Self-assembling biomaterials: liquid crystal phases of cholesteryl oligo(L-lactic acid) and their interactions with cells.
We report here on the synthesis and characterization of a series of self-assembling biomaterials with molecular features designed to interact with cells and scaffolds for tissue regeneration. The molecules of these materials contain cholesteryl moieties, which have universal affinity for cell membranes, and short chains of lactic acid, a common component of biodegradable tissue engineering matrices. The materials were synthesized in good yields with low polydispersities in the range of 1.05-1.15, and their characterization was carried out by small-angle x-ray diffraction, transmission electron microscopy, electron diffraction, differential scanning calorimetry, and atomic force microscopy. These molecular materials form layered structures that can be described as smectic phases and can also order into single-crystal stacks with an orthorhombic unit cell. Their layer spacings range from 58 to 99 A, corresponding to bilayers of oligomers with an average of 10 and 37 lactic acid residues, respectively. The self-organized layered structures were found to promote improved fibroblast adhesion and spreading, although the specific mechanism for this observed response remains unknown. The ability of self-assembling materials to present ordered and periodic bulk structures to cells could be a useful strategy in tissue engineering.
Department of Materials Science and Engineering, Department of Chemistry, Feinberg School of Medicine, Northwestern University, Evanston, IL 60208, USA.
Julia J
JJ
Hwang
Subramani N
SN
Iyer
Li-Sheng
LS
Li
Randal
R
Claussen
Daniel A
DA
Harrington
Samuel I
SI
Stupp
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning / Q000379:methods; D002478:Cells, Cultured; D002784:Cholesterol / Q000031:analogs & derivatives / Q000737:chemistry*; D003460:Crystallization; D005347:Fibroblasts / Q000166:cytology; D007773:Lactates / Q000737:chemistry*; D051379:Mice; D008854:Microscopy, Electron; D008968:Molecular Conformation; D013816:Thermodynamics
D001672:Biocompatible Materials; D007773:Lactates; C464654:cholesteryl oligo(lactic acid); D002784:Cholesterol