Multilayer nanofibrous scaffold for skin tissue engineering: in vitro and vivo assays

Project 1; IntroductionIn this research, fabrication of multilayer nanofibrous scaffold for skin tissue engineering was studied. The nanofibers were fabricated using electrospinning technique comprising natural and biocompatible polymers.MethodsChitosan (Sigma Aldrich) and gelatin (Sigma Aldrich) blend solution were prepared by dissolving the polymers in the co-solvent system of TFA and DCM (70:30). Gelatin and chondroitin sulfate (Sigma Aldrich) blend solution was prepared by dissolving the polymers in the co-solvent system of TFE/water (50/50) (Merck). The two solutions were subjected to the electrospinning process. Four electrospun layers were attached to each other using small physical shrinkage of nanofibrous samples at ethanol and engaging of interface fibers. The prepared samples were crosslinked, washed and sterilized. The in-vivo wound healing was evaluated using 10 male Wistar rats aged at 60 days with an average body weight of 200-250 g.Project 2; IntroductionIn this study, electrospinning process is used to fabricate a novel three-layer active wound dressing based on ε-polycaprolactone (PCL), polyvinylalcohol (PVA), and curcumin (CU) as a biologically active compound.MethodsMTT assay was used to study the viability of L929 cells exposed to several prepared electrospun dressings. Anti-bacterial test measures the efficiency of manufactured dressings in killing Gram-negative and Gram-positive bacteria. For this reason, the anti-bacterial activities of wound dresses were investigated against model microbial species, including Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive).Project 1; ResultsThe fabricated scaffold exhibited uniform fiber morphology with different fiber diameter and no bead was observed. Healing wounds were observed at the 10th and 14th days. Central wounded area was investigated after two weeks post-transplantation using H&E and Masson’s trichrome staining. Following 2 weeks in-vivo, the control group had evidence of larger amounts of macrophages and foreign body type giant cells compared to other groups. The case of wound implanted by multilayer scaffold after 2 weeks reveal complete re-epithelialization, reparation of dermis with parallel collagen deposition and loss of appendages and mild chronic inflammation.Project 2; ResultsThe results illustrate that a three-layer dressing based on PCL/curcumin containing PVA as a middle layer with optimized thickness which is placed over the incision, absorbs three times exudates in comparison with pristine dressing. Anti-bacterial tests reveal that the dressing containing 16% curcumin exhibits anti-bacterial activity without sacrificing the acceptable level of cell viability.ConclusionIt is concluded that these multilayer nanofibrous scaffolds containing chondroitin sulfate and chitosan or ε-polycaprolactone (PCL), polyvinylalcohol (PVA), and curcumin (CU) have great potential in skin tissue engineering because of high surface area and similarity to the native tissue ECM structure.

کلیدواژه ها:

Electrospun ، Skin tissue engineering ، Multilayer nanofibrous scaffold