title: Caffeic Acid-PLGA Conjugate to Design Protein Drug Delivery Systems Stable to Irradiation.
abstract: This work reports the feasibility of caffeic acid grafted PLGA (g-CA-PLGA) to design biodegradable sterile microspheres for the delivery of proteins. Ovalbumin (OVA) was selected as model compound because of its sensitiveness of γ-radiation. The adopted grafting procedure allowed us to obtain a material with good free radical scavenging properties, without a significant modification of Mw and Tg of the starting PLGA (Mw PLGA = 26.3 ± 1.3 kDa vs. Mw g-CA-PLGA = 22.8 ± 0.7 kDa; Tg PLGA = 47.7 ± 0.8 °C vs. Tg g-CA-PLGA = 47.4 ± 0.2 °C). By using a W1/O/W2 technique, g-CA-PLGA improved the encapsulation efficiency (EE), suggesting that the presence of caffeic residues improved the compatibility between components (EEPLGA = 35.0% ± 0.7% vs. EEg-CA-PLGA = 95.6% ± 2.7%). Microspheres particle size distribution ranged from 15 to 50 µm. The zeta-potential values of placebo and loaded microspheres were -25 mV and -15 mV, respectively. The irradiation of g-CA-PLGA at the dose of 25 kGy caused a less than 1% variation of Mw and the degradation patterns of the non-irradiated and irradiated microspheres were superimposable. The OVA content in g-CA-PLGA microspheres decreased to a lower extent with respect to PLGA microspheres. These results suggest that g-CA-PLGA is a promising biodegradable material to microencapsulate biological drugs.
authors.affiliation: Università degli Studi di Milano, Department of Pharmaceutical Sciences-via Giuseppe Colombo, 71-20133 Milano, Italy. francesca.selmin@unimi.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Selmin
authors.affiliation: Università degli Studi della Calabria, Department of Pharmacy, Health and Nutritional Sciences, 87036 Arcavacata di Rende, Italy. francesco.puoci@unical.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Puoci
authors.affiliation: Università degli Studi della Calabria, Department of Pharmacy, Health and Nutritional Sciences, 87036 Arcavacata di Rende, Italy. ortensia.parisi@unical.it.
authors.forename: Ortensia I
authors.initials: OI
authors.lastname: Parisi
authors.affiliation: Università degli Studi di Milano, Department of Pharmaceutical Sciences-via Giuseppe Colombo, 71-20133 Milano, Italy. silvia.franze@unimi.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Franzé
authors.affiliation: Università degli Studi di Milano, Department of Pharmaceutical Sciences-via Giuseppe Colombo, 71-20133 Milano, Italy. umberto.musazzi@unimi.it.
authors.forename: Umberto M
authors.initials: UM
authors.lastname: Musazzi
authors.affiliation: Università degli Studi di Milano, Department of Pharmaceutical Sciences-via Giuseppe Colombo, 71-20133 Milano, Italy. francesco.cilurzo@unimi.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cilurzo