One major obstacle in the application of drug delivery systems for cancer chemotherapy is their poor penetration in tumor tissues. Conjugating active ligand moieties to the surface of nanoparticles may be a promising approach for enhancing the tumor accumulation and penetration of nanoparticles. Herein, the cell-penetrating peptide twin-arginine translocation (Tat)-conjugated epirubicin-loaded poly(lactic-glycolic acid) nanoparticles were prepared to achieve deep tumor penetration. The morphology and size of nanoparticles were characterized by scanning electron microscopy and dynamic light scattering, and the biological behaviors of nanoparticles were evaluated. It is demonstrated that Tat-conjugated nanoparticles have a significant improvement in antitumor activity and biodistribution compared with nonconjugated nanoparticles. Importantly, Tat conjugated on the surface of nanoparticles could facilitate the encapsulated drug penetration into deeper tumor tissue. Additionally, Tat-conjugated nanoparticles have good biocompatibility, as demonstrated by hemolytic tests, in vitro cytotoxicity, and histology study. These results suggested that the Tat-conjugated nanoparticles, as a powerful delivery system for chemotherapeutic drug, would have a promising application in human cancer therapy. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:4185–4196, 2015

Salidroside is a natural product isolated from Rhodiola rosea L. which possesses a wide range of biological activities, especially neuroprotective effects in the treatment of ischemic stroke. In an attempt to improve its neuroprotective effects, a series of novel salidroside analogues were synthesized and their neuroprotective activities were evaluated against the glucose and serum depletion-induced cell death in differentiated PC12 cells. Most target compounds displayed protective effects on the cell viability, especially for compound 6, which had a great potency superior to salidroside. MTT assay and Hoechst 33342 staining collectively showed that pretreatment with 6 attenuated cell viability loss and reduced apoptotic death in cultured PC12 cells with glucose and serum depletion. And its neuroprotective effects might be associated with the increase of the apoptosis-related protein Bcl-2/Bax expression ratio, and also with the inhibition of caspase-3 activation. Therefore, our new findings may provide potentially important information for further development of salidroside analogues and lay the basis for further studies on the cerebral ischemic stroke and neurodegenerative diseases for human clinical treatment.

In this article, polyamide (PA) 6 was dissolved in 98 wt % formic acids with a concentration of 13 wt %, and then the electrospun PA 6 nanofiber membranes were prepared. The filtration potential of the nanofiber membranes were firstly analyzed based on the scanning electron microscope images and pore size measurements, and then the effects of thermal treatment on the dimensional stability were studied. Subsequently, the continuous production process based on the above experiments and the deposition areas of the nanofibers on the collecting meshes was designed. Finally, the mechanical properties and the filtration performances of the electrospun PA 6 nanofiber membranes were assessed. The results showed the membranes with a thickness of 71 μm (electrospinning for 15 min) had good filtration potential for the microparticles with 0.3 μm diameter. After being treated by tension and relaxation heat setting, the membranes demonstrated excellent dimensional stability, the breaking tenacity, and the elongation reached 4.71 ± 1.66 MPa and (69.97 ± 6.56)%, respectively. The permeability decreased with the increase of the membranes thickness. However, the permeability of membranes with (72.9 ± 1.04) μm thickness still maintained 516 L/m² s, and the actual filtration efficiency of 0.3 μm particles reached 99.98%. The above results showed that the membranes fabricated by the continuous production process could meet the demands of high efficiency filtration and provide a reference for the industrial use of electrospun nanofiber membranes. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

In this study, electrospinning was used to fabricate silk-fibroin (SF)-based mats, which served as substrates for the culturing of rat Schwann cells. Microscopic observation and physical parameter measurements revealed that the electrospun SF mats had a nanofibrous structure with favorable physical properties. Fourier transform infrared analysis provided chemical characterization of the molecular confirmation of the SF proteins in the mats. The morphology and immunocytochemistry showed that the mats supported the survival and growth of the cultured Schwann cells, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis indicated that the electrospun SF mat extract had no cytotoxic effects on Schwann cell proliferation. Collectively, all of the results suggest that the electrospun SF mats might become a candidate scaffold for tissue-engineered nerve grafts to promote peripheral nerve regeneration. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

An organic/inorganic hybrid gel of alginate–SiO₂ (ALG–SiO₂) was used to immobilize the partially purified potato polyphenol oxidase (PPO) for the treatment of phenolic wastewater. The influences of alginate concentration, quantity of both enzyme and tetramethoxysilane (TMOS) on immobilization were investigated. The Michaelis constant for immobilized PPO was determined as 14.7 mmol L⁻¹ at 25 °C, and the highest activity of immobilized PPO was achieved at pH 7.0. The ALG–SiO₂ immobilized PPO was more stable than the free PPO or ALG(alone) immobilized PPO. This study suggests that ALG–SiO₂ immobilized PPO might be a potential tool for the removal of phenolic compounds from industrial wastewater. Copyright © 2008 Society of Chemical Industry