title: Delivery of Methylene Blue and meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate from cross-linked poly(vinyl alcohol) hydrogels: a potential means of photodynamic therapy of infected wounds.
abstract: Poly(vinyl alcohol)-borate complexes were evaluated as a potentially novel drug delivery platform suitable for in vivo use in photodynamic antimicrobial chemotherapy (PACT) of wound infections. An optimised formulation (8.0%w/w PVA, 2.0%w/w borax) was loaded with 1.0 mg ml(-1) of the photosensitisers Methylene Blue (MB) and meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP). Both drugs were released to yield receiver compartment concentrations (>5.0 microg ml(-1)) found to be phototoxic to both planktonic and biofilm-grown methicillin-resistant Staphylococcus aureus (MRSA), a common cause of wound infections in hospitals. Newborn calf serum, used to simulate the conditions prevalent in an exuding wound, did not adversely affect the properties of the hydrogels and had no significant effect on the rate of TMP-mediated photodynamic kill of MRSA, despite appreciably reducing the fluence rate of incident light. However, MB-mediated photodynamic kill of MRSA was significantly reduced in the presence of calf serum and when the clinical isolate was grown in a biofilm. Results support the contention that delivery of MB or TMP using gel-type vehicles as part of PACT could make a contribution to the photodynamic eradication of MRSA from infected wounds.
authors: School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK.
authors: Ryan F
authors: RF
authors: Donnelly
authors: Corona M
authors: CM
authors: Cassidy
authors: Ryan G
authors: RG
authors: Loughlin
authors: Anthony
authors: A
authors: Brown
authors: Michael M
authors: MM
authors: Tunney
authors: Mark G
authors: MG
authors: Jenkins
authors: Paul A
authors: PA
authors: McCarron
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002417:Cattle; D016503:Drug Delivery Systems; D006801:Humans; D020100:Hydrogels / Q000737:chemistry* / Q000494:pharmacology; D008027:Light; D055624:Methicillin-Resistant Staphylococcus aureus / Q000528:radiation effects; D008751:Methylene Blue / Q000008:administration & dosage* / Q000737:chemistry; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D011166:Porphyrins / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D044967:Serum / Q000737:chemistry; D014946:Wound Infection / Q000188:drug therapy
chemical_list: D020100:Hydrogels; D017319:Photosensitizing Agents; D011166:Porphyrins; C021096:tetra(4-N-methylpyridyl)porphine; D011142:Polyvinyl Alcohol; D008751:Methylene Blue