Nucleoporin 93, a new substrate of the E3 ubiquitin protein ligase HECTD1, promotes esophageal squamous cell carcinoma progression.

Nucleoporin 93 (NUP93) is an important component of the nuclear pore complex, exhibiting pro-tumorigenic properties in some cancers. However, its function in esophageal squamous cell carcinoma (ESCC) has not been elucidated. This study aimed to investigate the effects of NUP93 in ESCC and the underlying mechanisms involved. Through analysis of public human cancer datasets, we observed higher expression of NUP93 in esophageal cancer tissues than in normal tissues. Stable ESCC cell lines with NUP93 overexpression or knockdown were established by lentiviral vector transduction and puromycin selection. NUP93 knockdown suppressed the proliferation, colony formation, cell cycle transition, migration, and invasion of ESCC cells, while the overexpression of NUP93 displayed opposite effects. NUP93 positively regulated epithelial-mesenchymal transition and AKT signaling transduction in ESCC cells. In addition, NUP93 increased the expression of programmed death ligand 1 (PD-L1) in ESCC cells and attenuated NK cell-mediated lysis of ESCC cells. In vivo experiments demonstrated that NUP93 promotes the growth of ESCC in nude mice, enhances Ki67 and PD-L1 expression, and promotes AKT signaling transduction in xenografts. Mechanistically, we demonstrated that the HECT domain E3 ubiquitin protein ligase 1 (HECTD1) contributes to the ubiquitination and degradation of NUP93 and acts as a tumor suppressor in ESCC. To conclude, this study has shown that NUP93 has pro-tumor properties in ESCC and that HECTD1 functions as an upstream regulator of NUP93 in ESCC. These findings may contribute to the investigation of potential therapeutic targets in ESCC.

Neoadjuvant camrelizumab combined with paclitaxel and nedaplatin for locally advanced esophageal squamous cell carcinoma: A single-arm phase 2 study (cohort study).

BACKGROUND: Neoadjuvant administration of immune checkpoint inhibitors (ICIs) combined with chemotherapy demonstrated promising efficacy and manageable safety in locally advanced esophageal squamous cell carcinoma (ESCC). This prospective, single-arm, phase 2 study evaluated the efficacy and safety of neoadjuvant therapy with camrelizumab plus paclitaxel and nedaplatin for 2-4 cycles in ESCC. METHODS: Patients with locally advanced stage IIa-IIIb ESCC were enrolled in the study and received camrelizumab (200 mg), paclitaxel (155 mg/m2), and nedaplatin (80 mg/m2) intravenously on day one every three weeks. Patients underwent surgery after 2-4 cycles of treatment regimes. The primary endpoint was the pathological complete response (pCR) rate. Secondary endpoints included the major pathological response (MPR) rate, R0 resection rate, tumor regression, objective response rate (ORR), and disease-free survival (DFS). Programmed cell death 1 ligand 1 (PD-L1) expression in tumor tissues was measured and quantified using immunohistochemistry staining and combined positive score (CPS), respectively. RESULTS: In total, 75 patients were enrolled and received neoadjuvant treatment. Of them, 45 (60%) received two cycles, 18 (24%) received three cycles, and 10 patients (13.3%) received four cycles of neoadjuvant therapy. Ultimately, 62 (82.7%) patients underwent surgery. Patients achieved a pCR of 27.4% (95% CI 16.9-40.2), an MPR of 45.2% (95% CI 33.1-59.2), and an ORR of 48.4% (95% CI 35.5-61.4); all patients had an R0 resection. T and N downstaging occurred in 55 (88.7%) and 27 patients (43.5%). Moreover, ESCC patients with CPS ≥ 10 tended to have enhanced ORR, pCR, and MPR compared to those with CPS < 10. Treatment-related adverse events (TRAEs) of grade 1-2 occurred in 59 (78.7%) patients, grade 3 TRAEs in four (5.3%), and one patient (1.3%) experienced a grade 4 TRAE. CONCLUSIONS: Neoadjuvant camrelizumab combined with chemotherapy showed promising efficacy in locally advanced ESCC, with a manageable safety profile, when administered flexibly in two to four cycles.

Methyltransferase-like 3 facilitates the stem cell properties of esophageal cancer by upregulating patched homolog 1 via N6-methyladenosine methylation.

Patched homolog 1 (PTCH1) has been proven to facilitate cell proliferation and self-renewal in esophageal cancer (EC). The present study intended to exploit the influence of PTCH1 on EC cells and the potential mechanisms. PTCH1 and methyltransferase-like 3 (METTL3) expression were examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot in EC cell lines. Following the loss- and gain-of-function assays, cell proliferation was examined by cell counting kit (CCK)-8 and clone formation assays, invasion and migration by Transwell and scratch assays, and the sphere-forming ability of stem cells by cell sphere-forming assay. The expression of stemness genes NANOG homeobox protein (NANOG), octamer-binding transcription factor 4 (Oct4), and sex-determining region Y-box 2 (SOX2) was detected by Western blot. Methylated RNA immunoprecipitation (Me-RIP) assay was performed to test N6-methyladenosine (m6A) modification levels of PTCH1 mRNA, RIP and photoactivatable ribonucleoside-enhanced crosslinking and immunoprecipitation (PAR-CLIP) assays to assess the binding of METTL3 to PTCH1, and actinomycin D treatment to examine PTCH1 mRNA stability. A xenograft tumor model in nude mice was established for further in vivo verification. PTCH1 and METTL3 expression was high in EC cells. Knockdown of METTL3 reduced m6A level and stability of PTCH1 mRNA. Knockdown of PTCH1 or METTL3 declined invasion, proliferation, migration, and NANOG, Oct4, and SOX2 levels in EC cells, and reduced sphere-forming abilities of EC stem cells. Overexpression of PTCH1 abolished the suppressive effect of METTL3 knockdown on EC cells in vitro. METTL3 knockdown repressed tumor growth in nude mice, which was negated by further overexpressing PTCH1. METTL3 facilitated growth and stemness of EC cells via upregulation of PTCH1 expression by enhancing PTCH1 m6A modification.NEW & NOTEWORTHY PTCH1 has been proved to facilitate cell proliferation and self-renewal in esophageal cancer. We studied the upstream regulation mechanism of PTCH1 by METTL3 through m6A modification. Our results provide a new target and theoretical basis for the treatment of esophageal cancer.

Development and validation of the novel subclassification of pN3 for patients with esophageal cancer.

Background: Patients with stage pN3 esophageal cancer (EC) have a large number of metastatic lymph nodes (mLNs) and have poor prognosis. This study was to elucidate whether subclassification of pN3 according to the number of mLNs could improve the discrimination ability of EC patients. Methods: This study retrospectively analyzed patients with pN3 EC from the Surveillance, Epidemiology, and End Results (SEER) database as a training cohort and SEER validation cohort. Patients with pN3 esophageal cancer from the Affiliated Cancer Hospital of Harbin Medical University were used as the validation cohort. The optimal cutoff value of mLNs was identified using the X-tile software, and group pN3 into pN3-I and pN3-II based on mLNs. Kaplan-Meier method and log-rank test were used to analyze the disease-specific survival (DSS). The Cox proportional hazards regression analysis was used to identify the independent prognostic factors. Results: For the training cohort, patients with 7 to 9 mLNs were categorized as pN3-I, while those with more than 9 mLNs were categorized as pN3-II. There were 183 (53.8%) pN3-I and 157 (46.2%) pN3-II. The 5-year DSS rates of pN3-I and pN3-II in the training cohort were 11.7% and 5.2% (P=0.033), and the pN3 subclassification was an independent risk factor associated with patient prognosis. More RLNs may not improve patient prognosis, but the use of mLNs/RLNs is effective in predicting patient prognosis. Furthermore, the pN3 subclassification was well validated in the validation cohort. Conclusion: Subclassification of pN3 can better distinguish survival differences in EC patients.

Development of a cuproptosis-related signature for prognosis prediction in lung adenocarcinoma based on WGCNA.

Background: Cuproptosis is a novel mitochondrial respiration-dependent cell death mechanism induced by copper that can kill cancer cells via copper carriers in cancer therapy. However, the clinical significance and prognostic value of cuproptosis in lung adenocarcinoma (LUAD) remains unclear. Methods: We performed a comprehensive bioinformatics analysis of the cuproptosis gene set, including copy number aberration, single-nucleotide variation, clinical characteristics, survival analysis, etc. Cuproptosis-related gene set enrichment scores (cuproptosis Z-scores) were calculated in The Cancer Genome Atlas (TCGA)-LUAD cohort using single-sample gene set enrichment analysis (ssGSEA). Modules significantly associated with cuproptosis Z-scores were screened by weighted gene co-expression network analysis (WGCNA). The hub genes of the module were then further screened by survival analysis and least absolute shrinkage and selection operator (LASSO) analysis, in which TCGA-LUAD (497 samples) and GSE72094 (442 samples) were used as the training and validation cohorts, respectively. Finally, we analyzed the tumor characteristics, immune cell infiltration levels, and potential therapeutic agents. Results: Missense mutation and copy number variant (CNV) events were general in the cuproptosis gene set. We identified 32 modules, of which the MEpurple (107 genes) and MEpink (131 genes) modules significantly positively and negatively correlated with cuproptosis Z-scores, respectively. We identified 35 hub genes significantly related to overall survival and constructed a prognostic model consisting of 7 cuproptosis-related genes in patients with LUAD. Compared with the low-risk group, patients in the high-risk group had a worse overall survival and gene mutation frequency, as well as significantly higher tumor purity. In addition, infiltration of immune cells was also significantly different between the 2 groups. Furthermore, the correlation between the risk scores and half-maximum inhibitory concentration (IC50) of antitumor drugs in the Genomics of Drug Sensitivity in Cancer (GDSC) v. 2 database was explored, revealing differences in drug sensitivity across the 2 risk groups. Conclusions: Our study provided a valid prognostic risk model for LUAD and improved understanding of its heterogeneity, which may aid in the development of personalized treatment strategies.

Response to neoadjuvant immune checkpoint inhibitors and chemotherapy in Chinese patients with esophageal squamous cell carcinoma: the role of tumor immune microenvironment.

BACKGROUND: Immune checkpoint inhibitors (ICIs) through programmed cell death 1 blockade improve the survival outcomes of patients with advanced esophageal squamous cell carcinoma (ESCC). Recently, the use of neoadjuvant immunotherapy for the treatment of ESCC has been gradually increasing. We aimed to evaluate the efficacy of neoadjuvant treatment of ICIs with chemotherapy and explore tumor microenvironment (TME) immune profiles of ESCC samples during neoadjuvant therapy. METHODS: Patients with previously untreated, resectable, locally advanced ESCC (stage II or III) in Harbin Medical University Cancer Hospital were enrolled. Each patient received two to four cycles of neoadjuvant ICIs combined with chemotherapy before surgical resection. The TME immune profiles of formalin-fixed paraffin-embedded tumor samples at baseline and after surgery were evaluated by multiplex staining and multispectral imaging. RESULTS: In all, 18 patients were enrolled, and all patients received surgery with R0 resection. The postoperative pathological evaluation indicated that 7 (38.9%) patients had a pathological complete response (pCR) and 11 (61.1%) patients had a partial response. The neoadjuvant therapeutic regimens had acceptable side effect profiles. The TME immune profiles at baseline observed higher densities of stroma CD3 + , PD-1 + , and PD-1 + CD3 + cells in pCR patients than in non-pCR patients. Comparing TME immune profiles before and after neoadjuvant treatment, an increase in CD8 + T cells and a decrease in CD163 + CD68 + M2-like macrophage cells were observed after neoadjuvant treatment. CONCLUSIONS: Neoadjuvant ICIs combined with chemotherapy produced a satisfactory treatment response, demonstrating its anti-tumor efficacy in locally advanced ESCC. Further large-scale studies are required to understand the role of tumor immunities and ICIs underlying ESCC.

Prognostic Value of Combination of Controlling Nutritional Status and Tumor Marker in Patients with Radical Non-Small-Cell Lung Cancer.

Background: Controlling nutritional status (CONUT) and tumor markers are associated with prognosis in patients with non-small-cell lung cancer (NSCLC). This study is aimed at exploring the potential usefulness of T-CONUT, constructed by combining CONUT and tumor markers, for NSCLC patients undergoing radical surgery. Methods: A total of 483 patients with NSCLC underwent radical surgical resection. The receiver characteristic operating curve (ROC) was used to select the tumor marker with the highest predictive performance, and CONUT was combined with this marker to construct the T-CONUT. The Kaplan-Meier method and log-rank test were used to analyze the overall survival (OS), and chi-square analysis was used to analyze the association between T-CONUT and clinicopathological characteristics. The independent risk factors were analyzed by Cox regression. A nomogram was constructed by R studio. Calibration plots, the c-index, and decision curves were evaluated for the performance of the nomogram. Results: ROC analysis showed that the predictive performance of CYFRA21-1 was better than that of CEA, NSE, and SCC. CYFRA21-1 was selected for combining with CONUT to construct T-CONUT. Elevated T-CONUT indicates poor prognosis of patients. Histological type, pTNM, and T-CONUT are independent risk factors associated with patient prognosis. The areas under the curve of the nomogram for predicting 3- and 5-year OS were 0.760 and 0.761, respectively. Conclusion: T-CONUT comprising CYFRA21-1 and CONUT can effectively predict the prognosis of NSCLC patients.

Identification and validation of an eight-lncRNA signature that predicts prognosis in patients with esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is correlated with worse clinical prognosis and lacks available targeted therapy. Thus, identification of reliable biomarkers is required for the diagnosis and treatment of ESCC. METHODS: We downloaded the GSE53625 dataset as a training dataset to screen differentially expressed RNAs (DERs) with the criterion of false discovery rate (FDR) < 0.05 and |log2fold change (FC)| > 1. A support vector machine classifier was used to find the optimal feature gene set that could conclusively distinguish different samples. An eight-lncRNA signature was identified by random survival forest algorithm and multivariate Cox regression analysis. The RNA sequencing data from The Cancer Genome Atlas (TCGA) database were used for external validation. The predictive value of the signature was assessed using Kaplan-Meier test, time-dependent receiver operating characteristic (ROC) curves, and dynamic area under the curve (AUC). Furthermore, a nomogram to predict patients' 3-year and 5-year prognosis was constructed. CCK-8 assay, flow cytometry, and transwell assay were conducted in ESCC cells. RESULTS: A total of 1136 DERs, including 689 downregulated mRNAs, 318 upregulated mRNAs, 74 downregulated lncRNAs and 55 upregulated lncRNAs, were obtained in the GES53625 dataset. From the training dataset, we identified an eight-lncRNA signature, (ADAMTS9-AS1, DLX6-AS1, LINC00470, LINC00520, LINC01497, LINC01749, MAMDC2-AS1, and SSTR5-AS1). A nomogram based on the eight-lncRNA signature, age, and pathologic stage was developed and showed good accuracy for predicting 3-year and 5-year survival probability of patients with ESCC. Functionally, knockdown of LINC00470 significantly suppressed cell proliferation, G1/S transition, and migration in two ESCC cell lines (EC9706 and TE-9). Moreover, knockdown of LINC00470 downregulated the protein levels of PCNA, CDK4, and N-cadherin, while upregulating E-cadherin protein level in EC9706 and TE-9 cells. CONCLUSION: Our eight-lncRNA signature and nomogram can provide theoretical guidance for further research on the molecular mechanism of ESCC and the screening of molecular markers.

MicroRNA-421 promotes proliferation and invasion of non-small cell lung cancer cells through targeting PDCD4.

Recent evidence highlights that microRNAs serve as crucial regulators of tumorigenesis, including non-small cell lung cancer (NSCLC). The present study was designed to investigate the expression profile, clinical significance and biological role of miR-421 in NSCLC. The results showed that miR-421 expression was markedly increased in NSCLC tissues and cell lines. Further experimental data indicated that knockdown of miR-421 significantly inhibited NSCLC cell proliferation and induced cell cycle arrest in vitro. The migratory and invasive abilities of NSCLC cells were also attenuated following miR-421 knockdown. Furthermore, PDCD4 was identified as a direct target of miR-421, and its expression was inversely correlated with miR-421 expression in NSCLC tissues. PDCD4 also abrogated the oncogenic role of miR-421 in NSCLC cells. Collectively, our study revealed that miR-421 is significantly upregulated in NSCLC and might represent a potential therapeutic target for NSCLC patients.

The construction and analysis of the aberrant lncRNA-miRNA-mRNA network in non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the most common cancer and the pathogenesis remain unclear. According to the competing endogenous RNA (ceRNA) theory, long noncoding RNA (lncRNA) have a competition with mRNAs for the connecting with miRNAs that affecting the level of mRNA. In this work, the ceRNA network and the important genes to predict the survival prognosis were explored. METHODS: In the study, we recognized differently expressed genes (mRNAs, lncRNAs and miRNAs) between NSCLC and normal tissues from The Cancer Genome Atlas database (fold change >2, P<0.01) using edgeR. Then, the interaction between lncRNA and miRNA or mRNA and miRNA was explored by miRcode, miRDB, TargetScan, and miRanda. Furthermore, the functions and KEGG pathway were analyzed with DAVID and KOBAS. The connections of these mRNAs were explored by STRING online database. The relation between genes in the network and survival time were further explored by survival package in R. RESULTS: By bioinformatics tools, we explored 155 lncRNAs, 30 miRNAs and 68 mRNAs and constructed ceRNA network. The functions and KEGG pathway of 68 mRNAs were further analyzed. AQP2, EGF, SLC12A1, TRPV5 and AVPR2 was in the center of network and may play key roles in the development of NSCLC. And mRNA (CCNB1, COL1A1, E2F7, EGLN3, FOXG1 and PFKP), miRNA (miR-31, miR-144 and miR-192) and lncRNA (AC080129.1, AC100791.1, AL163952.1, AP000525.1, AP003064.2, C2orf48, C10orf91, FGF12-AS2, HOTAIR, LINC00518, LNX1-AS1, MED4-AS1, MIG31HG, MUC2, TTTY16 and UCA1) were closely related with overall survival (OS). CONCLUSIONS: In summary, the present study provides a deeper understanding of the lncRNA-related ceRNA network in NSCLC and some genes may be new target to treat for NSCLC patients.

Small Bowel Transit and Altered Gut Microbiota in Patients With Liver Cirrhosis.

Disturbance of the gut microbiota is common in liver cirrhosis (LC) patients, the underlying mechanisms of which are yet to be unfolded. This study aims to explore the relationship between small bowel transit (SBT) and gut microbiota in LC patients. Cross-sectional design was applied with 36 LC patients and 20 healthy controls (HCs). The gut microbiota was characterized by 16S rRNA gene sequencing. The Firmicutes/Bacteroidetes (F/B) ratio and the Microbial Dysbiosis index (MDI) were used to evaluate the severity of microbiota dysbiosis. The scintigraphy method was performed in patients to describe the objective values of SBT. Patients were then subdivided according to the Child-Pugh score (threshold = 5) or SBT value (threshold = 0.6) for microbiota analysis. LC patients were characterized by an altered gut microbiota; F/B ratios and MDI were higher than HC in both Child_5 (14.00 ± 14.69 vs. 2.86 ± 0.99, p < 0.01; 0.49 ± 0.80 vs. -0.47 ± 0.69, p < 0.01) and Child_5+ (15.81 ± 15.11 vs. 2.86±0.99, p < 0.01; 1.11 ± 1.05 vs. -0.47 ± 0.69, p < 0.01) sub-groups in patients. Difference in the gut microbiota between Child_ 5 and Child_5+ patients was inappreciable, but the SBT was relatively slower in Child_5+ patients (43 ± 26% vs. 80 ± 15%, p < 0.05). Compared with the Child-Pugh score indicators, SBT showed stronger associations with bacterial genera. A clear difference in the gut microbiota was observed between SBT_0.6- and SBT_0.6+ patients [Pr(>F) = 0.0068, pMANOVA], with higher F/B ratios and MDI in SBT_0.6- patients (19.71 ± 16.62 vs. 7.33 ± 6.65, p < 0.01; 1.02 ± 0.97 vs. 0.20 ± 0.58, p < 0.01). Similar results were observed between the SBT_0.6- and SBT_0.6+ sub-groups of patients with normal liver function and a Child-Pugh score of 5. SBT was negatively correlated with both the F/B ratio and MDI (r = -0.34, p < 0.05; r = -0.38, p < 0.05). Interestingly, an increased capacity for the inferred pathway "bacterial invasion of epithelial cells" in patients, was highly negatively correlated with SBT (r = -0.57, p < 0.01). The severity of microbiota dysbiosis in LC patients depends on SBT rather than Child-Pugh score. SBT per se might be significantly related to the gut microbiota abnormalities observed in patients with LC.

Cholesterol Esterification Enzyme Inhibition Enhances Antitumor Effects of Human Chimeric Antigen Receptors Modified T Cells.

Chimeric antigen receptor-modified T cell (CART) therapy has been demonstrated to have significant effect on hematologic tumor in patients. However, many persistent obstacles and challenges still limit the application. It is known that CD8 T cells are a key component of antitumor immunity. An avasimibe-induced inhibition of cholesterol esterification has been shown to improve the antitumor response of CD8 T cells in mice. In this study, using human CD19-directed CART cells as effector cells and CD19-overexpressing K562 cells as target cells, we detected whether cholesterol acyltransferase inhibition by avasimibe can enhance the antitumor effect of human CART cells. After avasimibe treatment, the infection rate was dropped by up to 50% (P<0.05). The cytotoxic effect of CART cells was significantly increased than the control group in a dose-dependent manner. Moreover, the level of secreted interferon-γ increased in almost half of the cases (P<0.05); the ratio of CD8CD4 T cells was increased among the total T cells and the CART cells in some of cases (P<0.05). Our study suggests that inhibition of cholesterol acyltransferase can promote the antitumor effect of CART cells, and provides a new option for a combination therapy by regulating T-cell metabolism to enhance antitumor effects.

[Effect of seasonal high temperature and drought on carbon flux of bamboo forest ecosystem in subtropical region].

The carbon flux of subtropical bamboo forest ecosystem was continuously measured using eddy covariance technique in Anji County of Zhejiang Province, China. The monthly net ecosystem productivity (NEP), ecosystem respiration (Re) and gross ecosystem productivity (GEP) data from 2011 to 2013 were selected to analyze the impacts of seasonal high temperature and drought on the carbon flux of bamboo forest ecosystem. The results showed that there were big differences among annual NEP of bamboo forest from 2011 to 2013. Because of the asynchronization of precipitation and heat, the seasonal high temperature and drought in July and August of 2013 caused significant decline in NEP by 59.9% and 80.0% when compared with the same months in 2011. Correlation analysis of the NEP, Re, GEP and environmental factors suggested that the atmosphere temperatures were significantly correlated with Re and GEP in 2011 and 2013 (P<0.05). However, to air and soil moisture, Re and GEP had different responses, that was, GEP was more vulnerable by the decrease of the soil moisture compared with Re. Besides, the raising of saturation vapour pressure promoted the Re modestly but inhibited the GEP, which was supposed to be the main reason for NEP decrease of bamboo forest ecosystem in Anji, from July to August in 2013.

[Characteristics of CO2 flux in an old growth mixed forest in Tianmu Mountain, Zhejiang, China].

The old-growth, multiple ages, multispecies natural forest has played an important role in terrestrial ecosystem dynamics model and the global carbon budget. However, carbon fluxes of old forests in subtropical regions are rarely reported in China. In the present study, the CO2 flux of an old-growth subtropical evergreen and deciduous broad-leaved mixed forest was observed using eddy covariance technique in Tianmu Mountain of Zhejiang Province. Based on the data sets which were observed from July 2013 to June 2014, the variations of net ecosystem exchange (NEE), eco-system respiration (Re), and gross ecosystem exchange (GEE) were analyzed. The results showed that during the study period, the monthly NEE all had a negative value (acted as a carbon sink) except for December and February (acted as a carbon source). The average monthly NEE was -61.52 g C · m⁻², the monthly carbon sequestration showed a double-peak curve and the maximum carbon sink was -149.40 g C · m⁻², which occurred in June while the maximum carbon source was 23.45 g C · m⁻², which occurred in February. The maximum of monthly mean CO2 flux occurred in June with a value of -0.98 mg · m⁻² · s⁻¹, while the minimum value occurred in December with a value of -0.35 mg · m⁻² · s⁻¹. The NEE at the time point of positive and negative conversion had typical seasonal characteristics. The yearly NEE, Re, and GEE were -738.18, 931.05 and -1669.23 g C · m⁻², respectively. Compared with other forest ecosystems located at the similar latitude, the carbon fixation of the old-growth forest was larger, likely due to its complicated structure within the canopy and the presence of young-growth regeneration and successional stands. This showed that other than in carbon neutral, old-growth forests of Tianmu Mountain in subtropical China had a strong capability in carbon sequestration.

Fabrication of multipotent poly-para-xylylene particles in controlled nanoscopic dimensions.

In this study, poly-para-xylylene-based multifunctional nanoparticles (PPX-NPs) were fabricated. Based on the solubility characteristics determined for asymmetrically substituted poly-para-xylylenes in polar solvents, well-dispersed nanocolloids with a controllable size ranging from 50 to 800nm were produced in solution by the displacement of the solvent (water). These size ranges were found to have acceptable cellular compatibility through examinations of cultured 3T3 fibroblasts and adipose-derived stem cells treated with the PPX-NPs. In addition, these nanoscale PPX-NPs exhibited versatile bioconjugation properties in that a variety of available functional groups can be adopted from their counterpart, thin-film poly-para-xylylenes, during the production of these nanoparticles. For instance, bifunctional PPX-NPs with maleimide and benzoyl moieties were produced to enable immobilization via a maleimide-thiol reaction concurrent with a photochemical reaction. A cleavable PPX-NP was also produced with a thiol-exchangeable surface property. Additionally, by performing electrohydrodynamic jetting of parallel polymer solutions of selected poly-para-xylylenes, Janus-type or multicompartment PPX-NPs were created. The PPX-NPs can potentially be used for various biomedical applications such as combined diagnostics and drug delivery, multiplexing of detection, multiple-drug loading, and the targeted delivery of biomolecules or drugs.