ABSTRACT
Emulsions are crucial in the treatment of snake bites to bust the antibody response of the inmunogen. The widely used Freund's emulsion typically combines 50/50 water-oil (W/O) phase. However, its use is limited because it is associated with tissue damage. We formulated and characterized a Pickering Emulsion 70/30 (W/O) that uses a chemically modified hydrophobic hydroxyapatite as surfactant. This Pickering emulsion has similar rheologic behavior to Freund's emulsion 50/50, but with lower oil and surfactant concentration. Evaluation of cell recruitment, antibody response and adhering tissue in mice immunized with B. asper of Pacific venom and treated with Freund's and Pickering 70/30 emulsions resulted in similar adjuvant activity (only 18% lower in Pickering 70/30 emulsion). However, Pickering 70/30 emulsions minimized negative side effects in the host animals and showed better ease of flow that favors injection of the host. Our results open up room for optimization and improvement of Pickering emulsion based on modified nanoparticles for medical applications.
Subject(s)
Adjuvants, Immunologic/chemistry , Antibodies/metabolism , Durapatite/chemistry , Emulsions/chemistry , Nanoparticles/chemistry , Snake Venoms/immunology , Animals , Mice , Snake Venoms/chemistry , Snakes/metabolism , Surface-Active Agents/chemistryABSTRACT
Simple surface modification of nano-hydroxyapatite, through acid-basic reactions, allows expanding the properties of this material. Introduction of organic groups such as hydrophobic alkyl chains, carboxylic acid, and amide or amine basic groups on the hydroxyapatite surface systematically change the polarity, surface area, and reactivity of hydroxyapatite without modifying its phase. Physical and chemical properties of the new derivative particles were analyzed. The biocompatibility of modified Nano-Hap on Raw 264.7 cells was also assessed.
Subject(s)
Bone Substitutes/chemical synthesis , Bone Substitutes/toxicity , Durapatite/chemical synthesis , Durapatite/toxicity , Nanoparticles/chemistry , Nanoparticles/ultrastructure , Animals , Cell Survival/drug effects , Materials Testing , Mice , Nanoparticles/toxicity , Particle Size , Phase Transition , RAW 264.7 Cells , Surface PropertiesABSTRACT
OBJECTIVE: Nosocomial Candidiasis in low birth weight (LBW) infants have increased. Toxic side effects limit the use of conventional Amphotericin B for treatment of fungal infections. The liposomal forms have lowered this risk considerably, even at higher doses. Our aim was to evaluate treatment response to liposomal Amphotericin B in neonates with Candidiasis. PATIENTS AND METHODS: Fifteen neonates diagnosed both clinically and biologically of Candidiasis infection and who were treated with liposomal Amphotericin B from June 1994 through July 1997 were included. Duration of treatment, when culture became negative, secondary effects, complications, other medication, basal pathology and clinical course were analyzed. RESULTS: Mean gestational age was 36 +/- 6 weeks and 60% were preterm. Mean age at diagnosis was 13.4 days. Eleven patients presented sepsis (1 C. Sp., 9 C. albicans and 1 C. parapsilosis). They were treated with liposomal Amphotericin B, starting dose 0.5-1 mg/kg/day). One patient had associated 5-fluorocytosine. Cultures became negative at approximately 13 days and mean duration of therapy was 21.13 days. Seven patients showed additional bacterial infections. Side effects during treatment were anemia and hypotension. CONCLUSIONS: Liposomal Amphotericin B has been effective in the treatment of Candidiasis without toxic signs that can be attributed solely to the medication.
