Recent Developments of Silk-Based Scaffolds for Tissue Engineering and Regenerative Medicine Applications: A Special Focus on the Advancement of 3D Printing

Abstract

Regenerative medicine has received potential attention around the globe, with improving cell performances, one of the necessary ideas for the advancements of regenerative medicine. It is crucial to enhance cell performances in the physiological system for drug release studies because the variation in cell environments between in vitro and in vivo develops a loop in drug estimation. On the other hand, tissue engineering is a potential path to integrate cells with scaffold biomaterials and produce growth factors to regenerate organs. Scaffold biomaterials are a prototype for tissue production and perform vital functions in tissue engineering. Silk fibroin is a natural fibrous polymer with significant usage in regenerative medicine because of the growing interest in leftovers for silk biomaterials in tissue engineering. Among various natural biopolymer-based biomaterials, silk fibroin-based biomaterials have attracted significant attention due to their outstanding mechanical properties, biocompatibility, hemocompatibility, and biodegradability for regenerative medicine and scaffold applications. This review article focused on highlighting the recent advancements of 3D printing in silk fibroin scaffold technologies for regenerative medicine and tissue engineering.

Keywords: 3D printing; biomaterials; fibroin; regenerative medicine; scaffolds; tissue engineering.

Figure 1

3D bioprinting has evidenced significant development and potential applications for the biomedical area.

Figure 2

(A) Schematic representation of the SF-based 3D bioprinted scaffold from fundamental to biomedical applications. (B) Various types of 3D- printing techniques used for preparation SF-based 3D bioprinted scaffold in Tissue Engineering applications.

Figure 3

Schematic representation of the synthesis GeIMA/SFMA-based 3D printing scaffold embedded with BMSCs and FTY-720 for bone regeneration [145].

Figure 4

(A) Schematic representation of the preparation of the 3D bioprinted bilayered scaffold embedded with growth factors for osteochondral repair. (B) Cell viability of embedded BMSCs in the scaffold and fluorescence imaging of cartilage layer and bone layer incubated with BMSCs. (C) In vivo investigations of the bi-layered scaffold-assisted osteochondral tissue repair. Photographic image implantation studies of the control, pristine, and G.F. bilayered scaffold after 3 months. The Hematoxylin and Eosin staining of regenerated tissue after 12 weeks. Reproduced with permission [154]. Copyright 2021, Whioce Publishing.

Figure 5

Schematic representation of the 3D bioprintable electroconductive bioink-mediated graphene oxide grafted SF Reproduced with permission [130]. Copyright 2020, ACS.

Figure 6

(A) Schematic representation of the synthesis of SF photo crosslinked 4-arm PEG scaffold [171]. (B) Photographic images of the formation of a 3D bioprinted scaffold of keratin layer with fibroblast cells. The hematoxylin and eosin-stained after the incubation for two and six weeks. Reproduced with permission [171]. Copyright 2019, Elsevier, Science direct.