Effect of bioglass nanoparticles on the properties and bioactivity of poly(lactic acid) films

Abstract

Bioglass nanoparticles (n‐BGs, 54SiO2:40CaO:6P2O5 mol %) with about 27 nm diameter were synthesized by the sol–gel method and incorporated into a poly(lactic acid) (PLA) matrix by the melting process in order to obtain nanocomposites with filler contents of 5, 10, and 25 wt %. Our results showed that during the cooling scan, the crystallization temperature (Tc) of the PLA/n‐BG nanocomposites decreased 13°C as compared to neat PLA. The presence of nanoparticles also decreased the thermal stability of the PLA matrix, as nanocomposites presented up to about 20°C lower degradation temperatures in a nitrogen atmosphere. The presence of n‐BG increased the stiffness of the polymer matrix, and for instance the composite with 25 wt % of filler presented about 52.6% higher Young's modulus than neat PLA. n‐BG incorporation into PLA increased also the hydrolytic degradation of the polymer over time. When the PLA composites were immersed in simulated body fluid, an apatite layer was formed on their surface, as verified by Fourier transform infrared, X‐Ray Diffraction (XRD), and scanning electron microscopy‐EDS, showing that the presence of n‐BG induced bioactivity on the PLA matrix. Moreover, the viability of cervical uterine adenocarcinoma cells was higher on PLA/n‐BG nanocomposite with 25 wt % of filler. The presence of n‐BG barely gave an antibacterial effect on the polymer matrix, despite the well‐known biocidal properties of these nanoparticles. Our results show that the presence of n‐BGs is a proper route for improving the bioactivity of PLA with potential application in tissue engineering.

Biocompatibility Assessment of Polylactic Acid (PLA) and Nanobioglass (n-BG) Nanocomposites for Biomedical Applications

“…Additionally, the symmetric strain band corresponding to the carbonate ion and the band corresponding to the free OH groups of water are found at 1424 and 1591 cm −1 . These observations are similar to previous works [ 5 , 25 ].…”

“…The bending band centered at 802 cm −1 corresponds to the Si-O bond. Finally, the band at 586 cm −1 corresponds to the antisymmetric bending of the P-O bond [ 5 ]. However, it should be noted that the P-O bond band overlaps with the characteristic Si-O bands.…”

“…X-ray diffraction (XRD) allows for quantitative and qualitative measurements of the crystalline phases of compounds from their diffraction planes. Figure 2 shows the XRD spectrum for the n-BGs, which shows that the amorphous phase predominated over the crystalline phase [ 5 ]. However, between the phases of the n-BGs and their crystalline phase, a broad peak emerged around the 2θ angle of 29°, indicating a higher population density and a smaller distance from any central atom [ 26 ].…”

“…Generally, nanostructured materials produce three-dimensional surfaces of scaffolds with nanometric characteristics [ 4 ]. Within these materials are nanoparticles [ 5 ], nanofibers [ 6 ], nanocomposites [ 7 ], and nanosheets [ 8 ], which increase cell interaction and promote integration into the host tissue [ 9 ]. However, biocompatibility is limited by the architecture of the scaffold, as it provides an optimized microenvironment for synthesizing new tissue.…”

Poly (lactic acid)/D‐limonene/ZnO bio‐nanocompositeswith antimicrobial properties

“…where ΔH o m is the enthalpy of fusion of an ideal 100% crystalline PLA (93 JÁg À1 ), 3,38 ΔH m and ΔH cc are the melting and cold crystallization enthalpies, respectively, and f PLA is the effective weight fraction of PLA. 16 In order to characterize the crystalline structure in depth, the lamellar thicknesses were calculated applying the Thomson-Gibbs equation (Equation 2), based on the temperatures associated with the melting transitions, 39,40…”