Mixed-phenotype (B-lymphocytic/myeloid) acute leukemia with ETV6-ABL1 expression.

Objectives: Mixed-phenotype acute leukemia (MPAL) is rare in the clinic, accounting for approximately 2%-5% of acute leukemia cases. Methods: In this study the cohort included 126 patients, of which 125 cases were from re-examined published data and current patients from Shenzhen Longhua District Central Hospital, carrying an ETV6-ABL1 rearrangement from April 15, 2020 to December 19, 2020. The ETS variant transcription factor 6-Abelson proto-oncogene 1 (ETV6-ABL1) fusion gene is mainly seen in malignant hematological diseases such as acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), myeloproliferative neoplasms (MPNs). Positivity of both MPAL and ETV6-ABL1 suggest a poor prognosis. This is the first report of B lymphocytic/myeloid mixed-phenotype acute leukemia with ETV6-ABL1 fusion gene positivity. Complete remission was achieved with chemotherapy for lymphoid and myeloid leukemia and targeted therapy with tyrosine kinase inhibitors (TKIs). Results: The level of ETV6-ABL1/ABL decreased from 23.056% to 11.165%. After consolidation chemotherapy, the patient underwent allogeneic hematopoietic stem cell transplantation but died due to intestinal rejection. There are 126 cases of ETV6-ABL1 fusion gene transcript expression in numerous hematologic malignancies reported to date, including 48 cases of ALL, 12 of AML, and 65 of MPN. Eosinophilia is a common characteristic, especially in MPN patients. Conclusion: Survival analysis suggests that the survival time of ALL and MPN patients receiving TKI treatment is better than that of patients not receiving this treatment. Dasatinib or nilotinib, especially the former, is more effective than imatinib for MPN.

Room-Object Entity Prompting and Reasoning for Embodied Referring Expression.

Given a high-level instruction, the task of Embodied Referring Expression (REVERIE) requires an embodied agent to localise a remote referred object via navigating in the unseen environment. Previous vision-language navigation methods utilise the provided fine-grained instruction as step-by-step navigation guidance to conduct strict instruction-following, while REVERIE aims to achieve efficient goal-oriented exploration according to the high-level command. In this work, we propose a Cross-modal Knowledge Reasoning (abbreviated as CKR+) framework, which incorporates the prior knowledge as decision guidance to learn the navigation scheme comprehensively. Specifically, we design a Room-Object Aware (ROA) mechanism to explicitly decouple the room- and object-related clues from instruction and visual observations. Moreover, we propose a Knowledge-enabled Entity Relation Reasoning (KERR+) module to leverage the structured knowledge from the knowledge graph explicitly and unstructured knowledge from pre-trained model implicitly, to learn the internal-external correlations among room- and object-entities for the agent to make proper decisions. We devise an Entity Prompter (EP) that embeds in the KERR+ module, which utilises the navigation history and visual entities as prompts to transfer knowledge from the pre-trained CLIP model. In addition, we develop a Reinforced End Decider (RED) to learn the stopping scheme specifically, which is achieved by a customised reinforcement learning strategy and knowledge enhanced matching. Two techniques are also introduced to improve navigation efficiency further. Extensive experiments conducted on the REVERIE benchmark demonstrate the effectiveness and superiority of our proposed methods, which boosts the key metrics, i.e., SPL and REVERIE-success rate, to 14.46% and 13.81% respectively.

The effects of gonadotropin-releasing hormone agonist on final adult height among girls with early and fast puberty.

Introduction: This study aimed to explore the impact of gonadotropin-releasing hormone agonists (GnRHa) on final adult height (FAH) in girls with early and fast puberty. Methods: A retrospective study was conducted by reviewing data from the medical records of the Pediatric Endocrinology Clinics between January 1, 2010, and December 31, 2020, at MacKay Children's Hospital. The treatment group included 109 patients who received 3.75 mg monthly for at least 1 year, whereas the control group consisted of 95 girls who received no treatment. Results: The treatment group was significantly older at the time of inclusion(chronological age (CA1), treatment vs. control, 8.7 vs. 8.4 years, p < 0.001), had a more advanced bone age (BA) (BA1, 11.5 vs. 10.8 years, p < 0.001), BA1-CA1 (2.7 vs. 2.2 years, p < 0.001), and shorter predicted adult height (PAH1) (153.3 vs. 157.1 cm, p = 0.005) that was significantly lower than their target height (Tht)(PAH1-Tht, -3.9 vs. -1.3 cm, p = 0.039). The FAHs of the GnRHa and the control group were similar (157.0 vs. 156.7 cm, p = 0.357) and were not significantly different from their Tht (FAH vs. Tht in the GnRHa group, 157.0 vs. 157.0 cm; control group, 156.7 vs. 157.0 cm). In the subgroup analysis, FAH was significantly higher after GnRHa treatment in those with PAH1 less than 153 cm and Tht (154.0 vs. 152.0 cm, p = 0.041), and those whose CA1 was between 8 and 9 years (158.0 vs. 155.4 cm, p = 0.004). We defined satisfactory FAH outcome as FAH-PAH1≥5 cm and significant factors were GnRHa therapy, PAH1 shorter than their Tht, age younger than 9 years, and faster growth velocity during the first year. Discussion: GnRHa is effective in restoring the Tht in some early and fast pubertal girls, especially in those with poorly PAH (PAH lower than 153 cm and shorter than their target height). A younger age at initiation of treatment and a faster growth velocity during treatment are associated with a better height gain.

Perfluoro-tert-butyl Group-Derived Capmatinib: Synthesis, Biological Evaluation and Its Application in 19 F Magnetic Resonance Imaging.

Capmatinib is an FDA-approved drug to treat metastatic non-small cell lung cancer with MET-exon 14 skipping. Herein, the perfluoro-tert-butyl group, which possesses nine chemically identical fluorine atoms, was introduced on Capmatinib to afford a targeted 19 F magnetic resonance imaging (MRI) probe, perfluoro-tert-butyl group-derived Capmatinib (9F-CAP). The 19 F MRI concentration limit was found to be 25 mM in FLASH sequence. Molecular docking simulation, surface plasmon resonance (SPR) (with a Kd of 40.7 µM), half-inhibitory concentration (with a IC50 of 168 nM), Annexin V, and cytotoxicity assays jointly demonstrated that the 9F-CAP targeted cMET protein specifically. Therefore, the targeted imaging capability of 9F-CAP is of great significance for the preoperative diagnosis of specific cancers.

Biological evaluation of a novel stable peptide PET molecular probe [18F]AlF-NOTA-DVAP targeting to tumor cell surface GRP78.

BACKGROUNDS: Glucose-Regulated Protein 78 (GRP78) is an attractive anticancer target for its selective anchoring on the surface of tumor cells and cancer endothelial cells rather than normal cells. Cell-surface GRP78 overexpression of tumor indicates that GRP78 is a crucial target for relative tumor imaging and clinical treatment. Herein, we report the design and preclinical evaluation of a new D peptide ligand [18F]AlF-NOTA-DVAP recognizing GRP78 expressed on the cell surface of breast cancer. METHODS: Radiochemical synthesis of [18F]AlF-NOTA-DVAP was achieved via a one-pot labeling process by heating NOTA-DVAP in the presence of in situ prepared [18F]AlF for 15 min at 110 °C and purified through HPLC. RESULTS: The radiotracer showed high in vitro stability in rat serum at 37 °C over 3 h. Both biodistribution studies and in vivo micro-PET/CT imaging studies in BALB/c mice bearing 4 T1 tumor showed [18F]AlF-NOTA-DVAP had a rapid and high uptake in tumor, as well as a long residence time. The high hydrophilicity of the radiotracer enables its fast clearance from most normal tissues and thus improves the tumor-to-normal tissue ratios (4.40 at 60 min) which is better than [18F]FDG (1.31 at 60 min). Pharmacokinetic studies showed the average in vivo mean residence time of the radiotracer was just 0.6432 h and indicated that this hydrophilic radiotracer was quickly eliminated from the body to reduce the distribution of non-target tissues. CONCLUSIONS: These results suggest that [18F]AlF-NOTA-DVAP is a very promising PET probe for tumor-specific imaging of cell-surface GRP78-positive tumor.

The Neurobase of ambiguity loss aversion about decision making.

In our daily decision-making, there are two confusing problems: risk and ambiguity. Many psychological studies and neuroscience studies have shown that the prefrontal cortex (PFC) is an important neural mechanism for modulating the human brain in risk and ambiguity decision-making, especially the dorsolateral prefrontal cortex (DLPFC). We used transcranial direct current stimulation (tDCS) to reveal the causal relationship between the DLPFC and ambiguity decision-making. We design two experimental tasks involving ambiguity to gain and ambiguity to loss. The results of our study show that there is a significant effect on left DLPFC stimulation about ambiguity to loss, there is an insignificant effect on left DLPFC stimulation about ambiguity to gain, and there is an insignificant effect on right DLPFC stimulation about ambiguity to gain and ambiguity to loss. This result indicates that people are more sensitive to ambiguity loss than ambiguity gain. Further analysis found that the degree of participants' attitudes toward ambiguity loss who received anodal simulation was lower than that who received sham stimulation across the left DLPFC, which means that the subjects had a strong ambiguity loss aversion after the participants received the anodal simulation of the left DLPFC.

18F-FDG PET as an imaging biomarker for the response to FGFR-targeted therapy of cancer cells via FGFR-initiated mTOR/HK2 axis.

Rationale: The overall clinical response to FGFR inhibitor (FGFRi) is far from satisfactory in cancer patients stratified by FGFR aberration, the current biomarker in clinical practice. A novel biomarker to evaluate the therapeutic response to FGFRi in a non-invasive and dynamic manner is thus greatly desired. Methods: Six FGFR-aberrant cancer cell lines were used, including four FGFRi-sensitive ones (NCI-H1581, NCI-H716, RT112 and Hep3B) and two FGFRi-resistant ones (primary for NCI-H2444 and acquired for NCI-H1581/AR). Cell viability and tumor xenograft growth analyses were performed to evaluate FGFRi sensitivities, accompanied by corresponding 18F-fluorodeoxyglucose (18F-FDG) uptake assay. mTOR/PLCγ/MEK-ERK signaling blockade by specific inhibitors or siRNAs was applied to determine the regulation mechanism. Results: FGFR inhibition decreased the in vitro accumulation of 18F-FDG only in four FGFRi-sensitive cell lines, but in neither of FGFRi-resistant ones. We then demonstrated that FGFRi-induced transcriptional downregulation of hexokinase 2 (HK2), a key factor of glucose metabolism and FDG trapping, via mTOR pathway leading to this decrease. Moreover, 18F-FDG PET imaging successfully differentiated the FGFRi-sensitive tumor xenografts from primary or acquired resistant ones by the tumor 18F-FDG accumulation change upon FGFRi treatment. Of note, both 18F-FDG tumor accumulation and HK2 expression could respond the administration/withdrawal of FGFRi in NCI-H1581 xenografts correspondingly. Conclusion: The novel association between the molecular mechanism (FGFR/mTOR/HK2 axis) and radiological phenotype (18F-FDG PET uptake) of FGFR-targeted therapy was demonstrated in multiple preclinical models. The adoption of 18F-FDG PET biomarker-based imaging strategy to assess response/resistance to FGFR inhibition may benefit treatment selection for cancer patients.

The long-circulating effect of pegylated nanoparticles revisited via simultaneous monitoring of both the drug payloads and nanocarriers.

The long-circulating effect is revisited by simultaneous monitoring of the drug payloads and nanocarriers following intravenous administration of doxorubicin (DOX)-loaded methoxy polyethylene glycol-polycaprolactone (mPEG-PCL) nanoparticles. Comparison of the kinetic profiles of both DOX and nanocarriers verifies the long-circulating effect, though of limited degree, as a result of pegylation. The nanocarrier profiles display fast clearance from the blood despite dense PEG decoration; DOX is cleared faster than the nanocarriers. The nanocarriers circulate longer than DOX in the blood, suggesting possible leakage of DOX from the nanocarriers. Hepatic accumulation is the highest among all organs and tissues investigated, which however is reversely proportionate to blood circulation time. Pegylation and reduction in particle size prove to extend circulation of drug nanocarriers in the blood with simultaneous decrease in uptake by various organs of the mononuclear phagocytic system. It is concluded that the long-circulating effect of mPEG-PCL nanoparticles is reconfirmed by monitoring of either DOX or the nanocarriers, but the faster clearance of DOX suggests possible leakage of a fraction of the payloads. The findings of this study are of potential translational significance in design of nanocarriers towards optimization of both therapeutic and toxic effects.

Symbiont-Induced Phagosome Changes Rather than Extracellular Discrimination Contribute to the Formation of Social Amoeba Farming Symbiosis.

Symbiont recognition is essential in many symbiotic relationships, especially for horizontally transferred symbionts. Therefore, how to find the right partner is a crucial challenge in these symbiotic relationships. Previous studies have demonstrated that both animals and plants have evolved various mechanisms to recognize their symbionts. However, studies about the mechanistic basis of establishing protist-bacterium symbioses are scarce. This study investigated this question using a social amoeba Dictyostelium discoideum and their Burkholderia symbionts. We found no evidence that D. discoideum hosts could distinguish different Burkholderia extracellularly in chemotaxis assays. Instead, symbiont-induced phagosome biogenesis contributed to the formation of social amoeba symbiosis, and D. discoideum hosts have a higher phagosome pH when carrying symbiotic Burkholderia than nonsymbiotic Burkholderia. In conclusion, the establishment of social amoeba symbiosis is not linked with extracellular discrimination but related to symbiont-induced phagosome biogenesis, which provides new insights into the mechanisms of endosymbiosis formation between protists and their symbionts. IMPORTANCE Protists are single-celled, extremely diverse eukaryotic microbes. Like animals and plants, they live with bacterial symbionts and have complex relationships. In protist-bacterium symbiosis, while some symbionts are strictly vertically transmitted, others need to reestablish and acquire symbionts from the environment frequently. However, the mechanistic basis of establishing protist-bacterium symbioses is mostly unclear. This study uses a novel amoeba-symbiont system to show that the establishment of this symbiosis is not linked with extracellular discrimination. Instead, symbiont-induced phagosome biogenesis contributes to the formation of social amoeba-bacterium symbiosis. This study increases our understanding of the mechanistic basis of establishing protist-bacterium symbioses.

A drug-free nanozyme for mitigating oxidative stress and inflammatory bowel disease.

Inflammatory bowel disease (IBD) is an incurable disease of the gastrointestinal tract with a lack of effective therapeutic strategies. The proinflammatory microenvironment plays a significant role in both amplifying and sustaining inflammation during IBD progression. Herein, biocompatible drug-free ceria nanoparticles (CeNP-PEG) with regenerable scavenging activities against multiple reactive oxygen species (ROS) were developed. CeNP-PEG exerted therapeutic effect in dextran sulfate sodium (DSS)-induced colitis murine model, evidenced by corrected the disease activity index, restrained colon length shortening, improved intestinal permeability and restored the colonic epithelium disruption. CeNP-PEG ameliorated the proinflammatory microenvironment by persistently scavenging ROS, down-regulating the levels of multiple proinflammatory cytokines, restraining the proinflammatory profile of macrophages and Th1/Th17 response. The underlying mechanism may involve restraining the co-activation of NF-κB and JAK2/STAT3 pathways. In summary, this work demonstrates an effective strategy for IBD treatment by ameliorating the self-perpetuating proinflammatory microenvironment, which offers a new avenue in the treatment of inflammation-related diseases.

COVID-19 risk perception and tourist satisfaction: A mixed-method study of the roles of destination image and self-protection behavior.

This study aimed to examine the effects of COVID-19 risk perception on negative destination image and self-protection behavior, and the resultant effects on tourist satisfaction. Hence, this study applied a continuous interpretive mixed-method design combining quantitative and qualitative analyses. A quantitative survey (n = 486) in the cities of Ningbo, Huangshan, and Chengdu, China, and 19 qualitative interviews were conducted online. The results of the quantitative study show that: (1) Risk perception and negative destination image are antecedent variables influencing tourist satisfaction, and (2) there are significant positive correlations between risk perception and negative destination image, risk perception and tourist self-protection behavior, and negative destination image and tourist self-protection behavior. Moreover, (3) negative destination image had a partial mediating effect between risk perception and satisfaction. Furthermore, to supplement the research data and expand the quantitative findings, this study further examined whether the above variables are related to tourist satisfaction, through in-depth interviews with tourists. The findings showed that COVID-19 risk perception, negative destination image, and self-protection behavior all affect tourist satisfaction. The findings provide valuable crisis management suggestions for the government and should contribute to the efforts of tourist destinations to build a healthy and safe image, thereby contributing to the sustainable development of tourism industries in the post-epidemic era.

Graves disease is more prevalent than Hashimoto disease in children and adolescents with type 1 diabetes.

Introduction: Autoimmune thyroid disease (AITD) is the most common associated autoimmune disorder in type 1 diabetes (T1D). Early detection of AITD is crucial to optimize glycemic control, growth, and intellectual development. In this prospective cohort study, we sought to characterize the prevalence, incident ages and risk factors of AITD in children and adolescents with T1D. Materials and methods: Patients with T1D diagnosed at ≤ 18 years at MacKay Children's Hospital, Taipei, from 1990 to 2019 underwent annual screening for AITD. Institutional Review Board-approved data on age, sex, and disease profile are collected. Statistical analysis was performed by using independent sample t test for continuous variables, chi-squared test for categorical variables, and Kaplan-Meier estimates of cumulative incidence of AITD were calculated. A p value of <0.05 was considered statistically significant. Results: We prospectively followed up 808 patients with T1D, 761 patients were included in the study. Of these patients, 197 (25.9%) of them had thyroid autoimmunity, meaning positivity of thyroid autoantibodies. Females had a higher prevalence of thyroid autoimmunity than males (59.9%, p = 0.012). Altogether, 5.5% patients developed AITD (4.1% had Graves disease; 1.4% had Hashimoto disease), at a mean age of 17.8 ± 8.5 years. The cumulative incidence of AITD at 30 years of disease duration was 0.29 in the total group and was significantly higher in females (0.39, n = 397) than in males (0.15, n = 364, p<0.001). Discussion: In Taiwan, the prevalence of AITD in pediatric population with T1D increases with age, a longer disease duration and female sex. For early detection of autoimmune thyroid disease in Taiwanese children and adolescents with T1D, an annual AITD screening program should be implemented.

Effectiveness of traditional Chinese medicine in treating gastrointestinal dysfunction in patients with acute stroke: a systematic review and meta-analysis of 16 randomized controlled trials.

BACKGROUND: Gastrointestinal dysfunction is one of the complications after stroke. If it is not treated in time, it will affect the rehabilitation process after stroke and reduce the quality of life of patients. In this study, we conducted a systematic review and meta-analysis of the reports on the treatment of gastrointestinal dysfunction after stroke with traditional Chinese medicine (TCM) in recent years to provide evidence for clinical diagnosis and treatment. METHODS: The clinical randomized controlled trials (RCTs) published in Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Medline, and Web of Science databases from January 2010 to August 2021 were searched. After screening the qualified literatures, literature quality evaluation was performed. The software Stata 16.0 was used to analyze and compare the outcome indicators of TCM and conventional western medicine treatment, and the utility of TCM in the treatment of gastrointestinal disorders after stroke was comprehensively evaluated. RESULTS: A total of 16 studies were finally selected including a total of 1,589. Meta-analysis showed that TCM treatment of gastrointestinal disorders after stroke was more effective than conventional western medicine treatment [odds ratio (OR) =3.94; 95% confidence interval (CI): 2.63 to 5.89; P=0.000]. It was also shown that TCM can reduce the recovery time of bowel sounds and is superior to conventional western medicine [standard mean difference (SMD) =-1.92; 95% CI: -2.51 to -1.34; P=0.000]; reduce defecation and flatulence recovery time (SMD =-2.51; 95% CI: -3.41 to -1.61; P=0.000); increase gastrin level (SMD =0.80; 95% CI: 0.35 to 1.25; P=0.001); increase motilin level (SMD =2.27; 95% CI: 1.55 to 3.00; P=0.000); increase serum albumin level (SMD =0.72; 95% CI: 0.54 to 0.90; P=0.000); increase transferrin levels (SMD =1.11; 95% CI: 0.86 to 1.36; P=0.000); and it can increase serum prealbumin levels (SMD =1.50; 95% CI: 0.78 to 2.22; P=0.000). DISCUSSION: The use of TCM in the treatment of gastrointestinal dysfunction after stroke can effectively reduce symptoms, shorten the recovery time of bowel sounds, the first defecation and flatulence time, promote gastric motility and gastrointestinal hormone secretion, and improve the nutritional status of patients.

Nose-to-brain delivery of borneol modified tanshinone IIA nanoparticles in prevention of cerebral ischemia/reperfusion injury.

Targeted treatment of cerebral ischemia/reperfusion injury (CIRI) remains a problem due to the difficulty in drug delivery across the blood-brain barrier (BBB). In this study, we developed Bo-TSA-NP, a novel tanshinone IIA (TSA) loaded nanoparticles modified by borneol, which has long been proved with the ability to enhance other drugs' transport across the BBB. The Bo-TSA-NP, with a particle size of about 160 nm, drug loading of 3.6%, showed sustained release and P-glycoprotein (P-gp) inhibition property. It demonstrated a significantly higher uptake by 16HBE cells in vitro through the clathrin/caveolae-mediated endocytosis and micropinocytosis. Following intranasal (IN) administration, Bo-TSA-NP significantly improved the preventive effect on a rat model of CIRI with improved neurological scores, decreased cerebral infarction areas and a reduced content of malondialdehyde (MDA) and increased activity of superoxide dismutase (SOD) in rat brain. In conclusion, these results indicate that Bo-TSA-NP is a promising nose-to-brain delivery system that can enhance the prevention effect of TSA on CIRI.

Transport and Retention of Free-Living Amoeba Spores in Porous Media: Effects of Operational Parameters and Extracellular Polymeric Substances.

Amoebas are protists that are widespread in water and soil environments. Some species are pathogenic, inducing potentially lethal effects on humans, making them a major threat to public health. Nonpathogenic amoebas are also of concern because they have the potential to carry a mini-microbiome of bacteria, either transiently or via more long-term stable transport. Due to their resistance to disinfection processes, the physical removal of amoeba by filtration is necessary to prevent their propagation throughout drinking water distribution networks and occurrence in tap water. In this study, a model amoeba species Dictyostelium discoideum was used to study the transport and retention behavior of amoeba spores in porous media. The key factors affecting the transport behavior of amoeba spores in fully saturated media were comprehensively evaluated, with experiments performed using a quartz crystal microbalance with dissipation monitoring (QCM-D) and parallel plate chamber system. The effects of ionic strength (IS) on the deposition of spores were found to be in contrast to the predicted Derjaguin-Landau-Verwey-Overbeek (DLVO) theory that more deposition is observed under lower-IS conditions. The presence of extracellular polymeric substances (EPS) was found to be the main contributor to deposition behavior. Overall, these results provide plausible evidence for the presence of amoeba in tap water. Furthermore, this is one of the first studies to examine the mechanisms affecting the fate of amoeba spores in porous media, providing a significant baseline for future research to minimize the safety risk presented by amoeba in drinking water systems.

Both viable and inactivated amoeba spores protect their intracellular bacteria from drinking water disinfection.

In drinking water systems, waterborne pathogens constitute a significant threat. While most studies focus on a single infectious agent, such as bacteria, fungi, viruses, and protists, the effect of interactions among these infectious agents on disinfection treatment has largely been ignored. In this study, we find that dormant amoeba spores, a frequently found protist in drinking water systems, can protect their intracellular bacteria from drinking water disinfection. Bacteria-containing amoeba spores were constructed and treated with various disinfection techniques (Cl2, ClO2, and UV254). The three disinfection methods could kill the bacteria alone efficiently (6-log inactivation). However, the inactivation efficiency of bacteria that hid within amoeba spore was significantly inhibited (2-3-log inactivation). We also found that inactivated amoeba spores can still protect their intracellular bacteria. This study provides direct evidence that viable and inactivated amoeba spores can protect their hitchhiking bacteria from disinfection treatment, which is crucial for future decision-making about the dosage for sufficient bacterial disinfection in drinking water systems.

The biological fate of orally administered mPEG-PDLLA polymeric micelles.

The biological fate of polymeric micelles (PMs) following oral administration was investigated in this study to better understand the contribution of transport of integral PMs to oral absorption. To track integral PMs, near-infrared fluorophores with aggregation-caused quenching properties were utilized to label PMs comprised of methoxy poly(ethylene glycol)-poly(D,L-lactic acid) (mPEG-PDLLA) copolymers and methoxy poly(ethylene glycol)-distearoyl phosphoethanolamine (DSPE-PEG). The particle size of PMs prepared from mPEG2.5k-PDLLA1.25k, mPEG2.5k-PDLLA2.5k, mPEG5k-PDLLA3k, mPEG5k-PDLLA5k and DSPE-PEG2k was 24.5, 29.5, 34.0, 41.4 and 15.6 nm, respectively. After oral administration by gavage to rats, PMs were retained in the gastrointestinal tract for at least 4 h, and the copolymer block chain lengths did not have significant influence. The emergence of fluorescence in the blood and liver served as direct evidence to support oral absorption of integral PMs. Approximately 1-2% of intact particles were absorbed via the lymphatic pathway, but the total amount of PMs that reach the systemic circulation await further elucidation. Confocal laser scanning microscopy added more evidence to support the penetration of integral PMs into the basolateral tissues of microvilli. Cellular uptake efficiency was about 4-7% in Caco-2 cell lines for all PM groups, but was reduced to 1-3% in Caco-2/HT29-MTX co-culture models due to the hindrance by the mucus layers. Approximately 6-12% of integral PMs were transported across Caco-2/HT29-MTX/Raji monolayers, whereas only approximately one-tenth of that amount was transported across Caco-2 and Caco-2/HT29-MTX monolayers. Differences, but not statistically significant, were observed between PM groups in lymphatic uptake, biodistribution, cellular uptake and trans-monolayer transport, possibly owing to difference in block chain lengths as well as particle size. In conclusion, evidence obtained in this study supports penetration of integral PMs across the enteric epithelia, but the total amount may be limited.

Effect of Surface Charges on Oral Absorption of Intact Solid Lipid Nanoparticles.

Surface charge is a crucial factor that determines the in vivo behaviors of drug nanocarriers following administration via different routes. However, there is still a lack of comprehensive knowledge of how surface charges affect the in vivo behaviors of particles, especially for oral delivery. In this study, solid lipid nanoparticles (SLNs), as model drug nanocarriers, are modified to bear either anionic, cationic, or net neutral surface charges. The effect of surface charges on oral absorption of intact SLNs was investigated by tracking the in vivo transport of the particles. The fluorescent bioimaging strategy exploits the aggregation-caused quenching property to discriminate the particles. Both in vitro and in vivo lipolysis studies confirm slowed-down lipolysis by anionic charges in comparison with both unmodified and net neutral SLNs but accelerated degradation by cationic charges. The scanning of ex vivo tissues and organs reveals limited absorption of unmodified SLNs into the circulation. Nevertheless, all three types of surface charge modifications are able to enhance the oral absorption of intact SLNs with the fastest and highest absorption observed for net neutral SLNs, possibly owing to promoted mucus penetration. Anionic SLNs, though repulsed by the mucus layer, show the second highest absorption owing to enhanced lymphatic transport. The efficacy of cationic charge modification is less significant due to entrapment and retention in mucus layers as well as increased lability to lipolysis. In conclusion, surface charges may serve as initiators to guide the in vivo behaviors and enhance the oral absorption of intact SLNs.

Slowing down lipolysis significantly enhances the oral absorption of intact solid lipid nanoparticles.

Only a limited amount of orally administered lipid nanoparticles are absorbed as intact particles due to lipolysis by lipases in the gastrointestinal tract. It is hypothesized that by counteracting lipolysis, more particles will survive gastrointestinal digestion and be absorbed as intact particles. In this study, incorporation of a lipase inhibitor orlistat (OLST), as well as polyethylene glycol (PEG) coating, is employed to slow down the lipolysis using solid lipid nanoparticles (SLNs) as model particles. To explore the in vivo behaviors of the particles, near-infrared fluorescent probes with absolute aggregation-caused quenching (ACQ) properties are used to label and track the unmodified, PEG-coated and OLST-loaded SLNs. The in vitro lipolysis study indicates very fast first-order degradation of unmodified SLNs and significantly decreased degradation of OLST-SLNs. Live imaging reveals the same trend of slowed-down lipolysis in vivo which correlates well with the in vitro lipolysis. The scanning of ex vivo gastrointestinal segments confirms the considerably prolonged residence time of OLST-SLNs, mirroring the significantly decreased lipolysis rate. The observation of fluorescence in the blood, though very weak, and in the liver speaks of the oral absorption of intact SLNs. The substantially higher hepatic levels of OLST-SLNs than unmodified SLNs should be attributed to the significantly enhanced survival rate because both particles exhibit similar cellular recognition as well as similar physicochemical properties except for the survival rate. Similarly, slowing down lipolysis also contributes to the significantly enhanced cumulative lymphatic transport of OLST-SLNs (7.56% vs. 1.27% for the unmodified SLNs). The PEG coating slows down the lipolysis rate as well but not to the degree as done by OLST. As a result, the gastrointestinal residence time of PEG-SLNs has been moderately prolonged and the hepatic levels moderately increased. The weakened cellular recognition of PEG-SLNs implies that the enhanced oral absorption is solely ascribed to the slowed-down lipolysis and enhanced mucus penetration. In conclusion, the oral absorption of intact SLNs can be significantly enhanced by slowing down lipolysis, especially by OLST, showing potential as carriers for the oral delivery of labile biomacromolecules.

TCF21 inhibits tumor-associated angiogenesis and suppresses the growth of cholangiocarcinoma by targeting PI3K/Akt and ERK signaling.

Tumor-associated angiogenesis plays a critical role in the pathogenesis of cholangiocarcinoma (CCA). In this study, we examined the biological effects and molecular mechanisms of transcription factor 21 (TCF21) on CCA-associated angiogenesis. TCF21 expression was compared between 15 pairs of peritumor normal tissues and CCA tissues and also between normal bile duct epithelial cells and two CCA cell lines (QBC-939 and TFK-1) using real-time PCR and Western blot. With the use of both CCA cell lines as the model system, we stably expressed TCF21 by lentiviral transduction (Lv-TCF21). In vivo, we monitored xenograft growth from different CCA cells, measured tumor-associated angiogenesis by histological analysis, and determined the expressions and circulatory levels of VEGFA and PDGF-BB by immunohistochemistry and ELISA, respectively. In vitro, we assessed the effects of conditioned medium collected from different CCA cells on the viability, migration, and tube formation of endothelial cells and explored the significance of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), as well as ERK1/2 signaling in this process. TCF21 was significantly downregulated in CCA tissues or cell lines. Ectopic expression of TCF21 in CCA cells inhibited xenograft growth or tumor-associated angiogenesis in vivo and targeted the expression and secretion of proangiogenic factors, VEGFA and PDGF-BB. In vitro, the conditioned medium collected from Lv-TCF21 CCA cells significantly reduced the viability, migration, and tube formation of endothelial cells. On the molecular level, the targeting of PI3K/Akt and ERK1/2 signaling mediated the anti-angiogenic activity of TCF21. TCF21 presents growth-inhibitory and anti-angiogenic activities, and thus the elevation of TCF21 expression may provide therapeutic benefits for CCA. NEW & NOTEWORTHY Transcription factor 21 (TCF21) is downregulated in cholangiocarcinoma (CCA) tissues or cells. TCF21 inhibits the growth of xenografts derived from CCA cells. TCF21 suppresses in vivo tumor-associated angiogenesis. TCF21 targets expression and production of proangiogenic factors from CCA cells. The targeting of phosphatidylinositol 3-kinase/protein kinase B and ERK1/2 signaling mediates the anti-angiogenesis of TCF21.