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Single- and two-photon absorption induced photocleavage of dimeric coumarin linkers: Therapeutic versus passive photocleavage in ophthalmologic applications

Paper ID Volume ID Publish Year Pages File Format Full-Text
28016 44056 2008 6 PDF Available
Title
Single- and two-photon absorption induced photocleavage of dimeric coumarin linkers: Therapeutic versus passive photocleavage in ophthalmologic applications
Abstract

Phototriggered chemical reactions are elegant and spatially selective. However, in application a general problem is that aside of the desired changes, e.g. induced by laser, undesired changes may occur, e.g. induced by daylight or sunlight. One such example which we are studying here is the phototriggered release of drugs from materials suitable for polymeric intraocular lenses (IOL). Through such an IOL sunlight needs to pass for several years without affecting the drug loading, but at the therapeutically required moment the drug release shall be triggered also by light. We studied this using a novel coumarin dimer (7,7′-[3-(tert-butyldimethylsilyloxy)propoxy]-dicoumarin) synthesized from the monomer in a photochemical [2π + 2π] cycloaddition reaction. The cleavage of the obtained photodimer by single-photon (SPA) and two-photon absorption (TPA) excitation was investigated in acetonitrile solution and in polymethylmethacrylate in order to exclude major matrix entrapment effects. The cleavage quantum yields and TPA cross-section were determined to be Φ ≈ 0.13 and δTPA ≈ 2.7 GM, respectively. It was found that 10% undesired drug release would require more than 16 years of continuous exposure to sunlight. Release of 90% of drug under therapeutic conditions would be completed within seconds. This shows that photochemically triggered drug release is capable to become a powerful tool for drug delivery in ophthalmology.

Keywords
Coumarin dimer; Two-photon absorption; Controlled drug delivery; Intraocular lenses
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Single- and two-photon absorption induced photocleavage of dimeric coumarin linkers: Therapeutic versus passive photocleavage in ophthalmologic applications
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Photochemistry and Photobiology A: Chemistry - Volume 197, Issues 2–3, 25 June 2008, Pages 239–244
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us