title: Comparative evaluation of in vivo biocompatibility and biodegradability of regenerated silk scaffolds reinforced with/without natural silk fibers.
abstract: Nowadays, exceptional advantages of silk fibroin over synthetic and natural polymers have impelled the scientists to application of this biomaterial for tissue engineering purposes. Recently, we showed that embedding natural degummed silk fibers in regenerated Bombyx mori silk-based scaffold significantly increases the mechanical stiffness, while the porosity of the scaffolds remains the same. In the present study, we evaluated degradation rate, biocompatibility and regenerative properties of the regenerated 2% and 4% wt silk-based composite scaffolds with or without embedded natural degummed silk fibers within 90 days in both athymic nude and wild-type C57BL/6 mice through subcutaneous implantation. In all scaffolds, a suitable interconnected porous structure for cell penetration was seen under scanning electron microscopy. Compressive tests revealed a functional relationship between fiber reinforcement and compressive modulus. In addition, the fiber/fibroin composite scaffolds support cell attachment and proliferation. On days 30 to 90 after subcutaneous implantation, the retrieved tissues were examined via gross morphology, histopathology, immunofluorescence staining and reverse transcription-polymerase chain reaction as shown in Figure 1. Results showed that embedding the silk fibers within the matrix enhances the biodegradability of the matrix resulting in replacement of the composite scaffolds with the fresh connective tissue. Fortification of the composites with degummed fibers not only regulates the degradation profile but also increases the mechanical performance of the scaffolds. This report also confirmed that pore size and structure play an important role in the degradation rate. In conclusion, the findings of the present study narrate key role of additional surface area in improving in vitro and in vivo biological properties of the scaffolds and suggest the potential ability of these fabricated composite scaffolds for connective tissue regeneration. spjba;30/6/793/FIG10885328215601925F1fig1-0885328215601925Figure 1.Illustrative summary of the main methods and findings.RS: regenerated silk; RSF: regenerated fibroin/ silk fiber composite scaffolds; H&E: Hematoxylin and eosin; COX-1: Cyclooxygenase.
authors.affiliation: Department of Tissue Engineering, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Sahba
authors.initials: S
authors.lastname: Mobini
authors.affiliation: Department of Tissue Engineering, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Taghizadeh-Jahed
authors.affiliation: Department of Tissue Engineering, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Manijeh
authors.initials: M
authors.lastname: Khanmohammadi
authors.affiliation: Department of Tissue Engineering, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Moshiri
authors.affiliation: Department of Tissue Engineering, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Mohammad-Mehdi
authors.initials: MM
authors.lastname: Naderi
authors.affiliation: Department of Tissue Engineering, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Hamed
authors.initials: H
authors.lastname: Heidari-Vala
authors.affiliation: Department of Pathology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran.
authors.forename: Javad
authors.initials: J
authors.lastname: Ashrafi Helan
authors.affiliation: Department of Tissue Engineering, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Sayeh
authors.initials: S
authors.lastname: Khanjani
authors.affiliation: Centre for Translational Bone, Joint and Soft Tissue Research, University Hospital Carl Gustav Carus and Medical Faculty of Technische Universität Dresden, Dresden, Germany.
authors.forename: Armin
authors.initials: A
authors.lastname: Springer
authors.affiliation: Department of Tissue Engineering, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Mohammad-Mehdi
authors.initials: MM
authors.lastname: Akhondi
authors.affiliation: Department of Tissue Engineering, Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran s.kazemnejad@avicenna.ac.ir kazemnejad_s@yahoo.com.
authors.forename: Somaieh
authors.initials: S
authors.lastname: Kazemnejad
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis; D002470:Cell Survival / Q000502:physiology; D004867:Equipment Design; D019544:Equipment Failure Analysis; D048091:Guided Tissue Regeneration / Q000295:instrumentation*; D006244:Hardness; D008297:Male; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D012038:Regeneration / Q000502:physiology*; D047011:Silk / Q000737:chemistry*; D013718:Tensile Strength; D023822:Tissue Engineering / Q000295:instrumentation; D054457:Tissue Scaffolds
chemical_list: D001672:Biocompatible Materials; D047011:Silk
keywords: Silk fibroin; biocompatibility; biodegradability; fiber-reinforced composites; tissue engineering