ABSTRACT
Topical photodynamic therapy with zinc phthalocyanine (ZnPc), second-generation photosensitizer, can be an alternative method for the treatment of skin cancer. However, ZnPc has poor penetration in the skin. This study was aimed at investigating whether the presence of oleic acid (chemical enhancer) in propylene glycol can improve the topical delivery of ZnPc. The topical (to the skin) and transdermal (across the skin) delivery of ZnPc were evaluated in vitro using suine ear skin mounted in Franz diffusion cell. Photosensitizer was quantified by fluorescence emission, which is a sensitive and selective method. At 5 and 10%, oleic acid increased the topical and transdermal delivery significantly. When the concentration of oleic acid was further increased (20-60% w/w), the topical delivery of ZnPc was still elevated, but its transdermal delivery was substantially reduced. It was concluded that oleic acid (in propylene glycol formulations) can promote the topical delivery of ZnPc, with reduced transdermal delivery. This approach can be effective for the treatment of skin cancer by topical photodynamic therapy.
Subject(s)
Drug Delivery Systems/methods , Indoles/administration & dosage , Indoles/chemistry , Oleic Acid/administration & dosage , Oleic Acid/chemistry , Organometallic Compounds/administration & dosage , Organometallic Compounds/chemistry , Photosensitizing Agents/administration & dosage , Photosensitizing Agents/chemistry , Administration, Cutaneous , Administration, Topical , Animals , Chemistry, Pharmaceutical/methods , Drug Stability , Ear, External/metabolism , Indoles/pharmacokinetics , Isoindoles , Oleic Acid/pharmacokinetics , Organometallic Compounds/pharmacokinetics , Permeability , Photochemotherapy/methods , Photosensitizing Agents/pharmacokinetics , Propylene Glycol/chemistry , Skin/drug effects , Skin/metabolism , Skin Neoplasms/drug therapy , Skin Neoplasms/metabolism , Swine , Zinc CompoundsABSTRACT
FMRFamide-like immunoreactive cells have been identified in almost all insect species studied. However, the functions of this peptide are still unknown, although several studies have suggested that FMRFamide may play a role in controlling peristalsis, digestion, development and reproduction in insects. Differences in the number, morphology, and distribution of FMRFamide-like cells have been observed among insects. Social bees are characterized by the presence of well-defined castes, each with a different behavior, energy demand and nutrient consumption. In this work, we used immunofluorescence to assess the number, morphology,and distribution of FMRFamide-like immunoreactive cells in different castes of the bee Melipona quadrifasciata anthidioides. These immunoreactive cells were observed only in the posterior region of the midgut, whereas FMRFamide-immunoreactive nerve fibers were more abundant in the fore-and hind-midgut boudary . However, htere were no differences in the number and distribution of FMRFamide-like cells among the castes. This localization of immunoreactivity may indicate that the nervous system controls the passage of food through the cardiac and pyloric valves, while the passge of food through the midgut is controlled by midgut endocrine cells. The number, morphology and distribution of midgut FMRFamide-like cells were not influencend by behavior, feeding habits, cast, or sex in this species.
