Poly(1,8-octanediol citrate) (POC) is a recently developed biodegradable crosslinked elastomer that possesses good cytocompatibility and matchable mechanical properties to soft tissues. However, the thermosetting characteristic reveals a big challenge to manufacture its porous scaffold. Herein, POC elastomer was electrospun into fiber mat using poly(L-lactic acid) (PLLA) as a spinnable carrier. The obtained POC/PLLA fiber mats were characterized by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), uniaxial tensile test, static-water-contact-angle, thermal analysis, in vitro degradation and biocompatibility test. It was found that the fibrous structure could be formed so long as the POC pre-polymer’s content was no more than 50 wt%. The presence of elastic POC component not only strengthened the fiber mats but also toughened the fiber mats. The hydrophilicity of 50/50 fiber mat significantly improved. In vitro degradation rate of POC based fiber mats was much faster than that of pure PLLA. Cyto- and histo-compatibility tests confirmed that the POC/PLLA fiber mats had good biocompatibility for potential applications in soft tissue engineering.Open image in new window

The ultra-strong nanocomposite fiber mats based on biodegradable polydioxanone (PDO) and chitin nanocrystals (ChiNCs) were successfully prepared by means of electrospinning. The ChiNCs are uniformly dispersed in the PDO matrix and mostly oriented along fiber long axis, resulting in a significant improvement in mechanical property. Moreover, the introduction of ChiNCs led to the increase of the glass-transition temperature (Tg) and thermal decomposition temperature (Td) of PDO elucidated by thermal analyses. In addition, the loading of ChiNCs caused very different In vitro degradation behavior compared to neat PDO fiber mat. Furthermore, in vitro cell culture results indicated that the addition of ChiNCs improved the cellular adhesion and proliferation.

•Chitin nanofibril/polycaprolactone nanocomposite fiber mats were fabricated by electrospinning.•Nanocomposite fiber mats exhibited a significant improvement in mechanical property.•The surface wettability transformed from hydrophobicity to hydrophilicity.•Cellular infiltration and migration were highly improved.Nanocomposite fiber mats based on biodegradable polycaprolactone (PCL) and chitin nanofibril (n-chitin) were produced via electrospinning. The morphologies, thermal and mechanical properties as well as surface wettability of the fiber mats were studied by scanning electron microscopy, differential scanning calorimetry analysis, thermogravimetric analysis, dynamic mechanical analysis and static water-contact-angle analysis, respectively. The addition of chitin nanofibrils into PCL resulted in a small change in thermal behavior, but a significant improvement in mechanical properties. Moreover, the surface wettability of electrospun fiber mats transformed from hydrophobicity to hydrophilicity when the chitin nanofibril content was more than 25 wt%. In addition, in vitro cell culture results indicated that the addition of chitin nanofibrils can strongly improve the cellular infiltration and migration confirming that the chitin nanofibril was a good reinforcing as well as bioactive filler for PCL.

Chitin nanocrystal (ChiNC), a biocompatible and biodegradable nanofiller, was used to regulate the mechanical properties of poly(1,8-octanediol citrate) (POC) elastomer. The facile casting/evaporation method was utilized to prepare ChiNC/POC nanocomposite and its structure and properties were characterized by Fourier transform infrared spectroscopy, wide angle X-ray diffraction, scanning electron microscopy, dynamic mechanical analysis, uniaxial tensile test and static water-contact-angle analysis. The results showed the ChiNCs were uniformly distributed in the POC matrix at any test loading ratio and proved to be chemically bonded to the POC network, leading to a gradually increasing tensile modulus and strength, concomitantly without causing damage to elongation at break. Thus regulation of the strength and modulus of POC by loading with ChiNCs can be realized. Furthermore, the incorporation of ChiNCs into POC networks provided more hydrophilicity and the equilibrium swelling degree in PBS buffer was as low as 11%, which is in favour of in vivo usage.

•A new bioelastomer was synthesized by one-pot melt polycondensation.•Chitin nanocrystal as emulsifier to stabilize pre-polymer and form Pickering emulsion.•An eco-friendly emulsion casting process was used to prepare chitin nanocrystal reinforced nanocomposite elastomers.•Filler-well-dispersed nanocomposite elastomers exhibited ultra-strong mechanical properties.Chitin nanocrystal (ChiNC) is a promising reinforcing nanofiller for biomedical polymers. However, its self-aggregation characteristics caused processing difficulty in developing ChiNC-based nanocomposites. Herein, a new degradable crosslinked bioelastomer, designated as poly(1,8-octanediol-co-Pluronic F127 citrate) (POFC) was synthesized by melt polycondensation of citric acid, 1,8-octanediol, and Pluronic F127. In comparison to poly(1,8-octanediol citrate) (POC), POFC pre-polymer exhibited self-emulsifying property. Once ChiNC was introduced into the emulsion, a ChiNC stabilized Pickering emulsion was formed. Coupled with a facile green emulsion casting/evaporation method, the ChiNC ultimately reinforced ChiNC/POFC nanocomposite elastomer was fabricated. The presence of F127 segments endowed POFC with better hydrophilicity and shorter degradation time relative to POC. The incorporation of ChiNC into POFC network led to highly increased tensile modulus and strength. In vitro cytotoxicity tests indicated that the ChiNC/POFC elastomer nanocomposite had a good cytocompatibility and it appeared as a potential biomaterial for tissue engineering application.