Biomimetic, Osteoconductive Non-mulberry Silk Fiber Reinforced Tricomposite Scaffolds for Bone Tissue Engineering

Abstract

Composite biomaterials as artificial bone graft materials are pushing the present frontiers of bioengineering. In this study, a biomimetic, osteoconductive tricomposite scaffold made of hydroxyapatite (HA) embedded in non-mulberry Antheraea assama (A. assama) silk fibroin fibers and its fibroin solution is explored for its osteogenic potential. Scaffolds were physico-chemically characterized for morphology, porosity, secondary structure conformation, water retention ability, biodegradability, and mechanical property. The results revealed a ∼5-fold increase in scaffold compressive modulus on addition of HA and silk fibers to liquid silk as compared to pure silk scaffolds while maintaining high scaffold porosity (∼90%) with slower degradation rates. X-ray diffraction (XRD) results confirmed deposition of HA crystals on composite scaffolds. Furthermore, the crystallite size of HA within scaffolds was strongly regulated by the intrinsic physical cues of silk fibroin. Fourier transform infrared (FTIR) spectroscopy studies indicated strong interactions between HA and silk fibroin. The fabricated tricomposite scaffolds supported enhanced cellular viability and function (ALP activity) for both MG63 osteosarcoma and human bone marrow stem cells (hBMSCs) as compared to pure silk scaffolds without fiber or HA addition. In addition, higher expression of osteogenic gene markers such as collagen I (Col-I), osteocalcin (OCN), osteopontin (OPN), and bone sialoprotein (BSP) further substantiated the applicability of HA composite silk scaffolds for bone related applications. Immunostaining studies confirmed localization of Col-I and BSP and were in agreement with real-time gene expression results. These findings demonstrate the osteogenic potential of developed biodegradable tricomposite scaffolds with the added advantage of the affordability of its components as bone graft substitute materials.

Hydroxyapatite nanowire/collagen elastic porous nanocomposite and its enhanced performance in bone defect repair

“…9,45,46 In addition, the implanted scaffolds provide sufficient mechanical strength and mechanical stability in vivo to withstand mechanical loading and support the new formed bone. 7,47 In this work, the compressive mechanical properties of the collagen sample and biomimetic UHANWs/Col porous nanocomposite were investigated under dry and rehydrated states, as shown in Fig. 7.…”

“…However, the clinical applications of the autogra and allogra are limited by the donor-site morbidity, limited supply, risks of infection and immunological reaction. [5][6][7] To overcome the shortcomings of the autogra and allogra, various types of synthetic bone gra substitutes have been extensively investigated to full bone integration and bone regeneration in vivo.…”

Porous Nanocomposite Comprising Ultralong Hydroxyapatite Nanowires Decorated with Zinc‐Containing Nanoparticles and Chitosan: Synthesis and Application in Bone Defect Repair

“…[57,58] In addition, the porous scaffolds with good degradation properties can release the bioactive ionic products and provide ap ositive chemicale nvironmentf or bone regenerationv ia inducing osteogenesis or angiogenesis. Gradual degradation of the implanted scaffold is required for the ingrowth of newly formed bone tissue and their integration.…”

Mussel‐inspired bio‐based water‐resistant soy adhesives with low‐cost dopamine analogue‐modified silkworm silk Fiber

“…Unlike soy isolate protein fiber, silkworm silk fiber (SF) has superior mechanical properties and is an abundant, cheap, and sustainable natural protein . SF may thus be an ideal natural fiber filler candidate to improve the toughness of soy‐based adhesives .…”

“…Many efforts have been made to improve the interfacial bonding strength between SF and various matrixes . Unfortunately, the traditional acid/alkaline treatments, chemical grafting, and oxidation treatments are not environmentally safe, and tend to damage the microstructures of the SF …”