Initiating fibro-proliferation through interfacial interactions of myoglobin colloids with collagen in solution

Area of Science:

• Biophysics
• Materials Science
• Biochemistry

Background:

• Collagen, a key extracellular matrix protein, forms fibrous structures essential for tissue integrity.
• Myoglobin (Mb), a globular protein, can interact with collagen, potentially influencing fibril assembly.
• Understanding protein-colloid interactions is crucial for biomaterials and tissue engineering.

Purpose of the Study:

• To investigate the fibro-proliferation of collagen induced by myoglobin (Mb) colloids.
• To elucidate the role of pH, surface charge, and hydrophilic-hydrophobic balance in Mb-collagen interactions.
• To determine how Mb colloids affect collagen fibril organization and growth.

Main Methods:

• Preparation of myoglobin (Mb) colloids at pH 4.5 and 7.5.
• Characterization of Mb colloids using Transmission Electron Microscopy and Zeta Sizer.
• Analysis of Mb secondary structure via Circular Dichroism (CD) spectroscopy.
• Study of Mb-collagen interface interactions using Dilational Rheology, Quartz Crystal Microbalance with Dissipation (QCM-D), and Differential Scanning Calorimetry (DSC).

Main Results:

• Mb colloids exhibited sizes of 100-200nm, with CD spectra indicating a shift towards beta-sheet structures.
• Interactions were influenced by charge compensation and pH-dependent collagen assembly.
• Positive Mb colloids (pH 4.5) stabilized collagen fibrils (pH 7.5), promoting dehydration, cross-linking, and anisotropic growth.
• At pH 7.5, collagen fibril formation dominated over Mb clustering, indicating pH and hydrophobicity dependence.

Conclusions:

• Fibro-proliferation is significantly modulated by the interplay between myoglobin colloid properties and collagen.
• The study highlights the critical roles of pH and hydrophilic-hydrophobic balance in directing collagen fibril assembly.
• Findings offer insights into controlling extracellular matrix formation through protein-colloid interactions.