A Novel One-Pot Synthesis and Characterization of Silk Fibroin/α-Calcium Sulfate Hemihydrate for Bone Regeneration

Ching-Shuan Huang,Aivaras Kareiva,Aditi Pandey,Jen-Chang Yang,Shu-Lien Cheng,Agnese Brangule,Tzu-Sen Yang

doi:10.3390/polym13121996

Ching-Shuan Huang, Aivaras Kareiva + Show 5 more

Open Access

https://doi.org/10.3390/polym13121996

Copy DOI

Abstract

This study aims to fabricate silk fibroin/calcium sulfate (SF/CS) composites by one-pot synthesis for bone regeneration applications. The SF was harvested from degummed silkworm cocoons, dissolved in a solvent system comprising of calcium chloride:ethanol:water (1:2:8), and then mixed with a stoichiometric amount of sodium sulfate to prepare various SF/CS composites. The crystal pattern, glass transition temperature, and chemical composition of SF/CS samples were analyzed by XRD, DSC, and FTIR, respectively. These characterizations revealed the successful synthesis of pure calcium sulfate dihydrate (CSD) and calcium sulfate hemihydrate (CSH) when it was combined with SF. The thermal analysis through DSC indicated molecular-level interaction between the SF and CS. The FTIR deconvolution spectra demonstrated an increment in the β-sheet content by increasing CS content in the composites. The investigation into the morphology of the composites using SEM revealed the formation of plate-like dihydrate in the pure CS sample, while rod-like structures of α-CSH surrounded by SF in the composites were observed. The compressive strength of the hydrated 10 and 20% SF-incorporated CSH composites portrayed more than a twofold enhancement (statistically significant) in comparison to that of the pure CS samples. Reduced compressive strength was observed upon further increasing the SF content, possibly due to SF agglomeration that restricted its uniform distribution. Therefore, the one-pot synthesized SF/CS composites demonstrated suitable chemical, thermal, and morphological properties. However, additional biological analysis of its potential use as bone substitutes is required.

Highlights

Introduction distributed under the terms andThe field of restoration and regeneration of critical bone defects, challenging for scientists, has amazed humanity by its advancements through the changing times [1].This trend of exploring new methods in the context of bone defects assists in developing techniques for accelerating bone healing
Unlike the typical dialysis process for salt removal, in this study, calcium chloride was used as the raw material to react with sodium sulfate to form an effective dispersion of calcium sulfate in silk fibroin, inducing the precipitation of silk fibroin/calcium sulfate (SF/Calcium sulfate (CS)) composites through a one-pot reaction
Correspond to crystal patterns of calcium sulfate dihydrate (CSD), the diffraction peaks at 14.76◦ (110), 25.67◦ (310), 29.77◦ (220), and 31.91◦ (−114) indicate the crystal patterns of calcium sulfate hemihydrate (CSH) [17]

Summary

Introduction

The field of restoration and regeneration of critical bone defects, challenging for scientists, has amazed humanity by its advancements through the changing times [1]. This trend of exploring new methods in the context of bone defects assists in developing techniques for accelerating bone healing. Lost bone involves osteogenesis, osteoconduction, and osteoinduction, which promotes regeneration at the affected site [2]. Complications, such as the need for a second surgery (in autografting), and immunogenicity (in allografts and xenografts) led to the development of synthetic bone substitutes (alloplasts) [3,4]. The α-CSH form usually dissolves slower in comparison to the β-CSH form due to its density and stability; it is often chosen for bone-filling applications [13]

Objectives

Methods

Results

Conclusion