Investigation on hydrogen bonds and conformational changes in protein/polysaccharide/ceramic based tri-component...

Area of Science:

• Biomaterials Science
• Materials Chemistry
• Biochemistry

Background:

• Molecular interactions, particularly hydrogen bonds, are crucial for determining biocomposite properties.
• Silk fibroin, sodium alginate, and hydroxyapatite form a promising tri-component system for advanced applications.

Purpose of the Study:

• To investigate the molecular-level interactions at the interface of silk fibroin/sodium alginate/hydroxyapatite biocomposites.
• To understand the role of hydrogen bonds and protein secondary structures in influencing biocomposite characteristics.
• To optimize biocomposite composition for enhanced applicability.

Main Methods:

• In-situ co-precipitation method to construct the tri-component system with varying proportions.
• Fourier Transform Infrared (FTIR) spectroscopy to analyze molecular hydrogen bonds and conformational changes.
• X-ray diffraction (XRD) and scanning electron microscopy (SEM) to study hydroxyapatite morphology and crystallographic profile.
• Simulated Body Fluid (SBF) immersion for biodegradation and swelling ratio analysis.
• In-vitro assays for biomineralization, cytotoxicity, and antibacterial activity.

Main Results:

• The biocomposites exhibited inter- and intra-molecular hydrogen bonds (OH⋯N, OH⋯O, OH⋯π, OH⋯OH), with varying strengths based on composition.
• Protein conformational changes from random coil to β-sheet structures were observed and confirmed by vibrational spectra.
• The polymer matrix significantly influenced the crystallographic profile and morphology of hydroxyapatite.
• Biodegradation and swelling ratio correlated with hydrogen bond types and protein secondary structures.
• The study detailed in-vitro biomineralization, cytotoxicity, and antibacterial activity of the developed composites.

Conclusions:

• Molecular-level hydrogen bonding and protein secondary structures are critical determinants of silk fibroin/sodium alginate/hydroxyapatite biocomposite properties.
• The in-situ co-precipitation method effectively produced biocomposites with tunable characteristics.
• The findings provide a foundation for designing advanced biocomposites with tailored biodegradation, biomineralization, and bioactivity for various applications.