Regulation of spermatogonial stem cell differentiation by Sertoli cells-derived exosomes through paracrine and autocrine signaling.

In the orchestrated environment of the testicular niche, the equilibrium between self-renewal and differentiation of spermatogonial stem cells (SSCs) is meticulously maintained, ensuring a stable stem cell reserve and robust spermatogenesis. Within this milieu, extracellular vesicles, specifically exosomes, have emerged as critical conveyors of intercellular communication. Despite their recognized significance, the implications of testicular exosomes in modulating SSC fate remain incompletely characterized. Given the fundamental support and regulatory influence of Sertoli cells (SCs) on SSCs, we were compelled to explore the role of SC-derived exosomes (SC-EXOs) in the SSC-testicular niche. Our investigation hinged on the hypothesis that SC-EXOs, secreted by SCs from the testes of 5-day-old mice-a developmental juncture marking the onset of SSC differentiation-participate in the regulation of this process. We discovered that exposure to SC-EXOs resulted in an upsurge of PLZF, MVH, and STRA8 expression in SSC cultures, concomitant with a diminution of ID4 and GFRA1 levels. Intriguingly, obstructing exosomal communication in a SC-SSC coculture system with the exosome inhibitor GW4869 attenuated SSC differentiation, suggesting that SC-EXOs may modulate this process via paracrine signaling. Further scrutiny revealed the presence of miR-493-5p within SC-EXOs, which suppresses Gdnf mRNA in SCs to indirectly restrain SSC differentiation through the modulation of GDNF expression-an indication of autocrine regulation. Collectively, our findings illuminate the complex regulatory schema by which SC-EXOs affect SSC differentiation, offering novel perspectives and laying the groundwork for future preclinical and clinical investigations.

Live birth of chimeric monkey with high contribution from embryonic stem cells.

A formal demonstration that mammalian pluripotent stem cells possess preimplantation embryonic cell-like (naive) pluripotency is the generation of chimeric animals through early embryo complementation with homologous cells. Whereas such naive pluripotency has been well demonstrated in rodents, poor chimerism has been achieved in other species including non-human primates due to the inability of the donor cells to match the developmental state of the host embryos. Here, we have systematically tested various culture conditions for establishing monkey naive embryonic stem cells and optimized the procedures for chimeric embryo culture. This approach generated an aborted fetus and a live chimeric monkey with high donor cell contribution. A stringent characterization pipeline demonstrated that donor cells efficiently (up to 90%) incorporated into various tissues (including the gonads and placenta) of the chimeric monkeys. Our results have major implications for the study of primate naive pluripotency and genetic engineering of non-human primates.

Nonspecific intraventricular conduction delay predicts the prognosis of dilated cardiomyopathy.

PURPOSE: Left bundle branch block (LBBB) has been confirmed to be independently associated with adverse outcomes in dilated cardiomyopathy (DCM). However, prognostic data on nonspecific intraventricular conduction delay (NSIVCD) are still limited and conflicting. We aimed to evaluate the prognosis of DCM with NSIVCD. METHODS: A total of 548 DCM patients who underwent cardiovascular magnetic resonance imaging (CMR) from January 2016 to December 2017 were consecutively enrolled. The cohort was divided into four groups: 87 with LBBB, 27 with RBBB, 61 with NSIVCD, and 373 without intraventricular conduction delay (IVCD). After a median follow-up of 58 months (interquartile range: 47-65), 123 patients reached the composite endpoints, which included cardiovascular death, heart transplantation, and malignant arrhythmias. The associations between different patterns of IVCD and the outcomes of DCM were analysed by Kaplan‒Meier analysis and Cox proportional hazards regression analysis. RESULTS: Of 548 DCM patients, there were 398 males (72.6%), and the average age was 46 ± 15 years, ranging from 18 to 76 years. In Kaplan‒Meier analysis, patients with NSIVCD and LBBB showed higher event rates than patients without IVCD, while RBBB patients did not. By multivariate Cox regression analysis, LBBB, NSIVCD, NYHA class, left ventricular ejection fraction (LVEF), indexed left ventricular end-diastolic diameter (LVEDDI), percentage of late gadolinium enhancement mass (LGE%), and global longitudinal strain (GLS) were found to be independently associated with the outcomes of DCM. CONCLUSIONS: In addition to LBBB, NSIVCD was an unfavourable prognostic marker in patients with DCM, independent of LVEDDI, NYHA class, LVEF, LGE%, and GLS.

Powell lens-based line-field spectral domain optical coherence tomography system for cellular resolution imaging of biological tissue.

A Powell lens is used in a line-field spectral domain OCT (PL-LF-SD-OCT) system to generate a line-shaped imaging beam with almost uniform distribution of the optical power in the line direction. This design overcomes the severe sensitivity loss (∼10 dB) observed along the line length direction (B-scan) in LF-OCT systems based on cylindrical lens line generators. The PL-LF-SD-OCT system offers almost isotropic spatial resolution (Δx and Δy ∼2 µm, Δz ∼1.8 µm) in free space and sensitivity of ∼87 dB for 2.5 mW imaging power at 2,000 fps imaging rate with only ∼1.6 dB sensitivity loss along the line length. Images acquired with the PL-LF-SD-OCT system allow for visualization of the cellular and sub-cellular structure of biological tissues.

A systematic analysis of the global and regional burden of colon and rectum cancer and the difference between early- and late-onset CRC from 1990 to 2019.

The burden of colorectal cancer (CRC) varies substantially across different geographical locations. However, there was no further quantitative analysis of regional social development and the disease burden of CRC. In addition, the incidence of early- and late-onset CRC has increased rapidly in developed and developing regions. The main purpose of this study was to investigate the trends in CRC burden across different regions, in addition to the epidemiological differences between early and late-onset CRC and their risk factors. In this study, estimated annual percentage change (EAPC) was employed to quantify trends in age-standardized incidence rate (ASIR), mortality rate, and disability-adjusted life-years. Restricted cubic spline models were fitted to quantitatively analyze the relationship between trends in ASIR and Human Development Index (HDI). In addition, the epidemiological characteristics of early- and late-onset CRC were investigated using analyses stratified by age groups and regions. Specifically, meat consumption and antibiotic use were included to explore the differences in the risk factors for early- and late-onset CRC. The quantitative analysis showed that the ASIR of CRC was exponentially and positively correlated with the 2019 HDI in different regions. In addition, the growing trend of ASIR in recent years varied substantially across HDI regions. Specifically, the ASIR of CRC showed a significant increase in developing countries, while it remained stable or decreased in developed countries. Moreover, a linear correlation was found between the ASIR of CRC and meat consumption in different regions, especially in developing countries. Furthermore, a similar correlation was found between the ASIR and antibiotic use in all age groups, with different correlation coefficients for early-onset and late-onset CRC. It is worth mentioning that the early onset of CRC could be attributable to the unrestrained use of antibiotics among young people in developed countries. In summary, for better prevention and control of CRC, governments should pay attention to advocate self-testing and hospital visits among all age groups, especially among young people at high risk of CRC, and strictly control meat consumption and the usage of antibiotics.

E-cadherin maintains the undifferentiated state of mouse spermatogonial progenitor cells via ß-catenin.

BACKGROUND: Cadherins play a pivotal role in facilitating intercellular interactions between spermatogonial progenitor cells (SPCs) and their surrounding microenvironment. Specifically, E-cadherin serves as a cellular marker of SPCs in many species. Depletion of E-cadherin in mouse SPCs showed no obvious effect on SPCs homing and spermatogenesis. RESULTS: Here, we investigated the regulatory role of E-cadherin in regulating SPCs fate. Specific deletion of E-cadherin in germ cells was shown to promote SPCs differentiation, evidencing by reduced PLZF+ population and increased c-Kit+ population in mouse testes. E-cadherin loss down-regulated the expression level of ß-catenin, leading to the reduced ß-catenin in nuclear localization for transcriptional activity. Remarkably, increasing expression level of Cadherin-22 (CDH22) appeared specifically after E-cadherin deletion, indicating CDH22 played a synergistic effect with E-cadherin in SPCs. By searching for the binding partners of ß-catenin, Lymphoid enhancer-binding factor 1 (LEF1), T-cell factor (TCF3), histone deacetylase 4 (HDAC4) and signal transducer and activator 3 (STAT3) were identified as suppressors of SPCs differentiation by regulating acetylation of differentiation genes with PLZF. CONCLUSIONS: Two surface markers of SPCs, E-cadherin and Cadherin-22, synergically maintain the undifferentiation of SPCs via the pivotal intermediate molecule ß-catenin. LEF1, TCF3, STAT3 and HDAC4 were identified as co-regulatory factors of ß-catenin in regulation of SPC fate. These observations revealed a novel regulatory pattern of cadherins on SPCs fate.

Magnetic Nanodroplets for Enhanced Deep Penetration of Solid Tumors and Simultaneous Magnetothermal-Sensitized Immunotherapy against Tumor Proliferation and Metastasis.

The central cells of solid tumors are more proliferative and metastatic than the marginal cells. Therefore, more intelligent strategies for targeting cells with deep spatial distributions in solid tumors remain to be explored. In this work, a biocompatible nanotheranostic agent with a lipid membrane-coated, Fe3 O4 and perfluoropentane (PFP)-loaded, cRGD peptide (specifically targeting the integrin αvß3 receptor)-grafted, magnetic nanodroplets (MNDs) is developed. The MNDs exhibit excellent magnetothermal conversion and controllable magnetic hyperthermia (MHT) through alternating magnetic field regulation. Furthermore, MHT-mediated magnetic droplet vaporization (MDV) induces the expansion of the MNDs to transform them into ultrasonic microbubbles, increasing the permeability of tissue and the cell membrane via the ultrasound-targeted microbubble destruction (UTMD) technique and thereby promoting the deep penetration of MNDs in solid tumors. More importantly, MHT not only causes apoptotic damage by downregulating the expression of the HSP70, cyclin D1, and Bcl-2 proteins in tumor cells but also improves the response rate to T-cell-related immunotherapy by upregulating PD-L1 expression in tumor cells, thus inhibiting the growth of both primary and metastatic tumors. Overall, this work introduces a distinct application of nanoultrasonic biomedicine in cancer therapy and provides an attractive immunotherapy strategy for preventing the proliferation and metastasis of deeply distributed cells in solid tumors.

Performance of artificial intelligence-based coronary artery calcium scoring in non-gated chest CT.

OBJECTIVES: To evaluate the risk category performance of artificial intelligence-based coronary artery calcium score (AI-CACS) software used in non-gated chest computed tomography (CT) on three types of CT machines, considering the manual method as the standard. METHODS: A total of 901 patients who underwent both chest CT and electrocardiogram (ECG)-gated non-contrast-enhanced cardiac CT with the same equipment within a 3-month period were enrolled in the study. AI-CACS software was based on a deep learning algorithm and was trained on multi-vendor, multi-scanner, and multi-hospital anonymized data from the chest CT database. The AI-CACS was automatically obtained from chest CT data by the AI-CACS software, while the manual CACS was obtained from cardiac CT data by the manual method. The correlation of the AI-CACS and manual CACS, concordance rate and kappa value of the risk categories determined by the two methods were calculated. The chi-square test was used to evaluate the differences in risk categories among the three types of CT machines from different manufacturers. The risk category performance of the AI-CACS for dichotomous risk categories bounded by 0, 100 and 400 was assessed. RESULTS: The correlation of the AI-CACS with the manual CACS was ρ = 0.893 (p < 0.001). The Bland-Altman plot (AI-CACS minus manual CACS) showed a mean difference of -27.2 and 95% limits of agreement of -290.0 to 235.6. The agreement of risk categories for the CACS was kappa (κ) = 0.679 (p < 0.001), and the concordance rate was 80.6%. The risk categories determined by the AI-CACS software on three types of CT machines were not significantly different (p = 0.7543). As dichotomous risk categories bounded by 0, 100 and 400, the accuracy, kappa value, and area under the curve of the AI-CACS were 88.6% vs. 92.9% vs. 97.9%, 0.77 vs. 0.77 vs. 0.83, and 0.885 vs. 0.964 vs. 0.981, respectively. CONCLUSIONS: There was good correlation and agreement between the AI-CACS and manual CACS in terms of the risk category. It is feasible to obtain the CACS using AI software based on non-gated chest CT data in a short time without increasing the radiation dose or economic burden. The AI-CACS software algorithm has good clinical universality and can be applied to CT machines from different manufacturers.

Tumor-self-targeted "thermoferroptosis-sensitization" magnetic nanodroplets for multimodal imaging-guided tumor-specific therapy.

Ferroptosis-based nanomedicine has drawn increasing attention in antitumor therapy because of the advantages of this unconventional mode of apoptosis, but the difficulties of delivery to the tumor site and surface-to-core penetration after arrival seriously hinder further clinical transformation and application. Herein, we propose an unprecedented strategy of injecting magnetic nanodroplets (MNDs) to solve these two longstanding problems. MNDs are nanocarriers that can carry multifunctional drugs and imaging materials. MNDs can effectively accumulate in the tumor site by active tumor targeting (multifunctional drugs) and passive tumor targeting (enhanced permeability and retention effect), allowing diffusion of the MNDs from the surface to the core through mild-temperature magnetic fluid hyperthermia (MHT) under multimodal imaging guidance. Finally, the ferroptosis pathway is activated deep within the tumor site through the drug release. This approach was inspired by the ability of mild-temperature MHT to allow MNDs to quickly pass through the blood vessel-tumor barrier and deeply penetrate the tumor tissue from the surface to the core to amplify the antitumor efficacy of ferroptosis. This strategy is termed as "thermoferroptosis sensitization". Importantly, this behavior can be performed under the guidance of multimodal imaging, making the design of MNDs for cancer therapy safer and more reasonable.

PLZF suppresses differentiation of mouse spermatogonial progenitor cells via binding of differentiation associated genes.

Promyelocytic leukaemia zinc finger (PLZF) is a key factor in inhibiting differentiation of spermatogonial progenitor cells (SPCs), but the underlying mechanisms are still largely unknown. In this study, the regulation of PLZF on Kit, Stra8, Sohlh2, and Dmrt1 (SPCs differentiation related genes) was investigated. We found some PLZF potential binding sites existed in the promoters of Kit, Stra8, Sohlh2, and Dmrt1. Additionally, the expressions of KIT, STRA8, SOHLH2, and DMRT1 were upregulated when PLZF was knockdown in SPCs. Furthermore, chromatin immunoprecipitation quantitative polymerase chain reaction revealed PLZF directly bound to the promoters of Kit, Stra8, Sohlh2, and Dmrt1. Besides, dual luciferase assay verified PLZF repressed those gene expressions. Collectively, our finding indicate that PLZF binds to the promoter regions of Kit, Stra8, Sohlh2, and Dmrt1 to regulate SPCs differentiation, which facilitate us to further understand the regulatory mechanism of PLZF in SPCs fates.

Androgen Indirectly Regulates Gap Junction Component Connexin 43 Through Wilms Tumor-1 in Sertoli Cells.

In mammals, spermatogenesis is closely related to intercellular interactions of germ cells and surrounding Sertoli cells, that is, blood-testis barrier and gap junction, which are subjected to hormone signals in testicular seminiferous tubules. Androgen signal plays pivotal role in regulating spermatogenesis, but the underlying mechanism is largely unknown. Our recent study demonstrated a novel regulatory pattern of androgen in regulation of spermatogonia differentiation, in which androgen indirectly regulates the expression of ITGB1 on Sertoli Cells through intermediate molecule Wilms tumor-1 (Wt-1) during spermatogenesis. In this study, we identified that Connexin 43 (Cx43), the key component for gap junction distributed between spermatogonia and Sertoli cells, was also regulated by androgen signal. Chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR) demonstrated that WT1 occupied Cx43 promoter in Sertoli cells, suggesting WT1 as an intermediate molecule in regulation of Cx43. Finally, we revealed a regulatory pattern of Cx43 by androgen in Sertoli cells, and the Sertoli cells in germ cell depleted microenvironment were sensitive to androgen signal, which enhances the understanding of the mechanism of spermatogenesis.

Herceptin-decorated paclitaxel-loaded poly(lactide-co-glycolide) nanobubbles: ultrasound-facilitated release and targeted accumulation in breast cancers.

Ultrasound can promote the drug release from drug-loaded substances and alter the tumor local microenvironment to facilitate the transport of drug carriers into the tumor tissues. Based on the altered tumor microenvironment, nanobubbles (NBs) as drug carriers with surfaces functionalized with targeting ligands can reach the tumor sites, thereby increasing the efficacy of chemotherapy. Herein, paclitaxel (PTX)-loaded poly(lactide-co-glycolide) (PLGA) NBs are prepared as drug carriers with covalently conjugated herceptin (anti-HER2 monoclonal antibody) on the surface to guide the target. The effect of ultrasound on the drug release and targeting of the herceptin-conjugated drug-loaded nanobubbles (PTX-NBs-HER) on the cancerous cells is determined. The use of ultrasound significantly improves the cell targeting capability in vitro, and efficiency of enhanced permeability and retention in vivo. The combination of PTX-NBs-HER and ultrasound facilitates the release of PTX, as well as the uptake and cell apoptosis in vitro. The in vivo application of both PTX-NBs-HER and ultrasound enhances the PTX targeting and accumulation in breast cancers while reducing the transmission and distribution of PTX in healthy organs. The combination of ultrasound with PTX-NBs-HER as contrast agents and drug carriers affords an image-guided drug delivery system for the precise targeted therapy of tumors.

Radiomics Analysis of Dynamic Contrast-Enhanced Magnetic Resonance Imaging for the Prediction of Sentinel Lymph Node Metastasis in Breast Cancer.

Purpose: To investigate whether a combination of radiomics and automatic machine learning applied to dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of primary breast cancer can non-invasively predict axillary sentinel lymph node (SLN) metastasis. Methods: 62 patients who received a DCE-MRI breast scan were enrolled. Tumor resection and sentinel lymph node (SLN) biopsy were performed within 1 week after the DCE-MRI examination. According to the time signal intensity curve, the volumes of interest (VOIs) were delineated on the whole tumor in the images with the strongest enhanced phase. Datasets were randomly divided into two sets including a training set (~80%) and a validation set (~20%). A total of 1,409 quantitative imaging features were extracted from each VOI. The select K best and least absolute shrinkage and selection operator (Lasso) were used to obtain the optimal features. Three classification models based on the logistic regression (LR), XGboost, and support vector machine (SVM) classifiers were constructed. Receiver Operating Curve (ROC) analysis was used to analyze the prediction performance of the models. Both feature selection and models construction were firstly performed in the training set, then were further tested in the validation set by the same thresholds. Results: There is no significant difference between all clinical and pathological variables in breast cancer patients with and without SLN metastasis (P > 0.05), except histological grade (P = 0.03). Six features were obtained as optimal features for models construction. In the validation set, with respect to the accuracy and MSE, the SVM demonstrated the highest performance, with an accuracy, AUC, sensitivity (for positive SLN), specificity (for positive SLN) and Mean Squared Error (MSE) of 0.85, 0.83, 0.71, 1, 0.26, respectively. Conclusions: We demonstrated the feasibility of combining artificial intelligence and radiomics from DCE-MRI of primary tumors to predict axillary SLN metastasis in breast cancer. This non-invasive approach could be very promising in application.

Androgen promotes differentiation of PLZF+ spermatogonia pool via indirect regulatory pattern.

BACKGROUND: Androgen plays a pivotal role in spermatogenesis, accompanying a question how androgen acts on germ cells in testis since germ cells lack of androgen receptors (AR). Promyelocytic leukemia zinc-finger (PLZF) is essential for maintenance of undifferentiated spermatogonia population which is terminologically called spermatogonia progenitor cells (SPCs). AIMS: We aim to figure out the molecular connections between androgen and fates of PLZF+ SPCs population. METHOD: Immunohistochemistry was conducted to confirm that postnatal testicular germ cells lacked endogenous AR. Subsequently, total cells were isolated from 5 dpp (day post partum) mouse testes, and dihydrotestosterone (DHT) and/or bicalutamide treatment manifested that Plzf was indirectly regulated by androgen. Then, Sertoli cells were purified to screen downstream targets of AR using ChIP-seq, and gene silence and overexpression were used to attest these interactions in Sertoli cells or SPCs-Sertoli cells co-culture system. Finally, these connections were further verified in vivo using androgen pharmacological deprivation mouse model. RESULTS: Gata2 is identified as a target of AR, and ß1-integrin is a target of Wilms' tumor 1 (WT1) in Sertoli cells. Androgen signal negatively regulate ß1-integrin on Sertoli cells via Gata2 and WT1, and ß1-integrin on Sertoli cells interacts with E-cadherin on SPCs to regulate SPCs fates. CONCLUSION: Androgen promotes differentiation of PLZF+ spermatogonia pool via indirect regulatory pattern.

Magnetic nanobubbles with potential for targeted drug delivery and trimodal imaging in breast cancer: an in vitro study.

AIM: The aim of this study was to improve tumor-targeted therapy for breast cancer by designing magnetic nanobubbles with the potential for targeted drug delivery and multimodal imaging. MATERIALS & METHODS: Herceptin-decorated and ultrasmall superparamagnetic iron oxide (USPIO)/paclitaxel (PTX)-embedded nanobubbles (PTX-USPIO-HER-NBs) were manufactured by combining a modified double-emulsion evaporation process with carbodiimide technique. PTX-USPIO-HER-NBs were examined for characterization, specific cell-targeting ability and multimodal imaging. RESULTS: PTX-USPIO-HER-NBs exhibited excellent entrapment efficiency of Herceptin/PTX/USPIO and showed greater cytotoxic effects than other delivery platforms. Low-frequency ultrasound triggered accelerated PTX release. Moreover, the magnetic nanobubbles were able to enhance ultrasound, magnetic resonance and photoacoustics trimodal imaging. CONCLUSION: These results suggest that PTX-USPIO-HER-NBs have potential as a multimodal contrast agent and as a system for ultrasound-triggered drug release in breast cancer.

Periostin contributes to arsenic trioxide resistance in hepatocellular carcinoma cells under hypoxia.

Hypoxia has been suggested to induce chemoresistance in tumor cells. In this study, we aimed to test the hypothesis that hypoxia-inducible factor-1alpha (HIF-1α)/periostin axis might promote arsenic trioxide resistance in hepatocellular carcinoma (HCC) cells under hypoxia. HCC cells were exposed to hypoxia and measured for periostin expression. Loss-of-function studies were done to assess the role of periostin in arsenic trioxide resistance. In vivo xenograft mouse studies were performed to determine the effect of periostin silencing on HCC susceptibility to arsenic trioxide. It was found that periostin expression was significantly increased in SMMC7721 and Hep3B HCC cells after hypoxic treatment. Depletion of HIF-1α blocked the upregulation of periostin induced by hypoxia. HCC cells under hypoxia displayed more resistant to arsenic trioxide than those under normoxia. Interestingly, downregulation of periostin re-sensitized hypoxic SMMC7721 and Hep3B cells to arsenic trioxide, which was accompanied by increased apoptosis. Luciferase reporter assay revealed that periostin overexpression enhanced HIF-1α-dependent transcriptional activity and induced the expression of vascular endothelial growth factor, Mcl-1, and Bcl-xL in SMMC7721 cells. Administration of arsenic trioxide resulted in a significant inhibition of SMMC7721 tumor growth. Notably, downregulation of periostin significantly enhanced the anticancer effect of arsenic trioxide against SMMC7721 tumors and reduced the percentage of Ki-67-positive proliferating cells. Taken together, periostin contributes to arsenic trioxide resistance in HCC under hypoxic microenvironment, which is likely associated with promotion of HIF-1α-dependent activation of survival genes. Targeting periostin may represent a promising strategy to improve arsenic trioxide-based anticancer therapy against HCC.

Monoclonal Antibodies Against Porcine sIgA and Their Use in Immunohistochemistry.

Secretory IgA (sIgA) is known as the predominant immunoglobulin in the mucosal system. It prevents pathogens from invading an animal's body through mucosa, making homeostasis. However, few studies examining the secretion of sIgA in mucosal-associated tissues of porcines based on immunohistochemistry methods have been done. In this study, BALB/c mice were immunized with porcine sIgA and the splenocytes were then fused with myeloma cells. Finally, three hybridoma cell lines secreting monoclonal antibody (MAb) against porcine sIgA were obtained. All three MAbs had no cross-reaction with porcine IgG confirmed by Western blot analysis. Furthermore, lungs, tracheas, and intestines were collected from healthy porcines to prepare tissue slices, followed by incubation with the MAb produced in this study. The results showed that sIgA existing in respiratory and digestive systems could be detected by this newly produced MAb. These generated MAbs against porcine sIgA might have a potential use in mucosal research of porcines.

Synthesis and evaluation of perfluorooctylbromide nanoparticles modified with a folate receptor for targeting ovarian cancer: in vitro and in vivo experiments.

BACKGROUND: Epithelial ovarian cancer is the leading cause of death among gynecologic malignancies. However, detecting ovarian cancer at an early stage remains challenging. In this work, we aimed to synthesize a folate-receptor-targeting perfluorooctylbromide nanoparticle (FR-TPNP) as a targeted computed tomography (CT) contrast agent for the early detection of ovarian cancer. METHODS: Perfluorooctylbromide (PFOB) was encapsulated in Poly (lactic-co-glycolic acid) (PLGA) by a two-step emulsion technique to construct the nanoparticles. Folate-poly (ethylene glycol)-carboxylic acid (Fol-PEG-COOH) was introduced to modify the surface of the nanoparticles through attachment to the PLGA. The effects of different volume ratios of PFOB to PLGA on the characteristics of the FR-TPNP emulsions were compared. The size distribution and potential of the FR-TPNPs were assessed with a laser particle size analyzer system. The in vitro targeting ability of the FR-TPNPs was observed with a confocal laser scanning microscope (CLSM), and the in vivo transportation of the FR-TPNPs was evaluated with CT. RESULTS: The sizes of the FR-TPNP emulsion with different volume ratios varied from 302.67 ± 27.83 nm to 563.68 ± 47.29 nm, and the mean CT value ranged from 233 ± 20.59 HU to 587.66 ± 159.51 HU. Both the size and mean CT value increased with the volume ratio. The FR-TPNPs showed greater cell affinity and targeting efficiency to SKOV3 cells than the control group and folic acid interference group in vitro, as observed by CLSM. A significant CT enhancement of ovarian cancer xenografts in the targeted group of a nude mice model was observed 2 h post-injection; it increased to a peak at 12 h and had a duration of 48 h. The mean CT value of the tumor in the targeted group was considerably higher than those in the non-targeted and other groups 6 h post-injection. CONCLUSION: The synthesized FR-TPNP emulsion was an effective CT contrast agent with highly efficient targeting ability and a long circulation time, thus representing a potential strategy for the earlier detection of ovarian cancer.

Phase-Shifted PFH@PLGA/Fe3O4 Nanocapsules for MRI/US Imaging and Photothermal Therapy with near-Infrared Irradiation.

Photothermal therapy (PTT) utilizes photothermal conversion reagents to generate heat energy from absorbed light to effectively treat various malignant diseases. This approach has attracted broad and increasing interest in cancer treatment. Near-infrared (NIR)-induced PTT is particularly attractive because of its minimal absorbance by normal tissue and relatively deep tissue penetration. To improve the efficacy of PTT, we have developed nanocapsules encapsulating superparamagnetic iron oxide (Fe3O4) as synergistic agents for NIR-induced PTT. In this study, phase-shift and NIR photoabsorbing poly(lactic-co-glycolic acid) (PLGA) nanocapsules (perfluorohexane (PFH)@PLGA/Fe3O4) were fabricated for MRI/US dual-modal imaging-guided PTT. The multifunctional nanocapsules can be used not only to increase the local tumor temperature by absorbing the NIR energy but also as bimodal contrast agents for both MRI and US imaging. Such nanocapsules can be converted into microbubbles under NIR irradiation, which produces excellent contrast for US imaging and enhanced cancer ablation. We refer to the nanocapsule phase transition process induced by the infrared lamp as NIR radiation droplet vaporization (NIRDV).

Preparation of the porcine secretory component and a monoclonal antibody against this protein.

Secretory component (SC) is a component of secretory IgA that is designated sIgA to distinguish it from IgA. The monoclonal antibody (MAb) against SC has been shown to be an excellent tool for the detection of the level of sIgA and for the evaluation of the efficacy of mucosal immunity. To prepare a monoclonal antibody against porcine SC, a recombinant porcine SC was expressed and purified. To develop this recombinant SC, the gene encoding the porcine SC was ligated into the pCold I vector. The recombinant vector was then transformed into Escherichia coli BL 21 (DE3), and gene expression was successfully induced by isopropyl-ß-D-thiogalactoside (IPTG). After affinity purification with Ni-NTA resin and gel recovery, the recombinant SC protein was used to immunize BALB/c mice. Finally, three hybridoma cell lines showing specific recognitions of both recombinant SC and native SC were used as stable secretors of MAbs against porcine SC and were confirmed to have no reaction to porcine IgA or IgG. The successful preparations of recombinant SC protein and MAbs provide valuable materials that can be used in the mucosal infection diagnosis for porcine disease and mucosal immune evaluation for porcine vaccine, respectively.