title: Dispersion of chitosan in liquid crystalline lamellar phase: Production of biofriendly hydrogel of nano cubic topology.
abstract: Bicontinuous cubic phases were produced with introduction of chitosan in phospholipid/water hydrogel, providing composites of defined molecular organization. The ratio of lipid/water was constant and swelling of lipids bilayer is delimited by incorporation of polymer molecules into the structure. By means of synchrotron small angle X-ray scattering we identified topologies of coexisting cubic phases. The expected liquid crystalline Lαlamellar phase was suppressed by 0.2wt% chitosan leading to formation of diamond Pn3m and gyroid Ia3d cubic topology, with close lattice distances. An increment to 0.4wt% chitosan caused large increase in Pn3m lattice distance. However a higher 0.6wt% evolved this phase to a newly acquired primitive Im3m topology. The structuring process of the three-dimensional complex network is principally governed by demands of chitosan physical requirements over lipids bilayers interfacial curvature. The composite hydrogel of specific topologies presents reduced time release of gallic acid and may find application as new material for time-sustained delivery of bioactive compounds.
authors.affiliation: Department of Animal Biology, Institute of Biology, State University of Campinas, 13083-970 Campinas, Brazil. Electronic address: patrickmathews83@gmail.com.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Mathews
authors.affiliation: Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo, 04023-062 Sao Paulo, Brazil. Electronic address: mertins@unifesp.br.
authors.forename: Omar
authors.initials: O
authors.lastname: Mertins
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D008055:Lipids; D050866:Liquid Crystals; D014867:Water; D014961:X-Ray Diffraction
chemical_list: D020100:Hydrogels; D008055:Lipids; D014867:Water; D048271:Chitosan
keywords: Biomembrane; Cubic phase; Phospholipid-chitosan gel; SAXS; Structure