title: Two-step self-assembly of liposome-multidomain peptide nanofiber hydrogel for time-controlled release.
abstract: Progress in self-assembly and supramolecular chemistry has been directed toward obtaining macromolecular assemblies with higher degrees of complexity, simulating the highly structured environment in natural systems. One approach to this type of complexity are multistep, multicomponent, self-assembling systems that allow approaches comparable to traditional multistep synthetic organic chemistry; however, only a few examples of this approach have appeared in the literature. Our previous work demonstrated nanofibrous mimics of the extracellular matrix. Here we demonstrate the ability to create a unique hydrogel, developed by stepwise self-assembly of multidomain peptide fibers and liposomes. The two-component system allows for controlled release of bioactive factors at multiple time points. The individual components of the self-assembled gel and the composite hydrogel were characterized by TEM, SEM, and rheometry, demonstrating that peptide nanofibers and lipid vesicles both retain their structural integrity in the composite gel. The rheological robustness of the hydrogel is shown to be largely unaffected by the presence of liposomes. Release studies from the composite gels loaded with different growth factors EGF, MCP-1, and PlGF-1 showed delay and prolongation of release by liposomes entrapped in the hydrogel compared to more rapid release from the hydrogel alone. This bimodal release system may have utility in systems where timed cascades of biological signals may be valuable, such as in tissue regeneration.
authors.affiliation: Departments of †Chemistry and ‡Bioengineering, Rice University , Bioscience Research Collaborative, 6500 Main Street, Houston, Texas 77030, United States.
authors.forename: Navindee C
authors.initials: NC
authors.lastname: Wickremasinghe
authors.forename: Vivek A
authors.initials: VA
authors.lastname: Kumar
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Hartgerink
mesh_terms: D003692:Delayed-Action Preparations / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D057139:Nanofibers / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D012212:Rheology
chemical_list: D003692:Delayed-Action Preparations; D036341:Intercellular Signaling Peptides and Proteins; D008055:Lipids; D008081:Liposomes; D010455:Peptides; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate