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3D nanostructural analysis of biomaterials by scanning probe nanotomography
A.E. Efimov, O.I. Agapova, I.I Agapov
Shumakov Federal Research Center of Transplantology and Artificial Organs, RU
Keywords: nanotomography, biomaterials, nanoporosity
Summary:
We have been developing a new methodology and unique instrumentation for 3D reconstruction of the nanoscale volume organization of soft matter – scanning probe nanotomography (SPNT). It combines SPM with an ultramicrotome or cryoultramicrotome and can be applied for serial section tomography of a wide range of soft biological and polymer materials. Integration of SPM with cryoultramicrotome permits in situ measurements of the sample surface after cryo sectioning without any modification of the ultrastructure or transfer of the sample. It provides unique capabilities to study native structures of soft biomaterials and biological systems stabilized by cryofixation. Here we present new results of SPNT 3D ultrastructure studies of such biomaterial systems as biodegradable polymer cell scaffolds based on the recombinant protein rS1/9 (an analog of spidroin 1, protein of dragline silk of Nephila clavipes spiders) expressed in yeast and fibroin from natural silkworm (Bombyx mori) silk. We performed quantitative investigation of size, density and interconnectivity of nanopores in the volume of scaffolds and found that nanoscale porosity is much more developed in rS1/9 scaffolds than in fibroin ones (24% vs. 0.5%). Detected high degree of pore interconnectivity and percolation can positively effect to in vivo cell proliferation and tissue regeneration.
