Neglect of preschool children in urban area of Xi an under the background of multi-child policy / 中国学校卫生

Objective@#To understand the situation of neglect of preschool children in the urban area of Xi an under the background of multi child policy, so as to provide a reference for making effective prevention.@*Methods@#In Novmber 2022, according to the multi stage stratified cluster sampling principle, 2 450 parents of children aged 3-6 years were randomly selected from 7 urban areas of Xi an to participate in the questionnaire survey. A questionnaire survey was conducted using the "Neglect Evaluation Norms of 3-6 Years Old (Preschool) Children in Urban Areas of China". SPSS 18.0 software was used for statistical description, Chi square test and variance analysis.@*Results@#The total neglect rate of preschool children in the urban area of Xi an was 29.0% and the total neglect score was (37.58±8.44). There was no statistical difference in the neglect status of children in different grade groups ( χ 2/ F =1.61, 2.98, P >0.05). The neglect score of boys was higher than girls ( t =2.45, P <0.05). There was no statistical difference in the neglect rate and neglect score of boys and girls in other levels ( P >0.05); except for the significant difference in the neglect degree of medical treatment, education and safety ( t =2.01, 2.28, 2.02, P <0.05). The rate and score of neglect in multi-child families were higher than only-child families ( χ 2/ t = 13.68, -4.54, P <0.05). There were significant differences in the rate and degree of neglect of children with different birth order, which were "third and fourth-born>second-born>first-born" ( χ 2/ F = 10.84 , 2.79, P <0.05). The neglect rate and score of "single parent family" were significantly higher than that of "nuclear family" and "three-generation family" ( χ 2/ F =4.78, 2.79, P <0.05).@*Conclusion@#The neglect situation of preschool children in urban area of Xi an is still serious, especially in multi-child families. It should actively explore the risk factors and formulate effective intervention measures.

Polydopamine-based nanoplatform for photothermal ablation with long-term immune activation against melanoma and its recurrence.

The high risk of tumor recurrence presents a big challenge in melanoma therapy. Photothermal therapy (PTT) has merged as a powerful weapon against tumor in recent years, which produces tumor-associated antigens (TAA) and recruits dendritic cells (DCs) to tumor sites through immunogenic cell death (ICD) for immune activation. However, due to the lack of activation signals of DCs, the immune effect induced by PTT is not sufficient to inhibit the recurrence and proliferation of tumor. To efficiently cooperate PTT and immunotherapy to circumvent tumor recurrence, here we constructed a polydopamine (PDA) based core-shell nanoplatform loading CpG ODNs to elicit robust photothermal ablation and antitumor immune responses. Cationized polydopamine coated with hyaluronic acid (HA) shell was proven an efficient photothermal agent that increased the surface temperature of tumor by 16 °C and induced ICD. CpG ODNs effectively induced maturation of DCs by elevating the expression of co-stimulating markers. PTT combined with CpG ODNs achieved a remarkable synergistic treatment effect in the maturation of DCs and activation of T cells in melanoma-bearing mice model compared with PTT or CpG ODNs alone. Furthermore, in a tumor recurrence model, photothermal-immune combination therapy increased the infiltration of CTLs in distant tumor compared with PTT or CpG ODNs alone. The combination therapy overcame insufficient immunity at distant tumor caused by PTT alone and relieved immunosuppression microenvironment of the tumor. Hence, the PDA based core-shell nanoplatform presents a potent photo-immunotherapy against proliferation and recurrence of melanoma. STATEMENT OF SIGNIFICANCE: In order to solve the insufficient immunity induced by photothermal therapy (PTT), CpG ODNs were utilized to enhance the weak immune response mediated by PTT through inducing DCs maturation. Hence, we designed a polydopamine (PDA) based core-shell nanoplatform loading CpG ODNs followed by hyaluronic acid named PPP/CpG/HA to elicit robust photothermal ablation and antitumor immune responses. CpG ODNs were delivered to the tumor site through the targeting effect of the HA shell. The core-shell nanoplatform achieved a remarkable synergistic treatment effect in the maturation of DCs and activation of T cells, thereby overcoming insufficient immunity at distant tumor caused by PTT alone. The core-shell nanoplatform presents a potent photo-immunotherapy against proliferation and recurrence of melanoma.

A "dual-guide" bioinspired drug delivery strategy of a macrophage-based carrier against postoperative triple-negative breast cancer recurrence.

Recurrence after tumor resection is mainly caused by post-operative inflammation and residual cancer cells, which is a serious obstacle to breast cancer treatment. Traditional nanoparticles rely primarily on the enhanced permeability and retention (EPR) effect in well-vascularized tumors. In this study, a macrophage-based carrier is designed to enhance the efficiency of targeting to recurrent tumors through a "dual-guide" strategy. After tumor resection, a burst of inflammatory factors occurs in the resection wound, which can recruit monocytes/macrophages rapidly. Combined with the tropism of monocyte chemoattractant protein, a large number of macrophage-mediated carriers will be recruited to surgical recurrence sites. Octaarginine (RRRRRRRR, R8)-modified liposomes in macrophages contain two agents with different pharmacological mechanisms, paclitaxel (PTX) and resveratrol (Res), which have enhanced therapeutic effects. In vitro study demonstrated that macrophage-mediated carriers approach 4 T1 cells through an inflammatory gradient and reach recurrence tumors through a "dual-guide" strategy. Then, membrane fusion and inflammation-triggered release deliver the drug into the recurrent tumor cells. In vivo experiments show that macrophage-based carriers exhibit effective tumor-targeting ability, especially in post-operation situations. More importantly, macrophage-mediated liposomes encapsulated with PTX and Res inhibit tumor recurrence in both ectopic and orthotopic 4 T1 post-operative recurrence models.

Multifunctional polymeric micelle-based chemo-immunotherapy with immune checkpoint blockade for efficient treatment of orthotopic and metastatic breast cancer.

Immunotherapy has become a highly promising paradigm for cancer treatment. Herein, a chemo-immunotherapy was developed by encapsulating chemotherapeutic drug doxorubicin (DOX) and Toll-like receptor 7 agonist imiquimod (IMQ) in low molecular weight heparin (LMWH)-d-α-tocopheryl succinate (TOS) micelles (LT). In this process, LMWH and TOS were conjugated by ester bond and they were not only served as the hydrophilic and hydrophobic segments of the carrier, but also exhibited strong anti-metastasis effect. The direct killing of tumor cells mediated by DOX-loaded micelles (LT-DOX) generated tumor-associated antigens, initiating tumor-specific immune responses in combination with IMQ-loaded micelles (LT-IMQ). Furthermore, the blockade of immune checkpoint with programmed cell death ligand 1 (PD-L1) antibody further elevated the immune responses by up-regulating the maturation of DCs as well as the ratios of CD8+ CTLs/Treg and CD4+ Teff/Treg. Therefore, such a multifunctional strategy exhibited great potential for inhibiting the growth of orthotopic and metastatic breast cancer.

Size-adjustable micelles co-loaded with a chemotherapeutic agent and an autophagy inhibitor for enhancing cancer treatment via increased tumor retention.

Autophagy plays a key role in the stress response of tumor cells, which contributes to cancer cell survival and resistance to chemotherapy by degrading cytoplasmic proteins to provide energy and clear the hazardous substances. Therefore, combined treatment of chemotherapeutics and autophagy inhibitors is thought to obtain a desirable antitumor effect. Nanoparticles (NPs) show potential in tumor-targeting drug delivery because of the enhanced permeability and retention (EPR) effect. However, NPs with fixed particle size cannot achieve optimal delivery effect. Herein, a strategy based on Cu (I)-catalyzed click chemistry-triggered aggregation of azide/alkyne-modified micelles was developed for the co-delivery of the chemotherapeutic drug doxorubicin (Dox) and the autophagy inhibitor wortmannin (Wtmn). In vitro experiments showed that the size of micelles increased in a time-dependent manner, which enhanced micelle accumulation in both B16F10 and 4 T1 cells. The fluorescence resonance energy transfer (FRET) experiment and biodistribution study further demonstrated that the aggregation of micelles through click cycloaddition significantly improved the accumulation of drug-loading micelles at the tumor region. Furthermore, the decreased amount of autophagosomes observed by transmission electron microscopy (TEM), the declined expression of LC3-II, and the increased level of p62 by western blotting and immunohistochemistry (IHC) confirmed the obvious inhibition of autophagy induced by Dox/Wtmn co-loaded size-adjustable micelles, which had a synergistic effect in cancer suppression. In addition, the co-loaded size-adjustable micelles showed outstanding cytotoxicity and antitumor effect. Therefore, this strategy effectively suppressed melanoma and breast cancer in mice. STATEMENT OF SIGNIFICANCE: The therapeutic effects of chemotherapy can be limited by autophagy; hence, combined use of autophagy inhibitors with chemotherapeutics achieves desirable anticancer efficacy. In the present study, we designed size-adjustable micelles by modifying the click reaction substrate azide group and the alkyne group on the surface of micelles, and subsequently, the autophagy inhibitor wortmannin and the chemotherapeutic drug doxorubicin were co-loaded. The micelles could aggregate by click reaction at the tumor site when the catalysts were intratumorally injected. The results showed that the size-adjustable micelles achieved efficient drug delivery, penetration, and retention in tumors; through the combined effect of wortmannin-mediated autophagy inhibition and doxorubicin-mediated cytotoxicity, this strategy exerted significant anticancer effect in melanoma and breast cancer treatment.

Tumor-Targeted Chemoimmunotherapy with Immune-Checkpoint Blockade for Enhanced Anti-Melanoma Efficacy.

Chemoimmunotherapy with chemotherapeutics and immunoadjuvant inhibits tumor growth by activating cytotoxic T cells. However, this process also upregulates the expression of PD-1/PD-L1 and consequently leads to immune suppression. To maximize the anti-tumor immune responses and alleviate immunosuppression, PD-L1 antibody was combined with paclitaxel (PTX) and the immunoadjuvant α-galactosylceramide (αGC), which were coencapsulated into pH-sensitive TH peptide-modified liposomes (PTX/αGC/TH-Lip) to treat melanoma and lung metastasis. Compared to treatment with PD-L1 antibody or PTX/αGC/TH-Lip alone, the combination of PD-L1 antibody and PTX/αGC/TH-Lip further elevated the tumor-specific cytotoxic T cell responses and promoted apoptosis in tumor cells, leading to enhanced anti-tumor and anti-metastatic effects. In adoptive therapy, PD-L1 antibody further alleviated immunosuppression and enhanced the anti-tumor effect of CD8+ T cells. The combination of PD-L1 antibody and chemoimmunotherapy PTX/αGC/TH-Lip provides a promising strategy for enhancing treatment for melanoma and lung metastasis.

PD-L1 knockdown via hybrid micelle promotes paclitaxel induced Cancer-Immunity Cycle for melanoma treatment.

The Cancer-Immunity Cycle is a series of anticancer immune responses initiated and allowed to proceed and expand iteratively. Paclitaxel (PTX) is a classic chemotherapeutic agent, which could induce immunogenic cell death (ICD) to trigger the Cancer-Immunity Cycle. However, the Cycle is severely impaired by tumor cell immunosuppression of host T cell antitumor activity through the programmed cell death receptor 1 (PD-1) and programmed cell death ligand 1 (PD-L1) (PD-1/PD-L1) immune checkpoint pathway. Here, we demonstrated that PTX mediated the Cancer-Immunity Cycle could be enhanced by PD-L1 knockdown (KD) and followed mTOR pathway inhibition in tumor cells. PD-L1 siRNA (siP) and the hydrophobic chemotherapy drug PTX were co-delivered with a rationally designed hybrid micelle (HM). We showed clear evidence that the HM-siP/PTX is capable of delivering siP and PTX simultaneously to the B16F10 cells both in vitro and in vivo. We demonstrated that HM-PTX/siP reduced the expression of PD-L1 and p-S6K (a marker of mTOR pathway activation) both in vitro and in melanoma-bearing mice and attenuated synergistically tumor growth by chemical toxicity, promoting cytotoxic T-cell immunity and suppressing the mTOR pathway.

Enhanced chemo-immunotherapy against melanoma by inhibition of cholesterol esterification in CD8+ T cells.

Cholesterol facilitated the formation of T cell receptor on cytotoxic CD8+ T lymphocytes (CTLs). However, the activation of CD8+ T cells always resulted in the upregulation of acetyl-CoA acetyltransferase-1 (ACAT-1) and enhanced the esterification of cholesterol. To relieve the suppression on CD8+ T cells, an ACAT-1 inhibitor avasimibe was combined with chemo-immunotherapy. Paclitaxel and immunoadjuvant αGC were co-encapsulated in liposomes modified with pH sensitive TH peptide (PTX/αGC-TH-Lip). After intravenous injections, the combination of avasimibe significantly elevated the free cholesterol level and relieved the inhibition of CD8+ T cells caused by PTX/αGC-TH-Lip, leading to enhanced CTL responses and anti-tumor effects of PTX/αGC-TH-Lip in B16F10 melanoma xenograft and lung metastasis models. The adoptive immunotherapy further confirmed the enhanced anti-tumor immune responses of the combined strategy. The combination of avasimibe and PTX/αGC-TH-Lip was proven as a feasible approach to enhance the antitumor effects of chemo-immunotherapy by relieving the inhibition of CD8+ T cells.

pH-sensitive folic acid and dNP2 peptide dual-modified liposome for enhanced targeted chemotherapy of glioma.

Effective chemotherapy for clinical glioma treatment is still lacking due to the poor penetration of blood-brain barrier (BBB) and the poor internalization into tumor cells. To facilitate the transmigration across the BBB as well as the glioma targeting of chemotherapeutics, we constructed cell penetrating peptide dNP2 and tumor microenvironment-cleavable folic acid (FA) dual modified, paclitaxel (PTX) loaded liposome for the targeted delivery of glioma. The modification of dNP2 significantly enhanced the transmigration across the BBB in an in vitro BBB model. The acid-cleavable cFd-Lip/PTX exhibited sensitive cleavage of FA at pH 6.8, which led to enhanced cellular uptake mediated by both cell penetrating peptide dNP2 and the interaction between FA and folate receptor (FR) on the glioma cells. After intravenous injection, compared with non-cleavable Fd-Lip and single modified liposomes, cFd-Lip enhanced the accumulation in orthotropic glioma and improved the anti-tumor effect of glioma-bearing mice. The dual modified liposomes also facilitated deep penetration into tumor cells and consequently enhanced the cytotoxicity of PTX-loaded liposomes. The acid-cleavable dual modified strategy retained the BBB penetrating and tumor targeting ability, meanwhile, the cleavage of FA further maximized the cell permeability of dNP2, exhibiting enhanced tumor targeting effect. The multi-targeting strategy provides a promising approach towards targeted chemotherapy for glioma.

Dual receptor recognizing liposomes containing paclitaxel and hydroxychloroquine for primary and metastatic melanoma treatment via autophagy-dependent and independent pathways.

Autophagy acts as a cytoprotective mechanism for malignant tumors, thus maintaining the survival and promoting proliferation and metastasis of malignant tumors. Recent studies have showed that autophagy inhibitors can enhance the chemotherapeutic efficacy of anti-tumor growth. However, the antimetastasis effects and the possible mechanisms of chemotherapeutics combined with autophagy inhibitors have not been thoroughly explored. Here, we prepared R8-dGR peptide modified paclitaxel (PTX) and hydroxychloroquine (HCQ) co-loaded liposomes (PTX/HCQ-R8-dGR-Lip) for enhanced delivery by recognizing integrin αvß3 receptors and neuropilin-1 receptors on B16F10 melanoma cells. Our results showed that R8-dGR modified liposomes (R8-dGR-Lip) enhanced tumor-targeting delivery in vitro and in vivo. Besides, PTX/HCQ-R8-dGR-Lip exhibited the optimum inhibitory effects on migration, invasion and anoikis resistance of B16F10 cells in vitro, and showed enhanced efficiency on inhibiting primary tumor growth and reducing lung metastasis in vivo. Meanwhile, the antimetastasis mechanism studies confirmed that the combination of the chemotherapeutic PTX and the autophagy inhibitor HCQ further suppressed the degradation of paxillin, the expression of MMP9 and MMP2. Moreover, HCQ disturbed the CXCR4/CXCL12 axis which could induce invasion and metastasis of malignant melanoma in an autophagy-independent way.

Synergistic tumor microenvironment targeting and blood-brain barrier penetration via a pH-responsive dual-ligand strategy for enhanced breast cancer and brain metastasis therapy.

Cancer associated fibroblasts (CAFs) which shape the tumor microenvironment (TME) and the presence of blood brain barrier (BBB) remain great challenges in targeting breast cancer and its brain metastasis. Herein, we reported a strategy using PTX-loaded liposome co-modified with acid-cleavable folic acid (FA) and BBB transmigrating cell penetrating peptide dNP2 peptide (cFd-Lip/PTX) for enhanced delivery to orthotopic breast cancer and its brain metastasis. Compared with single ligand or non-cleavable Fd modified liposomes, cFd-Lip exhibited synergistic TME targeting and BBB transmigration. Moreover, upon arrival at the TME, the acid-cleavable cFd-Lip/PTX showed sensitive cleavage of FA, which reduced the hindrance effect and maximized the function of both FA and dNP2 peptide. Consequently, efficient targeting of folate receptor (FR)-positive tumor cells and FR-negative CAFs was achieved, leading to enhanced anti-tumor activity. This strategy provides a feasible approach to the cascade targeting of TME and BBB transmigration in orthotopic and metastatic cancer treatment.