| Electrospinning is attracting more and more attentions as a kind of nanofibrous scaffolds which can produce biomimetic extracellular matrix.With the development of electrospinning technology,the emergence of different spinning processes and methods have broken out,these spinning process to produce the scaffolds are very different.Because of its higher pore size and porosity than the traditional nanofibrous scaffold,nanostructured scaffolds have a broader prospect in tissue repair.In addition,coaxial electrospinning technology,which can carry growth factors or small molecule drugs,that has potential application value.In this study,a novel drug-loaded nanocomposite scaffold,which is capable of carrying small molecule drugs and allowing cells to grow into the interior of the material,which was produced by a novel electrospinning technique.In this study,ICG-001 was used as the core layer and collagen I(Col I)/ poly(lactide-caprolactone)(P(LLA-CL))as the shell layer.The co-axial electrospinning technique was used to fabricate core/shell nanofibers,and the ICG-001 was used as the core,the electrospun nanofibers collected through different methods: Dynamic liquid electrospinning and Conjugated electrospinning.The morphologies and diameters of the scaffolds were characterized by high power scanning electron microscopy(SEM).Transmission electron microscopy(TEM)was used to characterize the loading of the nanofibers.The contact angle,mechanical properties,pore size,rate of standard volume method analysis and comparison of different scaffolds.The results showed that the nanoyarn(D-DLY)prepared by co-axial-dynamic liquid electrospinning and the drug-loaded nanoyarn(D-CY)prepared by coaxial-conjugated electrospinning(DLY)prepared by separate dynamic liquid spinning technology and nanoyarn(CY)prepared by separate conjugated spinning electrospinning technique showed no significant difference.The fiber diameters of D-DLY and DLY are larger than D-CY and CY.Mechanical force DLY tensile force is greater than CY,also greater than the traditional electrospinning technology to prepare nanofibers(NF).The hydrophilicity of DLY and CY was better than that of NF,while the hydrophilicity of DLY was better than that of CY.Pore diameter and porosity DLY are greater than CY and NF.The study of material properties showed that DLY was stronger than other scaffolds in all indexes.In vitro biocompatibility was evaluated by selecting the dog urethral fibroblasts as seeded cells.MTT results showed that the number of experimental fibroblasts loaded with ICG-001 was significantly smaller in the various scaffolds than in the non-drug-loaded group,while DLY showed biocompatibility higher than that of CY and NF,On the growth rate faster than other scaffolds,DLY has a larger porosity,it can provide more space for cells to grow.The results of immunofluorescence staining confirmed that DLY can promote cell growth better.Cells were grown on different scaffolds for 2 weeks and 3 weeks with H&E stained sections.The results showed that the cells can grow into the scaffold on DLY compared to CY and NF,because the pore size of DLY was suitable for cell size.The cells migrate easily to the inside,while the CY and NF pore size is smaller than the DLY,so only a small amount of cells can grow into the material inside.From the characterization of materials to in vitro biocompatibility evaluation,it was proved that DLY was more suitable for tissue repair.Therefore,only DLY(D-DLY)was selected as the scaffold in animal experiments.DLY and D-DLY scaffolds were cut into appropriate sizes to repair the defects of the dog urethra in situ.Two months later,H&E section,Masson staining,in situ angiography to characterize the urethral repair.The results showed that the urethra in the D-DLY group was intact and no urethral restenosis occurred,and the animals did not show inflammation.The results of the DLY group showed that the collagen content in the repair site was high and the urethral restenosis occurred. |
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