Fabrication, Crystalline Behavior, Mechanical Property and In-Vivo Degradation of Poly(l–lactide) (PLLA)–Magnesium Oxide Whiskers (MgO) Nano Composites Prepared by In-Situ Polymerization

Abstract

The present work focuses on the preparation of poly(l–lactide)–magnesium oxide whiskers (PLLA–MgO) composites by the in-situ polymerization method for bone repair and implant. PLLA–MgO composites were evaluated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and solid-state 13C and 1H nuclear magnetic resonance spectroscopy (NMR). It was found that the whiskers were uniformly dispersed in the PLLA matrix through the interfacial interaction bonding between PLLA and MgO; thereby, the MgO whisker was found to be well-distributed in the PLLA matrix, and biocomposites with excellent interface bonding were produced. Notably, the MgO whisker has an effect on the crystallization behavior and mechanical properties; moreover, the in vivo degradation of PLLA–MgO composites could also be adjusted by MgO. These results show that the whisker content of 0.5 wt % and 1.0 wt % exhibited a prominent nucleation effect for the PLLA matrix, and specifically 1.0 wt % MgO was found to benefit the enhanced mechanical properties greatly. In addition, the improvement of the degrading process of the composite illustrated that the MgO whisker can effectively regulate the degradation of the PLLA matrix as well as raise its bioactivity. Hence, these results demonstrated the promising application of PLLA–MgO composite to serve as a biomedical material for bone-related repair.

Effect of Organic Modifier and Clay Content on Non-Isothermal Cold Crystallization and Melting Behavior of Polylactide/Organovermiculite Nanocomposites

“…PLA is a semicrystalline polymer, and its physical/mechanical properties are determined by the extent of crystallization and the crystalline morphology. The addition of nanofillers to a polymer matrix affects not only its mechanical properties but also the crystallization and melt behavior, and thus its applications [17][18][19][20]. Therefore, the understanding of the crystallization of both polymer and polymer composites is necessary for establishing the relationship among the processing conditions, the developed structure, and the properties of the final products.…”

3D printed PLGA/MgO/PDA composite scaffold by low-temperature deposition manufacturing for bone tissue engineering applications

“…Our results elicited that when the MgO ratio reached 10%, the compactness of the material surface had a higher density, the scaffold material had a smaller water contact angle, and the material had a higher hydrophilicity, compressive strength, and elastic modulus; It is consistent with that coaxial-MgO with the core-shell fiber structure has a better property of hydrophilicity [ 36 ]. Consistently, MgO with good bioactivity is beneficial to improving polylactide (PLA) biocompatibility and mechanical properties during the bone repair process [ 37 ]. The implanted scaffolds will degrade gradually along with tissue regeneration [ 38 ].…”

Biodegradable Poly(Lactic Acid) Nanocomposites for Fused Deposition Modeling 3D Printing

“… The distribution of magnesium nanoparticles increased with the addition of vitamin E, addition of stearic acid, the oxidation of the magnesium to magnesium oxide, or the functionalization of magnesium with PEI and CTAB [ 53 ]. The Mg 2+ ions released during PLA/MgO degradation increased bone cell growth [ 57 ]. …”

“…More recently magnesium has been incorporated into PLLA matrices in the form of MgO nanowhiskers. The functionalization of magnesium to magnesium oxide increased the dispersion of the nanoparticles and improved the mechanical properties [ 57 , 58 ]. These MgO nanowhisker-containing materials undergo in vivo degradation, which is modulated by the amount of MgO incorporated and the molecular weight of PLLA in the matrix.…”

“…These MgO nanowhisker-containing materials undergo in vivo degradation, which is modulated by the amount of MgO incorporated and the molecular weight of PLLA in the matrix. With the incorporation of MgO, an increase in bone cells occurs, likely due to the positive effect of the Mg 2+ degradation product on osteogenesis [ 57 ]. This finding indicates that increased MgO content increased desirable properties for bone implants.…”