Tumor-homing photosensitizer-conjugated glycol chitosan nanoparticles for synchronous photodynamic imaging and therapy based on cellular on/off system

Herein, we developed the photosensitizer, protoporphyrin IX (PpIX), conjugated glycol chitosan (GC) nanoparticles (PpIX-GC-NPs) as tumor-homing drug carriers with cellular on/off system for photodynamic imaging and therapy, simultaneously. In order to prepare PpIX-GC-NPs, hydrophobic PpIXs were chemically conjugated to GC polymer and the amphiphilic PpIX-GC conjugates formed a stable nanoparticle structure in aqueous condition, wherein conjugated PpIX molecules formed hydrophobic inner-cores and they were covered by the hydrophilic GC polymer shell. Based on the nanoparticle structure, PpIX-GC-NPs showed the self-quenching effect that is 'off' state with no fluorescence signal and phototoxicity with light exposure. It is due to the compact crystallized PpIX molecules in the nanoparticles as confirmed by dynamic light scattering and X-ray diffraction methods. However, after cellular uptake, compact nanoparticle structure gradually decreased to generate strong fluorescence signal and singlet oxygen generation when irradiated. Importantly, PpIX-GC-NPs-treated mice presented prolonged blood circulation, enhanced tumor targeting ability, and improved in vivo therapeutic efficiency in tumor-bearing mice, compared to that of free PpIX-treated mice. These results proved that this tumor-homing cellular 'on/off' nanoparticle system of PpIX-GC-NPs has a great potential for synchronous photodynamic imaging and therapy in cancer treatment.     

Gold nanoparticle-incorporated human red blood cells (RBCs) for X-ray dynamic imaging

Time-resolved dynamic imaging of bio-fluids can provide valuable information for clinical diagnosis and treatment of circulatory disorders. Quantitative information on non-transparent blood flows can be directly obtained by particle-tracing dynamic X-ray imaging, which needs better spatial resolution and enhanced image contrast compared to static imaging. For that use, tracer particles tagging along the flow streams are critically required. In this study, taking the advantage of high X-ray absorption, gold nanoparticles (AuNPs) are incorporated into human red blood cells (RBC) to produce contrast-enhanced tracers designed for dynamic X-ray imaging of blood flows. RBCs are advantageous tracers for blood flow measurements since they are natural and primary components of blood. The loading efficiency of AuNPs into RBCs is investigated in terms of the surface properties of the AuNPs. The AuNP-incorporated RBC provides a potential in the dynamic X-ray imaging of blood flows which can be used for clinical applications.     

The effect of internalizing human single chain antibody fragment on liposome targeting to epithelioid and sarcomatoid mesothelioma

Immunoliposomes (ILs) anchored with internalizing human antibodies capable of targeting all subtypes of mesothelioma can be useful for targeted imaging and therapy of this malignant disease. The objectives of this study were to evaluate both the in vitro and in vivo tumor targeted internalization of novel internalizing human single chain antibody (scFv) anchored ILs on both epithelioid (M28) and sarcomatoid (VAMT-1) subtypes of human mesothelioma. ILs were prepared by post-insertion of mesothelioma-targeting human scFv (M1) onto preformed liposomes and radiolabeled with (111)In ((111)In-IL-M1), along with control non-targeted liposomes ((111)In-CL). Incubation of (111)In-IL-M1 with M28, VAMT-1, and a control non-tumorigenic cell line (BPH-1) at 37 °C for 24 h revealed efficient binding and rapid internalization of ILs into both subtypes of tumor cells but not into the BPH-1 cells; internalization accounted for approximately 81-94% of total cell accumulation in mesothelioma cells compared to 37-55% in control cells. In tumor-bearing mice intravenous (i.v.) injection of (111)In-IL-M1 led to remarkable tumor accumulation: 4% and 4.7% injected dose per gram (% ID/g) for M28 and VAMT-1 tumors, respectively, 48 h after injection. Furthermore, tumor uptake of (111)In-IL-M1 in live xenograft animal models was verified by single photon emission computed tomography (SPECT/CT). In contrast, i.v. injection of (111)In-CL in tumor-bearing mice revealed very low uptake in both subtypes of mesothelioma, 48 h after injection. In conclusion, M1 scFv-anchored ILs showed selective tumor targeting and rapid internalization into both epithelioid and sarcomatoid subtypes of human mesothelioma, demonstrating its potential as a promising vector for enhanced tumor drug targeting.     

Expression and characterization of a second L-amino acid deaminase isolated from Proteus mirabilis in Escherichia coli

L-amino acid deaminases catalyze the deamination of natural L-amino acids. Two types of L-amino acid deaminase have been identified in Proteus species. One exhibits high levels of activity toward a wide range of aliphatic and aromatic L-amino acids, typically L-phenylalanine, whereas the other acts on a relatively narrow range of basic L-amino acids, typically L-histidine. In this study, we cloned, expressed, and characterized a second amino acid deaminase, termed Pm1, from P. mirabilis KCTC 2566. Homology alignment of the deduced amino acid sequence of Pm1 demonstrated that the greatest similarity (96%) was with the L-amino acid deaminase (LAD) of P. vulgaris, and that homology with Pma was relatively low (72%). Also, similar to LAD, Pm1 was most active on L-histidine, indicating that Pm1 belongs to the second type of amino acid deaminase. In agreement with this conclusion, the V(max) and K(m) values of Pm1 were 119.7 (μg phenylpyruvic acid/mg/min) and 31.55 mM phenylalanine, respectively, values lower than those of Pma. The Pml deaminase will be very useful industrially in the preparation of commercially valuable materials including urocanic acid and α-oxoglutarate.     

Inhibitory effect of Psidium guajava water extract in the development of 2,4-dinitrochlorobenzene-induced atopic dermatitis in NC/Nga mice

Atopic dermatitis (AD) is a chronic, relapsing, and inflammatory skin disease associated with eczematous symptoms and IgE hyperproduction. Psidium guajava is an important food crop and medicinal plant with anti-oxidant, anti-inflammatory, and anti-allergic activities, supporting its traditional uses. Our previous studies have shown that P. guajava extract inhibits Th2 chemokine expression by suppressing the activation of NF-κB and STAT1 co-stimulated with TNF-α and INF-γ. In this study, we investigated the inhibitory effect of P. guajava water extract (PGW) on 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin lesions in NC/Nga mice. Treatment of cream containing PGW onto DNCB-induced AD-like skin lesions in NC/Nga mice ameliorated lesion intensity scores, levels of IgE, thymus and activation-regulated chemokine (TARC), TNF-α, and IL-4 in serum and ears. In contrast, PGW increased level of the immunosuppressive cytokine IL-10. Histological analyses demonstrated decreased thickening of the epidermis/dermis as well as dermal infiltration by inflammatory cells. These results suggest that cream containing PGW may be a potential therapeutic modality for AD and adjunctive agent to control pruritus in AD.     

A single amino acid change in HC-Pro of soybean mosaic virus alters symptom expression in a soybean cultivar carrying <Emphasis Type="Italic">Rsv1</Emphasis> and <Emphasis Type="Italic">Rsv3</Emphasis>

It is generally believed that infidelity of RNA virus replication combined with R-gene-driven selection is one of the major evolutionary forces in overcoming host resistance. In this study, we utilized an avirulent soybean mosaic virus (SMV) mutant to examine the possibility of emergence of mutant viruses capable of overcoming R-gene-mediated resistance during serial passages. Interestingly, we found that the emerged progeny virus induced severe rugosity and local necrotic lesions in Jinpumkong-2 (Rsv1 + Rsv3) plants, while SMV-G7H provoked a lethal systemic hypersensitive response. Genome sequence analysis of the emerged progeny virus revealed that the mutation in CI that had caused SMV-G7H to lose its virulence was restored to the original sequence, and a single amino acid was newly introduced into HC-Pro, which means that the symptom alteration was due to this single amino acid mutation in HC-Pro. Our results suggest that SMV HC-Pro functions as a symptom determinant in the SMV-soybean pathosystem.     

Proteomic analysis of phosphotyrosyl proteins in human embryonic stem cell-derived neural stem cells

Phosphorylation can reveal essential cell functions, such as cell differentiation, signal transduction, metabolic maintenance and cell division. The aim of this study was to investigate phosphorylated protein expression changes during neuronal lineage differentiation from hESCs. To measure the phosphorylated protein expression change during neuronal differentiation, we performed a comparative phosphoproteome analysis using 2-DE after MALDI-TOF MS and an MS/MS protein identification method, making a comparison between neural lineage differentiating cells and normal embryoid bodies (EBs) differentiated from human embryonic stem cells (hESCs) and profiling constituent phosphorylated proteins. Of 36 differentially expressed protein spots, 12 spots were shown to be up-regulated in differentiating neural cells. Specifically, the 7 up-regulated proteins of the 12 have potential roles in neuronal differentiation or neuronal damage recovery, including ACTB, heterogeneous nuclear ribonucleoprotein A2B1 (hnRNP A2B1), heterogeneous nuclear ribonucleoprotein L (hnRNP L), SET, chaperonin-containing TCP-1, vimentin and voltage-dependent anion channel protein 1 (VDAC1). These proteins are discussed further below.     

Granulocyte colony stimulating factor attenuates hyperoxia-induced lung injury by down-modulating inflammatory responses in neonatal rats

Purpose

Granulocyte colony stimulating factor (G-CSF) has been known to increase neutrophil production and have anti-inflammatory properties, but the effect of G-CSF on pulmonary system is in controversy. We investigated whether G-CSF treatment could attenuate hyperoxia-induced lung injury, and whether this protective effect is mediated by the down-modulation of inflammatory responses in a neonatal rat model.

Materials and Methods

Newborn Sprague-Dawley rats (Orient Co., Seoul, Korea) were subjected to 14 days of hyperoxia (90% oxygen) beginning within 10 h after birth. G-CSF (20 µg/kg) was administered intraperitoneally on the fourth, fifth, and sixth postnatal days.

Results

This treatment significantly improved hyperoxia-induced reduction in body weight gain and lung pathology such as increased mean linear intercept, mean alveolar volume, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling positive cells. Hyperoxia-induced activation of nicotinamide adenine dinucleotide phosphate oxidase, which is responsible for superoxide anion production, as evidenced by upregulation and membrane translocation of p67^phox was significantly attenuated after G-CSF treatment, as were inflammatory responses such as increased myeloperoxidase activity and mRNA expression of transforming growth factor-β. However, the attenuation of other proinflammatory cytokines such as tumor necrosis factor-α and interleukin-6 was not significant.

Conclusion

In sum, G-CSF treatment significantly attenuated hyperoxia-induced lung injury by down-modulating the inflammatory responses in neonatal rats.     

Transient increase of higher-order aberrations after lateral rectus recession in children

The changes of higher-order aberrations (HOAs) after bilateral lateral rectus muscle recession were evaluated. Forty eyes of 20 children were enrolled and their wavefront information was assessed until postoperative 3 months. Even though the root mean square (RMS) of total aberration was not changed, the RMS of HOA was transiently increased at postoperative 1 week and returned to baseline level after 1 month. Among individual Zernike coefficient, secondary astigmatism, quadrafoil, secondary coma, secondary trefoil, and pentafoil showed similar tendency with the RMS of HOA. However, coma, trefoil, and spherical aberration were not changed. Regarding recession amount, it did not correlate with any Zernike coefficient. In summary, our data imply that the HOAs are transiently increased after lateral rectus recession surgery. These results are in collusion with previous reports that strabismus surgery induced transient corneal astigmatism.