The surface plasmon resonance (SPR) sensor is an important tool widely used for studying binding kinetics between biomolecular species. The SPR approach offers unique advantages in light of its real-time and label-free sensing capabilities. Until now, nearly all established SPR instrumentation schemes are based on single- or several-channel configurations. With the emergence of drug screening and investigation of biomolecular interactions on a massive scale these days for finding more effective treatments of diseases, there is a growing demand for the development of high-throughput 2-D SPR sensor arrays based on imaging. The so-called SPR imaging (SPRi) approach has been explored intensively in recent years. This review aims to provide an up-to-date and concise summary of recent advances in SPRi. The specific focuses are on practical instrumentation designs and their respective biosensing applications in relation to molecular sensing, healthcare testing, and environmental screening.

Thermal optofluidics is an emerging field that promises to create numerous research and application opportunities in biophysics, biochemistry, and clinical biology. Innovation in plasmonic optics has led to the development of various invaluable tools in the fields of biosensing and microfluidic manipulation. The optothermal effect originates from light–matter interactions during photon–phonon conversion, which can lead to micro‐ or nanoscale inhomogeneities in the thermal distribution. This further induces a series of hydrodynamic phenomena such as natural convection, Marangoni convection, thermophoresis, the electrolyte Seebeck effect, depletion forces, and interfacial effects in colloidal particles. Light–matter interactions are particularly important for three aspects of microfluidics, namely the motion of colloidal particles, fluidic actuation, and biochemical reactions. This review first systematically elucidates the role of both nanoscale plasmonic thermal generation and heat‐induced fluidic motion in optofluidic microsystems. Then, recent state‐of‐the‐art thermal optofluidic applications of the above‐listed three aspects are presented. The paper aims to provide an insightful reference for future research in optofluidic biochemical systems.

The signal transducers and activators of transcription 3 (STAT3) signaling pathway plays critical roles in the pathogenesis and progression of various human cancers, including non-small cell lung cancer (NSCLC). In this study, we aimed to evaluate the therapeutic potential of physalin A, a bioactive withanolide derived from Physalis alkekengi var. francheti used in traditional Chinese medicine, was evaluated in human NSCLC cells. Its and determined whether it effect oninhibited both constitutive and induced STAT3 activity, through repressing the phosphorylation levels of JAK2 and JAK3, resulting in anti-proliferation and pro-apoptotic effects on NSCLC cells was also determined, and. theThe antitumor effects of physalin A were also validated usingin an in vivo mouse xenograft models of NSCLC cells. Physalin A had anti-proliferative and pro-apoptotic effects in NSCLC cells with constitutively activated STAT3; it also suppressed both constitutive and induced STAT3 activity by modulating the phosphorylation of JAK2 and JAK3. Furthermore, physalin A abrogated the nuclear translocation and transcriptional activity of STAT3, thereby decreasing the expression levels of STAT3, its target genes, such as Bcl-2 and XIAP. Knockdown of STAT3 expression by small interfering RNA (siRNA) significantly enhanced the pro-apoptotic effects of physalin A in NSCLC cells. Moreover, physalin A significantly suppressed tumor xenograft growth. Thus, as an inhibitor of JAK2/3-STAT3 signaling, physalin A, has potent anti-tumor activities, which may facilitate the development of a therapeutic strategy for treating NSCLC.

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Polyphyllin D (PD) is a potent anticancer agent isolated from a traditional medicinal herb Paris polyphylla that has been used in China for many years to treat cancer. PD is not a substrate of p-glycoprotein, and it can bypass the multi-drug resistance in cancer cell line R-HepG2. However, the effect of PD on the induction of cell death in human erythrocytes remains unknown. Given that PD is a small molecule that can depolarize the mitochondrial membrane potential and release apoptosis-inducing factor (AIF) in isolated mitochondria, we hypothesized that the apoptogenic effect of PD in human erythrocytes devoid of mitochondria would be minimal. This study therefore tried to evaluate the in vitro effect of PD on hemolysis and apoptosis in human erythrocytes. Apoptosis in human red blood cells (RBCs), also known as eryptosis or erythroptosis, after PD treatment was determined by flow cytometry and confocal microscopy for the phosphatidyl-serine externalization and other apoptosis feature events. False to our prediction, PD caused hemolysis and eryptosis/erythroptosis in human RBCs. Mechanistically, elevation in the cytosolic Ca²⁺ ion level seems to be a key but not the only mediator in the PD-mediated eryptosis/erythroptosis because depletion of the external Ca²⁺ could not eliminate the PD effect. Also, PD was able to permeabilize the membrane of RBC ghosts in a way similar to digitonin. Taken together, we report here for the first time the toxicity of PD in human RBCs as well as its underlying mechanism for the hemolysis and eryptosis/erythroptosis.

Optical tweezers are a well-established tool for manipulating small objects. However, their integration with microfluidic devices often requires an objective lens. More importantly, trapping of non-transparent or optically sensitive targets is particularly challenging for optical tweezers. Here, for the first time, we present a photon-free trapping technique based on electro-thermally induced forces. We demonstrate that thermal-gradient-induced thermophoresis and thermal convection can lead to trapping of polystyrene spheres and live cells. While the subject of thermophoresis, particularly in the micro- and nano-scale, still remains to be fully explored, our experimental results have provided a reasonable explanation for the trapping effect. The so-called thermal tweezers, which can be readily fabricated by femtosecond laser writing, operate with low input power density and are highly versatile in terms of device configuration, thus rendering high potential for integration with microfluidic devices as well as lab-on-a-chip systems.

BackgroundMore than a decade after the outbreak of human coronaviruses (HCoVs) SARS in Guangdong province and Hong Kong SAR of China in 2002, there is still no reoccurrence, but the evolution and recombination of the coronaviruses in this region are still unknown. Therefore, surveillance on the prevalence and the virus variation of HCoVs circulation in this region is conducted.MethodsA total of 3298 nasopharyngeal swabs samples were collected from cross-border children (<6 years, crossing border between Southern China and Hong Kong SAR) showing symptoms of respiratory tract infection, such as fever (body temperature > 37.5 °C), from 2014 May to 2015 Dec. Viral nucleic acids were analyzed and sequenced to study the prevalence and genetic diversity of the four human coronaviruses. The statistical significance of the data was evaluated with Fisher chi-square test.Results78 (2.37%; 95%CI 1.8-2.8%) out of 3298 nasopharyngeal swabs specimens were found to be positive for OC43 (36;1.09%), HKU1 (34; 1.03%), NL63 (6; 0.18%) and 229E (2;0.01%). None of SARS or MERS was detected. The HCoVs predominant circulating season was in transition of winter to spring, especially January and February and NL63 detected only in summer and fall. Complex population with an abundant genetic diversity of coronaviruses was circulating and they shared homology with the published strains (99-100%). Besides, phylogenetic evolutionary analysis indicated that OC43 coronaviruses were clustered into three clades (B,D,E), HKU1 clustered into two clades(A,B) and NL63 clustered into two clades(A,B). Moreover, several novel mutations including nucleotides substitution and the insertion of spike of the glycoprotein on the viral surface were discovered.ConclusionsThe detection rate and epidemic trend of coronaviruses were stable and no obvious fluctuations were found. The detected coronaviruses shared a conserved gene sequences in S and RdRp. However, mutants of the epidemic strains were detected, suggesting continuous monitoring of the human coronaviruses is in need among cross-border children, who are more likely to get infected and transmit the viruses across the border easily, in addition to the general public.