Polydopamine-based Implantable Multifunctional Nanocarpet for Highly Efficient Photothermal-chemo Therapy.

We report a design and fabricate multifunctional localized platform for cancer therapy. Multiple stimuli-responsive polydopamine (PDA) was used for surface modification of electrospun doxorubicin hydrochloride (DOX) loaded polycaprolactone (PCL) fibers to make a designated platform. Photothermal properties such as photothermal performance and stability of the resulting composite mats were studied under the irradiation of the near-infrared (NIR) laser of 808 nm. With the incorporation of PDA into the fiber, a remarkable increase of local temperature was recorded under NIR illumination in a concentration-dependent manner with excellent stability. Drug released assay results revealed PDA coated PCL-DOX mats showed pH and NIR dual responsive behavior thereby exhibiting improved drug release in an acidic medium compared to physiological pH condition (pH 7.4) which is further increased by NIR exposure. The cancer activity in vitro of the mats was evaluated using cell counting (CCK) and live and dead cell assays. The combined effect of NIR mediated hyperthermia and chemo release resulting improved cells death has been reported. In summary, this study presents a major step forward towards a therapeutic model to cancer treatment utilizing pH and NIR dual responsive property from PDA alone in a fibrous mat.

Sacrificial template-based synthetic approach of polypyrrole hollow fibers for photothermal therapy.

In the present work, polypyrrole hollow fibers (PPy-HFs) were fabricated by sacrificial removal of soft templates of electrospun polycaprolactone (PCL) fibers with polypyrrole (PPy) coating through chemical polymerization of pyrrole monomer. Different physicochemical properties of as-fabricated PPy-HFs were then studied by Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, Differential scanning calorimetry/Thermogravimetric analysis (DSC/TGA), and X-ray photoelectron spectroscopy (XPS). The photothermal activity of PPy-HF was studied by irradiating 808-nm near infra-red (NIR) light under different power values with various concentrations of PPy-HFs dispersed in phosphate buffer solution (PBS, pH 7.4). These PPy-HFs exhibited enhanced photothermal performance compared with polypyrrole nanoparticles (PPy-NPs). Furthermore, these PPy-HFs showed photothermal effect that was laser-power- and concentration-dependent. The photothermal toxicity of the resulting nanofiber was evaluated using cell counting kit-8 (CCK-8) and live and dead cell assays. Results showed that these PPy-HFs were more effective in killing cancer cells under NIR irradiation. In contrast, hollow-fiber showed no cytotoxicity without NIR exposure. Among different nanofiber formulations, PPy-160 exhibited the highest photothermal toxicity. It could be explained by its enhanced photothermal performance compared to other specimens. The resulting PPy-HFs showed superior drug-loading capacity to PPy-NPs. This might be attributed to adequate binding of the drug into both luminal and abluminal hollow-fiber surfaces. Fabrication of this substrate type opens a promising new avenue for architectural design of biocompatible organic polymer for biomedical field.