Photosensitive controlled release with polyethylene glycol–anthracene modified alginate

• Published in: European journal of pharmaceutics and biopharmaceutics Vol. 79; no. 2; pp. 304 - 313
• Main Authors: Wells, L.A., Sheardown, H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2011; Elsevier
• Subjects: Alginate; Alginates - chemistry; Alginates - radiation effects; Anthracene; Anthracenes - chemistry; Anthracenes - radiation effects; Biological and medical sciences; Cross-Linking Reagents - chemistry; Cross-Linking Reagents - radiation effects; Delayed-Action Preparations; Drug delivery; Drug Delivery Systems - methods; General pharmacology; Hydrogel, Polyethylene Glycol Dimethacrylate - chemistry; Hydrogel, Polyethylene Glycol Dimethacrylate - radiation effects; Medical sciences; Pharmaceutical technology. Pharmaceutical industry; Pharmacology. Drug treatments; Photoresponsive; Polyethylene Glycols - chemistry; Polyethylene Glycols - radiation effects; Rosaniline Dyes - chemistry; Smart biomaterials; Ultraviolet Rays; PBS; Photoresponsive; UV; Smart biomaterials; Anthracene; Control PEG hydrogel; TBS; EDC; Boc-PEG-amine; Drug delivery; PEG; PEG–diamine; NHS; Photogel; MES; Alginate; Pharmaceutical technology; Controlled release form; Control release polymer; Uronide polymer; Drug carrier; Alginates; Ethylene oxide polymer; Polyelectrolyte; Cyclic ether polymer; Dosage form; Oside polymer; Biomaterial
• ISSN: 0939-6411; 1873-3441
• DOI: 10.1016/j.ejpb.2011.03.023

Photoresponsive alginate – 365-nm UV light causes anthracene dimerization along the alginate polymer backbones of photogels to cause decreases in the release rates of small and large molecules. Covalent modification of alginate with polyethylene glycol–conjugated anthracene molecules has the potential to both stabilize the alginate and act as a photosensitive crosslinker. Release studies with Coomassie Blue show lengthy release times from the alginate photogels that extend past 70 days with, for example, 17% versus 27% release at 1750 h (73 days) for photogels with and without 365-nm UV light treatment for 30 min at 10 mW/cm 2 in the initial release period. Photocrosslinking of the photogels after loading effectively “locks” in drug compounds to control their release. Effective crosslinking densities and controls of polyethylene glycol-crosslinked alginate and physically crosslinked calcium alginate gels suggest strong interactions between Coomassie Blue and both alginate and anthracene. Photogels containing anthracene-capped star-polyethylene glycol show increased photosensitivity with modified release profiles. Ultimately, the covalent modification of alginate with photoactive crosslinkers has the potential to produce a long-term, photosensitive, controlled release system.