Preparation of electroactive nanofibers of star-shaped polycaprolactone/polyaniline blends

Piezoelectric conductive electrospun nanocomposite PCL/Polyaniline/Barium Titanate scaffold for tissue engineering applications

Recent trends in tissue engineering technology have switched to electrical potentials generated through bioactive scaffolds regarding their appropriate effects on cell behaviors. Preparing a piezo-electrical stimuli scaffold with high electrical conductivity for bone and cartilage tissue regeneration is the ultimate goal of the present study. Here, Barium Titanate nanoparticles (BaTiO₃ NPs) were used as piezoelectric material and highly conductive binary doped Polyaniline nanoparticles (PANI NPs) were synthesized by oxidative polymerization. Polycaprolactone (PCL) was applied as carrier substrate polymer and conductive spun nanofibrous scaffolds of PCL/PANI composites were prepared in two different amounts of PANI (3 and 5 wt.%). The conductivity of PCL/PANI nanofibers has been analyzed by standard four probes test. Based on the obtained results, the PCL/PANI5 (with 5 wt.% PANI) was selected due to the superior electrical conductivity of 8.06 × 10^-4 s cm ^- 1. Moreover, the piezoelectric nanofibrous scaffolds of PCL/BT composite were electrospun in three different amounts of BT (20, 30, and 40 wt.%). To investigate the synergic effect of conductive PANI and piezoelectric BT, ternary nanocomposite scaffolds of PCL/PANI/BT were prepared using the dual jet electrospinning technique. The piezoelectric properties have been analyzed by determining the produced voltage. The morphological assessment, contact angle, mechanical test, and MTT assay have been conducted to evaluate other properties including biocompatibility of nanofibrous scaffolds. The PCL/PANI5/BT40 composite resulted in an unprecedented voltage of 1.9 Volt. SEM results confirm that BT NPs have been distributed and embedded inside PCL fibers quite appropriately. Also, the chosen scaffolds were homogeneously intertwined and possessed an average fiber diameter of 288 ± 180 nm, and a contact angle of 92 ± 7°, making it a desirable surface for cell attachment and protein interactions. Moreover, Young's modulus, ultimate tensile stress, and elongation were obtained as 11 ± 1 MPa, 5 ± 0.6 MPa, and 109 ± 15% respectively. Obtained results assert the novel potential of piezo-electrical stimuli conductive nanocomposite scaffold for tissue engineering applications.

Fabrication of Cellulase Catalysts Immobilized on a Nanoscale Hybrid Polyaniline/Cationic Hydrogel Support for the Highly Efficient Catalytic Conversion of Cellulose

A novel conductive nanohydrogel hybrid support was prepared by in situ polymerization of polyaniline nanorods on an electrospun cationic hydrogel of poly(ε-caprolactone) and a cationic phosphine oxide macromolecule. Subsequently, the cellulase enzyme was immobilized on the hybrid support. Field-emission scanning electron microscopy and Brunauer-Emmett-Teller analyses confirmed a mesoporous, rod-like structure with a slit-like pore geometry for the immobilized support and exhibiting a high immobilization capacity and reduced diffusion resistance of the substrate. For comparison, the catalytic activity, storage stability, and reusability of the immobilized and free enzymes were evaluated. The results showed that the immobilized enzymes have higher thermal stability without changes in the optimal pH (5.5) and temperature (55 °C) for enzyme activity. A high immobilization efficiency (96%) was observed for the immobilized cellulose catalysts after optimization of parameters such as the pH, temperature, incubation time, and protein concentration. The immobilized enzyme retained almost 90% of its original activity after 4 weeks of storage and 73% of its original activity after the ninth reuse cycle. These results strongly suggest that the prepared hybrid support has the potential to be used as a support for protein immobilization.

Synthesis and meticulous molecular, morphological and thermal characterization of linear and star-shaped polycaprolactones

Linear and star-shaped polycaprolactones: two-dimensional separation.

Nanofibrous polylactide composite scaffolds with electroactivity and sustained release capacity for tissue engineering

A conveniently fabricated electroactive nanofibrous composite scaffold serves as a sustained drug release system and promotes myoblast differentiation.