Biocompatible Single-Crystal Selenium Nanobelt Based Nanodevice as a Temperature-Tunable Photosensor

Selenium materials are widely used in photoelectrical devices, owing to their unique semiconductive properties. Single-crystal selenium nanobelts with large specific surface area, fine photoconductivity, and biocompatibility provide potential applications in biomedical nanodevices, such as implantable artificial retina and rapid photon detector/stimulator for optogenetics. Here, we present a selenium nanobelt based nanodevice, which is fabricated with single Se nanobelt. This device shows a rapid photo response, different sensitivities to visible light of variable wave length, and temperature-tunable property. The biocompatibility of the Se nanobelts was proved by MTT test using two cell lines. Our investigation introduced a photosensor that will be important for multiple potential applications in human visual system, photocells in energy or MEMS, and temperature-tunable photoelectrical device for optogenetics research

Optical Model and Optimization for Coherent-Incoherent Hybrid Organic Solar Cells with Nanostructures

Embedding nanostructures in organic solar cells (OSCs) is a well-known method to improve the absorption efficiency of the device by introducing the plasma resonance and scattering effects without increasing the active layer thickness. The introduction of nanostructures imposes greater demands on the optical analysis method for OSCs. In this paper, the generalized rigorous coupled-wave analysis (GRCWA) is presented to analyze and optimize the performance of coherent-incoherent hybrid organic solar cells (OSCs) with nanostructures. Considering the multiple reflections of light scattered within the glass substrate by the device, the correction vector g is derived, then the modified expressions for the field and absorption distribution in OSCs are provided. The proposed method is validated by comparing the simulated results of various structures with results obtained by the generalized transfer matrix method (GTMM) and the “equispaced thickness method” (ETM). The results demonstrate that the proposed method can reduce the number of simulations by at least half compared to the ETM while maintaining accuracy. With the proposed method, we discussed the device performance depending on the geometrical parameters of nanostructures, and the optimization and analysis are accomplished for single and tandem OSCs. After optimization based on the proposed method, the performance of OSCs are significantly improved, which further demonstrates the practicality of the method

Risk factors of brain metastasis of lung squamous cell carcinoma: a retrospective analysis of 188 patients from single center

Abstract Background To explore risk factors and the efficacy of treatment strategies for brain metastasis (BM) in squamous cell carcinoma (SCC) of the lung. Methods The clinical data of 188 pathologically confirmed as squamous cell carcinoma or adenosquamous carcinoma patients were studied retrospectively. Factors including age (<60 vs. ≥60), gender, stage at diagnosis, T status (T1–2 vs. T3–4), N status (N0–1 vs. N2–3), histology (squamous vs. adenosquamous), smoking history (non-smoker vs. current smoker) and serum tumor markers (normal vs. elevated) were analyzed. Results The incidence of BM was 19.1% (36/188) in our cohort. Patients who were female (p = 0.005), had advanced disease at diagnosis (p < 0.001), had adenosquamous carcinoma histology (p = 0.033) or had elevated serum level of CEA at diagnosis (p < 0.001) had significantly higher incidence of BM. In multivariate analysis, female (p = 0.034, HR = 18.874) and elevated serum level of CEA at diagnosis (p = 0.009, HR = 19.824) were independent risk factors of BM. BM patients who received additional systemic therapy after local therapy had significantly longer post-BM survival than those who received local therapy only (p = 0.004, HR = 0.058). Gemcitabine/platinum-containing regimen (GP) and taxans/platinum-containing regimen (TP) led to comparable brain-metastasis-free survival (BMFS) (p = 0.10). Conclusions Females and patients with elevated serum level of CEA at diagnosis had a higher risk of developing BM. The following systemic therapy after local therapy prolonged the survival of BM patient, but the efficacy of GP and TP was comparable in terms of preventing BM

A surface-eroding poly(1,3-trimethylene carbonate) coating for magnesium based cardiovascular stents with stable drug release and improved corrosion resistance

Magnesium alloys with integration of degradability and good mechanical performance are desired for vascular stent application. Drug-eluting coatings may optimize the corrosion profiles of magnesium substrate and reduce the incidence of restenosis simultaneously. In this paper, poly (trimethylene carbonate) (PTMC) with different molecular weight (50,000 g/mol named as PTMC5 and 350,000 g/mol named as PTMC35) was applied as drug-eluting coatings on magnesium alloys. A conventional antiproliferative drug, paclitaxel (PTX), was incorporated in the PTMC coating. The adhesive strength, corrosion behavior, drug release and biocompatibility were investigated. Compared with the PLGA control group, PTMC coating was uniform and gradually degraded from surface to inside, which could provide long-term protection for the magnesium substrate. PTMC35 coated samples exhibited much slower corrosion rate 0.05 μA/cm2 in comparison with 0.11 μA/cm2 and 0.13 μA/cm2 for PLGA and PTMC5 coated counterparts. In addition, PTMC35 coating showed more stable and sustained drug release ability and effectively inhibited the proliferation of human umbilical vein vascular smooth muscle cells. Hemocompatibility test indicated that few platelets were adhered on PTMC5 and PTMC35 coatings. PTMC35 coating, exhibiting surface erosion behavior, stable drug release and good biocompatibility, could be a good candidate as a drug-eluting coating for magnesium-based stent

Is extracellular matrix (ECM) a promising scaffold biomaterial for bone repair?

The increasing demand for bone grafts and the scarcity of donors worldwide are promoting researchers to seek alternatives. The extracellular matrix (ECM) has been reported to enhance properties of osteoconduction and osteoinduction by simulating the molecular structure of bone and facilitating cell infiltration for bone repair. As one of several novel biomaterials, ECM has many desirable properties, including biocompatibility, bioactivity, and biosafety. Thus, we evaluated whether ECM is a promising scaffold biomaterial for bone repair. In this review, we explore ECM composition, the sources and fabrication methods, especially the decellularization technique, of ECM scaffolds. Furthermore, we highlight recent progress in the use of ECM as a scaffold biomaterial for bone repair. Generally, ECM is used in 1) threedimensional (3D) cell cultures to promote osteogenic differentiation, 2) combinations with other biomaterials to increase their osteogenic effects, 3) 3D printing to produce customized or patient-tailored scaffolds for bone repair, and 4) hydrogels derived from ECM used for bone repair. In addition, we focus on future prospects for application of ECM as a scaffold material used for bone repair. From this review, we expect to have a perfect understanding of ECM-based scaffold materials in the hope that this leads to further research of the production of ECM biomaterials to meet the clinical needs for bone repair

Risk factors and treatments for brain metastasis in patients with adenocarcinoma of the lung: a retrospective analysis of 373 patients

Abstract Background Risk factors and treatments for brain metastasis (BM) in patients with adenocarcinoma have not been fully profiled in previous studies because of the enrolment of patients with tumours of mixed histology. Thus, we specifically addressed the issue in patients with adenocarcinoma. Methods Clinical data for 373 patients with pathologically confirmed adenocarcinoma were studied retrospectively. Factors including age (≤60 vs. > 60), gender (male vs. female), stage at diagnosis, T status (T1–2 vs. T3–4), N status (N0–1 vs. N2–3), epidermal growth factor receptor (EGFR) mutation status (wild-type vs. mutant) and smoking status (never vs. current) were analyzed. Results In multivariate analysis, age (P = 0.006) and N status (P = 0.041) were independent risk factors for BM. In patients with BM, adding systemic therapy to local therapy improved median post-brain-metastasis survival (mPBMS) (P = 0.02). However, if stratification was conducted according to the recursive partitioning analysis (RPA) classification or graded prognostic assessment (GPA) scoring, only patients in RPA class II (P = 0.020) or with GPA score 1.5-2.5 (P = 0.032) could benefit from local plus systemic therapy. Those who received both pemetrexed and tyrosine kinase inhibitors (TKIs) as systemic therapies had a longer mPBMS than those who received TKIs alone, regardless of whether local therapy was applied. In patients with EGFR-sensitive mutations, TKIs therapy led to a longer mPBMS than conventional chemotherapy (P = 0.002). Conclusions Adenocarcinoma patients who were younger than 60 years of age and those with N2–3 disease have a significantly higher risk of BM. The addition of systemic therapy to local therapy can significantly prolong mPBMS, but the survival benefit confined in certain populations. Patients with opportunity to receive both pemetrexed and TKIs had the longest mPBMS

In vitro and in vivo degradation behavior of Mg–2Sr–Ca and Mg–2Sr–Zn alloys

Magnesium alloys with integration of degradability and good mechanical performance are desired for orthopedic implants. In this paper, Mg–2Sr–Ca and Mg–2Sr–Zn alloys were prepared and the degradation as well as the bone response were investigated. Compared with the binary Mg–2Sr alloys, the addition of Ca and Zn improved the in vitro and in vivo corrosion resistance. Mg–2Sr–Ca and Mg–2Sr–Zn alloys exhibited more uniform corrosion and maintained the configuration of the implants 4 weeks post-implantation. The in vivo corrosion rates were 0.85 mm/yr for Mg–2Sr–Zn and 1.10 mm/yr for Mg–2Sr–Ca in comparison with 1.37 mm/yr for Mg–2Sr. The in vitro cell tests indicated that Mg–2Sr–Ca and Mg–2Sr–Zn alloys exhibited higher MG63 cell viability than Mg–2Sr alloy. Furthermore, these two alloys can promote the mineralization and new bone formation without inducing any significant adverse effects and this sound osteogenic properties suggest its attractive clinical potential

Stiff Extracellular Matrix Promotes Invasive Behaviors of Trophoblast Cells

The effect of extracellular matrix (ECM) stiffness on embryonic trophoblast cells invasion during mammalian embryo implantation remains largely unknown. In this study, we investigated the effects of ECM stiffness on various aspects of human trophoblast cell behaviors during cell ECM interactions. The mechanical microenvironment of the uterus was simulated by fabricating polyacrylamide (PA) hydrogels with different levels of stiffness. The human choriocarcinoma (JAR) cell lineage was used as the trophoblast model. We found that the spreading area of JAR cells, the formation of focal adhesions, and the polymerization of the F actin cytoskeleton were all facilitated with increased ECM stiffness. Significantly, JAR cells also exhibited durotactic behavior on ECM with a gradient stiffness. Meanwhile, stiffness of the ECM affects the invasion of multicellular JAR spheroids. These results demonstrated that human trophoblast cells are mechanically sensitive, while the mechanical properties of the uterine microenvironment could play an important role in the implantation process