Gene Delivery Efficacy of Polyethyleneimine-Introduced Chitosan Shell/Poly(methyl Methacrylate) Core Nanoparticles for Rat Mesenchymal Stem Cells

This work investigated polyethyleneimine (PEI)-introduced chitosan (CS) (CS/PEI) nanoparticles as nonviral carrier of plasmid DNA for rat mesenchymal stem cells (MSCs). The CS/PEI nanoparticles were prepared by the emulsifier-free emulsion polymerization of methyl methacrylate monomer induced by a small amount of t-butyl hydroperxide in the presence of different concentrations of PEI mixed with CS. The resulting nanoparticles were characterized by their surface properties and buffering capacity. In vitro gene transfection was also evaluated. The introduction of PEI affected the surface charge, dispersing stability and buffering capacity of the nanoparticles. The CS/PEI nanoparticles formed a complex upon mixing with a plasmid DNA of luciferase. The complex enhanced the level of gene transfection and prolonged the time period of expression for MSCs, compared with those of plasmid DNA–original CS and PEI nanoparticles. Cytotoxicity of CS/PEI complexes with plasmid DNA was significantly low, depending on the amount of PEI introduced. It is concluded that the CS/PEI nanoparticle was a promising carrier for gene delivery of MSCs

Preparation of Folate-Conjugated Pluronic F127/Chitosan Core-Shell Nanoparticles Encapsulating Doxorubicin for Breast Cancer Treatment

A targeting drug delivery system using folate-conjugated pluronic F127/chitosan core-shell nanoparticles was developed to deliver doxorubicin (DOX) to the target cancer cells. First, DOX was encapsulated in pluronic F127 micelle cores in the presence of sodium dodecyl sulfate (SDS) by a self-assembly method. To form a shell, a layer of either chitosan or folate-conjugated chitosan was deposited onto the pluronic micelles. The encapsulation efficiency was approximately 58.1±4.7%. The average size of the core-shell nanoparticles was 37.4±2.0 nm, while the zeta potential was 12.9±2.3 mV, indicating the presence of a shell layer and more stable particles. In an in vitro DOX release study, an initial burst release, followed by a sustained release, was observed within 24 hours. In addition, the core-shell nanoparticles showed greater cytotoxicity towards MCF-7 cells than free DOX, suggesting a better therapeutic efficacy in treating cancer

Streptococcus pneumoniae Causing Invasive Diseases in Children and Adults in Central Thailand, 2012–2016

Longitudinal data regarding the serotype distribution and antimicrobial susceptibility of S. pneumoniae-causing invasive pneumococcal disease (IPD) in developing countries are limited. Our aim was to monitor the antimicrobial susceptibility, serotype distribution, and serotype coverage rates of the pneumococcal conjugate vaccines (PCVs) and emerging non-vaccine serotypes (NVT) between 2012 and 2016 in central Thailand. Pneumococcal isolates from sterile specimens of patients, collected within a long-standing collaborative hospital network in central Thailand between 2012 and 2016, were studied. The pneumococcal serotypes included in the 15-valent PCV were identified by the quellung reaction, while the non-PCV15 serotypes were identified by multiplex PCR. Antimicrobial susceptibilities were determined by the microbroth dilution or disk diffusion method. Of the 276 pneumococcal isolates, 129 (46.7%) were from children aged ≤5 years. Only 9.0% of patients with available data received the PCV prior to the onset of the IPD. The most common vaccine serotypes were 6B (17.4%), 19A (13.0%), and 14 (11.2%), respectively. Non-PCV15 serotypes were detected in 27.9%; the most common serotypes were 15B/C (5.1%), 15A/F (4.0%), and 23A (3.6%), respectively. The serotype coverage rates of PCV10 in children aged ≤5 years was 55.8%, and 53.3% across all ages. PCV13 provided similar coverage rates to that of PCV15, 71.3% in children aged ≤5 years, and 72.1% across all ages. High susceptibilities to cefotaxime (94.6%), ofloxacin (98.2%), linezolid (99.6%), and vancomycin (100.0%) were observed, while the susceptibility to erythromycin (50.0%), TMP-SMZ (41.3%), and tetracycline (27.2%) were low. The susceptibilities to penicillin, meropenem, and clindamycin were 85.9%, 85.9%, and 84.8%, respectively. Serotype 19A was associated with a lower susceptibility than the non-19A isolates for penicillin (75.0% vs. 87.5%, p = 0.045), meropenem (52.8% vs. 90.8%, p < 0.001), erythromycin (33.3% vs. 53.8%, p = 0.022), and TMP-SMZ (16.7% vs. 45.0%, p = 0.001). Although the majority of the pneumococcal serotypes causing IPD in central Thailand were covered by the currently available PCVs, 25% of IPD were caused by NVT. Several emerging NVT identified were 15B/C, 15A/F, and 23A. The high rates of resistance to penicillin, meropenem, erythromycin, TMP-SMZ, and tetracycline observed is a major concern. Serotype 19A was associated with lower antimicrobial susceptibilities in comparison to the non-19A serotypes

Acceleration of gene transfection efficiency in neuroblastoma cells through polyethyleneimine/poly(methyl methacrylate) core-shell magnetic nanoparticles

Tewin Tencomnao,1,* Kewalin Klangthong,2,* Nuttaporn Pimpha,3 Saowaluk Chaleawlert-umpon,3 Somsak Saesoo,3 Noppawan Woramongkolchai,3 Nattika Saengkrit,31Center for Excellence in Omics-Nano Medical Technology Development Project, 2Graduate Program in Clinical Biochemistry and Molecular Medicine, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 3National Nanotechnology Center, National Science and Technology Development Agency, Pathumthani, Thailand*Both authors contributed equally to this workBackground: The purpose of this study was to demonstrate the potential of magnetic poly(methyl methacrylate) (PMMA) core/polyethyleneimine (PEI) shell (mag-PEI) nanoparticles, which possess high saturation magnetization for gene delivery. By using mag-PEI nanoparticles as a gene carrier, this study focused on evaluation of transfection efficiency under magnetic induction. The potential role of this newly synthesized nanosphere for therapeutic delivery of the tryptophan hydroxylase-2 (TPH-2) gene was also investigated in cultured neuronal LAN-5 cells.Methods: The mag-PEI nanoparticles were prepared by one-step emulsifier-free emulsion polymerization, generating highly loaded and monodispersed magnetic polymeric nanoparticles bearing an amine group. The physicochemical properties of the mag-PEI nanoparticles and DNA-bound mag-PEI nanoparticles were investigated using the gel retardation assay, atomic force microscopy, and zeta size measurements. The gene transfection efficiencies of mag-PEI nanoparticles were evaluated at different transfection times. Confocal laser scanning microscopy confirmed intracellular uptake of the magnetoplex. The optimal conditions for transfection of TPH-2 were selected for therapeutic gene transfection. We isolated the TPH-2 gene from the total RNA of the human medulla oblongata and cloned it into an expression vector. The plasmid containing TPH-2 was subsequently bound onto the surfaces of the mag-PEI nanoparticles via electrostatic interaction. Finally, the mag-PEI nanoparticle magnetoplex was delivered into LAN-5 cells. Reverse-transcriptase polymerase chain reaction was performed to evaluate TPH-2 expression in a quantitative manner.Results: The study demonstrated the role of newly synthesized high-magnetization mag-PEI nanoparticles for gene transfection in vitro. The expression signals of a model gene, luciferase, and a therapeutic gene, TPH-2, were enhanced under magnetic-assisted transfection. An in vitro study in neuronal cells confirmed that using mag-PEI nanoparticles as a DNA carrier for gene delivery provided high transfection efficiency with low cytotoxicity.Conclusion: The mag-PEI nanoparticle is a promising alternative gene transfection reagent due to its ease of use, effectiveness, and low cellular toxicity. The mag-PEI nanoparticle is not only practical for gene transfection in cultured neuronal cells but may also be suitable for transfection in other cells as well.Keywords: magnetic nanoparticle, non-viral vector, gene delivery, tryptophan hydroxylase-2, LAN-5, neuronal cell

Inhibiting Metastasis and Improving Chemosensitivity via Chitosan-Coated Selenium Nanoparticles for Brain Cancer Therapy

Selenium nanoparticles (SeNPs) were synthesized to overcome the limitations of selenium, such as its narrow safe range and low water solubility. SeNPs reduce the toxicity and improve the bioavailability of selenium. Chitosan-coated SeNPs (Cs-SeNPs) were developed to further stabilize SeNPs and to test their effects against glioma cells. The effects of Cs-SeNPs on cell growth were evaluated in monolayer and 3D-tumor spheroid culture. Cell migration and cell invasion were determined using a trans-well assay. The effect of Cs-SeNPs on chemotherapeutic drug 5-fluorouracil (5-FU) sensitivity of glioma cells was determined in tumor spheroids. An in vitro blood–brain barrier (BBB) model was established to test the permeability of Cs-SeNPs. SeNPs and Cs-SeNPs can reduce the cell viability of glioma cells in a dose-dependent manner. Compared with SeNPs, Cs-SeNPs more strongly inhibited 3D-tumor spheroid growth. Cs-SeNPs exhibited stronger effects in inhibiting cell migration and cell invasion than SeNPs. Improved 5-FU sensitivity was observed in Cs-SeNP-treated cells. Cellular uptake in glioma cells indicated a higher uptake rate of coumarin-6-labeled Cs-SeNPs than SeNPs. The capability of coumarin-6 associated Cs-SeNPs to pass through the BBB was confirmed. Taken together, Cs-SeNPs provide exceptional performance and are a potential alternative therapeutic strategy for future glioma treatment

Efficacy of Agricultural and Food Wastes as the Growing Media for Sunflower and Water Spinach Microgreens Production

The growing media is one of the significant elements affecting microgreens’ yield and quality. This experiment investigated the possibility of waste utilization instead of employing peat moss to produce sunflower and water-spinach microgreens. The treatments consisted of peat moss (Control), coconut coir dust (CD), leaf compost (LC), food waste compost (FC), CD:LC = 1:1 v/v, CD:FC = 1:1 v/v, LC:FC = 1:1 v/v, and CD:LC:FC = 1:1:1 v/v. The results proved that the highest yield of sunflower microgreens was observed when cultivated in 1:1 v/v of CD:LC media (10,114.81 g m−2), whereas the highest yield of water spinach microgreens was recorded under the treatments of CD, Control, 1:1 v/v of CD:LC, and 1:1:1 v/v of CD:LC:FC media (10,966.67–9800.00 g m−2). The biochemical composition of the microgreens varied within the types. Our findings demonstrated that a tendency of an increase in chlorophyll and carotenoid contents depended on the growth of both microgreens under different growing media. All growing media did not cause excess nitrate residue or pathogenic contamination in both microgreens, namely Clostridium perfringens, Salmonella spp., and Staphylococcus aureus. In contrast, almost all the growing media resulted in a higher population of Bacillus cereus contamination in both microgreens than the standard set limit, except for sunflower microgreens grown in the control and CD growing media. These findings could suggest that the 1:1 v/v of CD:LC and CD media were the most effective growing media for sunflower and water spinach microgreens, respectively, but further cleaning before consumption is recommended to avoid or reduce the foodborne incidences caused by B. cereus in microgreens