Photodynamic tissue adhesion with chlorin(e6) protein conjugates

Area of Science:

• Biomaterials Science
• Ophthalmic Surgery
• Photodynamic Therapy

Background:

• Scleral incisions require secure closure to prevent leakage and ensure proper intraocular pressure.
• Photodynamic laser-activated tissue solders offer a potential alternative to traditional suturing methods.
• Optimizing the formulation of these solders is crucial for achieving effective wound sealing.

Purpose of the Study:

• To compare the efficacy of covalently linked versus noncovalently mixed photosensitizer-protein conjugates as laser-activated tissue solders.
• To test the hypothesis that covalent linkage improves solder performance in sealing scleral incisions.
• To evaluate different protein types and ratios for optimal solder strength.

Main Methods:

• Preparation of chlorin(e6) (photosensitizer) conjugates and mixtures with albumin, fibrinogen, and gelatin.
• Application of solders to penetrating scleral incisions in human cadaveric eyes.
• Activation of solders using a blue-green argon laser and measurement of wound leakage pressure.

Main Results:

• Both covalent conjugates and noncovalent mixtures demonstrated a light dose-dependent increase in leaking pressure.
• An albumin-chlorin(e6) conjugate with additional albumin (2.5:1 molar ratio) exhibited significantly higher weld strength compared to other preparations.
• This specific formulation outperformed other protein conjugates and mixtures in sealing scleral incisions.

Conclusions:

• This study presents the first report of dye-protein conjugates utilized as tissue solders.
• Covalently linked photosensitizer-protein conjugates show promise for enhanced wound closure in ophthalmic surgery.
• These novel conjugates may offer significant applications in ophthalmology for improved surgical outcomes.