One-pot encapsulation of luminescent quantum dots synthesized in aqueous solution by amphiphilic polymers.

A simple one-pot polymer encapsulation method is developed for group II-VI semiconductor quantum dots (QDs) synthesized in aqueous solution. The micelles of amphiphilic polymers, such as octadecylamine-modified poly(acrylic acid), capture and encapsulate the QDs when the original hydrophilic ligands, namely 3-mercaptopropionic acid (MPA), capped on the CdTe/CdS core/shell QDs are partially or fully exchanged by the hydrophobic ligands, 1-dodecanethiol. The molar ratio of the amphiphilic polymer to QDs plays a crucial role in determining the final morphology of the encapsulated structures, including the number of QDs encapsulated in one polymeric micelle. Importantly, the polymer coating significantly improves the optical properties of the QDs, which enhances the photoluminescence quantum yield by about 50%. Furthermore, the photostability of the amphiphilic polymer-coated QDs is much better than that of the synthesized QDs capped with MPA.

Customized Borosilicate Bioglass Scaffolds With Excellent Biodegradation and Osteogenesis for Mandible Reconstruction.

Graft reconstruction of the mandible is an important approach that aims at improving the appearance and functionality of defected mandibles. The traditional implant materials are generally bioinert, non-degradable, and that they lack favorable pore structures for cell proliferation, which limit their clinical application. In this study, we used boron-containing bioactive glass which was combined with a three-dimensional (3D) printing technology to construct an osteoinductive implant scaffold, according to the imaging instructions of CT scan on bone defects. Here, the boron-containing bioglass scaffold (B-BGs) was prepared through sol-gel processing and a 3D print technique. Different boron content of borosilicate bioglass was prepared by incorporating B2O3 (molar: 19.4 and 38.8%) into 58S bioglass to replace parts of SiO2. For fabricated mandible implants through three-dimensional 3D printing of B-BGs (size: 8 × 2 mm; pore size: 250 µm) modified with borosilicate bioglass powder and sodium alginate. Notably, the compressive strength of the B-BGs was about 3.8 Mpa, which supported mandibular activity. Subsequently, the excellent biocompatibility of B-BGs was confirmed using cytotoxicity in vitro studies. Finally, data from in vivo experiments demonstrated that the B-BGs could promote bone regeneration and they could almost get completely degraded within 4 weeks. Our results showed that the boron-containing bioglass could repair mandibular defects.

X-ray shielding structural and properties design for the porous transparent BaSO4/cellulose nanocomposite membranes.

Since effective shielding of X-rays was required in medical, aviation and nuclear fields, a novel X-ray shielding BaSO4/cellulose nanocomposite membrane (BSCM) material with porous transparent structure has been designed. The effects of carboxylated nano-BaSO4 (BS) addition on the physical and morphological properties of the cellulose membrane (CM) were investigated. Meanwhile, the influence of X-ray shielding capacity was studied by different layers of composite membranes and the shielding mechanism of the X-ray was also discussed. Scanning electron microscopy (SEM) images displayed the aggregations of BS in the cellulose surface. Fourier transform infrared spectroscopy (FTIR) showed that the incorporation of BS into CM caused molecular interactions between CM and BS. Brunauer-Emmett-Teller (BET) indicated that the load of BS contributed little to the specific surface area and pore size. Meanwhile, the water vapor transmission rates (WVTR) also stayed at the same level before and after the binding of BS. The swelling ratios, weight loss ratios and mechanical property were decreased along with the addition of BS. The radiation shielding ability was enhanced. Therefore, this work was regarded as a possible example that the BSCM was designed as X-ray radiation shielding material or sandwich filler material in the implication of radiation shielding glass.