Polyurethane/chitosan/ Propolis scaffolds are biocompatible and provide an enriched environment for the growth and proliferation of fibroblasts

Background and Aim : Biodegradable polymers can replace damaged tissue components using tissue engineering techniques. Polymer scaffolds are used in skin grafts,providing a suitable area for the growth and proliferation of fibroblast cells capable of wound repair. In this study,we evaluated whether the addition of Propolis, to polyurethane (PU) polymer affects scaffold morphology and cell activity of fibroblasts,prepared from human foreskin tissues. Methods : After preparing the scaffolding,Electrospun process was conducted by an electrospinning machine having a high voltage source of up to 50 kV, two positive and negative electrodes.Nano networks were then collected on an aluminum collector according to previously published methods.Then tensile properties of electrospun nanofibrous scaffolds were determined with a tabletop Micro Tester. Finally,The effect of scaffolds on fibroblast cells cultured was investigated by techniques such as DAPI Staining,Scanning Electron Microscopy (SEM),Trypan Blue Exclusion Assay,MTT Assay, Flow Cytometry. Results : Results showed that cell viability and the number of cells, using MTT and trypan blue exclusion assay; respectively, increased significantly at 24h, 48h, and 72h of culture in PU/CH/ Propolis scaffold compared to Propolis, CH/Propolis, and PU/ Propolis. Moreover, PU/ Propolis at 48h and 72h also increased cell viability and cell numbers compared to Propolis and CH/Propolis scaffolds. However, scaffolds at 72h had limited space for cell growth. Moreover, SEM data demonstrated that fibroblasts were able to proliferate, penetrate, migrate and survive on PU/Propolis and PU/CH/Propolis three-dimensional scaffolds, especially during the first 48 hours. Furthermore, DAPI confirmed that fibroblasts could penetrate PU scaffolds and showed higher cell viability and lower cellular damage in PU/CH/Propolis, compared to CH/Propolis and PU/Propolis scaffolds. Finally, flow cytometry using CD90 and CD105 surface markers revealed that > 90% of cells isolated from the human dermis were fibroblasts Conclusion : PU/Propolis and PU/CH/Propolis scaffolds were found to be biocompatible and provided a suitable environment for the growth and proliferation of fibroblasts,which filled and covered all pores between the fibers. The new scaffold used in this study, made of synthetic and natural polymers, is a good candidate for applications in tissue engineering. It is therefore recommended to use PU in grafts or in wound dressing.

Keywords:

Polyurethane , Chitosan , Propolis scaffolds , fibroblasts