The laminin receptor is a receptor for Micropterus salmoides rhabdovirus.

Micropterus salmoides rhabdovirus (MSRV) is an important pathogen of largemouth bass. Despite extensive research, the functional receptors of MSRV remained unknown. This study identified the host protein, laminin receptor (LamR), as a cellular receptor facilitating MSRV entry into host cells. Our results demonstrated that LamR directly interacts with MSRV G protein, playing a pivotal role in the attachment and internalization processes of MSRV. Knockdown of LamR with siRNA, blocking cells with LamR antibody, or incubating MSRV virions with soluble LamR protein significantly reduced MSRV entry. Notably, we found that LamR mediated MSRV entry via clathrin-mediated endocytosis. Additionally, our findings revealed that MSRV G and LamR were internalized into cells and co-localized in the early and late endosomes. These findings highlight the significance of LamR as a cellular receptor facilitating MSRV binding and entry into target cells through interaction with the MSRV G protein. IMPORTANCE: Despite the serious epidemic caused by Micropterus salmoides rhabdovirus (MSRV) in largemouth bass, the precise mechanism by which it invades host cells remains unclear. Here, we determined that laminin receptor (LamR) is a novel target of MSRV, that interacts with its G protein and is involved in viral attachment and internalization, transporting with MSRV together in early and late endosomes. This is the first report demonstrating that LamR is a cellular receptor in the MSRV life cycle, thus contributing new insights into host-pathogen interactions.

Different EGF-induced receptor dimer conformations for signaling and internalization.

The structural basis of the activation and internalization of EGF receptors (EGFR) is still a matter of debate despite the importance of this target in cancer treatment. Whether agonists induce dimer formation or act on preformed dimers remains discussed. Here, we provide direct evidence that EGF-induced EGFR dimer formation as best illustrated by the very large increase in FRET between snap-tagged EGFR subunits induced by agonists. We confirm that Erlotinib-related TK (tyrosine kinase) inhibitors also induce dimer formation despite the inactive state of the binding domain. Surprisingly, TK inhibitors do not inhibit EGF-induced EGFR internalization despite their ability to fully block EGFR signaling. Only Erlotinib-related TK inhibitors promoting asymmetric dimers could slow down this process while the lapatinib-related ones have almost no effect. These results reveal that the conformation of the intracellular TK dimer, rather than the known EGFR signaling, is critical for EGFR internalization. These results also illustrate clear differences in the mode of action of TK inhibitors on the EGFR and open novel possibilities to control EGFR signaling for cancer treatment.

Selection of internalizing RNA aptamers into human breast cancer cells derived from primary sites.

Breast cancer is the most common cancer in women. Although chemotherapy is still broadly used in its treatment, adverse effects remain a challenge. In this scenario, aptamers emerge as a promising alternative for theranostic applications. Studies using breast cancer cell lines provide useful information in laboratory and preclinical investigations, most of which use cell lines established from metastatic sites. However, these cell lines correspond to cell populations of the late stage of tumor progression. On the other hand, studies using breast cancer cells established from primary sites make it possible to search for new theranostic approaches in the early stages of the disease. Therefore, this work aimed to select RNA aptamers internalized by MGSO-3 cells, a human breast cancer cell line, derived from a primary site previously established in our laboratory. Using the Cell-Internalization SELEX method, we have selected two candidate aptamers (ApBC1 and ApBC2). We evaluated their internalization efficiencies, specificities, cellular localization by Reverse Transcription-qPCR (RT-qPCR) and confocal microscopy assays. The results suggest that both aptamers were efficiently internalized by human breast cancer cells, MACL-1, MDA-MB-231, and especially by MGSO-3 cells. Furthermore, both aptamers could effectively distinguish human breast cancer cells derived from normal human mammary cell (MCF 10A) and prostate cancer cell (PC3) lines. Therefore, ApBC1 and ApBC2 could be promising candidate molecules for theranostic applications, even in the early stages of tumor progression.

Melanin-concentrating hormone receptor 1 is discarded by exosomes after internalization.

Melanin-concentrating hormone (MCH) receptor 1 (MCHR1), a G protein-coupled receptor, is poised for interaction with its ligands on the plasma membrane. Analyses of MCHR1 knockout mice suggest that this receptor could be a therapeutic target for the treatment of appetite disorders, glucose metabolism, psychiatric disorders, and inflammation. Binding of MCH to MCHR1 initiates calcium signaling, which is subsequently attenuated through receptor internalization. However, the ultimate destiny of the receptor post-internalization remains unexplored. In this study, we report the extracellular secretion of MCHR1 via exosomes. The recruitment of MCHR1 to exosomes occurs subsequent to its internalization, which is induced by stimulation with the ligand MCH. Although a highly glycosylated form of MCHR1, potentially representing a mature form, is selectively recruited to exosomes, the MCHR1 transferred into other cells does not exhibit functionality. The truncation of MCHR1 at the C-terminus not only impairs its response to MCH but also hinders its recruitment to exosomes. These findings imply that functional MCHR1 could be secreted extracellularly via exosomes, a process that may represent a mechanism for the termination of intracellular MCHR1 signaling.

A Quantitative Method to Distinguish Cytosolic from Endosome-Trapped Cell-Penetrating Peptides.

Cell-penetrating peptides are known to penetrate cells through endocytosis and translocation. The two pathways are hardly distinguished in current cell assays. We developed a reliable, simple and robust method to distinguish and quantify independently the two routes. The assay requires (DABCYL) 4-(dimethylaminoazo)benzene-4-carboxylic acid- and (CF) carboxyfluorescein-labeled peptides. When the labeled peptide is intact, the fluorescence signal is weak thanks to the dark quenching property of DABCYL. A 10-fold higher fluorescence signal is measured when the labeled peptide is degraded. By referring to a standard fluorescent curve according to the concentration of the hydrolyzed peptide, we have access to the internalized peptide quantity. Therefore, cell lysis after internalization permits to determine the total quantity of intracellular peptide. The molecular state of the internalized peptide (intact or degraded), depends on its location in cells (cytosol vs endo-lysosomes), and can be blocked by boiling cells. This boiling step results indeed in denaturation and inhibition of the cellular enzymes. The advantage of this method is the possibility to quantify translocation at 37 °C and to compare it to the 4 °C condition, where all endocytosis processes are inhibited. We found that ranking of the translocation efficacy is DABCYL-R6-(ϵCF)K≫DABCYL-R4-(ϵCF)K≥CF-R9.

Cutibacterium acnes biofilm formation is influenced by bone microenvironment, implant surfaces and bacterial internalization.

BACKGROUND: The bacterial persistence, responsible for therapeutic failures, can arise from the biofilm formation, which possesses a high tolerance to antibiotics. This threat often occurs when a bone and joint infection is diagnosed after a prosthesis implantation. Understanding the biofilm mechanism is pivotal to enhance prosthesis joint infection (PJI) treatment and prevention. However, little is known on the characteristics of Cutibacterium acnes biofilm formation, whereas this species is frequently involved in prosthesis infections. METHODS: In this study, we compared the biofilm formation of C. acnes PJI-related strains and non-PJI-related strains on plastic support and textured titanium alloy by (i) counting adherent and viable bacteria, (ii) confocal scanning electronic microscopy observations after biofilm matrix labeling and (iii) RT-qPCR experiments. RESULTS: We highlighted material- and strain-dependent modifications of C. acnes biofilm. Non-PJI-related strains formed aggregates on both types of support but with different matrix compositions. While the proportion of polysaccharides signal was higher on plastic, the proportions of polysaccharides and proteins signals were more similar on titanium. The changes in biofilm composition for PJI-related strains was less noticeable. For all tested strains, biofilm formation-related genes were more expressed in biofilm formed on plastic that one formed on titanium. Moreover, the impact of C. acnes internalization in osteoblasts prior to biofilm development was also investigated. After internalization, one of the non-PJI-related strains biofilm characteristics were affected: (i) a lower quantity of adhered bacteria (80.3-fold decrease), (ii) an increase of polysaccharides signal in biofilm and (iii) an activation of biofilm gene expressions on textured titanium disk. CONCLUSION: Taken together, these results evidenced the versatility of C. acnes biofilm, depending on the support used, the bone environment and the strain.

Systematic assessment of chemokine ligand bias at the human chemokine receptor CXCR2 indicates G protein bias over ß-arrestin recruitment and receptor internalization.

BACKGROUND: The human CXC chemokine receptor 2 (CXCR2) is a G protein-coupled receptor (GPCR) interacting with multiple chemokines (i.e., CXC chemokine ligands CXCL1-3 and CXCL5-8). It is involved in inflammatory diseases as well as cancer. Consequently, much effort is put into the identification of CXCR2 targeting drugs. Fundamental research regarding CXCR2 signaling is mainly focused on CXCL8 (IL-8), which is the first and best described high-affinity ligand for CXCR2. Much less is known about CXCR2 activation induced by other chemokines and it remains to be determined to what extent potential ligand bias exists within this signaling system. This insight might be important to unlock new opportunities in therapeutic targeting of CXCR2. METHODS: Ligand binding was determined in a competition binding assay using labeled CXCL8. Activation of the ELR + chemokine-induced CXCR2 signaling pathways, including G protein activation, ß-arrestin1/2 recruitment, and receptor internalization, were quantified using NanoBRET-based techniques. Ligand bias within and between these pathways was subsequently investigated by ligand bias calculations, with CXCL8 as the reference CXCR2 ligand. Statistical significance was tested through a one-way ANOVA followed by Dunnett's multiple comparisons test. RESULTS: All chemokines (CXCL1-3 and CXCL5-8) were able to displace CXCL8 from CXCR2 with high affinity and activated the same panel of G protein subtypes (Gαi1, Gαi2, Gαi3, GαoA, GαoB, and Gα15) without any statistically significant ligand bias towards any one type of G protein. Compared to CXCL8, all other chemokines were less potent in ß-arrestin1 and -2 recruitment and receptor internalization while equivalently activating G proteins, indicating a G protein activation bias for CXCL1,-2,-3,-5,-6 and CXCL7. Lastly, with CXCL8 used as reference ligand, CXCL2 and CXCL6 showed ligand bias towards ß-arrestin1/2 recruitment compared to receptor internalization. CONCLUSION: This study presents an in-depth analysis of signaling bias upon CXCR2 stimulation by its chemokine ligands. Using CXCL8 as a reference ligand for bias index calculations, no ligand bias was observed between chemokines with respect to activation of separate G proteins subtypes or recruitment of ß-arrestin1/2 subtypes, respectively. However, compared to ß-arrestin recruitment and receptor internalization, CXCL1-3 and CXCL5-7 were biased towards G protein activation when CXCL8 was used as reference ligand.

Women's Relationships With Healthcare and Providers: The Role of Weight Stigma in Healthcare and Weight Bias Internalization.

BACKGROUND: Weight stigma (devaluation due to body weight) in healthcare is common and influences one's engagement in healthcare, health behaviors, and relationship with providers. Positive patient-provider relationships (PPR) are important for one's healthcare engagement and long-term health. PURPOSE: To date, no research has yet investigated whether weight bias internalization (self-stigma due to weight; WBI) moderates the effect of weight stigma on the PPR. We predict that weight stigma in healthcare is negatively associated with (i) trust in physicians, (ii) physician empathy, (iii) autonomy and competence when interacting with physicians, and (iv) perceived physician expertise. We also predict that those with high levels of WBI would have the strongest relationship between experiences of weight stigma and PPR outcomes. METHODS: We recruited women (N = 1,114) to complete a survey about weight stigma in healthcare, WBI and the previously cited PPR outcomes. RESULTS: Weight stigma in healthcare and WBI were associated with each of the PPR outcomes when controlling for age, BMI, education, income, race, and ethnicity. The only exception was that WBI was not associated with trust in physicians. The hypothesis that WBI would moderate the effect of weight stigma in healthcare on PPR outcomes was generally not supported. CONCLUSIONS: Overall, this research highlights how weight stigma in healthcare as well as one's own internalization negatively impact PPRs, especially how autonomous and competent one feels with their provider which are essential for one to take an active role in their health and healthcare.

Being treated differently because of your weight is common in healthcare. Being treated poorly because of one's weight when interacting with physicians can influence whether they make appointments with their doctors, how they eat, and how they interact with doctors in the future. This is important because the relationship one has with their doctor impacts their health. We expected that negative experiences with doctors about weight would impact whether people trust doctors, think their doctor is empathetic, think their doctor is an expert, and think they can be themselves around their doctor. We also expected this to be impacted by how people feel about their own body weight. 1,114 women completed a questionnaire about all these topics. Negative experiences with doctors about weight and thinking poorly of their own weight were associated with each of the expected outcomes. The only exception is that the way one felt about their own body was not associated with trusting doctors. Also, the way people felt about their own weight did not impact the effect that negative experiences had on these outcomes. Overall, this study shows how important feelings and conversations about weight are when interacting with one's doctor.

Design, synthesis, anti-tumor activity and mechanism of novel PROTACs as degraders of PD-L1 and inhibitors of PD-1/PD-L1 interaction.

Currently, antibody drugs targeting programmed cell death ligand 1 (PD-L1) have achieved promising results in cancer treatment, while the development of small-molecule drugs lags behind. In this study, we designed and synthesized a series of PD-L1-degrading agents based on the PROTAC design principle, utilizing the PD-L1 inhibitor A56. Through systematic screening of ligands and linkers and investigating the structure-activity relationship of the degraders, we identified two highly active compounds, 9i and 9j. These compounds enhance levels of CD4+, CD8+, granzyme B, and perforin, demonstrating significant in vivo antitumor effects with a tumor growth inhibition (TGI) of up to 57.35 %. Both compounds facilitate the internalization of PD-L1 from the cell surface and promote its degradation through proteasomal and lysosomal pathways, while also maintaining inhibition of the PD-1/PD-L1 interaction. In summary, our findings provide a novel strategy and mechanism for developing biphenyl-based PROTAC antitumor drugs targeting and degrading PD-L1.

The role of P2Y6 receptor in the pathogenesis of cardiovascular and inflammatory diseases.

The purinergic receptor P2Y6 receptor (P2Y6R) is a member of the G protein-coupled receptors (GPCR) family. P2Y6R is widely expressed in various cell types and plays a critical role in physiological processes, where it is activated by extracellular uridine diphosphate (UDP) and mobilizes Ca2+ via the Gαq/11 protein pathway. We have recently discovered the pathophysiological role of P2Y6R in cardiovascular and inflammatory diseases, including inflammatory bowel disease and non-alcoholic fatty liver disease. Furthermore, we uncovered the redox-dependent internalization of P2Y6R. In this review, we provide a comprehensive overview of the pathophysiological activity of P2Y6R in cardiovascular and inflammatory diseases. Additionally, we discuss the concept of atypical internalization control of GPCRs, which may be applied in the prevention and treatment of intestinal inflammation and cardiovascular remodeling.

Nanoparticle-mediated dsRNA delivery for precision insect pest control: a comprehensive review.

Nanoparticle-based delivery systems have emerged as powerful tools in the field of pest management, offering precise and effective means of delivering double-stranded RNA (dsRNA), a potent agent for pest control through RNA interference (RNAi). This comprehensive review aims to evaluate and compare various types of nanoparticles for their suitability in dsRNA delivery for pest management applications. The review begins by examining the unique properties and advantages of different nanoparticle materials, including clay, chitosan, liposomes, carbon, gold and silica. Each material's ability to protect dsRNA from degradation and its potential for targeted delivery to pests are assessed. Furthermore, this review delves into the surface modification strategies employed to enhance dsRNA delivery efficiency. Functionalization with oligonucleotides, lipids, polymers, proteins and peptides is discussed in detail, highlighting their role in improving stability, cellular uptake, and specificity of dsRNA delivery.This review also provides valuable guidance on choosing the most suitable nanoparticle-based system for delivering dsRNA effectively and sustainably in pest management. Moreover, it identifies existing knowledge gaps and proposes potential research directions aimed at enhancing pest control strategies through the utilization of nanoparticles and dsRNA.

Exploring the interplay of weight-based teasing and sociodemographic factors in adolescent weight bias internalization.

OBJECTIVE: Research has highlighted the potential adverse effects of weight bias internalization (WBI) on adolescents, but there has been little examination of WBI and sources of weight teasing (family, peers, or both) or across racial/ethnic diversity of adolescents. We aimed to examine the relationship between WBI and sources of weight teasing across sociodemographic characteristics and weight status in a diverse community sample of adolescents. METHODS: Data were collected from a U.S. sample of 1859 adolescents aged 10-17 years (59% female; 43% White, 27% Black or African American, and 25% Latino). An online questionnaire was used to assess participants' experiences of weight teasing from family members, peers, or both, and their weight status, weight-related goals, WBI, and sociodemographic characteristics. RESULTS: Adolescents experiencing weight teasing from both family and peers reported the highest levels of WBI, while those reporting no teasing exhibited the lowest levels. These patterns were observed across sex, race/ethnicity, weight status, and weight goals, and persisted after controlling for depressive symptoms. Notably, family influences played a salient role, with adolescents reporting higher WBI if teased by family only compared to teasing from peers only. Sex and racial differences were also observed in adolescents' experiences with weight-based teasing. CONCLUSION: Our study reveals associations between adolescent weight-based teasing, WBI, and sociodemographic factors. Weight-based teasing, whether from family and peers or from family only, was associated with increased WBI. Interventions targeting weight stigma in youth should not be limited to peer-focused efforts, but should also emphasize supportive family communication.

The "Young Athlete Body Project"-A pilot study evaluating the acceptability of and results from an eating disorder prevention program for adolescent athletes.

BACKGROUND: The high frequency of eating disorders (EDs) in sports speaks of a need for early-stage preventive measures. OBJECTIVES: This study evaluated the acceptability of an age, sex, and sports adapted version of the "Body Project" and changes in mental health symptoms. METHODS: This noncontrolled pilot study included a class of athletes from 18 sports (N = 73, 13-14 years) at a sport-specialized junior high school in six small-group workshops. We interviewed 34 athletes on program acceptability, and all athletes responded to questionnaires at pretest, posttest, and 6-month follow-up including the Body Appreciation Scale 2-Children, Social Attitudes towards Appearance Questionnaire-4 revised, Eating Disorder Examination Questionnaire Short form-12 modified, and questions about body appearance pressure (BAP). RESULTS: Athletes found the program acceptable and beneficial, but some missed physically oriented activities or did not identify with the focus, particularly boys. There were acceptable levels in mental health constructs before the workshops. There were temporary changes in the percentage of boys experiencing "BAP in society" by -14.8% points (95% CI: -.6 to .0, p = .04), % in total group experiencing "BAP at school" by +11% points (95% CI: .0-.2, p = .05), thinness idealization by girls (g = .6, p = .002) and total group (g = .4, p = .006), and muscularity idealization by boys (g = .3, p = .05) and total group (g = .23, p = .04). DISCUSSION: Athletes experienced benefits from the Young Athlete Body Project. Seeing stabilization in outcomes may mean a dampening of the otherwise expected worsening in body appreciation and ED symptoms over time. PUBLIC SIGNIFICANCE: Adolescent athletes are at risk for developing EDs. Due to lack of prevention programs for this group, we adapted and evaluated a well-documented effective program, the Body Project, to fit male and female athletes <15 years. The athletes accepted the program and experienced participation benefits, with stronger acceptance among girls. Our promising findings encourage larger scaled randomized controlled trials to further evaluate a refined version this program among very young athletes.

Beyond Age, BMI, Gender Identity, and Gender Minority Stress, Weight Bias Internalization Is Uniquely Associated With More Eating and Body Image Disturbances and Poor Physical and Mental Health in Chinese Gender-Diverse Adults.

OBJECTIVE: Weight bias internalization (WBI) is a robust, positive correlate of negative health outcomes; however, this evidence base primarily reflects cisgender individuals from Western cultural contexts. Gender-diverse individuals from non-Western cultural contexts (e.g., China) are at potentially high risk for WBI. Yet, no research has examined WBI and associated negative health consequences in this historically underrepresented population. METHOD: A cross-sectional, online survey sampled Chinese gender-diverse individuals (N = 410, Mage = 22.33 years). Variables were self-reported, including demographics, WBI, body shame, body dissatisfaction, disordered eating, physical and mental health status, and gender minority stress (e.g., internalized cisgenderism). Analyses included correlations and multiple hierarchical regressions. RESULTS: Pearson bivariate correlations demonstrated associations between higher WBI and more eating and body image disturbances and poor physical and mental health. After adjusting for age, BMI, gender identity, and gender minority stress, higher WBI was uniquely and positively associated with higher body shame, higher body dissatisfaction, higher disordered eating, and poor physical and mental health. Notably, WBI accounted for more unique variance in eating and body image disturbances (13%-25% explained by WBI) than physical and mental health (1%-4% explained by WBI). DISCUSSION: While replication with longitudinal and experimental designs is needed to speak to the temporal dynamics and causality, our findings identify WBI as a unique, meaningful correlate of eating and body image disturbances in Chinese gender-diverse adults.

Dissonance-Based Eating Disorder Prevention for Body-Dissatisfied Brazilian Cisgender Gay and Bisexual Men: A Randomized Controlled Trial With a 1-Year Follow-Up.

OBJECTIVE: Gay and bisexual men are at an increased risk for eating disorders (EDs) and muscle dysmorphia (MD) compared with their heterosexual counterparts. Existing dissonance-based (DB) EDs prevention programs for this population have been evaluated in the United States; however, these programs have not been evaluated in the Brazilian context. Thus, we investigated the feasibility, acceptability, and efficacy of a DB ED prevention program (i.e., the PRIDE Body Project) among Brazilian cisgender gay and bisexual men. METHOD: Eligible men were randomly assigned to either a DB intervention (n = 74) condition or an assessment-only control (AOC) condition (n = 75). Participants completed measures assessing ED and MD risk and protective factors at baseline, post-intervention, 1-month, 6-month, and 1-year follow-up. Those in the intervention condition also completed acceptability measures. RESULTS: Feasibility and acceptability ratings were highly favorable. Regarding efficacy, post-intervention results were not significant, except for self-objectification, which showed a significantly greater decrease in the DB condition compared with the AOC condition at all time-points of follow-ups (Cohen's d = -0.31 to -0.76). At follow-up, the DB condition showed significantly greater decreases in appearance-ideal internalization, drive for muscularity, self-objectification, ED and MD symptoms at 1-month, 6-month, and 1-year follow-ups (d = -0.33 to -0.92) compared with the AOC condition. Significant increases were observed in the DB compared with the AOC condition for body appreciation at 1-month, 6-month, and 1-year follow-ups (d = 0.31-0.81). DISCUSSION: Results support the feasibility, acceptability, and efficacy of the PRIDE Body Project up to 1-year in Brazilian cisgender gay and bisexual men. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (ReBEC; available at http://www.ensaiosclinicos.gov.br/) number of registration: RBR-62fctqz.

Experienced and internalized weight stigma among Spanish adolescents.

BACKGROUND AND OBJECTIVE: Weight stigma has negative consequences for both physiological and psychological health. Studies on weight stigma in adolescence, particularly from general populations, are scarce in the Mediterranean area. The main aim of this study is to describe the prevalence of experienced and internalized weight stigma among a representative sample of adolescents from the Spanish city of Terrassa, and to determine its association with sociodemographic variables and weight status. METHODS: Drawing on data from the initial assessment of a longitudinally funded project on weight stigma in adolescents, a cross-sectional survey-based study was conducted using random multistage cluster sampling. Weight stigma experiences, their frequency and sources, and weight bias internalization with the Modified Weight Bias Internalization Scale (WBISM) were assessed in a sample of 1016 adolescents. Adjusted odds ratios (AOR) between sociodemographic variables, weight status and having experienced weight stigma, and having reported high scores of WBISM (WBISM ≥ 4) were estimated by multiple logistic regression models. RESULTS: The prevalence of weight-related stigma experiences was 43.2% in the sample (81.8 in adolescents with obesity) and the prevalence of high levels of weight bias internalization was 19.4% (50.7 in adolescents with obesity). Other kids and school were the most prevalent sources of weight stigma, with society and family being other significant sources of stigma reported by girls. A significantly higher risk of having experienced weight stigma was observed in girls (AOR = 2.6) and in older adolescents (AOR = 1.9). Compared to normal weight adolescents, all weight statuses showed higher risk, being 3.4 times higher in adolescents with underweight and reaching 11.4 times higher risk in those with obesity. Regarding high levels of weight bias internalization, girls had a risk 6.6 times higher than boys. Once again, a "J-shaped" pattern was observed, with a higher risk at the lowest and highest weight statuses. The risk was 6.3 times higher in adolescents with underweight, and 13.1 times higher in adolescents with obesity compared to those with normal weight. CONCLUSIONS: Considering the high prevalence of experienced and internalized weight stigma among adolescents in Spain, especially in adolescents with obesity and girls, it seems important to implement preventive strategies in different settings and address all sources of stigma.

Mechanism of transport and toxicity response of Chlorella sorokiniana to polystyrene nanoplastics.

The toxicity of nanoparticles to freshwater microalgae is of significant importance in maintaining the overall stability of aquatic ecosystems. However, the transport mechanism and toxicity response of microalgae towards nanoplastics (NPs) remain to be further investigated. In this study, we examined the toxicity and internalization mechanisms of polystyrene nanoplastics (PS-NPs) in the microalga Chlorella sorokiniana. The results revealed that the PS-NPs inhibited algal cells' growth and disrupted cell integrity upon contact, leading to cell shrinkage or rupture. Moreover, amino-modified PS-NPs (Nano-PS-NH2) exhibited greater toxicity to C. sorokiniana than carboxyl-modified PS-NPs (Nano-PS-COOH). Furthermore, significant inhibition of PS-NPs internalization was observed when four different endocytosis-related inhibitors were used, indicating that internalized PS-NPs can enter algal cells through endocytic pathways. More importantly, C. sorokiniana exposed to Nano-PS-NH2 responded to the reduction in carbon sources and energy resulting from the suppression of photosynthesis by regulating the metabolism of carbohydrates. These findings elucidate the effects of PS-NPs on C. sorokiniana, including their impact on cell morphology and metabolism, while shedding light on the internalization mechanisms of NPs by C. sorokiniana which deepen our understanding of the toxicity of nanoplastics on algae and provide important theoretical support for solving such aquatic ecological environment problems.

Selective Cellular Uptake and Druggability Efficacy through Functionalized Chitosan-Conjugated Polyamidoamine (PAMAM) Dendrimers.

Nanotechnology has ushered in significant advancements in drug design, revolutionizing the prevention, diagnosis, and treatment of various diseases. The strategic utilization of nanotechnology to enhance drug loading, delivery, and release has garnered increasing attention, leveraging the enhanced physical and chemical properties offered by these systems. Polyamidoamine (PAMAM) dendrimers have been pivotal in drug delivery, yet there is room for further enhancement. In this study, we conjugated PAMAM dendrimers with chitosan (CS) to augment cellular internalization in tumor cells. Specifically, doxorubicin (DOX) was initially loaded into PAMAM dendrimers to form DOX-loaded PAMAM (DOX@PAMAM) complexes via intermolecular forces. Subsequently, CS was linked onto the DOX-loaded PAMAM dendrimers to yield CS-conjugated PAMAM loaded with DOX (DOX@CS@PAMAM) through glutaraldehyde crosslinking via the Schiff base reaction. The resultant DOX@CS@PAMAM complexes were comprehensively characterized using Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and dynamic light scattering (DLS). Notably, while the drug release profile of DOX@CS@PAMAM in acidic environments was inferior to that of DOX@PAMAM, DOX@CS@PAMAM demonstrated effective acid-responsive drug release, with a cumulative release of 70% within 25 h attributed to the imine linkage. Most importantly, DOX@CS@PAMAM exhibited significant selective cellular internalization rates and antitumor efficacy compared to DOX@PAMAM, as validated through cell viability assays, fluorescence imaging, and flow cytometry analysis. In summary, DOX@CS@PAMAM demonstrated superior antitumor effects compared to unconjugated PAMAM dendrimers, thereby broadening the scope of dendrimer-based nanomedicines with enhanced therapeutic efficacy and promising applications in cancer therapy.

Synergistic effects of quercetin-loaded CoFe2O4@Liposomes regulate DNA damage and apoptosis in MCF-7 cancer cells: based on biophysical magnetic hyperthermia.

INTRODUCTION: Breast cancer (BC) is the most common malignancy in women globally. Significant progress has been made in developing structural nanoparticles (NPs) and formulations for targeted smart drug delivery (SDD) of pharmaceuticals, improving the precision of tumor cell targeting in therapy. SIGNIFICANCE: Magnetic hyperthermia (MHT) treatment using magneto-liposomes (MLs) has emerged as a promising adjuvant cancer therapy. METHODS: CoFe2O4 magnetic NPs (MNPs) were conjugated with nanoliposomes to form MLs, and the anticancer drug quercetin (Que) was loaded into MLs, forming Que-MLs composites for antitumor approach. The aim was to prepare Que-MLs for DD systems (DDS) under an alternating magnetic field (AMF), termed chemotherapy/hyperthermia (chemo-HT) techniques. The encapsulation efficiency (EE), drug loading capacity (DL), and drug release (DR) of Que and Que-MLs were evaluated. RESULTS: The results confirmed successful Que-loading on the surface of MLs, with an average diameter of 38 nm and efficient encapsulation into MLs (69%). In vitro, experimental results on MCF-7 breast cells using MHT showed high cytotoxic effects of novel Que-MLs on MCF-7 cells. Various analyses, including cytotoxicity, apoptosis, cell migration, western blotting, fluorescence imaging, and cell membrane internalization, were conducted. The Acridine Orange-ethidium bromide double fluorescence test identified 35% early and 55% late apoptosis resulting from Que-MLs under the chemo-HT group. TEM results indicated MCF-7 cell membrane internalization and digestion of Que-MLs, suggesting the presence of early endosome-like vesicles on the cytoplasmic periphery. CONCLUSIONS: Que-MLs exhibited multi-modal chemo-HT effects, displaying high toxicity against MCF-7 BC cells and showing promise as a potent cytotoxic agent for BC chemotherapy.

In vitro evaluation of physicochemical-dependent effects of polymeric nanoparticles on their cellular uptake and co-localization using pulmonary calu-3 cell lines.

OBJECTIVE: The study evaluated physicochemical properties of eight different polymeric nanoparticles (NPs) and their interaction with lung barrier and their suitability for pulmonary drug delivery. METHODS: Eight physiochemically different NPs were fabricated from Poly lactic-co-glycolic acid (PLGA, PL) and Poly glycerol adipate-co-ω-pentadecalactone (PGA-co-PDL, PG) via emulsification-solvent evaporation. Pulmonary barrier integrity was investigated in vitro using Calu-3 under air-liquid interface. NPs internalization was investigated using a group of pharmacological inhibitors with subsequent microscopic visual confirmation. RESULTS: Eight NPs were successfully formulated from two polymers using emulsion-solvent evaporation; 200, 500 and 800 nm, negatively-charged and positively-charged. All different NPs did not alter tight junctions and PG NPs showed similar behavior to PL NPs, indicating its suitability for pulmonary drug delivery. Active endocytosis uptake mechanisms with physicochemical dependent manner were observed. In addition, NPs internalization and co-localization with lysosomes were visually confirmed indicating their vesicular transport. CONCLUSION: PG and PL NPs had shown no or low harmful effects on the barrier integrity, and with effective internalization and vesicular transport, thus, prospectively can be designed for pulmonary delivery applications.