Layer-by-layer assembly to modify poly(l-lactic acid) surface toward improving its cytocompatibility to human...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Surface Chemistry

Background:

• Poly(l-lactic acid) (PLLA) is a widely used biodegradable polymer in biomedical applications.
• Enhancing the cytocompatibility of PLLA scaffolds is crucial for successful tissue regeneration.
• Surface modification techniques are essential for improving cell-material interactions.

Purpose of the Study:

• To develop a novel method for surface modification of PLLA membranes.
• To enhance the cytocompatibility of PLLA for human endothelial cells (ECs).
• To investigate the effect of chitosan coating on EC attachment, proliferation, and function.

Main Methods:

• Aminolysis of ester groups on PLLA with diamine to introduce amino groups.
• Layer-by-layer assembly of poly(styrene sulfonate, sodium salt) (PSS) and chitosan onto PLLA.
• Monitoring deposition using UV-vis spectroscopy, fluorescence spectroscopy, and contact angle measurements.
• Evaluating EC attachment, activity, proliferation, and function on modified PLLA.

Main Results:

• Chitosan coating significantly improved PLLA cytocompatibility for human ECs.
• PLLA membranes with three or five bilayers of PSS/chitosan showed superior EC attachment, activity, and proliferation.
• ECs exhibited elongated morphology with abundant cytoplasm, forming a confluent layer within 4 days.
• Endothelial function was verified by measuring von Willebrand factor secretion.

Conclusions:

• A novel technique successfully introduced amino groups onto PLLA, enabling chitosan deposition.
• The PSS/chitosan coating significantly enhanced the biocompatibility of PLLA for endothelial cells.
• The modified PLLA membranes demonstrate potential for improved vascular tissue engineering applications.