title: Nano-engineered microcapsules of tannic acid and chitosan for protein encapsulation.
abstract: Tannic acid (TA), a high molecular weight polyphenol of natural origin, was assembled in alternation with chitosan (CH) using a layer-by-layer technique. The deposition of tannic acid and chitosan layers on flat supports was monitored by quartz crystal microbalance, UV-vis spectroscopy, and electrophoretic mobility measurements on microparticles. Hollow (TA/CH)4 capsules were built and their permeability as a function of pH and molecular weight of a penetrating compound was investigated. The pH-permeability threshold for TA/CH capsules is shifted to lower pH for 2 pH units, as compared with commonly used polyallylamine/polystyrene sulfonate capsules. A more pronounced dependence of the TA/CH capsules' permeability on molecular weight of encapsulated substances allows better control over their release properties. Bovine serum albumin was loaded into (TA/CH)4 capsules using a pH-driven method and released by decreasing pH. Biocompatible tannic acid/chitosan films and capsules have advantages toward capsules made of synthetic polyelectrolytes for drug encapsulation and as delivery and depot systems. Incorporating a layer of tannic acid with proved antioxidant and antimicrobial properties into capsule walls, provides defense for encapsulated materials.
authors.affiliation: Institute for Micromanufacturing and Chemistry Department, Louisiana Tech University, Ruston, LA, 71272, USA.
authors.forename: Tatsiana G
authors.initials: TG
authors.lastname: Shutava
authors.forename: Yuri M
authors.initials: YM
authors.lastname: Lvov
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002417:Cattle; D048271:Chitosan / Q000737:chemistry*; D004339:Drug Compounding; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods; D010539:Permeability; D011506:Proteins / Q000008:administration & dosage*; D012710:Serum Albumin, Bovine / Q000008:administration & dosage; D013053:Spectrophotometry; D013634:Tannins / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D011506:Proteins; D013634:Tannins; D012710:Serum Albumin, Bovine; D048271:Chitosan