Comparative Analysis of Three-Dimensional Nanostructure of Porous Biocompatible Scaffolds Made of Recombinant Spidroin and Silk Fibroin for Regenerative Medicine

Abstract

Aim.To perform a comparison of three-dimensional nanostructure of porous biocompatible scaffolds made of fibroinBombix moriand recombinant spidroin rS1/9.Materials and methods.Three-dimensional porous scaffolds were produced by salt leaching technique. The comparison of biological characteristics of the scaffolds shows that adhesion and proliferation of mouse fibroblastsin vitroon these two types of scaffolds do not differ significantly. Comparative experimentsin vivoshow that regeneration of bone tissue of rats is faster with implantation of recombinant spidroin scaffolds. Three-dimensional nanostructure of scaffolds and interconnectivity of nanopores were studied with scanning probe nanotomography (SPNT) to explain higher regenerative activity of spidroin-based scaffolds.Results.Significant differences were detected in the integral density and volume of pores: the integral density of nanopores detected on 2D AFM images is 46 μm–2 and calculated volume porosity is 24% in rS1/9-based scaffolds; in fibroin-based three-dimensional structures density of nanopores and calculated volume porosity were 2.4 μm–2 and 0.5%, respectively. Three-dimensional reconstruction system of nanopores and clusters of interconnected nanopores in rS1/9-based scaffolds showed that volume fraction of pores interconnected in percolation clusters is 35.3% of the total pore volume or 8.4% of the total scaffold volume.Conclusion.Scanning probe nanotomography method allows obtaining unique information about topology of micro – and nanopore systems of artificial biostructures. High regenerative activity of rS1/9-based scaffolds can be explained by higher nanoporosity of the scaffolds.

Biomedical Applications of Recombinant Silk‐Based Materials

“…For the bone implants, Roentgen and CT studies revealed that after four weeks a higher recovery took place in case of rS1/9 in terms of bone formation and maturation. [61b] Further, scanning probe nanotomography confirmed a better regeneration of bone tissue in rats using rS1/9 compared to B. mori fibroin, probably due to higher nanoporosity thereof …”

“…[61a] Moisenovich et al showed 3T3 fibroblasts attached and proliferated in rS1/9 scaffolds, whereby a homogeneous cell distribution throughout the material was obtained after 14 d as found by CLSM. [49,61b] Further, rS1/9 foams were compared to B. mori silk fibroin ones, which showed a similar result in terms of 3T3 fibroblast attachment and proliferation,[61b,104] but allowed a 5× faster migration through the network, leading to the conclusion that rS1/9 foams yielded a reduced motility of 3T3 cells. [61b] Freeze‐dried L‐RGDSx2 fibroin (LRF) scaffolds with a mean pore diameter of 80 µm showed promising results for bone and cartilage tissue engineering, where primary chondrocytes from white rabbits produced more cartilage‐like tissue on the surface of LRF than on native fibroin.…”

Three-dimensional analysis of micro- and nanostructure of biomaterials and cells by method of scanning probe nanotomography

“…Методы получения пористых клеточных мак-роносителей на основе регенерированного шелка при помощи выщелачивания с использованием в качестве порообразователя частиц хлорида натрия описаны в [20,34]. Форма и размеры использован-ных макроносителей: цилиндры с диаметром от 10 до 12 мм, высотой от 2 до 3 мм, размер макропор: от 50 до 600 мкм.…”

“…Для модификации поверхности образец порис-того макроносителя на основе регенерированного шелка [20,34] был предварительно дегазирован в эксикаторе до полного удаления из него воздуха и затем перенесен в пластиковую чашку Петри. На поверхность образца макроносителя была нанесе-на суспензия микрочастиц межклеточного матрикса децеллюляризованной печени крысы породы Wistar с концентрацией 20 мг/мл.…”

New Tissue-Engineered Vascular Matrix Based on Regenerated Silk Fibroin: in vitro Study

“…One type of natural material is silk fibroin (SF), which is obtained from Bombyx mori silk fibers [ 7 , 8 ]. In experiments in vitro and in vivo , SF demonstrates a high ability for adhesion, proliferation, and differentiation of stem cells [ 9 ], it is used to stimulate tissue regeneration [ 10 - 12 ], has low immunogenicity and antigenicity [ 13 ], and does not require stringent conditions for the production of biological matrices [ 14 ].…”