title: Sustained release of calcium hydroxide from poly(DL-lactide-co-glycolide) acid microspheres for apexification.
abstract: Calcium hydroxide (CH) loaded poly(DL-lactide-co-glycolide) acid (PLGA) microspheres (MS) might be used for apexification requiring a sustained release of Ca(2+). The aim of this study was to formulate and characterize CH-PLGA-MS. The CH-loaded MS were prepared by either oil-in-water (O/W) or water-in-oil/in-water (W/O/W) emulsion solvent evaporation technique. MS produced by the O/W technique exhibited a larger diameter (18.63 ± 7.23 μm) than the MS produced by the W/O/W technique (15.25 ± 7.37 μm) (Mann-Whitney U test P < 0.001). The CH encapsulation efficiency (E e) and Ca(2+) release were calculated from data obtained by absorption techniques. Ca(2+) release profile was evaluated for 30 days. To know the E e, the CH-loaded MS were dissolved in 1 M NaOH to release all its content and a Ca(2+) colorimetric marker was added to this solution. The reagent marked the Ca(2+) in blue color, which was then measured by a UV-Vis system (650 nm). The percentage of E e was calculated on the basis of the theoretical loading. The E e of the O/W-produced MS was higher (24 %) than the corresponding percentage of the W/O/W-produced MS (11 %). O/W- and W/O/W-produced MS released slower and lower Ca(2+) than a control CH paste with polyethylene glycol 400 (Kruskal-Wallis test). O/W-produced MS released higher Ca(2+) than W/O/W-produced MS (statistically significant differences; P < 0.05). In conclusion, the CH-PLGA-MS were successfully formulated; the technique of formulation influenced the size, encapsulation efficiency and release profile. The MS were better sustained release system than the CH paste.
authors.affiliation: Postgraduate Endodontics Program, Faculty of Dentistry, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava #2, Zona Universitaria, CP 78290, San Luis Potosí, SLP, Mexico. bernardino.cerda@uaslp.mx.
authors.forename: Bernardino Isaac
authors.initials: BI
authors.lastname: Cerda-Cristerna
authors.affiliation: Postgraduate Endodontics Program, Faculty of Dentistry, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava #2, Zona Universitaria, CP 78290, San Luis Potosí, SLP, Mexico.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Breceda-Leija
authors.affiliation: Postgraduate Endodontics Program, Faculty of Dentistry, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava #2, Zona Universitaria, CP 78290, San Luis Potosí, SLP, Mexico.
authors.forename: Verónica
authors.initials: V
authors.lastname: Méndez-González
authors.affiliation: Diagnostic and Surgical Sciences Deparment, Faculty of Dentistry, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Daniel
authors.initials: D
authors.lastname: Chavarría-Bolaños
authors.affiliation: Postgraduate Endodontics Program, Faculty of Dentistry, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava #2, Zona Universitaria, CP 78290, San Luis Potosí, SLP, Mexico.
authors.forename: Héctor
authors.initials: H
authors.lastname: Flores-Reyes
authors.affiliation: Postgraduate Pediatrics Dentistry Program, Universidad Autónoma de San Luis Potosí, San Luis Potosí, San Luis Potosí, Mexico.
authors.forename: Arturo
authors.initials: A
authors.lastname: Garrocho-Rangel
authors.affiliation: College of Dental Medicine, University of New England, Portland, ME, USA.
authors.forename: Takashi
authors.initials: T
authors.lastname: Komabayashi
authors.affiliation: Department of Neurosurgery, School of Medicine, University of Maryland, Bressler Research Building, Baltimore St, College Park, MD, USA.
authors.forename: Aniket S
authors.initials: AS
authors.lastname: Wadajkar
authors.affiliation: Postgraduate Endodontics Program, Faculty of Dentistry, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava #2, Zona Universitaria, CP 78290, San Luis Potosí, SLP, Mexico.
authors.forename: Amaury J
authors.initials: AJ
authors.lastname: Pozos-Guillén
mesh_terms: D056624:Apexification; D001672:Biocompatible Materials / Q000737:chemistry*; D002126:Calcium Hydroxide / Q000737:chemistry*; D003692:Delayed-Action Preparations; D019344:Lactic Acid / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer
chemical_list: D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D002126:Calcium Hydroxide
keywords: Apexification; Calcium hydroxide; Microspheres; Poly(DL-lactide-co-glycolide) acid; Sustained drug delivery system