Biologically Enabled Syntheses of Nanostructured 3-D Sensor Materials:the Potential for 3-D Genetically Engineered Microdevices (3-D GEMs)

Three-dimensional (3-D)self-assembly of nanos- tructures and nanodevices on a large scale remains a grand quest for mankind.Freestanding nanostructured assemblies with controlled 3-D shapes can exhibit attractive properties for sensor and other applications. Protocols for 3-D self-assembly that can be scaled up for mass production on a large up to tonnage)scale, while preserving morphological features on a small (down to nanometer)scale,are needed to allow for widespread use of 3-D nanostructures in advanced devices.However,these often conflicting requirements of scalability and precision pose a difficult challenge for synthetic (man-made)processing routes.

Synthesis and biocompatibility of a biodegradable and functionalizable thermo-sensitive hydrogel

Injectable thermal gels are a useful tool for drug delivery and tissue engineering.However,most thermal gels do not solidify rapidly at body temperature(37C).We addressed this by synthesizing a thermo-sensitive,rapidly biodegrading hydrogel.Our hydrogel,poly(ethylene glycol)-co-poly(propanol serinate hexamethylene urethane)(EPSHU),is an ABA block copolymer comprising A,methoxy poly ethylene glycol group and B,poly(propanol L-serinate hexamethylene urethane).EPSHU was characterized by gel permeation chromatography for molecular weight and 1H NMR and Fourier transformed infrared for structure.Rheological studies measured the phase transition temperature.In vitro degradation in cholesterol esterase and in Dulbecco’s phosphate buffered saline(DPBS)was tracked using the average molecular weight measured by gel permeation chromatography.LIVE/DEAD and resazurin reduction assays performed on NIH 3T3 fibroblasts exposed to EPSHU extracts demonstrated no cytotoxicity.Subcutaneous implantation into BALB/cJ mice indicated good biocompatibility in vivo.The biodegradability and biocompatibility of EPSHU together make it a promising candidate for drug delivery applications that demand carrier gel degradation withinmonths.

Electrophoretic deposition and an investigation of co-dopants effect on luminescence property of Mg2SiO4:Eu3+phosphors

Forsterite particles doped with europium ions（Eu^（3＋）） were synthesized via a solution combustion method. The effect of co-dopants on photoluminescence intensity was described. Different percentages of calcium（Ca^（2＋））, zinc（Zn^（2＋））, barium（Ba^（2＋）） and strontium（Sr^（2＋）） were added to the Mg2SiO4：Eu^（3＋）host.The synthesized sample was characterized by X-ray diffraction, transmission electron microscopy,scanning electron microscopy, spectrofluorometer and the FTIR spectroscopy. X-ray diffraction（XRD）results revealed that dominant phase was forsterite in all samples. Additionally, a negligible amount of periclase phase was recognized in the samples. The average size of the synthesized particles was less than 200 nm. The presence of co-dopant led to an enhancement in the photoluminescent property of the synthesized samples. The maximum increase in photoluminescence intensity was obtained by Ba^（2＋）ions as a co-dopant. Condensed films of photoluminescence particles were produced by utilizing electrophoresis technique to deposit particles. The results showed that polyvinyl pyrrolidone was the best surface modifier to raise the mass deposition of the samples on the substrate.

Amorphous calcium magnesium phosphate nanocomposites with superior osteogenic activity for bone regeneration

The seek of bioactive materials for promoting bone regeneration is a challenging and longterm task.Functionalization with inorganic metal ions or drug molecules is considered effective strategies to improve the bioactivity of various existing biomaterials.Herein,amorphous calcium magnesium phosphate(ACMP)nanoparticles and simvastatin(SIM)-loaded ACMP(ACMP/SIM)nanocomposites were developed via a simple co-precipitation strategy.The physiochemical property of ACMP/SIM was explored using transmission electron microscope(TEM),Fourier transform infrared spectroscopy(FTIR),powder X-ray diffraction(XRD)and highperformance liquid chromatograph(HPLC),and the role of Mg^(2+) in the formation of ACMP/SIM was revealed using X-ray absorption near-edge structure(XANES).After that,the transformation process of ACMP/SIM in simulated body fluid(SBF)was also tracked to simulate and explore the in vivo mineralization performance of materials.We find that ACMP/SIM releases ions of Ca^(2+),Mg^(2+)and PO_(4)^(3),when it is immersed in SBF at 37℃,and a phase transformation occurred during which the initially amorphous ACMP turns into self-assembled hydroxyapatite(HAP).Furthermore,ACMP/SIM displays high cytocompatibility and promotes the proliferation and osteogenic differentiation of MC3T3-E1 cells.For the in vivo studies,lamellar ACMP/SIM/Collagen scaffolds with aligned pore structures were prepared and used to repair a rat defect model in calvaria.ACMP/SIM/Collagen scaffolds show a positive effect in promoting the regeneration of calvaria defect after 12weeks.The bioactive ACMP/SIM nanocomposites are promising as bone repair materials.Considering the facile preparation process and superior in vitro/vivo bioactivity,the as-prepared ACMP/SIM would be a potential candidate for bone related biomedical applications.

Facile synthesis of nano-sized CuFe2S3:morphology and diverse functional tuning and crystal growth mechanism exploring

Ternary chalcogenide compounds are such promising and have been used for much practical applications.As a sort of these compounds,cubanite(CuFe2S3)possess some unique properties which can be used in different fields.In our study,we developed a facile one pot synthesis of CuFe2S3 nanocrystals(NCs)at a low reaction temperature,and achieved a morphology and phase composition tuning of the NCs through changing a variety of precursors and surfactants,meanwhile improved their magnetism and optical properties.Eventually,well-ordered and‘nano-brick’like CuFe2S3 NCs were obtained and showed best magnetism and near-infrared fluorescence properties.Furthermore,the NCs were proved with good biocompatibility and possibility for cell labeling.This kind of materials with lower toxicity and potential of magnetic is bound to remedy the defects of photoluminescence quantum dots(QDs)and be with higher potential in the field of biological diagnosis and multi-functional system construction.