Bioinspired Layer-by-Layer Microcapsules Based on Cellulose Nanofibers with Switchable Permeability.
Green, all-polysaccharide based microcapsules with mechanically robust capsule walls and fast, stimuli-triggered, and switchable permeability behavior show great promise in applications based on selective and timed permeability. Taking a cue from nature, the build-up and composition of plant primary cell walls inspired the capsule wall assembly, because the primary cell walls in plants exhibit high mechanical properties despite being in a highly hydrated state, primarily owing to cellulose microfibrils. The microcapsules (16 ± 4 μm in diameter) were fabricated using the layer-by-layer technique on sacrificial CaCO3templates, using plant polysaccharides (pectin, cellulose nanofibers, and xyloglucan) only. In water, the capsule wall was permeable to labeled dextrans with a hydrodynamic diameter of ∼6.6 nm. Upon exposure to NaCl, the porosity of the capsule wall quickly changed allowing larger molecules (∼12 nm) to permeate. However, the porosity could be restored to its original state by removal of NaCl, by which permeants became trapped inside the capsule's core. The high integrity of cell wall was due to the CNF and the ON/OFF alteration of the permeability properties, and subsequent loading/unloading of molecules, could be repeated several times with the same capsule demonstrating a robust microcontainer with controllable permeability properties.
Wallenberg Wood Science Center and Department of Fiber and Polymer Technology and ∥Fiber and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology , SE-10044 Stockholm, Sweden.
Thomas
0000-0001-5098-3525
T
Paulraj
Wallenberg Wood Science Center and Department of Fiber and Polymer Technology and ∥Fiber and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology , SE-10044 Stockholm, Sweden.
Anastasia V
AV
Riazanova
School of Biotechnology, Royal Institute of Technology , Alba Nova University Centre, 10691, Stockholm, Sweden.
Kun
K
Yao
Richard L
0000-0002-0236-5420
RL
Andersson
Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen , Universitetsparken 2, 2100 Copenhagen, Denmark.
Anette
A
Müllertz
Wallenberg Wood Science Center and Department of Fiber and Polymer Technology and ∥Fiber and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology , SE-10044 Stockholm, Sweden.
Anna J
0000-0002-4583-723X
AJ
Svagan
D040761:Biomimetic Materials / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry; D002214:Capsules; D002482:Cellulose / Q000737:chemistry* / Q000648:ultrastructure; D004337:Drug Carriers / Q000737:chemistry*; D065546:Drug Liberation; D005936:Glucans / Q000737:chemistry; D057139:Nanofibers / Q000737:chemistry* / Q000648:ultrastructure; D010368:Pectins / Q000737:chemistry; D010539:Permeability; D016062:Porosity; D013499:Surface Properties; D014990:Xylans / Q000737:chemistry
D002214:Capsules; D004337:Drug Carriers; D005936:Glucans; D014990:Xylans; C029353:xyloglucan; D010368:Pectins; D002482:Cellulose; D002119:Calcium Carbonate