bm9b01249_si_001.pdf (1.02 MB)
Effect of Atomized Delivery of Nutrients on the Growth Characteristics and Microstructure Morphology of Bacterial Cellulose
journal contribution
posted on 2019-12-06, 19:47 authored by Anna-Christina Amason, James F. Nowak, Johnson Samuel, Richard A. GrossThis work demonstrates a general strategy for introducing
remarkable
changes in matrix organization and, consequently, functional properties
of bacterial cellulose (BC). BC-producing cells were induced, using
a well-defined atomized droplet nutrient delivery (ADND) system, to
form pellicles with a regular layered morphology that persists throughout
the mat depth. In contrast, the morphology of mats formed by conventional
static medium nutrient delivery (SMND) is irregular with no distinguishable
pattern. ADND also resulted in larger meso-scale average pore sizes
but did not alter the fibril diameter (∼70 nm) and crystallinity
index (92–95%). The specific modulus and specific tensile strength
of ADND mats are higher than those of SMND mats. This is due to the
regularity of dense layers that are present in ADND mats that are
able to sustain tensile loads, when applied parallel to these layers.
The density of BC films prepared by ADND is 1.63-fold lower than that
of the SMND BC film. Consequently, the water contents (g/g) of ADND-
and SMND-prepared BC mats are 263 ± 8.85 and 99.6 ± 2.04,
respectively. A model that rationalizes differences in mat morphology
resulting from these nutrient delivery methods based on nutrient and
oxygen concentration gradients is proposed. This work raises questions
as to the extent that ADND can be used to fine-tune the matrix morphology
and how the resulting lower density mats will alter the diffusion
of actives from the films to wound sites and increase the ability
of cells to infiltrate the matrix during tissue engineering.