Abstract
The enantiomers poly(D-lactic acid) (PDLA) and poly(L-lactic acid) (PLLA) were alternately adsorbed directly on calcium carbonate (CaCO3) templates and on poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) multilayer precursors in order to fabricate a novel layer-by-layer (LBL) assembly. A single layer of poly(L-lysine) (PLL) was used as a linker between the (PDLA/PLLA)n stereocomplex and the cores with and without the polymeric (PSS/PAH)n/PLL multilayer precursor (PEM). Nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) were used to characterize the chemical composition and molecular weight of poly(lactic acid) polymers. Both multilayer structures, with and without polymeric precursor, were firstly fabricated and characterized on planar supports. A quartz crystal microbalance (QCM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and ellipsometry were used to evaluate the thickness and mass of the multilayers. Then, hollow, spherical microcapsules were obtained by the removal of the CaCO3 sacrificial template. The chemical composition of the obtained microcapsules was confirmed by differential scanning calorimetry (DSC) and wide X-ray diffraction (WXRD) analyses. The microcapsule morphology was evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements. The experimental results confirm the successful fabrication of this innovative system, and its full biocompatibility makes it worthy of further characterization as a promising drug carrier for sustained release.
Highlights
The polycationic/polyanionic layer-by-layer (LBL) deposition on surfaces has been widely studied since the first description by Decher et al [1,2,3]
We examined our poly(lactic acid) (PLA) microcapsules at pH 1 and 13, and no obvious change was found after 30 min of treatment with hydrochloride acid and sodium hydroxide, meaning that these PLA stereocomplex microcapsules are stable in acidic or basic conditions
PLA stereocomplex microcapsules were successfully fabricated by the LBL technique using CaCO3 as a sacrificial template and enantiomeric PLAs with and without PEM precursor as the shell material
Summary
The polycationic/polyanionic layer-by-layer (LBL) deposition on surfaces has been widely studied since the first description by Decher et al [1,2,3]. The alternate adsorption of negatively and positively charged poly(styrene sulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) on sacrificial templates have been the most widely characterized and applied materials for the production of hollow microcapsules [4,5,6]. The potential of these multilayer structures for biotechnological and biomedical applications, such as biosensors and carriers for drug delivery, led researchers to extend this technique beyond multilayer structure fabrication based on electrostatic interactions [7,8,9,10,11]. PLA capsules made by the LBL technique with an entirely biocompatible procedure remain a challenge [36,37,38]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
