Breakthrough in Mimicking Ion-Mediated Protein Adsorption on Implants and Biomaterials

IASST researchers stabilize lysozyme protein bilayers on silicon surfaces, advancing biomaterial integration research.

A team of researchers from the Institute of Advanced Study in Science and Technology (IASST), Guwahati, under the Department of Science and Technology (DST), has achieved a significant breakthrough in mimicking biological protein adsorption processes. The group successfully stabilized bilayers of lysozyme protein molecules on hydrophilic and hydrophobic silicon surfaces at room temperature. This advancement holds promise for improving the integration of implants and biomaterials in living organisms.

Lysozyme: A Model Protein in Biological Studies

Lysozyme, a protein found in human tears, sweat, milk, and saliva, is an ideal model for studying protein adsorption due to its robust structure, including four disulfide bonds. Ions, crucial to various biological processes like electrochemical regulation and muscle contraction, play a significant role in ion-mediated protein-surface interactions, particularly when implants are introduced into the body.

Innovative Methodology

The research team, led by Dr. Sarathi Kundu, along with Mr. Sanu Sarkar and Dr. Aditi Saikia, developed lysozyme bilayers in an ionic atmosphere. The bilayers were stabilized in the presence of mono-(Na+), di-(Ca2+), and trivalent (Y3+) ions.

The bilayer structure consisted of:

1. A bottom layer with lysozyme molecules in a side-on orientation.
2. An upper layer with molecules in side-on or tilted orientations.

The stabilization mechanism was attributed to modified hydrogen bonding, hydrophobic interactions, and electrostatic interactions facilitated by the ionic environment.

Observations and Results

The study revealed that lysozyme-lysozyme interactions competed with lysozyme-surface interactions. On hydrophilic surfaces, proteins retained their native globular form, while on hydrophobic surfaces, they exhibited a slightly elongated structure. The bilayer film's higher population of lysozyme molecules resulted in increased surface contact angles, further confirming the bilayer's stability.

Applications in Implant and Biomaterial Development

The successful stabilization of lysozyme bilayers at room temperature provides a framework for replicating real biological processes involving ion-mediated protein adsorption. This development could improve the design of biomaterials and implants, ensuring better compatibility and integration with living tissues.

Future Implications

The findings, published in the New Journal of Chemistry by the Royal Society of Chemistry, mark a step forward in understanding protein-surface interactions. These insights are expected to guide further research into biomaterials and their behavior within ionic biological environments.

This research underscores the potential for advancing medical technologies, particularly in areas where biomaterials and implants must closely mimic natural biological processes for optimal performance and safety.