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Updated: Jul 22, 2025

Fabrication of Extracellular Matrix-derived Foams and Microcarriers as Tissue-specific Cell Culture and Delivery Platforms
Published on: April 11, 2017
Excellent Specific Mechanical and Electrical Properties of Anisotropic Freeze-Cast Native and Carbonized Bacterial
Kaiyan Qiu1, Ulrike G K Wegst2
1Thayer School of Engineering Dartmouth College, Hanover, NH 03755, USA, School of Mechanical and Materials Engineering Washington State University, Pullman, WA 99164, USA.
Abstract:
Native and carbonized freeze-cast bacterial cellulose-alginate (BC-ALG) foams possess an ice-templated honeycomb-like architecture with remarkable properties. Their unique pore morphology consists of two levels of porosity: 20-50 μm diameter pores between, and 0.01-10 μm diameter pores within the cell-walls. The mechanical properties of the BC-ALG foams, a Young's modulus of up to 646.2 ± 90.4 kPa and a compressive yield strength of up to 37.1 ± 7.9 kPa, are high for their density and scale as predicted by the Gibson-Ashby model for cellular materials. Carbonizing the BC-ALG foams in an inert atmosphere at 1000-1200 °C in a second processing step, both pore morphology and mechanical properties of the BC-ALG remain well preserved with specific mechanical properties that are higher than those reported in the literature for similar foams. Also the electrical conductivity of the BC-ALG foams is high at 1.68 ± 0.04 S cm-1 at a density of only 0.055 g cm-3, and is found to increase with density as predicted, and as a function of the degree of carbonization determined by both carbonization temperature and atmosphere. The property profile makes freeze-cast BC-ALG foams and their carbonized foams attractive for energy applications and as a sorbent.

