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A series of novel bio-polyester nanocomposites based on glycerin and azelaic acid as monomers incorporating hydroxyapatite (HA) nanoparticles were fabricated via in situ polymerization method. Chemical structure of the samples was investigated by 1 H-NMR, 13 C-NMR, and Fourier-transform infrared spectroscopy (FTIR). Energy dispersive X-ray-mapping analysis illustrated that the nanoparticles were well dispersed in the poly (glycerol azelaic acid) (PGAZ) matrix. Viscoelastic properties of the samples under various frequencies were examined in which the PGAZ specimen containing 1.0 wt% of HA nanoparticles (PGAZH1.0) exhibited superlative properties. Furthermore, the alterations in the glass transition temperature of the samples were comprehensively discussed. Thermal gravimetric analysis displayed that nanocomposites generally have a difference in degradation patterns from that of the pristine sample. Dynamic contact angle demonstrated that the presence of HA nanoparticles imposed a significant influence on hydrophilicity. The hydrolytic degradation values at pH = 7 and pH = 11 were measured and determined that the degradation rate for the PGAZ sample containing 1.5 wt% HA (PGAZH1.5) was higher than those of the other samples. Moreover, in vitro studies elucidated that cell attachment on PGAZH1.0 and PAZH1.5 surfaces were acceptable.

Iron oxide nanoparticles were employed to fabricate a soft tissue scaffold with enhanced physicochemical and biological characteristics. Growth promotion effect of L-lysine coated magnetite (Lys@Fe3O4) nanoparticles on the liver cell lines was proved previously. So, in the current experiment these nanoparticles were employed to fabricate a soft tissue scaffold with growth promoting effect on the liver cells. Lys@Fe3O4 nanoparticles were synthesized via co-precipitation reaction. Resulted particles were ~7 nm in diameter and various concentrations (3, 5, and 10 wt%) of these nanoparticles were used to fabricate nanocomposite PCL fibers. Electrospinning technique was employed and physicochemical characteristics of the resulted nanofibers were evaluated. Electron micrographs and EDX-mapping analysis showed that nanoparticles were well dispersed in the PCL fibers and no bead structure were formed. As expected, incorporation of Lys@Fe3O4 to the PCL nanofibers resulted in a reduction in hydrophobicity of the scaffold. Nanocomposite scaffolds were shown increased tensile strength with increasing concentration of employed nanoparticles. In contrast to PCL scaffold, nearly 150% increase in the cell viability was observed after 3-days exposure to the nanocomposite scaffolds. This study indicates that incorporation of magnetite nanoparticles in the PCL fibers make them more prone to cell attachment. However, incorporated nanoparticles can provide the attached cells with valuable iron element and consequently promote the cells growth rate. Based on the results, magnetite enriched PCL nanofibers could be introduced as a scaffold to enhance the biological performance for liver tissue engineering purposes.

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Nanocomposites containing clay nanoparticles often present favorable properties such as good mechanical and thermal properties. They frequently have been studied for tissue engineering (TE) and regenerative medicine applications. On the other hand, poly(glycerol sebacate) (PGS), a revolutionary bioelastomer, has exhibited substantial potential as a promising candidate for biomedical application. Here, we present a facile approach to synthesizing stiff, elastomeric nanocomposites from sodium‐montmorillonite nano‐clay (MMT) in the commercial name of Cloisite Na+ and poly(glycerol sebacate urethane) (PGSU). The strong physical interaction between the intercalated Cloisite Na+ platelets and PGSU chains resulted in desirable property combinations for TE application to follow. The addition of 5% MMT nano‐clay resulted in an over two‐fold increase in the tensile modulus, increased the onset thermal decomposition temperature of PGSU matrix by 18°C, and noticeably improved storage modulus of the prepared scaffolds, compared with pure PGSU. As well, Cloisite Na+ enhanced the hydrophilicity and water uptake ability of the samples and accelerated the in‐vitro biodegradation rate. Finally, in‐vitro cell viability assay using L929 mouse fibroblast cells indicated that incorporating Cloisite Na+ nanoparticles into the PGSU network could improve the cell attachment and proliferation, rendering the synthesized bioelastomers potentially suitable for TE and regenerative medicine applications.