Complex calcium carbonate/polymer microparticles as carriers for aminoglycoside antibiotics

Abstract

Composite microparticles of CaCO 3 and two pectin samples (which differ by the functional group ratio) or corresponding nonstoichiometric polyelectrolyte complexes with different molar ratios (0.5, 0.9 and 1.2) are obtained, characterized and tested for loading and release of streptomycin and kanamycin sulphate. The synthesized carriers were characterized before and after drug loading in terms of morphology (by SEM using secondary electron and energy selective backscattered electron detectors), porosity (by water sorption isotherms) and elemental composition (by elemental mapping using energy dispersive X-ray and FTIR spectroscopy). The kinetics of the release mechanism from the microparticles was investigated using Higuchi and Korsmeyer-Peppas mathematical models. Electronic supplementary information (ESI) available: Chemical structure of materials used in this study; diffusion coefficients for pectin-CaCO 3 and NPEC-CaCO 3 composite microparticles, determined from sorption-desorption experimental data; sorption/desorption isotherms as relative humidity vs. weight variation; SEM images of pectin-CaCO 3 and NPEC-CaCO 3 microparticles aer STR and KAN retention and release; STR and KAN in vitro release curves; FTIR spectra of STR and KAN loaded samples; graphical representation of Higuchi and Korsmeyer-Peppas equations. See Scheme 1 The schematically representation of (I) NPECs synthesis, (II) formation of gel microparticles, (III) calcium carbonate growth with composite microparticles formation, (IV) drug loading and (V) release.This journal is

Encapsulation of Amikacin into Microparticles Based on Low-Molecular-Weight Poly(lactic acid) and Poly(lactic acid-co-polyethylene glycol)

“…Some PLA- or PLGA-based systems loaded with aminoglycosides (including AMI) have been reported in the literature, − and the ones most widely employed aid in the treatment of respiratory infections and osteomyelitis. ,,− It is worth noting, however, that those loaded with aminoglycosides are difficult to fabricate because of the hydrophobic character of the polymers employed, for example, PLA. The reason is that during emulsification, greater affinity for the drug exists in the external aqueous phase than that for the polymer (Figure S1).…”

Hydrophobic Composites Designed by a Nonwoven Cellulose-Based Material and Polymer/CaCO3 Patterns with Biomedical Applications

“…Calcium carbonate is one of the most abundant minerals in the world, having three anhydrous crystalline polymorphs (calcite, vaterite, and aragonite) whose crystal structures, dissolution behaviors, and growth on various substrates have been extensively studied. − The calcite phase has the highest thermodynamic stability, whereas the formation of vaterite and aragonite, the metastable polymorphs, using organic or macromolecular molecules has been studied to synthetically develop biomimetic systems. , Previous studies showed that macromolecules, as a soluble or an insoluble matrix, affect the crystallization of CaCO 3 . The functional groups (especially the carboxylic ones) on the gel-like structures influence the formation of crystals due to electrostatic interactions, spatial location, match of crystal lattices, and stereochemistry. − Nonstoichiometric polyelectrolyte complexes (NPECs) were also used to control the crystallization of CaCO 3 by rapid mixing of CaCl 2 and Na 2 CO 3 precursors in order to obtain uniform composite particles. − The studies show that the composite microparticle characteristics can be tuned not only by the polyanion characteristics but also using NPECs, obtaining multi-functional microparticles with the size, shape, and dissolution stability tuned by the used complex macromolecular template characteristics: polyions pairs, ratio between the complementary polyelectrolytes, addition mode.…”