In vitro and in vivo biocompatibility studies of a recombinant analogue of spidroin 1 scaffolds

The goal of this study was to generate porous scaffolds from the genetically engineered protein, an analogue of Nephila clavipes spidroin 1 (rS1/9) and to assess the properties of new rS1/9 scaffolds essential for bioengineering. The salt leaching technique was used to make the rS1/9 scaffolds of interconnected macroporous structure with spontaneously formed micropores. The tensile strength of scaffolds was 18 ± 5 N/cm2. Scaffolds were relatively stable in a phosphate buffer but degraded in oxidizing environment after 11 weeks of incubation. Applicability of the recombinant spidroin 1 as a substrate for cell culture was demonstrated by successful 3T3 cells growth on the surface of rS1/9 films (270 ± 20 cells/mm2 vs. 97 ± 8 cells/mm2 on the glass surface, p < 0.01). The 3T3 fibroblasts readily proliferated within the rS1/9 scaffold (from initially plated 19 ± 2 cells/mm3 to 3800 ± 304 cells/mm3 after 2 weeks). By this time, cells were uniformly distributed between the surface and deeper layers (27% ± 8% and 33% ± 4%, respectively; p > 0.05), whereas the initial distribution was 58% ± 7% and 11% ± 8%, respectively; p < 0.05). The rS1/9 scaffolds implanted subcutaneously into Balb/c mice were well tolerated. Over a 2‐month period, the scaffolds promoted an ingrowth of de novo formed vascularized connective tissue elements and nerve fibers. Thus, scaffolds made of the novel recombinant spidroin 1 analogue are potentially applicable in tissue engineering. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.