Dysregulated Microbial Fermentation of Soluble Fiber Induces Cholestatic Liver Cancer.

Dietary soluble fibers are fermented by gut bacteria into short-chain fatty acids (SCFA), which are considered broadly health-promoting. Accordingly, consumption of such fibers ameliorates metabolic syndrome. However, incorporating soluble fiber inulin, but not insoluble fiber, into a compositionally defined diet, induced icteric hepatocellular carcinoma (HCC). Such HCC was microbiota-dependent and observed in multiple strains of dysbiotic mice but not in germ-free nor antibiotics-treated mice. Furthermore, consumption of an inulin-enriched high-fat diet induced both dysbiosis and HCC in wild-type (WT) mice. Inulin-induced HCC progressed via early onset of cholestasis, hepatocyte death, followed by neutrophilic inflammation in liver. Pharmacologic inhibition of fermentation or depletion of fermenting bacteria markedly reduced intestinal SCFA and prevented HCC. Intervening with cholestyramine to prevent reabsorption of bile acids also conferred protection against such HCC. Thus, its benefits notwithstanding, enrichment of foods with fermentable fiber should be approached with great caution as it may increase risk of HCC.

Controlling Nutritional Status score is superior to Prognostic Nutritional Index score in predicting survival and complications in pancreatic ductal adenocarcinoma: a Chinese propensity score matching study.

Preoperative nutritional status plays an important role in predicting postoperative outcomes. Prognostic Nutritional Index (PNI) and Controlling Nutritional Status (CONUT) are good tools to assess patients' nutritional status. They have been used in predicting outcomes in various malignancies, but few studies have focused on pancreatic adenocarcinoma (PDAC) patients. Totally, 306 PDAC patients were enrolled. The propensity score matching (PSM) method was introduced to eliminate the baseline inequivalence. Patients with different PNI (or CONUT) scores showed inequivalence baseline characteristics, and patients with compromised nutritional status were related with a more advanced tumour stage. After PSM, the baseline characteristics were well balanced. Both low PNI (≤45) and high CONUT (≥3) were independent risk factors for poor overall survival (P < 0·05), and the result remained the same after PSM. Survival analysis demonstrated both patients with low PNI and high CONUT score were associated with poorer survival, and the result remained the same after PSM. The results of AUC indicated that CONUT might have a higher sensitivity and specificity in predicting complications and survival. Preoperative low PNI (≤45) and high CONUT (≥3) scores might be reliable predictors of prognosis and surgical complications in PDAC patients. Compared with PNI, CONUT might be more effective.

Self-Assembly of Extracellular Vesicle-like Metal-Organic Framework Nanoparticles for Protection and Intracellular Delivery of Biofunctional Proteins.

The intracellular delivery of biofunctional enzymes or therapeutic proteins through systemic administration is of great importance in therapeutic intervention of various diseases. However, current strategies face substantial challenges owing to various biological barriers, including susceptibility to protein degradation and denaturation, poor cellular uptake, and low transduction efficiency into the cytosol. Here, we developed a biomimetic nanoparticle platform for systemic and intracellular delivery of proteins. Through a biocompatible strategy, guest proteins are caged in the matrix of metal-organic frameworks (MOFs) with high efficiency (up to ∼94%) and high loading content up to ∼50 times those achieved by surface conjunction, and the nanoparticles were further decorated with the extracellular vesicle (EV) membrane with an efficiency as high as ∼97%. In vitro and in vivo study manifests that the EV-like nanoparticles can not only protect proteins against protease digestion and evade the immune system clearance but also selectively target homotypic tumor sites and promote tumor cell uptake and autonomous release of the guest protein after internalization. Assisted by biomimetic nanoparticles, intracellular delivery of the bioactive therapeutic protein gelonin significantly inhibits the tumor growth in vivo and increased 14-fold the therapeutic efficacy. Together, our work not only proposes a new concept to construct a biomimetic nanoplatform but also provides a new solution for systemic and intracellular delivery of protein.

Nucleus of Circulating Tumor Cell Determines Its Translocation Through Biomimetic Microconstrictions and Its Physical Enrichment by Microfiltration.

The mechanism of cells passing through microconstrictions, such as capillaries and endothelial junctions, influences metastasis of circulating tumor cells (CTCs) in vivo, as well as size-based enrichment of CTCs in vitro. However, very few studies observe such translocation of microconstrictions in real time, and thus the inherent biophysical mechanism is poorly understood. In this study, a multiplexed microfluidic device is fabricated for real-time tracking of cell translocation under physiological pressure and recording deformation of the whole cell and nucleus, respectively. It is found that the deformability and size of the nucleus instead of the whole cell dominate cellular translocation through microconstrictions under a normal physiological pressure range. More specifically, cells with a large and stiff nucleus are prone to be blocked by relatively small constrictions. The same phenomenon is also observed in the size-based enrichment of CTCs from peripheral blood of metastatic cancer patients. These findings are different from a popular viewpoint that the size and deformability of a whole cell mainly determine cell translation through microconstrictions, and thus may elucidate interactions between CTCs and capillaries from a new perspective and guide the rational design of size-based microfilters for rare cell enrichment.

A Spontaneous 3D Bone-On-a-Chip for Bone Metastasis Study of Breast Cancer Cells.

Bone metastasis occurs at ≈70% frequency in metastatic breast cancer. The mechanisms used by tumors to hijack the skeleton, promote bone metastases, and confer therapeutic resistance are poorly understood. This has led to the development of various bone models to investigate the interactions between cancer cells and host bone marrow cells and related physiological changes. However, it is challenging to perform bone studies due to the difficulty in periodic sampling. Herein, a bone-on-a-chip (BC) is reported for spontaneous growth of a 3D, mineralized, collagenous bone tissue. Mature osteoblastic tissue of up to 85 µm thickness containing heavily mineralized collagen fibers naturally formed in 720 h without the aid of differentiation agents. Moreover, co-culture of metastatic breast cancer cells is examined with osteoblastic tissues. The new bone-on-a-chip design not only increases experimental throughput by miniaturization, but also maximizes the chances of cancer cell interaction with bone matrix of a concentrated surface area and facilitates easy, frequent observation. As a result, unique hallmarks of breast cancer bone colonization, previously confirmed only in vivo, are observed. The spontaneous 3D BC keeps the promise as a physiologically relevant model for the in vitro study of breast cancer bone metastasis.

Evidence that histidine forms a coordination bond to the A(0A) and A(0B) chlorophylls and a second H-bond to the A(1A) and A(1B) phylloquinones in M688H(PsaA) and M668H(PsaB) variants of Synechocystis sp. PCC 6803.

The axial ligands of the acceptor chlorophylls, A(0A) and A(0B), in Photosystem I are the Met sulfur atoms of M688(PsaA) and M668(PsaB). To determine the role of the Met, His variants were generated in Synechocystis sp. PCC 6803. Molecular dynamics simulations on M688H(PsaA) show that there exist low energy conformations with the His coordinated to A(0A) and possibly H-bonded to A(1A). Transient EPR studies on M688H(PsaA) indicate a more symmetrical electron spin distribution in the A(1A) phyllosemiquinone ring consistent with the presence of an H-bond to the C1 carbonyl. Ultrafast optical studies on the variants show that the 150fs charge separation between P700 and A(0) remains unaffected. Studies on the ns timescale show that 57% of the electrons are transferred from A(0A)(-) to A(1A) in M688H(PsaA) and 48% from A(0B)(-) to A(1B) in M668H(PsaB); the remainder recombine with P700(+) with 1/e times of 25ns and 37ns, respectively. Those electrons that reach A(1A) and A(1B) in the branch carrying the mutation are not transferred to FX, but recombine with P700(+) with 1/e times of ~15µs and ~5µs, respectively. Hence, the His is coordinated to A0 in all populations, but in a second population, the His may be additionally H-bonded to A(1). Electron transfer from A(0) to A(1) occurs only in the latter, but the higher redox potentials of A(0) and A(1) as a result of the stronger coordination bond to A(0) and the proposed second H-bond to A(1) preclude electron transfer to the Fe/S clusters.

Splenic vessel preservation versus Warshaw's technique during spleen-preserving distal pancreatectomy: a meta-analysis and systematic review.

BACKGROUND: Splenic preservation can be achieved through splenic vessel resection by Warshaw's technique (WT) or by preserving the splenic vessels. This meta-analysis aims to provide evidence-based comparison regarding the perioperative outcome and long-term benefits between patients with and without splenic vessel preservation (SVP) during spleen-preserving distal pancreatectomy. METHOD: A meta-analysis was performed to evaluate studies comparing splenic vessel preservation versus resection groups. Ten retrospective studies including 699 patients were eligible for an analysis of general, perioperative, and long-term outcomes. A further analysis composed of five subgroups was also conducted in terms of laparoscopic approach. RESULTS: Warshaw's technique related to significant shorter operation time (P < 0.0001). There was no difference in blood loss (P = 0.45) as well as median tumor size (p = 0.1) between the two groups. The overall rate of complications indicated no difference between SVP and WT (P = 0.1), including pancreatic fistula rates, which were not statistically different among the treatment groups (P = 0.27). However, the occurrence of gastric varices and splenic infarction was significant higher in the WT group (P < 0.01). In laparoscopic subgroups, patients treated by WT had much lower blood loss (P = 0.002). CONCLUSION: In spleen-preserving distal pancreatectomy, comparing with SVP, there is no evidence of significant benefit of WT. Nonetheless, surgeons should master both techniques and choose an appropriate one based on personal experience and a "case by case" situation. However, the current available evidence is weak, and further randomized controlled data are warranted.

Adult primary retroperitoneal cavernous hemangioma: a case report.

Primary retroperitoneal cavernous hemangioma (PRCH) in an adult is extremely rare. We report on the diagnosis and treatment of a patient with PRCH with subtle clinical features and atypical findings on imaging scans. A 38-year-old man was admitted to hospital with a 5-day history of epigastralgia after alcohol drinking. Using various imaging methods, we found a giant cyst-like retroperitoneal mass compressing the surrounding organs. Surgical resection of the tumor was performed, and the mass was found to be a cavernous hemangioma measuring 90 × 80 × 60 mm, with a thick fibrotic wall and extensive intracystic hemorrhage. Physicians should be aware that PRCH may mimic a cystic neoplasm, and that a large tumor size probably indicates intracystic hemorrhage. Surgical resection is a curative approach for PRCH.

Appraisal of EUS-guided needle-based confocal laser endomicroscopy in the diagnosis of pancreatic lesions: A single Chinese center experience.

BACKGROUND AND OBJECTIVES: In the recent years, EUS is one of the routine procedures in the diagnosis of pancreatic diseases. EUS-guided needle-based confocal laser endomicroscopy (nCLE) is a novel minimally invasive imaging technique in diagnosis of pancreatic diseases. The pilot researches provided us some preliminary findings and conclusions with small samples, low rate of pathological correspondence. The aim of this current study was to evaluate the diagnostic efficacy of EUS-guided nCLE in solid pancreatic lesions (SPLs) and pancreatic cystic lesions (PCLs) based on large samples. The date was obtained on nCLE imaging findings and high rate of correlation with pathology. MATERIAL AND METHODS: Patients enrolled in the study were underwent EUS-nCLE to achieve the nCLE images and diagnosis. Comparing with the final diagnosis, including surgical histopathological results or cyto-/histopathology through FNA, the efficacy and accuracy of nCLE in diagnosis in solid and cystic pancreatic lesions were evaluated. In other cases, clinical diagnoses were achieved based on the combination with clinical history, image findings and fluid analysis and cytology, by 3 independent committee members strongly agreed with a concordant diagnosis. RESULTS: Totally 172 patients were enrolled into the study. The overall rate of final diagnosis was about 65% while 50% in cystic lesion. The mean sensitivity, specificity, negative predictive value, positive predictive value and accuracy of the nCLE in diagnosis of PDAC is 90.3%, 89.5%, 93.3%, 85.0% and 90.0% respectively. The efficacy and accuracy of pancreatic cystic lesions were very satisfying and some additional nCLE signs were found, including "black aggregates of cells, forming as gland-like structure, surrounding by fibro and vessels" in neuroendocrine tumors (NETs); "black columnar protrusions near vascular area" in the pseudopapillary solid tumor (SPT); macrophage in tuberculosis (TB) and small aggregate of black regular cells maybe corresponds to ovarian-like stroma in mucinous cystadenoma (MCN). In the study, 20 (11.6%) patients suffered complications, including symptomatic (5.2%) and asymptomatic (6.4%). CONCLUSIONS: nCLE observation could improve characterization of indeterminate cysts, or confirm the EUS impression, when cytological confirmation is missing. The technique may deliver information to better guide our clinical decisions.

Pancreatic adenocarcinoma: dynamic 64-slice helical CT with perfusion imaging.

BACKGROUND: Perfusion CT is able to outline blood perfusion changes in a tissue. Thus, in lesions of the tissues of the pancreas, this offers to increase the accuracy of CT diagnosis. In this study, our aim was to explore the perfusion characteristics of normal pancreas and pancreatic adenocarcinoma. METHODS: Dynamic 64-slice helical CT was conducted in 36 patients with non-pancreatic disease and in 40 patients with histopathologically proven pancreatic adenocarcinoma. Perfusion parameters including blood flow (BF), blood volume (BV), and permeability surface area product (PS) were recorded. RESULTS: There was no significant difference noted between the distribution of BF, BV, and PS values in different regions of the pancreas, namely the head, neck, body, and tail (P > 0.05). The BF, BV, and PS of normal pancreas were recorded as 135.24 +/- 48.36 ml min(-1) 100 g(-1), 200.55 +/- 54.96 ml 100 g(-1), and 49.75 +/- 24.27 ml min(-1) 100 g(-1), respectively. BF, BV, and PS values of the tumor tissue of pancreatic adenocarcinoma decreased significantly compared to normal pancreas (P < 0.05). CONCLUSIONS: Normal pancreas appears homogenous on perfusion CT. A significant decrease of BF, BV, and PS was observed in pancreatic adenocarcinoma. Dynamic 64-slice helical CT with perfusion imaging should be considered a potential modality to increase the accuracy of CT diagnosis for pancreatic adenocarcinoma.

Drain Contamination after Distal Pancreatectomy: Incidence, Risk Factors, and Association with Postoperative Pancreatic Fistula.

OBJECTIVE: Distal pancreatectomy (DP) remains associated with significant morbidity, but little data is available about the clinical significance of drain contamination. We explored the incidence, risk factors, and association with surgical outcomes of positive drainage culture (PDC) after DP. In addition, the predictive capacity of early PDC for postoperative pancreatic fistula (POPF) was evaluated. METHODS: We retrospectively analyzed our prospectively collected database of patients who underwent DP between January 2005 and December 2015. Surveillance drainage cultures for microorganisms were conducted until drain removal or positive culture. The relationships between clinical variables and PDC were examined. RESULTS: Of 480 consecutive cases who underwent DP, 176 (36.7%) had PDC. One hundred twelve patients (23.3%) developed POPF according to the 2016 ISGPS definition, with the 90-day mortality rate of 0.2%. Staphylococcus spp. was the most frequent isolate. Thirty-eight (21.6%) patients had PDC within 3 days after surgery, and 129 (73.3%) within the first 7 days of operation. Body mass index (BMI) ≥ 25 kg/m2 and massive intraoperative blood loss were independent predictors for PDC. PDC had a negative impact on surgical outcomes, including POPF. Early PDC was identified as a newly independent risk factor for POPF. Compared with other microorganisms, those contaminated with Staphylococcus and Klebsiella had higher incidences of POPF. CONCLUSIONS: PDC occurs commonly after DP and plays a critical role in the development of surgical morbidities including POPF. Extreme caution is warranted in patients involving contamination with specific types of microorganisms.

Delaying surgery after preoperative biliary drainage does not increase surgical morbidity after pancreaticoduodenectomy.

BACKGROUND: The effects of the time interval from preoperative biliary drainage to pancreaticoduodenectomy on morbidity and mortality have not been established, but a recent multicenter study found that an interval greater than 4 weeks resulted in fewer major complications. We investigated whether delaying pancreaticoduodenectomy after preoperative biliary drainage led to improved postoperative morbidity and mortality. METHODS: Patients who underwent elective open pancreaticoduodenectomy between January 2009 and December 2016 were retrospectively analyzed. They were divided into a short duration group (time interval to surgery <4 weeks) and a delaying surgery group (time interval to surgery ≥4 weeks). An unstented control group (no stent group) was added. Perioperative characteristics and surgical outcomes were compared. RESULTS: Of 603 patients who underwent pancreaticoduodenectomy, 183 (30.3%) had preoperative biliary drainage, 110 patients (18.2%) in the short duration group and 73 (12.1%) in the delaying surgery group. The median interval between preoperative biliary drainage and pancreaticoduodenectomy was 3 weeks (interquartile range, 2-3) for the former group and 6 weeks (interquartile range, 5-7) for the latter. With the exception of wound infection, which was significantly higher in the short duration group than in the controls (8.2% vs 1.7%, P = .002) but not significantly increased compared with the delaying surgery group (8.2% vs 4.1%, P = .368), other complications were comparable among the 3 groups. Subgroup analyses in the intermediate- and high-risk cohort based on either original or alternative Fistula Risk Score showed similar outcomes. Univariate and multivariate analyses showed that short stent duration and female sex were independent factors associated with wound infection. CONCLUSION: A time interval between preoperative biliary drainage and resection greater than 4 weeks does not have a negative impact on short-term surgical outcomes. This finding indicates the relative safety of postponing surgery, if necessary, for preoperative treatment, optimization, or preparation.

Enrichment of extracellular vesicles with lipid nanoprobe functionalized nanostructured silica.

Nanoscale extracellular vesicles (nEVs) have recently demonstrated potential value in cancer diagnostics and treatment monitoring, but translation has been limited by technical challenges in nEV isolation. Thus, we have developed a one-step nEV isolation platform that utilizes nEV size-matched silica nanostructures and a surface-conjugated lipid nanoprobe with an integrated microfluidic mixer. The reported platform has 28.8% capture efficiency from pancreatic cancer plasma and can sufficiently enrich nEVs for simpler positive identification of point mutations, particularly KRAS, in nEV DNA from the plasma of pancreatic cancer patients.

Size-based separation methods of circulating tumor cells.

Circulating tumor cells (CTCs) originate from the primary tumor mass and enter into the peripheral bloodstream. Compared to other "liquid biopsy" portfolios such as exosome, circulating tumor DNA/RNA (ctDNA/RNA), CTCs have incomparable advantages in analyses of transcriptomics, proteomics, and signal colocalization. Hence, CTCs hold the key to understanding the biology of metastasis and play a vital role in cancer diagnosis, treatment monitoring, and prognosis. Size-based enrichment features are prominent in CTC isolation. It is a label-free, simple and fast method. Enriched CTCs remain unmodified and viable for a wide range of subsequent analyses. In this review, we comprehensively summarize the differences of size and deformability between CTCs and blood cells, which would facilitate the development of technologies of size-based CTC isolation. Then we review representative size-/deformability-based technologies available for CTC isolation and highlight the recent achievements in molecular analysis of isolated CTCs. To wrap up, we discuss the substantial challenges facing the field, and elaborate on prospects.

In Situ Caging of Biomolecules in Graphene Hybrids for Light Modulated Bioactivity.

Remote and noninvasive modulation of protein activity is essential for applications in biotechnology and medicine. Optical control has emerged as the most attractive approach owing to its high spatial and temporal resolutions; however, it is challenging to engineer light responsive proteins. In this work, a near-infrared (NIR) light-responsive graphene-silica-trypsin (GST) nanoreactor is developed for modulating the bioactivity of trypsin molecules. Biomolecules are spatially confined and protected in the rationally designed compartment architecture, which not only reduces the possible interference but also boosts the bioreaction efficiency. Upon NIR irradiation, the photothermal effect of the GST nanoreactor enables the ultrafast in situ heating for remote activation and tuning of the bioactivity. We apply the GST nanoreactor for remote and ultrafast proteolysis of proteins, which remarkably enhances the proteolysis efficiency and reduces the bioreaction time from the overnight of using free trypsin to seconds. We envision that this work not only provides a promising tool of ultrafast and remotely controllable proteolysis for in vivo proteomics in study of tissue microenvironment and other biomedical applications but also paves the way for exploring smart artificial nanoreactors in biomolecular modulation to gain insight in dynamic biological transformation.

Genome-Wide Analysis Identified a Number of Dysregulated Long Noncoding RNA (lncRNA) in Human Pancreatic Ductal Adenocarcinoma.

BACKGROUND: Long noncoding RNAs have been shown to play crucial roles in cancer biology, while the long noncoding RNA landscapes of pancreatic ductal adenocarcinoma have not been completely characterized. We aimed to determine whether long noncoding RNA could serve as early diagnostic biomarkers for pancreatic ductal adenocarcinoma. METHOD: We conducted a genome-wide microarray analysis on pancreatic ductal adenocarcinoma and their adjacent noncancerous tissues from 8 Chinese patients. RESULTS: A total of 3352 significantly differentially expressed long noncoding RNAs were detected. Of total, 1249 long noncoding RNAs were upregulated and 2103 were downregulated (fold change ≥2, P < 0.05, FDR <0.05). These differentially expressed long noncoding RNAs were not evenly distributed among chromosomes in human genome. Hierarchical clustering of these differentially expressed long noncoding RNAs revealed large variabilities in long noncoding RNA expression among individual patient, indicating that certain long noncoding RNAs could play a unique role or be used as a biomarker for specific subtype of pancreatic ductal adenocarcinoma. Gene Ontology enrichment and pathway analysis identified several remarkably dysregulated pathways in pancreatic ductal adenocarcinoma tissue, such as interferon-γ-mediated signaling pathway, mitotic cell cycle and proliferation, extracellular matrix receptor interaction, focal adhesion, and regulation of actin cytoskeleton. The co-expression network analysis detected 393 potential interactions between 80 differentially expressed long noncoding RNAs and 105 messenger RNAs. We experimentally verified 7 most markedly dysregulated long noncoding RNAs from the network. CONCLUSION: Our study provided a genome-wide survey of dysregulated long noncoding RNAs and long noncoding RNA/messenger RNA co-regulation networks in pancreatic ductal adenocarcinoma tissue. These dysregulated long noncoding RNA/messenger RNA networks could be used as biomarkers to provide early diagnosis of pancreatic ductal adenocarcinoma or its subtype, predict prognosis, and evaluate treatment efficacy.

Central pancreatectomy with external drainage of monolayer pancreaticojejunostomy for prevention of postoperative pancreatic fistula: A retrospective cohort study.

OBJECTIVE: Postoperative pancreatic fistula (POPF) remains a common problem and leading cause of morbidity and mortality after central pancreatectomy (CP). The aim of this study was to present a technique of external drainage of monolayer pancreaticojejunostomy for prevention of POPF. METHODS: Patients received elective CP with external drainage of monolayer pancreaticojejunostomy between January 2010 and December 2016 were retrospectively analyzed. The occurrence and severity of POPF, overall complications, reoperation rate, in-hospital mortality, and length of postoperative hospital stay were measured. The 2016 updated definition and classification system of the International Study Group of Pancreatic Surgery (ISGPS) was used for POPF. In addition, a matched-pairs comparison with internal drainage of pancreaticojejunostomy was made. RESULTS: 33 consecutive patients underwent CP with external drainage of monolayer pancreaticojejunostomy during this period. 4 (12.1%) cases developed grade B POPF, among which one patient was classified as having Clavien-Dindo classification IIIa complication. None of the patients developed grade C POPF, delayed gastric emptying, or postpancreatectomy hemorrhage. There was no reoperation or in-hospital mortality occurred. Matched-pairs comparison revealed that patients with external drainage of pancreaticojejunostomy had significantly lower incidence of POPF. CONCLUSION: External drainage of monolayer pancreaticojejunostomy seems effective in prevention of POPF after CP.

Preoccupation of Empty Carriers Decreases Endo-/Lysosome Escape and Reduces the Protein Delivery Efficiency of Mesoporous Silica Nanoparticles.

Endo-/lysosome escape is a major challenge in nanoparticle-based protein delivery for cancer therapy. To enhance the endo-/lysosomal escape and increase the efficacy of protein delivery, current strategies mainly focus on destroying endo-/lysosomes by employing modified nanoparticles, such as pH-sensitive polyplexes, cell-penetrating peptides, and photosensitive molecules. Herein, we hypothesize that pretreatment with empty nanocarriers might make endo-/lysosomes occupied and affect the endo/lysosomal escape of protein subsequently delivery by nanocarriers. We first treated breast carcinoma MDA-MB-231 cells with a high concentration of empty nanocarriers, mesoporous silica nanoparticles (MSN), to occupy the endo-/lysosome. After 2 h, we treated the cells with a lower concentration of fluorescein isothiocyanate-labeled MSN (MSN-FITC) and investigated the intracellular spatial and temporal distribution of MSN-FITC and their colocalization with endo-/lysosomes. We discovered the preoccupation of endo-/lysosomes by the empty nanocarriers did exist, mainly through changing the spatial distribution of the subsequently introduced nanocarriers. Furthermore, for the protein delivery, we observed reduced MSN-saporin delivery after endo-/lysosome preoccupation by MSN empty carriers. A similar result is observed for the delivery of cytochrome C by MSN but not for the small-molecule anticancer drug doxorubicin. The results show that the empty nanocarriers inhibit the endo-/lysosome intracellular trafficking process and decrease the endo-/lysosome escape of proteins subsequently delivered by the nanocarriers. This new discovered phenomenon of declined endo-/lysosome escape after endo-/lysosome preoccupation indicates that repeated treatment by nanomaterials with low protein-loading capacity may not yield a good cancer therapeutic effect. Therefore, it provides a new insightful perspective on the role of nanomaterial carriers in intracellular protein delivery.

Mitochondria-based aircraft carrier enhances in vivo imaging of carbon quantum dots and delivery of anticancer drug.

The application of engineered bacteria-based drug delivery vehicles to treat cancer has been practiced for more than a century. Mitochondria, evolutionarily originated from bacteria, are ubiquitous, semi-autonomous cellular organelles. In this study, we present the first exploration of using mitochondria as a delivery system of carbon quantum dots (CQDs) for in vivo imaging and administration of the anticancer drug doxorubicin (DOX). The results show that mitochondria as carriers are compatible with CQD loading and preserve the optical properties of CQDs. Moreover, the mitochondria delivery system can improve the CQD bio-distribution in organs and prolong the retention time of CQDs after intravenous injection. Furthermore, mitochondria loaded with doxorubicin hydrochloride (Mito-DOX) show an enhanced therapeutic effect compared to free DOX. The mitochondria-based "aircraft" system may be a promising novel therapeutic platform with high potential for biological imaging and drug delivery to fight cancer and other diseases.

Separable Bilayer Microfiltration Device for Label-Free Enrichment of Viable Circulating Tumor Cells.

Analysis of rare circulating tumor cells enriched from metastatic cancer patients yields critical information on disease progression, therapy response, and the mechanism of cancer metastasis. Here we describe in detail a label-free enrichment process of circulating tumor cells based on its unique physical properties (size and deformability). Viable circulating tumor cells can be successfully enriched and analyzed, or easily released for further characterization due to the novel separable two-layer design.