Chitosan-based particles are desirable materials for drug delivery because of their muco-adhesiveness in tissues, biocompatibility, low toxicity and effectiveness in antigen transport. It is still a challenge to prepare chitosan-based particles with high stability and by an effective method. Here we developed chitosan-based nanoparticles for the delivery of toll-like receptor 9 ligands, cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODNs), which can induce the change from Th-2 type to Th-1 type immune response. Because of the low tolerance to DNase and less uptake into the cells of the free CpG ODNs, the development of positively charged carriers is necessary for the effective delivery of CpG ODNs into immune cells. Chitosan nanoparticles were prepared by ionic gelation, and the nanoparticles size and surface charge were measured by dynamic light spectroscopy and zeta potential analyzer, respectively. The synthesized chitosan nanoparticles showed two dispersion peaks, at 196 ± 29 nm and 1.33 ± 0.36 lm, with a zeta potential of þ3.3 ± 0.4 mV. The toxicity of the chitosan nanoparticles to murine RAW264 macrophages was measured by formazan dye assay utilizing the water-soluble tetrazolium salt WST-8. Our chitosan nanoparticles exhibited no cytotoxicity to RAW264 cells. Finally, we evaluated the immunostimulatory activity of CpG ODNs loaded on chitosan nanoparticles using human peripheral blood mononuclear cells. CpG ODNs significantly enhanced the secretion level of interleukin-6 and interferon-c by cells compared to the free CpG ODNs. These results indicated that chitosan nanoparticles could be a good candidate for the delivery of CpG ODNs.

Background: Liver is sensitive against hypoxia and hypoxia will stabilize HIF-1α. At the same time, hypoxia will produce reactive oxygen species (ROS) which can be scavenged by Cygb. The purpose of our study is to know, if normobaric hypoxia can induce Cygb expression and its association with HIF-1α stabilization.Methods: This is an experimental study using 28 male Sprague-Dawley rats, 150-200 g weight. Rats are divided into 7 groups: control group and treatment groups that are kept in hypoxic chamber (10% O2: 90% N2) for 6 hours, 1, 2, 3, 7 and 14 days. All rats are euthanized after treatment and liver tissue are isolated, homogenized and analyzed for oxidative stress parameter, expression of Cygb and HIF-1α.Results: Expression of Cygb mRNA and protein was increased on the day-1 after treatment and reach the maximum expression on the day-2 of hypoxia treatment. But, the expression was decreased after the day-3 and slightly increased at the day-14 of hypoxia. The correlation between expression of Cygb and oxidative stress parameter was strongly correlated. Cygb mRNA, as well as protein, showed the same kinetic as the HIF-1, all increased about day-1 and day-2.Conclusion: Systemic chronic hypoxia and/or oxidative stress up-regulated HIF-1α mRNA which is correlated with the Cygb mRNA and protein expression. Cygb mRNA as well as Cygb protein showed the same kinetic as the HIF-1, all increased about day-1 and day-2 suggesting that Cygb could be under the regulation of HIF-1, but could be controlled also by other factor than HIF-1.

It is known that Spirulina has so many healing functions to overcome oxidative stresses correlated to the aging process. One of them is Spirulina platensis (SP), a microalga that is abundant in the Java Indonesian seas and has been widely cultivated. SP is able to improve mitochondrial function and is widely used as a food supplement according to its protein and content of omega-6, gamma linolenic acid, carotenoid, and various vitamins. This research was conducted to evaluate the effect of SP on cell viability and used a mesenchymal stem cell (MSC) culture as a model treated with hydrogen peroxide together with SP. SP was obtained from the Java Sea and extracted with ethanol. Its content was determined with the thin layer chromatography method, and the known content was docked with the HIF-1 protein. This extract was tested to overcome oxidative stress in umbilical cord-derived mesenchymal stem cells (UC-MSCs) treated with 100 and 300 µM hydrogen peroxide. Cell viability was assessed by a dye exclusion method with trypan blue. The specific surface markers (CD73, CD90, and CD105) were measured with flow cytometry to evaluate MSC stemness. The content of SP, phycocyanobilin and canthaxanthin, were considered candidates affecting HIF-1 protein regulation. The SP ethanol extract (125 ng/ml) maintained the viability and stemness of UC-MSCs during oxidative stress exposure with hydrogen peroxide. The phycocyanobilin and canthaxanthin of SP were considered candidate substances that could affect HIF-1 signaling, and the ability to overcome oxidative stress should be observed further.

BACKGROUND High carbon dioxide (CO2) level from indoor environments, such as classrooms and offices, might cause sick building syndrome. Excessive indoor CO2 level increases CO2 level in the blood, and over-accumulation of CO2 induces an adaptive response that requires modulation of gene expression. This study aimed to investigate the adaptive transcriptional response toward hypoxia and oxidative stress in human peripheral blood mononuclear cells (PBMCs) exposed to elevated CO2 level in vitro and its association with cell viability. METHODS PBMCs were treated in 5% CO2 and 15% CO2, representatives a high CO₂ level condition for 24 and 48 hours. Extracellular pH (pHe) was measured with a pH meter. The levels of reactive oxygen species were determined by measuring superoxide and hydrogen peroxide with dihydroethidium and dichlorofluorescin-diacetate assay. The mRNA expression levels of hypoxia-inducible factor (HIF)-1α, HIF-2α, nuclear factor (NF)-κB, and manganese superoxide dismutase (MnSOD) were analyzed using a real-time reverse transcriptase-polymerase chain reaction (qRT-PCR). Cell survival was determined by measuring cell viability. RESULTS pHe increased in 24 hours after 15% CO₂ treatment, and then decreased in 48 hours. Superoxide and hydrogen peroxide levels increased after the 24- and 48-hour of high CO₂ level condition. The expression levels of NF-κB, MnSOD, HIF-1α, and HIF-2α decreased in 24 hours and increased in 48 hours. The increased antioxidant mRNA expression in 48 hours showed that the PBMCs were responsive under high CO2 conditions. Elevated CO2 suppressed cell viability significantly in 48 hours. CONCLUSIONS After 48 hours of high CO₂ level condition, PBMCs showed an upregulation in genes related to hypoxia and oxidative stress to overcome the effects of CO2 elevation.

No abstract