Inflammation contributes to neonatal brain injury. Pro-inflammatory cytokines represent key inflammatory meditators in neonatal hypoxic-ischemic (HI) brain injury. The high mobility group box-1 (HMGB1) protein is a nuclear protein with pro-inflammatory cytokine properties when it is translocated from the nucleus and released extracellularly after stroke in adult rodents. We have previously shown that HMGB1 is translocated from the nucleus to cytosolic compartment after ischemic brain injury in fetal sheep. In the current study, we utilized the Rice-Vannucci model to investigate the time course of HMGB1 translocation and release after HI injury in neonatal rats. HMGB1 was located in cellular nuclei of brains from sham control rats. Nuclear to cytoplasmic translocation of HMGB1 was detected in the ipsilateral-HI hemisphere as early as zero h after HI, and released extracellularly as early as 6 h after HI. Immunohistochemical double staining detected HMGB1 translocation mainly in neurons along with release from apoptotic cells after HI. Serum HMGB1 increased at 3 h and decreased by 24 h after HI. In addition, rat brains exposed to hypoxic injury alone also exhibited time dependent HMGB1 translocation at 3, 12 and 48 h after hypoxia. Consequently, HMGB1 responds similarly after HI injury in the brains of neonatal and adult subjects. We conclude that HMGB1 is sensitive early indicator of neonatal HI and hypoxic brain injury.

Developing sensors in the domains of food safety, soil analysis, water quality monitoring and healthcare often requires distinguishing between different species of bacteria. The most rapid, sensitive and specific method to identify bacteria is by analysing their DNA sequence, which comprises of disinfection and lysis of bacterial cells, amplification of the isolated DNA and detection of the amplified sequence. Seamless integration of these assays on a paper substrate remains a big challenge in paperfluidic nucleic acid analyis.Combining lysis and isothermal amplification in a single reaction step is difficult because the porosity of paper and the presence of cell debris following lysis reduces the efficiency of DNA amplification. On the other hand, extracting and purifying the DNA after lysis to improve the amplification efficiency involves addition of chemical reagents, one or more wash steps and manual intervention. This problem is even more complex for mycobacteria as its thick cell wall structure impedes lysis and the high GC-content of the genome requires careful optimization of enzymatic denaturation during isothermal amplification. Here we successfully combine thermal lysis and loop-mediated isothermal amplification (LAMP) into a single reaction step on paper without the need for any intermediate intervention. We demonstrate our integrated assay by amplifying DNA from 100 CFU/mL of Escherichia coli (MG1655) and Mycobacterium smegmatis (mc 2 155) cells in 30 min on a paper substrate. We also confirm that E. coli and M. smegmatis can be completely disinfected on paper by heating at 60 o C for 5 min and 15 min respectively, making this assay safe and suitable for incorporation into diverse paperfluidic sensors for field use.

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Developing sensors in the domains of food safety, soil analysis, water quality monitoring and healthcare often requires distinguishing between different species of bacteria. The most rapid, sensitive and specific method to identify bacteria is by analysing their DNA sequence, which comprises of disinfection and lysis of bacterial cells, amplification of the isolated DNA and detection of the amplified sequence. Seamless integration of these assays on a paper substrate remains a big challenge in paperfluidic nucleic acid analyis.Combining lysis and isothermal amplification in a single reaction step is difficult because the porosity of paper and the presence of cell debris following lysis reduces the efficiency of DNA amplification. On the other hand, extracting and purifying the DNA after lysis to improve the amplification efficiency involves addition of chemical reagents, one or more wash steps and manual intervention. This problem is even more complex for mycobacteria as its thick cell wall structure impedes lysis and the high GC-content of the genome requires careful optimization of enzymatic denaturation during isothermal amplification. Here we successfully combine thermal lysis and loop-mediated isothermal amplification (LAMP) into a single reaction step on paper without the need for any intermediate intervention. We demonstrate our integrated assay by amplifying DNA from 100 CFU/mL of Escherichia coli (MG1655) and Mycobacterium smegmatis (mc 2 155) cells in 30 min on a paper substrate. We also confirm that E. coli and M. smegmatis can be completely disinfected on paper by heating at 60 o C for 5 min and 15 min respectively, making this assay safe and suitable for incorporation into diverse paperfluidic sensors for field use.

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Gold nanoparticles absorb light energy and convert it to thermal energy that transfers to the surrounding environment, making them potentially useful for the hyperthermic treatments well known as photothermal therapy (PTT). Further, it is well documented that noble metal nanoparticles are capable of significantly enhancing the Raman scattering of molecules attached to their surfaces, a technique which is termed surface-enhanced Raman scattering (SERS). SERS combined with PTT has the ability to locate nanoparticles at depth and trigger heat production, providing an effective methodology to both seek and destroy diseased tissues. While PTT and SERS are often used in tandem and there are several ways of individually measuring SERS and thermal output, there is currently no method available that pre-screens both properties prior to in vitro or in vivo application. In this work, we have designed a 3D printed platform capable of coupling a commercially available Raman probe to a sample cuvette for SERS and heat output to be monitored simultaneously. We have compared the performance of morphologically complex gold nanoparticles, nanostars (AuNSs) and nanoplates (AuNPLs), which are both well utilized in SERS and photothermal experiments; and measured the SERS activity originating from common Raman reporter analytes 4-mercaptobenzoic acid (MBA) and 1,4-benzenedithiol (BDT). We were able to show that the system effectively measures the thermal output and SERS activity of the particles and can evaluate the effect that multiple irradiation cycles have on the SERS signal.