Characteristics of glucose and lipid metabolism and the interaction between gut microbiota and colonic mucosal immunity in pigs during cold exposure.

BACKGROUND: Cold regions have long autumn and winter seasons and low ambient temperatures. When pigs are unable to adjust to the cold, oxidative damage and inflammation may develop. However, the differences between cold and non-cold adaptation regarding glucose and lipid metabolism, gut microbiota and colonic mucosal immunological features in pigs are unknown. This study revealed the glucose and lipid metabolic responses and the dual role of gut microbiota in pigs during cold and non-cold adaptation. Moreover, the regulatory effects of dietary glucose supplements on glucose and lipid metabolism and the colonic mucosal barrier were evaluated in cold-exposed pigs. RESULTS: Cold and non-cold-adapted models were established by Min and Yorkshire pigs. Our results exhibited that cold exposure induced glucose overconsumption in non-cold-adapted pig models (Yorkshire pigs), decreasing plasma glucose concentrations. In this case, cold exposure enhanced the ATGL and CPT-1α expression to promote liver lipolysis and fatty acid oxidation. Meanwhile, the two probiotics (Collinsella and Bifidobacterium) depletion and the enrichment of two pathogens (Sutterella and Escherichia-Shigella) in colonic microbiota are not conducive to colonic mucosal immunity. However, glucagon-mediated hepatic glycogenolysis in cold-adapted pig models (Min pigs) maintained the stability of glucose homeostasis during cold exposure. It contributed to the gut microbiota (including the enrichment of the Rikenellaceae RC9 gut group, [Eubacterium] coprostanoligenes group and WCHB1-41) that favored cold-adapted metabolism. CONCLUSIONS: The results of both models indicate that the gut microbiota during cold adaptation contributes to the protection of the colonic mucosa. During non-cold adaptation, cold-induced glucose overconsumption promotes thermogenesis through lipolysis, but interferes with the gut microbiome and colonic mucosal immunity. Furthermore, glucagon-mediated hepatic glycogenolysis contributes to glucose homeostasis during cold exposure.

Identification of DNA-binding protein based multiple kernel model.

DNA-binding proteins (DBPs) play a critical role in the development of drugs for treating genetic diseases and in DNA biology research. It is essential for predicting DNA-binding proteins more accurately and efficiently. In this paper, a Laplacian Local Kernel Alignment-based Restricted Kernel Machine (LapLKA-RKM) is proposed to predict DBPs. In detail, we first extract features from the protein sequence using six methods. Second, the Radial Basis Function (RBF) kernel function is utilized to construct pre-defined kernel metrics. Then, these metrics are combined linearly by weights calculated by LapLKA. Finally, the fused kernel is input to RKM for training and prediction. Independent tests and leave-one-out cross-validation were used to validate the performance of our method on a small dataset and two large datasets. Importantly, we built an online platform to represent our model, which is now freely accessible via http://8.130.69.121:8082/.

Occurrence and ecological risk assessment of 16 phthalates in surface water of the mainstream of the Yangtze River, China.

Phthalic acid esters (PAEs), a class of typical endocrine disruptors, have received considerable attention due to their widespread applications and adverse effects on biological health. In this study, 30 water samples, along the mainstream of the Yangtze River (YR), were collected from Chongqing (upper stream) to Shanghai (estuary) from May to June in 2019. The total concentrations of 16 targeted PAEs ranged from 0.437 to 20.5 µg/L, with an average of 1.93 µg/L, where dibutyl phthalate (DBP, 0.222-20.2 µg/L), bis (2-ethylhexyl) phthalate (DEHP, 0.254-7.03 µg/L), and diisobutyl phthalate (DIBP, 0.0645-0.621 µg/L) were the most abundant PAEs. According to the pollution level in the YR to assess the ecological risk posed by PAEs, the results showed medium risk level of PAEs in the YR, among which DBP and DEHP posed a high ecological risk to aquatic organisms. The optimal solution for DBP and DEHP is found in ten fitting curves. The PNECSSD of them is 2.50 µg/L and 0.34 µg/L, respectively.

Effectiveness of ertapenem for treatment of infections in children: An evidence mapping and meta-analysis.

Objectives: To assess and summarize current evidence on the effectiveness and safety of ertapenem for treatment of childhood infections, in consideration of high infection prevalence in children and wide use of ertapenem. Methods: The following 8 databases were searched on 13th May 2021: Web of Science, Embase via Ovid SP, PubMed, The Cochrane Library (CENTRAL), Chinese BioMedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), VIP and Wanfang. The primary outcome was treatment success rate. Risk ratios (RRs) and 95% confidence interval (CI) were estimated using random-effect models. Subgroup analysis was conducted where heterogeneity was found. Results: Fifteen studies (8 randomized controlled trials, 1 observational comparative study, and 6 before and after studies) involving 2,528 patients were included in the final review. Ertapenem had similar treatment success rates with ß-lactam antibiotics [relative risk (RR) = 1.08, 95% CI: 0.99-1.19]. In a subgroup analysis, similar efficacy (RR = 1.08, 95% CI: 0.97-1.20) between ertapenem and other carbapenems. Compared with ß-lactam antibiotics, ertapenem did not increase the risk of any adverse events (RR = 1.02, 95%CI: 0.71-1.48), drug-related diarrhea (all non-Asian children, RR = 0.62, 95%CI: 0.31-1.25), or injection site pain (all non-Asian children, RR = 1.66, 95%CI: 0.59-4.68). Subgroup analysis showed no obvious difference between ertapenem group and carbapenems or non-carbapenems group on risk of adverse events. Conclusion: Our findings suggest that ertapenem is effective and safe in treatment for children with infection. Further comparative real-world data is needed to supplement clinical evidence on the overall benefits of ertapenem in this population.

Expression profiling of mRNA and functional network analyses of genes regulated by human papilloma virus E6 and E7 proteins in HaCaT cells.

Human papillomavirus (HPV) oncogenes E6 and E7 are essential for HPV-related cancer development. Here, we developed a cell line model using lentiviruses for transfection of the HPV16 oncogenes E6 and E7 and investigated the differences in mRNA expression during cell adhesion and chemokine secretion. Subsequently, RNA sequencing (RNA-seq) analysis was performed to explore the differences in mRNA expression. Compared to levels in the control group, 2,905 differentially expressed mRNAs (1,261 downregulated and 1,644 upregulated) were identified in the HaCaT-HPV16E6E7 cell line. To predict the functions of these differentially expressed genes (DEGs) the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases were used. Protein-protein interactions were established, and the hub gene was identified based on this network. Real-time quantitative-PCR (RT-qPCR) was conducted to confirm the levels of 14 hub genes, which were consistent with the RNA-seq data. According to this, we found that these DEGs participate in the extracellular matrix (ECM), cell adhesion, immune control, and cancer-related signaling pathways. Currently, an increasing number of clinicians depend on E6/E7mRNA results to make a comprehensive judgment of cervical precancerous lesions. In this study, 14 hub genes closely related to the expression of cell adhesion ability and chemokines were analyzed in HPV16E6E7-stably expressing cell lines, which will open up new research ideas for targeting E6E7 in the treatment of HPV-related cancers.

Plasma Calprotectin Is Predictive for Short-Term Functional Outcomes of Acute Ischemic Stroke.

Background: Blood-based prognostic biomarkers of acute ischemic stroke (AIS) are limiting. Calprotectin is suggested to be involved in directing post-stroke inflammatory conditions. However, the pathological alteration of circulating calprotectin in AIS is yet to be thoroughly elucidated. Therefore, this study aimed to investigate the levels and clinical relevance of calprotectin in AIS. Methods: This study recruited 271 patients with AIS within 24 h since symptom onset and 145 non-stroke healthy controls (HC) from February 1, 2018, to Dec 31, 2020. Patients were followed up for 2 weeks for observation of functional outcomes, as determined by the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS). Plasma calprotectin concentrations were determined by ELISA. Results: Plasma calprotectin concentrations were significantly higher in patients with AIS compared with controls [patients vs. control: median (IQR) 54.2 (39.01-99.04) vs. 50.04 (35.42-61.22), p < 0.001]. Besides, patients with poor prognosis, as defined by mRS ≥ 3, had significantly higher calprotectin levels than patients with good prognosis [poor prognosis patients vs. good prognosis patients: median (IQR) 61.99 (47.52-108) vs. 43.36 (33.39-60.2), p < 0.001]. Plasma calprotectin levels were positively associated with the disease severity of AIS, as reflected by infarction volume and NIHSS score at baseline. Furthermore, baseline calprotectin was found to be independently associated with poor prognosis [odds ratio (OR): 1.02, 95% CI: 1.01-1.03] and disease progression (OR: 1.03, 95% CI: 1.02-1.04) of AIS during a 2-week follow-up, with adjustment of possible confounding factors. Conclusion: Plasma calprotectin is associated with short-term functional outcomes of AIS.

The clinical effect and safety of new preoperative fasting time guidelines for elective surgery: a systematic review and meta-analysis.

Background: Traditional fasting and no drinking schemes (fasting for 8-12 hours and no drinking for 4-6 hours) affect the metabolism of the body. The new guidelines put forward by the American Association of Anesthesiologists (fasting for 6 hours, no drinking for 2 hours) obviously reduce the time of fasting and no drinking, but the clinical efficacy and safety need to be further confirmed. In this study, a meta-analysis of randomized controlled trials (RCTs) using the new guidelines and traditional protocols was conducted to provide an evidence-based foundation for elective surgery. Methods: The articles were searched in PubMed, EBSCO, MEDLINE, Science Direct, Cochrane Library, CNKI, China Biomedical Resources Database, Wanfang Database, Weipu, and Western Biomedical Journal Literature Database. RCTs related to fasting before surgery during the screening period were selected. Chinese and English search keywords included elective surgery, preoperative, fasting and no drinking, patient comfort, thirst, hunger, collapse, hypoglycemia, preoperative gastric volume, preoperative gastric juice pH, and intraoperative gastric volume. The RevMan 5.3 software provided by Cochrane collaboration network was used to evaluate the quality of included documents. Two professionals independently screened the literature, extracted data, and assessed the risk of bias. Results: A total of 6 studies were included. The incidence of hunger in patients undergoing elective surgery in the experimental group and control group was significantly different [Z=3.90; relative risk (RR) =0.58; 95% confidence interval (CI): 0.44, 0.76; P<0.0001]. The incidence of thirst was significantly different between the experimental group and control group (Z=7.22; RR =0.21; 95% CI: 0.13, 0.32; P<0.00001). Discussion: Meta-analysis results confirmed that the new guidelines can significantly reduce the hunger and thirst of patients, improve their satisfaction after surgery, and can be applied clinically.

pH-Responsive Nanoparticles for Enhanced Antitumor Activity by High-Intensity Focused Ultrasound Therapy Combined with Sonodynamic Therapy.

BACKGROUND: Therapeutic ultrasound (US) has been extensively explored for its inherent high tissue-penetrating capability and on-demand irradiation without radioactive damage. Although high-intensity focused ultrasound (HIFU) is evolved as such an outstanding US-based approach, its insufficient therapeutic effect and the high-intensity induced potential damage to surrounding normal tissues hindered its development towards practical application. As opposed to high intensity ultrasound, sonodynamic therapy (SDT) is a low intensity US-based method which exhibits certain therapeutic effects against cancer via sonosensitizers-generated reactive oxygen species (ROS) overproduction. METHODS: Hematoporphyrin monomethyl ether (HMME) loaded CaCO3 nanoparticles (designated as Ca@H) were synthesized by a gas diffusion method. The pH-responsive performance, in vitro SDT, ex vivo HIFU therapy (HIFUT), photoacoustic (PA) imaging and in vivo HIFUT combined with SDT were investigated thoroughly. RESULTS: Ca@H NPs gradually decomposed in acid tumor microenvironment, produced CO2 and released HMME. Both CO2 and HMME enhanced photoacoustic (PA) imaging. The generated CO2 bubbles also enhanced HIFUT by inducing an enlarged ablation area. The tumor ablation efficiency (61.04%) was significantly improved with a combination of HIFU therapy and SDT. CONCLUSION: pH-responsive Ca@H NPs have been successfully constructed for PA imaging-guided/monitored HIFUT combined with SDT. With the assistance of pH-responsive Ca@H NPs, the combination of these two US-based therapies is expected to play a role in the treatment of non-invasive tumor in the future.

An Analysis of the Motivation Mechanism of the Formation of Corporate Health Strategic Innovation Capability Based on the K-Means Algorithm.

Improving enterprises' independent innovation capability is critical to improving their competitive strength, industries' independent innovation capability, industries' international competitiveness, and countries' independent innovation capability, as well as building an innovative country. It is now the era of strategic innovation. Many growing businesses are focused on strategic innovation, but they overlook the issue of ensuring that strategic innovation is implemented. Management and innovation are perennial themes in the long-term development of businesses. The most pressing issue in enterprises' strategic innovation activities is how to combine their strategic direction with their superior ability and choose a strategic innovation path that is appropriate for their development. This paper uses data mining theory to establish the K-means clustering algorithm to identify the best strategic orientation of enterprise innovation strategic direction selection based on the existing advantages and capabilities of enterprises based on the analysis of the direction of enterprise strategic innovation.

Corrigendum: Effectiveness of ertapenem for treatment of infections in children: An evidence mapping and meta-analysis.

[This corrects the article DOI: 10.3389/fpsyt.2021.706625.].

Mitochondria-targeted nanoplatforms for enhanced photodynamic therapy against hypoxia tumor.

BACKGROUND: Photodynamic therapy (PDT) is a promising therapeutic modality that can convert oxygen into cytotoxic reactive oxygen species (ROS) via photosensitizers to halt tumor growth. However, hypoxia and the unsatisfactory accumulation of photosensitizers in tumors severely diminish the therapeutic effect of PDT. In this study, a multistage nanoplatform is demonstrated to overcome these limitations by encapsulating photosensitizer IR780 and oxygen regulator 3-bromopyruvate (3BP) in poly (lactic-co-glycolic acid) (PLGA) nanocarriers. RESULTS: The as-synthesized nanoplatforms penetrated deeply into the interior region of tumors and preferentially remained in mitochondria due to the intrinsic characteristics of IR780. Meanwhile, 3BP could efficiently suppress oxygen consumption of tumor cells by inhibiting mitochondrial respiratory chain to further improve the generation of ROS. Furthermore, 3BP could abolish the excessive glycolytic capacity of tumor cells and lead to the collapse of ATP production, rendering tumor cells more susceptible to PDT. Successful tumor inhibition in animal models confirmed the therapeutic precision and efficiency. In addition, these nanoplatforms could act as fluorescence (FL) and photoacoustic (PA) imaging contrast agents, effectuating imaging-guided cancer treatment. CONCLUSIONS: This study provides an ideal strategy for cancer therapy by concurrent oxygen consumption reduction, oxygen-augmented PDT, energy supply reduction, mitochondria-targeted/deep-penetrated nanoplatforms and PA/FL dual-modal imaging guidance/monitoring. It is expected that such strategy will provide a promising alternative to maximize the performance of PDT in preclinical/clinical cancer treatment.

Cancer cell membrane-coated nanoparticles for bimodal imaging-guided photothermal therapy and docetaxel-enhanced immunotherapy against cancer.

BACKGROUND: Mono-therapeutic modality has limitations in combating metastatic lesions with complications. Although emerging immunotherapy exhibits preliminary success, solid tumors are usually immunosuppressive, leading to ineffective antitumor immune responses and immunotherapeutic resistance. The rational combination of several therapeutic modalities may potentially become a new therapeutic strategy to effectively combat cancer. RESULTS: Poly lactic-co-glycolic acid (PLGA, 50 mg) nanospheres were constructed with photothermal transduction agents (PTAs)-Prussian blue (PB, 2.98 mg) encapsulated in the core and chemotherapeutic docetaxel (DTX, 4.18 mg)/ immune adjuvant-imiquimod (R837, 1.57 mg) loaded in the shell. Tumor cell membranes were further coated outside PLGA nanospheres (designated "M@P-PDR"), which acted as "Nano-targeted cells" to actively accumulate in tumor sites, and were guided/monitored by photoacoustic (PA)/ magnetic resonance (MR) imaging. Upon laser irradiation, photothermal effects were triggered. Combined with DTX, PTT induced in situ tumor eradication. Assisted by the immune adjuvant R837, the maturation rate of DCs increased by 4.34-fold compared with that of the control. In addition, DTX polarized M2-phenotype tumor-associated macrophages (TAMs) to M1-phenotype, relieving the immunosuppressive TME. The proportion of M2-TAMs decreased from 68.57% to 32.80%, and the proportion of M1-TAMs increased from 37.02% to 70.81%. Integrating the above processes, the infiltration of cytotoxic T lymphocytes (CTLs) increased from 17.33% (control) to 35.5%. Primary tumors and metastasis were significantly inhibited when treated with "Nano-targeted cells"-based cocktail therapy. CONCLUSION: "Nano-targeted cells"-based therapeutic cocktail therapy is a promising approach to promote tumor regression and counter metastasis/recurrence.

Production and characterization of functional wheat bran hydrolysate rich in reducing sugars, xylooligosaccharides and phenolic acids.

The aim was to enhance production of functional hydrolysate from wheat bran (WB). WB was hydrolyzed with 3000 U/mL ɑ-amylase and 1200 U/mL alkaline protease to prepare WB insoluble dietary fibre (WBIDF). Functional hydrolysate production from the extract containing crude xylan of WBIDF by xylanase was optimized by Taguchi method. The optimal condition for xylan degradation and functional substances production was 78.50 U/mL xylanase, pH 10.0, 50 °C, and reaction time 6 h. The maximum yield of reducing sugars was 614.0 µg/mL, xylobiose increased from 12.9 µg/mL to 213.3 µg/mL, xylotriose increased from 34.9 µg/mL to 174.0 µg/mL, ferulic acid 13.1 µg/mL made up 57.5 % of the total identifiable phenolic pool in the hydrolysate. The total antioxidant activity of hydrolysate was 141.8 mg ascorbic acid equivalents g-1 crude xylan, and the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity reached 92.7 %. The hydrolysate exhibited great potential in agricultural and food industry application.

Safety of longer linezolid regimen in children with drug-resistant tuberculosis and extensive tuberculosis in Southwest China.

OBJECTIVES: Linezolid (LNZ) has recently been listed by the World Health Organization (WHO) as a Group A agent for the treatment of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) in longer regimens (18-20 months). However, little is known about the safety of LNZ in longer TB treatment regimens in children. METHODS: Here we report 31 children who received LNZ treatment for drug-resistant tuberculosis (DR-TB) and extensive tuberculosis in the Children's Hospital of Chongqing Medical University, China, during September 2016 to March 2019. The mean duration of LNZ treatment was 8.56 months (range, 1-24 months). RESULTS: Of the 31 patients, 13 (42%) had suspected or confirmed adverse events (AEs) related to LNZ treatment, including digestive symptoms, haematological toxicity, neuropathy and lactic acidosis. Haematological toxicity was the most frequent AE, presenting as leukopenia (9/13) and anaemia (5/13). No hepatotoxicity or nephrotoxicity was observed. Two patients suffered from life-threatening lactic acidosis when the LNZ dose was increased to 1.2 g daily, however they recovered following LNZ withdrawal. CONCLUSION: A high rate of AEs of LNZ treatment was observed in children receiving a longer regimen, which might relate to the treatment course and dose. Haematological toxicity was the most frequent AE in children. It is necessary to regularly monitor the blood chemistry and lactic acid concentration during LNZ treatment.

Renal Safety of Intra-Arterial Treatment after Acute Ischemic Stroke with Multimodal CT Imaging selection.

BACKGROUND: Multimodal computed tomography imaging is used to identify eligible patients for intra-arterial treatment. A concern with this method is the multiple use of iodinated contrast material which presents a possible risk of renal toxicity. We compared the safety of intra-arterial treatment versus intravenous treatment during acute ischemic stroke treatment with a focus on renal safety. METHODS: Adult acute ischemic stroke patients who underwent a baseline Multimodal computed tomography, then intra-arterial treatment and/or intravenous treatment were identified. Primary outcomes were acute kidney injury and changes in serum creatinine at 24-72 hours (Δ serum creatinine). RESULTS: A total of 184 patients received intra-arterial treatment, while 68 received intravenous treatment. There were no differences in mean serum creatinine in the 24-72-hour time period, 24-hour urine volume, or rates of acute kidney injury, dialysis, or mortality. Univariate regression analysis identified diabetes mellitus, operation duration and times of embolectomy as predictors of creatinine increase while the multiple regression model identified diabetes mellitus as the only significant predictor. CONCLUSIONS: There were no significant differences in renal safety between the intra-arterial treatment and intravenous treatment groups. Diabetes mellitus may be a predictor of acute kidney injury. The use of Multimodal computed tomography imaging in the selection of patients who could benefit from endovascular therapy is safe.

New transformation pathway and cytotoxic derivatives from the acid hydrolysis of timosaponin B III.

Timosaponin B III is a major bioactive steroidal saponin isolated from Anemarrhena asphodeloides Bge. To potentially discover derivatives with better biological activity, timosaponin B III was structurally modified via acid hydrolysis to yield one new (2, timopregnane A I) C21 steroidal glycoside and seven known compounds. Their structures were elucidated on the basis of NMR spectroscopy and mass spectrometry. All eight compounds were evaluated for cytotoxic activity against MCF7, SW480, HepG2, and SGC7901 cell lines in vitro. As a result, compounds 6 and 7 showed significant activity (IC50 2.94-12.2 µM) against all tested cell lines. Structure-activity relationships of these compounds were investigated and the preliminary conclusions were provided. Moreover, a new transformation pathway was discovered in the acid hydrolysis of timosaponin B III for the first time.

Bioconversion of duck blood cell: process optimization of hydrolytic conditions and peptide hydrolysate characterization.

BACKGROUND: As the protein-laden by-product, red blood cells (RBCs) from poultry blood is a potential source of protein used as food and feed ingredient. However, RBC was currently underutilized. Therefore, it is an urgent need to develop feasible and cost-effective methods for converting poultry waste into nutritional and functional products. RESULTS: To take full advantage of this poultry waste, peptide hydrolysate was produced by deep controllable bioconversion of RBC, by means of synergistic combination of neutrase and flavourzyme. In this work, the functional properties and antioxidant activity of peptide hydrolysate were also characterized. The degree of hydrolysis (DH) was optimized using response surface methodology, and optimal hydrolysis conditions were found to be: temperature 51 °C, substrate concentration 14% (w/v), initial pH 7.0, and time 7.5 h. The red blood cell hydrolysate (RBCH) obtained not only possessed plentiful small peptides (< 3 kDa, 68.14%), but also was abundant in essential amino acids, accounting for over 50% of total amino acids. In addition to its excellent solubility (> 80%), emulsifying and foaming properties, RBCH also exhibited notable antioxidant activities, such as DPPH (2,2-diphenyl- 1-picrylhydrazyl) radical-scavenging activity (IC50, 4.16 mg/mL), reducing power, metal chelating ability and inhibiting lipid peroxidation. CONCLUSIONS: RBCH enriched in small peptides has the potential to be a new food additive with outstanding functional and antioxidant properties, and a process was established for converting poultry waste into peptide hydrolysate using neutrase and flavourzyme.

Gene expression profile changes in the jejunum of weaned piglets after oral administration of Lactobacillus or an antibiotic.

The small intestine plays an essential role in the health and well-being of animals. Previous studies have shown that Lactobacillus has a protective effect on intestinal morphology, intestinal epithelium integrity and appropriate maturation of gut-associated tissues. Here, gene expression in jejunum tissue of weaned piglets was investigated by RNA-seq analysis after administration of sterile saline, Lactobacillus reuteri, or an antibiotic (chlortetracycline). In total, 401 and 293 genes were significantly regulated by chlortetracycline and L. reuteri, respectively, compared with control treatment. Notably, the HP, NOX1 and GPX2 genes were significantly up-regulated in the L. reuteri group compared with control, which is related to the antioxidant ability of this strain. In addition, the expression of genes related to arachidonic acid metabolism and linoleic acid metabolism enriched after treatment with L. reuteri. The fatty acid composition in the jejunum and colon was examined by GC-MS analysis and suggested that the MUFA C18:1n9c, and PUFAs C18:2n6c and C20:4n6 were increased in the L. reuteri group, verifying the GO enrichment and KEGG pathway analyses of the RNA-seq results. The results contribute to our understanding of the probiotic activity of this strain and its application in pig production.

A Laser-Activated Biocompatible Theranostic Nanoagent for Targeted Multimodal Imaging and Photothermal Therapy.

Multifunctional nanoparticles have been reported for cancer detection and treatment currently. However, the accurate diagnosis and efficient treatment for tumors are still not satisfied. Here we report on the development of targeted phase change multimodal polymeric nanoparticles for the imaging and treatment of HER2-positive breast cancer. METHODS: We evaluated the multimodal imaging capabilities of the prepared nanoparticles in vitro using agar-based phantoms. The targeting performance and cytotoxicity of the nanoparticles were examined in cell culture using SKBR3 (over-expressing HER2) and MDA-MB-231 (HER2 negative) cells. We then tested the magnetic resonance (MR)/ photoacoustic (PA)/ ultrasound (US)/ near-infrared fluorescence (NIRF) multimodal imaging properties and photothermal effect of the nanoparticles in vivo using a SKBR3 breast xenograft model in nude mice. Tissue histopathology and immunofluorescence were also conducted. RESULTS: Both in vitro and in vivo systematical studies validated that the hybrid nanoparticles can be used as a superb MR/US/PA/NIRF contrast agent to simultaneously diagnose and guide tumor photothermal therapy (PTT). When irradiated by a near infrared laser, the liquid PFP vaporizes to a gas, rapidly expelling the contents and damaging surrounding tissues. The resulting micro-sized bubbles provide treatment validation through ultrasound imaging. Localization of DIR and SPIO in the tumor region facilitate photothermal therapy for targeted tumor destruction. The mice treated with HER2 targeted nanoparticles had a nearly complete response to treatment, while the controls showed continued tumor growth. CONCLUSION: This novel theranostic agent may provide better diagnostic imaging and therapeutic potential than current methods for treating HER2-positive breast cancer.

Enhancement of thermoalkaliphilic xylanase production by Pichia pastoris through novel fed-batch strategy in high cell-density fermentation.

BACKGROUND: Xylanase degrades xylan into monomers of various sizes by catalyzing the endohydrolysis of the 1,4-ß-D-xylosidic linkage randomly, possessing potential in wide industrial applications. Most of xylanases are susceptible to be inactive when suffering high temperature and high alkaline process. Therefore, it is necessary to develop a high amount of effective thermoalkaliphilic xylanases. This study aims to enhance thermoalkaliphilic xylanase production in Pichia pastoris through fermentation parameters optimization and novel efficient fed-batch strategy in high cell-density fermentation. RESULTS: Recombinant xylanase activity increased 12.2%, 7.4%, 12.0% and 9.9% by supplementing the Pichia pastoris culture with 20 g/L wheat bran, 5 mg/L L-histidine, 10 mg/L L-tryptophan and 10 mg/L L-methionine in shake flasks, respectively. Investigation of nutritional fermentation parameters, non-nutritional fermentation parameters and feeding strategies in 1 L bioreactor and 1 L shake flask revealed that glycerol and methanol feeding strategies were the critical factors for high cell density and xylanase activity. In 50 L bioreactor, a novel glycerol feeding strategy and a four-stage methanol feeding strategy with a stepwise increase in feeding rate were developed to enhance recombinant xylanase production. In the initial 72 h of methanol induction, the linear dependence of xylanase activity on methanol intake was observed (R2 = 0.9726). The maximum xylanase activity was predicted to be 591.2 U/mL, while the actual maximum xylanase activity was 560.7 U/mL, which was 7.05 times of that in shake flask. Recombinant xylanase retained 82.5% of its initial activity after pre-incubation at 80 °C for 50 min (pH 8.0), and it exhibited excellent stability in the broad temperature (60-80 °C) and pH (pH 8.0-11.0) ranges. CONCLUSIONS: Efficient glycerol and methanol fed-batch strategies resulting in desired cell density and xylanase activity should be applied in other P. pastoris fermentation for other recombinant proteins production. Recombinant xylanases with high pH- and thermal-stability showed potential in various industrial applications.