ACP-ESM2: The prediction of anticancer peptides based on pre-trained classifier.

Anticancer peptides (ACPs) are a type of protein molecule that has anti-cancer activity and can inhibit cancer cell growth and survival. Traditional classification approaches for ACPs are expensive and time-consuming. This paper proposes a pre-trained classifier model, ESM2-GRU, for ACP prediction to make it easier to predict ACPs, gain a better understanding of the structural and functional differences of anti-cancer peptides, and optimize the design for the development of more effective anti-cancer treatment strategies. The model is made up of the ESM2 pre-trained model, a bidirectional GRU recurrent neural network, and a fully connected layer. ACP sequences are first fed into the ESM2 model, which then expands the dimensions before feeding the findings back into the bidirectional GRU recurrent neural network. Finally, the fully connected layer generates the ultimate output. Experimental validation demonstrates that the ESM2-GRU model greatly improves classification performance on the benchmark dataset ACP606, with AUC, ACC, and MCC values of 0.975, 0.852, and 0.738, respectively. This exceptional prediction potential helps to identify specific types of anti-cancer peptides, improving their targeting and selectivity and, therefore, furthering the development of tailored medicine and treatments.

Biphasic photobiomodulation of inflammation in mouse models of common wounds, infected wounds, and diabetic wounds.

Bidirectional photobiomodulation (PBM) therapy is an active research area. However, most studies have focused on its dependence on optical parameters rather than on its tissue-dependent effects. We constructed mouse models of wounds in three inflammatory states (normal, low, and high levels of inflammations) to assess the bidirectional regulatory effect of PBM on inflammation. Mice were divided into three groups to prepare common wounds, diabetic wounds, and bacteria-infected wounds. The same PBM protocol was used to regularly irradiate the wounds over a 14 d period. PBM promoted healing of all three kinds of wounds, but the inflammatory manifestations in each were significantly different. In common wounds, PBM slightly increased the aggregation of inflammatory cells and expression of IL-6 but had no effect on the inflammatory score. For wounds in a high level of inflammation caused by infection, PBM significantly increased TNF-α expression in the first 3 d of treatment but quickly eliminated inflammation after the acute phase. For the diabetic wounds in a low level of inflammation, PBM intervention significantly increased inflammation scores and prevented neutrophils from falling below baseline levels at the end of the 14 d observation period. Under fixed optical conditions, PBM has a bidirectional (pro- or anti-inflammatory) effect on inflammation, depending on the immune state of the target organism and the presence of inflammatory stimulants. Our results provide a basis for the formulation of clinical guidelines for PBM application.

Ultrashort-term responses of riparian vegetation restoration to adjacent cycles of ecological water conveyance scheduling in a hyperarid endorheic river basin.

The management of ecological water conveyance (EWC) can allow riparian vegetation communities to survive the threat of degradation in hyperarid inland areas and promote the health of groundwater-recharged riparian ecosystems. However, the ultrashort-term effects of periodic EWC scheduling on riparian vegetation remain unclear. This study explored the spatiotemporal differentiation in species structure (herbs, shrubs, and trees), diversity (measured by the Simpson, Shannon-Wiener, Pielou, and Margalef indices), stability (evaluated via Godron fitting distances and abundance-biomass comparison curves), and integrity (proxied by the vegetation-based index of biotic integrity) of vegetation communities in the downstream Heihe River Basin, China. Empirical orthogonal function, Pearson correlation, canonical correspondence analysis (CCA), and partial CCA methods were used to evaluate the effects of dominant habitat environmental factors from the hydrogeographic features, soil physicochemical properties, and anthropogenic impacts. The results showed that the riparian vegetation community diversity, stability, and integrity varied moderately to slightly with hierarchical distance from near wetlands (<200 m; containing mainly herbs) to far desert edges (>800 m; occupied by shrubs/subshrubs). The middle transition zone (200-800 m; occupied mostly by trees/subtrees) had the best diversity and integrity but relatively poor stability. The most significant influencing factors were EWC and soil moisture. The simple diversity, fair-level integrity, and disturbed but not irreversibly damaged stability of the vegetation community were generally improved by 14.82%, 20.33%, and 30.57%, respectively, in the pre-EWC period but worsened in the post-EWC period. The difference in spatially distributed EWC quantities caused more apparent vegetation restoration in high water-supplied subareas where certain biological community instability existed. Therefore, adequate EWC management can be considered a prerequisite for the maintenance of high richness and structural stability in local communities and requires a good balance between interregional vegetation abundance and enhanced environmental tolerance.

Optimization of photo-biomodulation therapy for wound healing of diabetic foot ulcers in vitro and in vivo.

Unclear optical parameters make photo-biomodulation (PBM) difficult to implement in diabetic foot ulcer (DFU) clinically. Here, 12 wavelengths (400-900 nm) were used to conduct PBM to heal DFU wounds in vitro and in vivo. PBM at 10 mW/cm2 and 0.5-4 J/cm2 with all 12 wavelengths promoted proliferation of diabetic wound cells. In a mimic DFU (mDFU) rat model, PBM (425, 630, 730, and 850 nm, and a combination light strategy) promoted mDFU healing. The positive cell proliferation, re-epithelialization, angiogenesis, collagen synthesis, and inflammation were possible mechanisms. The combination strategy had the best effect, which can be applied clinically.

Effects of the Tibetan medicine Byur dMar Nyer lNga Ril Bu on Alzheimer's disease in mice models.

ETHNOPHARMACOLOGICAL RELEVANCE: Byur dMar Nyer lNga Ril Bu (BdNlRB) is a classic Tibetan medicine prescription for treating " white vein disease". Alzheimer's disease (AD) is a chronic degenerative disease of the central nervous system, characterized by distinct "white vein disease". In the absence of effective drugs for AD, BdNlRB may be a possible treatment for AD. AIM OF THE STUDY: To verify the therapeutic effect and possible mechanism of the proved Tibetan medicine BdNlRB on Alzheimer's disease. MATERIALS AND METHODS: 60 APP/PS1 double transgenic AD mice (Mt) and 60 Aß1-40 protein-induced AD mice (Mi) were divided into 3 groups according to the dose of BdNlRB: BdNlRB-100, BdNlRB-200 and BdNlRB-400, with 100, 200 and 400 mg/kg*weight, respectively. The mice were administrated by gavage for 8 weeks. The cognitive ability of mice was detected by Morris Water Maze, the expression of Aß protein, p-tau and microglia was detected by immunofluorescent staining, the protein expression in the hippocampus was detected by proteomics, and the abundance of fecal intestinal flora was detected by 16S RNA. RESULTS: The learning ability and memory ability of Mi mice were significantly improved after BdNlRB administration. The learning ability of Mt mice was significantly improved, while the memory ability was not improved after BdNlRB administration. After the treatment with low and medium doses of BdNlRB, the expression of p-tau decreased significantly (the rate of decrease in BdNlRB-100 and BdNlRB-200 groups was 8.05% and 12.7%, respectively), and the number of microglia increased (39.3% and 31.6%, respectively). BdNlRB significantly affected the protein expression in the hippocampus of Mt mice. 382 proteins in different expression in all three groups mainly involved in amino acid synthesis, fatty acid degradation, glutamine metabolism, synaptic vesicular cycle and oxidative phosphorylation, PPAR signaling pathway and Fc gamma-mediated phagocytosis were activated. Meanwhile, the administration of BdNlRB can regulate the intestinal flora of Mt mice, which reduces the abundance of Muribaculum and uncultured bacteroidales bacterium, and improves the abundance of Ruminococcus-1 and Ruminiclostridium-9. CONCLUSION: The oral administration of BdNlRB significantly improved the cognitive ability of AD mice, and neuroinflammation and intestinal flora regulation were the possible mechanisms.

Photodynamic therapy with light-emitting diode arrays producing different light fields induces apoptosis and necrosis in gastrointestinal cancer.

Introduction: Light-emitting diodes (LEDs) have become a new light source for photodynamic therapy (PDT) because of their excellent optical properties, small size, and low cost. LED arrays have so far been designed to meet the need for accurate illumination of irregular lesions. However, LED arrays determine not only the shape of the illuminated spot but also the light field, which has a significant impact on the efficacy of PDT. Methods: We designed three types of LED arrays producing different light fields, namely an intensive LED array for a uniform light field, a sparse LED array for a non-uniform light field, and a point LED array for a Gaussian-like light field, and investigated the effect and mechanism of these light fields on PDT for gastrointestinal cancer both in vitro and in vivo. Results: We found that intensive LED-PDT induced earlier and more serious cell death, including apoptosis and necrosis, than sparse LED-PDT and point LED-PDT. Among the three LED arrays, the intensive LED array induced cells to produce more differential proteins (DEPs), mainly related to mitochondria, ribosomes, and nucleic acids. DEPs in cells subjected to sparse LED- and point LED-PDT were mainly involved in extracellular activities. For MGC-803 tumor-bearing mice, intensive LED-PDT and point LED-PDT had better tumor ablation effect than sparse LED-PDT. Notably, recurrence was observed on day 7 after sparse LED-PDT. VCAM-1 and ICAM-1 were highly expressed in sparse LEDs-PDT treated tumor tissues and were associated tumor angiogenesis, which in turn lead to poor tumor suppression. Conclusions: Therefore, the type of LED array significantly affected the performance of PDT for gastrointestinal cancer. Uniform light field with low power densities work better than non-uniform and Gaussian-like light fields.

Study on Optimal Parameter and Target for Pulsed-Field Ablation of Atrial Fibrillation.

Pulsed-field ablation (PFA) had potential advantages in atrial fibrillation ablation, and we aim to confirm the optimal parameter and target of PFA for atrial fibrillation. Two ablation modes in vitro of single-cell system (ablation in electrode cup) and monolayer cell system (ablation in inserts with electrode tips) were established to perform PFA for myocardial cell H9C2 and smooth muscle cell A7r5. Ablation effect, calcium ion influx, the expression of Cx45, and surface morphological change were observed. Three Bama minipigs were used to verify the in vivo ablation effect of PFA. In monolayer cell system, H9C2 was significantly sensitive to PFA compared with A7r5, with shrinking of the whole monolayer. The ablation effect of bidirectional pulse was weaker than that of the two mono-polar pulses. Expressed Cx45 proteins were increased in H9C2 but decreased in A7r5 cells. Bidirectional PFA performed on Bama minipigs was able to effectively block electrical activity from the pulmonary vein to the atrium with week muscle contraction, not generating pulmonary vein stenosis. Bidirectional PFA was able to significantly ablate myocardial cells, maintain cell-cell connection, and reduce muscle contraction, which was a kind of optimized PFA strategy for atrial fibrillation.

Gut flora-targeted photobiomodulation therapy improves senile dementia in an Aß-induced Alzheimer's disease animal model.

BACKGROUND: Emerging evidence suggests that the gut microbiota plays an important role in the pathological progression of Alzheimer's disease (AD). Photobiomodulation (PBM) therapy is believed to have a positive regulatory effect on the imbalance of certain body functions, including inflammation, immunity, wound healing, nerve repair, and pain. Previous studies have found that the intestinal flora of patients with AD is in an unbalanced state. Therefore, we have proposed the use of gut flora-targeted PBM (gf-targeted PBM) as a method to improve AD in an Aß-induced AD mouse model. METHODS: PBM was performed on the abdomen of the mice at the wavelengths of 630 nm, 730 nm, and 850 nm at 100 J/cm2 for 8 weeks. Morris water maze test, immunofluorescence and proteomic of hippocampus, and intestinal flora detection of fecal were used to evaluate the treatment effects of gf-targeted PBM on AD rats. RESULTS: PBM at all three wavelengths (especially 630 nm and 730 nm) significantly improved learning retention as measured by the Morris water maze. In addition, we found reduced amyloidosis and tau phosphorylation in the hippocampus by immunofluorescence in AD mice. By using a quantitative proteomic analysis of the hippocampus, we found that gf-targeted PBM significantly altered the expression levels of 509 proteins (the same differentially expressed proteins in all three wavelengths of PBM), which involved the pathways of hormone synthesis, phagocytosis, and metabolism. The 16 s rRNA gene sequencing of fecal contents showed that PBM significantly altered the diversity and abundance of intestinal flora. Specifically, PBM treatment reversed the typical increase of Helicobacter and uncultured Bacteroidales and the decrease of Rikenella seen in AD mice. CONCLUSIONS: Our data indicate that gf-targeted PBM regulates the diversity of intestinal flora, which may improve damage caused by AD. Gf-targeted PBM has the potential to be a noninvasive microflora regulation method for AD patients.

Effects of photobiomodulation combined with MSCs transplantation on the repair of spinal cord injury in rat.

Stem cell transplantation has shown promising regenerative effects against neural injury, and photobiomodulation (PBM) can aid tissue recovery. This study aims to evaluate the therapeutic effect of human umbilical cord mesenchymal stem cells (hUCMSCs) and laser alone or combined on spinal cord injury (SCI). The animals were divided into SCI, hUCMSCs, laser treatment (LASER) and combination treatment (hUCMSCs + LASER) groups. Cell-enriched grafts of hUCMSCs (1 × 106 cells/ml) were injected at the site of antecedent trauma in SCI model rats. A 2 cm2 damaged area was irradiated with 630 nm laser at 100 mW/cm2 power for 20 min. Locomotion was evaluated using Basso-Beattie-Bresnahan (BBB) scores, and neurofilament repair were monitored by histological staining and diffusion tensor imaging (DTI). First, after SCI, the motor function of each group was restored with different degrees, the combination treatment significantly increased the BBB scores compared to either monotherapy. In addition, Nissl bodies were more numerous, and the nerve fibers were longer and thicker in the combination treatment group. Consistent with this, the in situ expression of NF-200 and glial fibrillary acidic protein in the damaged area was the highest in the combination treatment group. Finally, DTI showed that the combination therapy optimally improved neurofilament structure and arrangement. These results may show that the combination of PBM and hUCMSCs transplantation is a feasible strategy for reducing secondary damage and promoting functional recovery following SCI.

Comparison of actual and simulated tumoricidal effects induced by photodynamic therapy.

OBJECTIVES: Numerous studies employ mathematical methods, such as Monte Carlo simulation, to predict the tumor killing effects of photodynamic therapy (PDT) by simulating optical propagation, photosensitizer distribution, and oxygen distribution. Whether these models faithfully reflect tumor killing is unknown, and model validation using tumor cross sections in these studies is usually insufficient to answer this question. To fill this gap in our knowledge, we employed a mouse model of breast cancer to determine the spatiotemporal effects of PDT using direct histopathological and biochemical analyses of whole tumors. METHODS: We prepared approximately 700 5-µm-thick serial sections of breast tumors of syngeneic mice treated with PDT employing the photosensitizer photocarcinorin (PsD-007, a second-generation photosensitizer developed in China). Three adjoining sections were subjected to hematoxylin and eosin staining to assess necrosis, the TUNEL assay to evaluate apoptosis, and CD31 staining to detect angiogenesis, respectively. We then generated a three-dimensional (3D) reconstruction of the tumor to evaluate these processes. We simultaneously used the Monte Carlo method to develop a model of light distribution throughout the tumor to evaluate the actual and simulated tumor killing effects induced by PDT. RESULTS: Tumor necrosis decreased exponentially as a function of distance from the source of illumination, while the distributions of apoptosis and neovascularization were independent of light distribution. Most apoptosis occurred in the lower layers (3000-4000 µm) of the tumor where the light intensity was too low to excite the photosensitizer. Neovascularization occurred at depths ranging from 2500 to 3500 µm. These analyses provided a 3D view of how a tumor is destroyed using PDT. CONCLUSIONS: Although the optical distribution model predicted tumor necrosis caused by PDT, it was ineffective in predicting the sites of apoptosis and vascular destruction. Mathematical modeling is limited in its capabilities required to gain a comprehensive understanding of the spatiotemporal events associated with PDT. The mouse model developed here will serve as a platform for detailed direct histopathological, biochemical, and molecular genetic analyses of the effects of PDT, which will facilitate the development of optimized treatment strategies.

Deep proteome profiling of SW837 cells treated by photodynamic therapy (PDT) reveals the underlying mechanisms of metronomic and acute PDTs.

AIM: Metronomic photodynamic therapy (mPDT) with a longer irradiation time and lower energy compared with acute (or classic) photodynamic therapy (aPDT) is a more effective treatment than aPDT for tumor cells, especially colorectal cancer. However, the underlying mechanisms of the superior effects of mPDT are unknown. METHODS: we used SWATH-MS (sequential window acquisition of all theoretical mass spectra) to identify differentially expressed proteins (DEPs) specific to aPDT (conventional fluence rate, 20 mW/cm2, 4 min 10 s), mPDT (metronomic fluence rate, 0.4 mW/cm2, 3.5 h), and control groups of SW837 cells. The photosensitizer used in both PDT methods was aminolevulinic acid which were incubated with the cells before irradiation. RESULTS: A total of 6805 proteins were identified in the three groups of SW837 cells. aPDT induced 333 DEPs and mPDT induced 1716 DEPs compared with the control. We identified 185 common DEPs in the two PDT groups, 148 different DEPs in the aPDT group, and 1531 different DEPs in the mPDT group. Most of the 185 common DEPs were involved in the extracellular component, participated in the processes of vesicle transport and secretion, binding, and hydrolase/catalytic activity. They were also involved in PI3K-Akt, cGMP-PKG, RAS, and aAMP signaling pathways. In addition, the 1531 different DEPs in the mPDT group participated in similar processes and molecular functions, but in a more complex manner than those in the aPDT group. CONCLUSION: our proteome data suggest that mPDT has a complex tumor destruction mechanism with more involved proteins compared with aPDT, which may explain the better tumor killing effect of mPDT.

Metronomic photodynamic therapy with 5-aminolevulinic acid induces apoptosis and autophagy in human SW837 colorectal cancer cells.

Metronomic photodynamic therapy (mPDT) has emerged as an attractive treatment for the selective destruction of tumor cells by induction of apoptosis. Here, we compared the effects of mPDT and acute photodynamic therapy (aPDT) on human SW837 colorectal cancer (CRC) cells. CRC cells were subjected to mPDT using various exposure durations, concentrations of 5-aminolevulinic acid (ALA), fluence rates and energy densities. The effects were compared with those induced by aPDT. We found that apoptosis and autophagy were earlier induced to a greater extent by mPDT than by the same dose applied as aPDT. The survival rates for mPDT vs. aPDT were 35.2%, 32.4%,27.6%,31.6% vs. 85.7%, 71.1%, 67.8%, 42.1% after 3, 6, 12, and 24 h PDT, respectively. For the same time points, the apoptotic rates for mPDT vs. aPDT were 43.2%, 47.3%, 54.7%, and 50.3% vs. 14.6%, 17.6%, 27.1%, and 53.2%, respectively. mPDT induced a peak rate of autophagy of 20.0% at 3 h, whereas aPDT induced two smaller peaks at 3 h (14.1%) and 12 h (15.8%). Advanced autophagosomes were more abundant in mPDT- than aPDT-treated cells and appeared earlier after mPDT (3 h) than after aPDT (3-12 h). Western Bloting results showed that the ratio of LC3B-II/ß - actin at 3 h was higher (1.04 times) after mPDT than aPDT. Collectively, these datas indicated that ALA-mPDT was more effective than the same dose of ALA-aPDT at inducing SW837 CRC cell death via apoptosis and autophagy. Thus, mPDT may be a superior choice than aPDT for the treatment of human CRC.

Effect of photobiomodulation on neural differentiation of human umbilical cord mesenchymal stem cells.

Photobiomodulation therapy (PBMT) can enhance the mesenchymal stem cell (MSC) proliferation, differentiation, and tissue repair and can therefore be used in regenerative medicine. The objective of this study is to investigate the effects of photobiomodulation on the directional neural differentiation of human umbilical cord mesenchymal stem cells (hUC-MSCs) and provide a theoretical basis for neurogenesis. hUC-MSCs were divided into control, inducer, laser, and lasers combined with inducer groups. A 635-nm laser and an 808-nm laser delivering energy densities from 0 to 10 J/cm2 were used in the study. Normal cerebrospinal fluid (CSF) and injured cerebrospinal fluid (iCSF) were used as inducers. The groups were continuously induced for 3 days. Cellular proliferation was evaluated using MTT. The marker proteins nestin (marker protein of the neural precursor cells), NeuN (marker protein of neuron), and GFAP (glial fibrillary acidic protein, marker proteins of glial cells) were detected by immunofluorescence and western blot. We found that irradiation with 635-nm laser increased cell proliferation, and that with 808 nm laser by itself and combined with cerebrospinal fluid treatment generated significant neuron-like morphological changes in the cells at 72 h. Nestin showed high positive expression at 24 h in the 808 nm group. The expression of GFAP increased in the 808-nm combined inducer group at 24 h but decreased at 72 h. The expression of neuN protein increased only at 72 h in both the 808-nm combined inducer group and inducer group. We concluded that 808 nm laser irradiation could help CSF to induce neuronal differentiation of hUC-MSCs in early stage and tend to change to neuron rather than glial cells.

Effect of 405 nm low intensity irradiation on the absorption spectrum of in-vitro hyperlipidemia blood.

BACKGROUND: Laser therapy is reported to be clinically effective for improving microcirculation, rheological properties and blood lipid profiles despite the lack of certainty on the mechanism. OBJECTIVE: This study intends to provide methods to drop blood lipid level of hyperlipidemia samples by low-intensity laser irradiation therapy and provide reasoning of mechanism. METHODS: Twenty whole blood samples of high level of lipids profile are irradiated by 405 nm low-intensity laser at 12 J/cm2 twice a day for 3 days and compared with normal lipids profile group. Then whole blood sample are centrifuged to obtain result of erythrocyte for further interpretation. Multi-scan spectrum microplate reader is used to measure absorption spectrum and data is analyzed by software SPSS 14.0. RESULTS: Results show that after 405 nm low-intensity laser irradiation, whole blood samples of high lipid level statistically have higher absorbance peak value than normal samples while erythrocyte samples have lower absorbance peak value. CONCLUSIONS: From the divergence of absorption peak value change after low-intensity laser irradiation for whole blood sample and erythrocyte, we suspect that low level laser irradiation affects the enzymes activity of lipid metabolism, improves the cholesterol balance of plasma and cytoplasm in erythrocyte, and decreases aggregation of the erythrocyte.

Umbilical cord mesenchymal stem cell (UC-MSC) transplantations for cerebral palsy.

This study reports a case of a 4-year-old boy patient with abnormalities of muscle tone, movement and motor skills, as well as unstable gait leading to frequent falls. The results of the electroencephalogram (EEG) indicate moderately abnormal EEG, accompanied by irregular seizures. Based on these clinical characteristics, the patient was diagnosed with cerebral palsy (CP) in our hospital. In this study, the patient was treated with umbilical cord mesenchymal stem cell (UC-MSC) transplantation therapy. This patient received UC-MSC transplantation 3 times (5.3*107) in total. After three successive cell transplantations, the patient recovered well and showed obvious improvements in EEG and limb strength, motor function, and language expression. However, the improvement in intelligence quotient (IQ) was less obvious. These results indicate that UC-MSC transplantation is a promising treatment for cerebral palsy.

High-voltage pulsed electric field plus photodynamic therapy kills breast cancer cells by triggering apoptosis.

This study evaluated the effects and mechanism of action of combining irreversible electroporation (IRE) and photodynamic therapy (PDT) in breast cancer cells in vitro and in vivo. Jin's formula was used to assess killing efficacy of different IRE+PDT dosing combinations in breast cancer MCF-7 cells. Flow cytometry, high-content imaging, and confocal laser scanning microscopy were used to detect apoptosis. qRT-PCR and western blotting were used to evaluate expression of apoptosis-related genes and proteins. IRE+PDT combination therapy was administered to BALB/C mice with breast cancer tumors in vivo; tumor size was used to assess treatment efficacy. Killing mechanisms were examined using transmission electron microscopy and immunohistochemistry. We found that IRE+PDT combination therapy produced significant synergistic killing effects in breast cancer cells (highest Jin q value of 1.32). Early apoptosis rates were significantly higher in the IRE+PDT group (16.0%) than in IRE-alone (7.6%) and PDT-alone (4.6%) groups (P<0.05). qRT-PCR showed higher Caspase-1, -3, -5, -6, -7, -8, and -9 and TNFRSF1A expression with IRE+PDT than with control. Western blots showed increased cleaved Caspase-3, -7, and -9, and PARP levels in the IRE+PDT group. In vivo tumor suppression rate for IRE (1200 V)+PDT (10 mg/kg) was 68.3%. Combination therapy produced the most obvious apoptosis effects. Compared with controls, the IRE+PDT group exhibited lower new blood vessel (VEGF, CD31), metastasis (TGF-ß), and cell proliferation (Ki-67) indicators and higher inflammation indicator (TNF-α) 1 day post-treatment. Thus, combining IRE and PDT enhanced their anti-tumor effects in breast cancer, and apoptosis played a key role in this process.

Transport and release of colloidal 3-mercaptopropionic acid-coated CdSe-CdS/ZnS core-multishell quantum dots in human umbilical vein endothelial cells.

Colloidal semiconductor quantum dots (QDs) have been extensively researched and developed for biomedical applications, including drug delivery and biosensing assays. Hence, it is pivotal to understand their behavior in terms of intracellular transport and toxicological effects. In this study, we focused on 3-mercaptopropionic acid-coated CdSe-CdS/ZnS core-multishell quantum dots (3MPA-QDs) converted from the as-grown octadecylamine-coated quantum dots (ODA-QDs) and their direct and dynamic interactions with human umbilical vein endothelial cells (HUVECs). Live cell imaging using confocal fluorescence microscopy showed that 3MPA-QDs first attached to and subsequently aggregated on HUVEC plasma membrane ~25 min after QD deposition. The aggregated QDs started being internalized at ~2 h and reached their highest internalization degree at ~24 h. They were released from HUVECs after ~48 h. During the 48 h period, the HUVECs responded normally to external stimulations, grew, proliferated and wound healed without any perceptible apoptosis. Furthermore, 1) 3MPA-QDs were internalized in newly formed LysoTracker-stained early endosomes; 2) adenosine 5'-triphosphate-induced [Ca2+]i modulation caused a transient decrease in the fluorescence of 3MPA-QDs that were attached to the plasma membrane but a transient increase in the internalized 3MPA-QDs; and 3) fluorescence signal modulations of co-stained LysoTracker and QDs induced by the lysosomotropic agent Gly-Phe-ß-naphthylamide were spatially co-localized and temporally synchronized. Our findings suggest that 3MPA-QDs converted from ODA-QDs are a potential nontoxic fluorescent probe for future use in clinical applications. Moreover, the photophysical strategy and techniques reported in this work are easily applicable to study of direct interactions between other nanoparticles and live cells; contributing to awareness and implementation of the safe applications of nanoparticles.

The Distribution of Transplanted Umbilical Cord Mesenchymal Stem Cells in Large Blood Vessel of Experimental Design With Traumatic Brain Injury.

The authors aim to track the distribution of human umbilical cord mesenchymal stem cells (MSCs) in large blood vessel of traumatic brain injury -rats through immunohistochemical method and small animal imaging system. After green fluorescent protein (GFP) gene was transfected into 293T cell, virus was packaged and MSCs were transfected. Mesenchymal stem cells containing GFP were transplanted into brain ventricle of rats when the infection rate reaches 95%. The immunohistochemical and small animal imaging system was used to detect the distribution of MSCs in large blood vessels of rats. Mesenchymal stem cells could be observed in large vessels with positive GFP expression 10 days after transplantation, while control groups (normal group and traumatic brain injury group) have negative GFP expression. The vascular endothelial growth factor in transplantation group was higher than that in control groups. The in vivo imaging showed obvious distribution of MSCs in the blood vessels of rats, while no MSCs could be seen in control groups. The intravascular migration and homing of MSCs could be seen in rats received MSCs transplantation, and new angiogenesis could be seen in MSCs-transplanted blood vessels.

Quantum dots modulate intracellular Ca2+ level in lung epithelial cells.

While adverse effects of nanoparticles on lung health have previously been proposed, few studies have addressed the direct effects of nanoparticle exposure on the airway epithelium. In this work, we examine the response of the pulmonary airway to nanoparticles by measuring intracellular Ca2+ concentration ([Ca2+]i) in the Calu-3 epithelial layer stimulated by 3-mercaptopropionic-acid (3MPA) coated CdSe-CdS/ZnS core-multishell quantum dots (QDs). Simultaneous transient transepithelial electrical resistance (TEER) decrease and global [Ca2+]i increase in Calu-3 epithelial layer, accompanied by cell displacements, contraction, and expansion, were observed under QD deposition. This suggests that a QD-induced global [Ca2+]i increase in the Calu-3 epithelial layer caused the transient TEER decrease. The [Ca2+]i increase was marked and rapid in the apical region, while [Ca2+]i decreased in the basolateral region of the epithelial layer. TEER transient response and extracellular Ca2+ entry induced by QD deposition were completely inhibited in cells treated with stretched-activated (SA) inhibitor GdCl3 and store-operated calcium entry (SOCE) inhibitor BTP2 and in cells immersed in Ca2+-free medium. The voltage-gated calcium channel (VGCC) inhibitor nifedipine decreased, stabilized, and suppressed the TEER response, but did not affect the [Ca2+]i increase, due to QD deposition. This demonstrates that the Ca2+ influx activated by QDs' mechanical stretch occurs through activation of both SA and SOCE channels. QD-induced [Ca2+]i increase occurred in the Calu-3 epithelial layer after culturing for 15 days, while significant TEER drop only occurred after 23 days. This work provides a new perspective from which to study direct interactions between airway epithelium and nanoparticles and may help to reveal the pathologies of pulmonary disease.