A photo-triggered layered surface coating producing reactive oxygen species

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Photodynamic Therapy

Background:

• Controlling biological interactions at material surfaces is crucial for medical devices and tissue engineering.
• Existing methods for surface modification often lack precise spatiotemporal control.
• Developing materials that can be activated remotely offers new therapeutic and diagnostic possibilities.

Purpose of the Study:

• To create a photoactive surface coating capable of generating cytotoxic reactive oxygen species (ROS) upon near-infrared (NIR) light irradiation.
• To investigate the layer-by-layer assembly and tunable properties of the coating.
• To demonstrate the platform's potential for controlling biological events at the material-tissue interface.

Main Methods:

• Layer-by-layer assembly of cross-linked hyaluronic acid (HA) and poly-l-lysine (PLL).
• Modification of the coating with the photoactive molecule pheophorbide a.
• Fine-tuning of pheophorbide a loading by controlling the number of bilayers.
• Irradiation with NIR light to trigger ROS generation.

Main Results:

• Stable photoactive surface coatings were successfully fabricated.
• The amount of loaded pheophorbide a and subsequent ROS generation could be precisely controlled by adjusting the number of bilayers.
• The coatings demonstrated repeated and prolonged light-triggered ROS release.
• Demonstrated control over bacterial colonization, platelet adhesion, and mammalian cell attachment via light irradiation.

Conclusions:

• The developed photoactive surface coating provides a versatile platform for spatiotemporal control of biological events.
• NIR light-triggered ROS generation offers a non-invasive method for modulating material-tissue interactions.
• This technology has potential applications in antimicrobial surfaces, anti-thrombotic coatings, and regenerative medicine.