New Fluorophore and Its Applications in Visualizing Polystyrene Nanoplastics in Bean Sprouts and HeLa Cells.

In the domain of environmental science, pollutants of nanoscale plastic dimensions are acknowledged as subjects of intricate significance. Such entities, though minuscule, present formidable challenges to ecological systems and human health. The diminutive dimensions of these contaminants render their detection arduous, thus demanding the inception of avant-garde methodologies. The present manuscript postulates the employment of the tetraphenylethylene functional group with a fused xanthene (TPEF), a distinguished fluorophore, as an exemplary system for the discernment of nanoplastic particulates. The synthesis and characterization of TPEF have been exhaustively elucidated, revealing its paramount fluorescence attributes and inherent affinity for interaction with nanoplastics. When subjected to comparison with TPEF, nanoplastics are observed to manifest a more pronounced fluorescent luminescence than when associated with the conventional Nile Red (NR). Particularly, the TPEF has shown exceptional affinity for polystyrene (PS) nanoplastics. Further, the resilience of nanoplastics within the hypocotyl epidermis of soybeans, as well as their persistence in mung bean sprouts subsequent to rigorous rinsing protocols, has been meticulously examined. Additionally, this investigation furnishes empirical data signifying the existence of nano-dimensional plastic contaminants within HeLa cellular structures. The urgency of addressing the environmental ramifications engendered by these diminutive yet potent plastic constituents is emphatically highlighted in this manuscript. TPEF paves the way for prospective explorations, with the aspiration of devising efficacious mitigation strategies. Such strategies might encompass delineating the trajectories undertaken by nanoplastics within trophic networks or their ingress into human cellular architectures.

[Oral Care to Prevent Ventilator-Associated Pneumonia].

Ventilator-associated pneumonia (VAP), one of the most common nosocomial infections in critical care units, has been associated with adverse outcomes such as higher medical expenses, prolonged hospital stays, and higher mortality rates. Although studies have demonstrated the effectiveness of oral care in reducing VAP incidence and enhancing patient comfort, few critically ill patients are able to perform oral care independently. Moreover, related evaluations and execution require specialized nursing techniques that rely on well-trained nurses. Unfortunately, descriptions of oral evaluations, caring practices, and hygiene related to pathogenic mechanisms in critically ill patients are scarce in both textbooks and the scientific literature. Based on a review of the related literature, this article discusses: the pathogenic mechanism of VAP; the purpose, principals, and steps of providing oral care to endotracheal tube ventilated patients, with particular emphasis on current evidence on the effect of chlorhexidine on oral care; and the major factors impacting oral care effectiveness. This article is expected to raise awareness of oral care, update the current evidence-based knowledge base, and increase the quality of nursing care provided to critically ill populations.

Green Polymer Electrolytes Based on Polycaprolactones for Solid-State High-Voltage Lithium Metal Batteries.

Solid polymer electrolytes (SPEs) have attracted considerable attention for high energy solid-state lithium metal batteries (LMBs). In this work, potentially ecofriendly, solid-state poly(ε-caprolactone) (PCL)-based star polymer electrolytes with cross-linked structures (xBt-PCL) are introduced that robustly cycle against LiNi0.6 Mn0.2 Co0.2 O2 (NMC622) composite cathodes, affording long-term stability even at higher current densities. Their superior features allow for sufficient suppression of dendritic lithium deposits, as monitored by 7 Li solid-state NMR. Advantageous electrolyte|electrode interfacial properties derived from cathode impregnation with 1.5 wt% PCL enable decent cell performance until up to 500 cycles at rates of 1C (60 °C), illustrating the high potential of PCL-based SPEs for application in high-voltage LMBs.

Selenomethionine protects oxidative-stress-damaged bone-marrow-derived mesenchymal stem cells via an antioxidant effect and the PTEN/PI3K/AKT pathway.

Dental implant surgery is currently a routine therapy for the repair of missing dentition or dentition defects. Both clinical and basic research have elucidated that oxidative stress caused by the accumulation of reactive oxygen species (ROS) for various reasons impairs the process of osteointegration after dental implantation. Therefore, the osteogenic micro-environment must be ameliorated to decrease the damage caused by oxidative stress. Selenomethionine (SEMET) has been reported to play an important role in alleviating oxidative stress and accelerating cell viability and growth. However, it remains unclear whether it exerts protective effects on bone-marrow-derived mesenchymal stem cells (BMSCs) under oxidative stress. In this study, we explored the influence of selenomethionine on the viability and osteogenic differentiation of BMSCs under oxidative stress and the underlying mechanisms. Results showed that 1 µM selenomethionine was the optimum concentration for BMSCs under H2O2 stimulation. H2O2-induced oxidative stress suppressed the viability and osteogenic differentiation of BMSCs, manifested by the increases in ROS production and cell apoptosis rates, and by the decrease of osteogenic differentiation-related markers. Notably, the aforementioned oxidative damage and osteogenic dysfunction induced by H2O2 were rescued by selenomethionine. Furthermore, we found that the PTEN expression level was suppressed and its downstream PI3K/AKT pathway was activated by selenomethionine. However, when PTEN was stimulated, the PI3K/AKT pathway was down-regulated, and the protective effects of selenomethionine on BMSC osteogenic differentiation diminished, while the inhibition of PTEN up-regulated the protective effects of selenomethionine. Together, these results revealed that selenomethionine could attenuate H2O2-induced BMSC dysfunction through an antioxidant effect, modulated via the PTEN/PI3K/AKT pathway, suggesting that selenomethionine is a promising antioxidant candidate for reducing oxidative stress during the process of dental implant osteointegration.

Effects of epigallocatechin-3-gallate and acyclovir on herpes simplex virus type 1 infection in oral epithelial cells.

BACKGROUND/PURPOSE: Herpes simplex virus type 1 (HSV-1) is the pathogenic agent of human diseases, including gingivostomatitis and herpes labialis. The anti-viral activities of the tea polyphenol, epigallocatechin-3-gallate (EGCG), have been demonstrated. This study examined the combined effects of EGCG and the antiviral drug, acyclovir (ACV), on infection of HSV-1 in oral epithelial cells. METHODS: Cell viability was examined using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide. Viral yields were determined using the plaque assay. Viral proteins were detected using Western blotting analysis or confocal laser scanning microscopy. Viral DNA was detected using the real-time polymerase chain reaction. RESULTS: Cytotoxic effects of HSV-1 on the viability of oral epithelial cells were evidently reduced in the presence of EGCG (25 µg/ml) or/and ACV (50 µg/ml). Viral yields were also significantly reduced by treatment of cells with EGCG or/and ACV. Expression of viral immediate early protein, infected cell protein 0 (ICP0), was greatly inhibited when cells were treated with EGCG. Combined effects of EGCG and ACV were more evident for the expression of viral thymidine kinase, ICP5 and glycoprotein D. EGCG, but not ACV, significantly reduced the levels of viral particles and viral DNA during viral entry phase. However, at 20 h post infection, the intracellular viral DNA was evidently reduced in HSV-1 infected cells treated with EGCG and ACV. Moreover, the stimulatory effects of HSV-1 on phosphorylation of c-Jun N-terminal kinase could be reduced by ACV. CONCLUSION: The results demonstrated the additive effects of EGCG and ACV on HSV-1 infection in oral epithelial cells.

Desensitization of NMDA channels requires ligand binding to both GluN1 and GluN2 subunits to constrict the pore beside the activation gate.

N-methyl-D-aspartate (NMDA) receptor channels are activated by glutamate (or NMDA) and glycine. The channels also undergo desensitization, which denotes decreased channel availability, after prolonged exposure to the activating ligands. Glycine apparently has a paradoxical negative effect on desensitization, as the increase in ambient glycine in concentrations required for channel activation would increase sustained NMDA receptor currents. We hypothesized that this classical "glycine-dependent desensitization" could be glycine-dependent activation in essence. By performing electrophysiological recordings and biophysical analyses with rat brain NMDA receptors heterogeneously expressed in Xenopus laevis oocytes, we characterized that the channel opened by "only" NMDA (in nominally glycine-free condition probably with the inevitable nanomolar glycine) would undergo a novel form of deactivation rather than desensitization, and is thus fully available for subsequent activation. Moreover, external tetrapentylammonium ions (TPentA), tetrabutylammonium ions, and tetrapropylammonium ions (TPA, in higher concentrations) block the pore and prohibit channel desensitization with a simple "foot-in-the-door" hindrance effect. TpentA and TPA have the same voltage dependence but show different flow dependence in binding affinity, revealing a common binding site at an electrical distance of ~0.7 from the outside yet differential involvement of the flux-coupling region in the external pore mouth. The smaller tetraethylammonium ion and the larger tetrahexylammonium and tetraheptylammonium ions may block the channel but could not affect desensitization. We conclude that NMDA receptor desensitization requires concomitant binding of both glycine and glutamate, and thus movement of both GluN1 and GluN2 subunits. Desensitization gate itself embodies a highly restricted pore reduction with a physical distance of ~4 Å from the charged nitrogen atom of bound tetraalkylammonium ions, and is located very close to the activation gate in the bundle-crossing region in the external pore vestibule.

A self-assembled layer-by-layer surface modification to fabricate the neuron-rich model from neural stem/precursor cells.

BACKGROUND/PURPOSE: In vitro neural cell-based models have been widely used to mimic the in vivo neural tissue environments and quantitatively understand the effects of pharmaceutical molecules on neural diseases. Recently, several biomimetic neural tissue models have been widely developed by using biomaterials or surface modification. However, the complex protocols of material synthesis or surface modification lack an easy execution to fabricate the neuron favorite environment. METHODS: In this study, we utilized a layer-by-layer technique as a surface modification method for regulating the behaviors of neural stem/precursor cells (NSPCs) on material surfaces. Polyelectrolyte multilayers (PEMs) via alternate deposition of poly (allylamine hydrochloride) (PAH) and poly (sodium-4-styrenesulfonate) (PSS) were used to culture NSPCs. After incubation for 7 days, the neuronal differentiation of NSPCs and synapse function of differentiated neurons were identified by immunocytochemistry for lineage specific markers. RESULTS: Compared with the only PAH film, the PSS-ending film (neuron-rich model) was shown to significantly promote differentiation of NSPCs into neurons (more than 50%), form a neuronal network structure; and differentiated neurons exhibiting functional synaptic activity. CONCLUSION: This study shows that the PEMs provided an easily alternative approach to modify the surface properties; and might be a method to obtain a neuron-rich model for the biological/pharmaceutical applications.

Relative transmissibility of hand, foot and mouth disease from male to female individuals.

Hand, foot and mouth disease (HFMD) has spread widely and leads to high disease burden in many countries. However, relative transmissibility from male to female individuals remains unclear. HFMD surveillance database was built in Shenzhen City from 2013 to 2017. An intersex transmission susceptible-infectious-recovered model was developed to calculate the transmission relative rate among male individuals, among female individuals, from male to female and from female to male. Two indicators, ratio of transmission relative rate (Rß) and relative transmissibility index (RTI), were developed to assess the relative transmissibility of male vs. female. During the study period, 270 347 HFMD cases were reported in the city, among which 16 were death cases with a fatality of 0.0059%. Reported incidence of total cases, male cases and female cases was 0.0057 (range: 0.0036-0.0058), 0.0052 (range: 0.0032-0.0053) and 0.0044 (range: 0.0026-0.0047), respectively. The difference was statistically significant between male and female (t = 3.046, P = 0.002). Rß of male vs. female, female vs. female, from female to male vs. female and from male to female vs. female was 7.69, 1.00, 1.74 and 7.13, respectively. RTI of male vs. female, female vs. female, from female to male vs. female and from male to female vs. female was 3.08, 1.00, 1.88 and 1.43, respectively. Transmissibility of HFMD is different between male and female individuals. Male cases seem to be more transmissible than female.

Preparation of core-shell magnetic molecularly imprinted polymer nanoparticle for the rapid and selective enrichment of trace diuron from complicated matrices.

A novel magnetic MIPs (DUMIPs) was prepared by surface molecular imprinting method using superparamagnetic core-shell nanoparticle (Fe3O4@SiO2) as the sacrificial support matrix, herbicide diuron as template, α-methacrylic acid as the functional monomer, trimethylolpropane trimethacrylate as the crosslinker, azobisisobutyronitrile as the initiator, and acetonitrile as the porogen. Highly cross-linked porous surface and excellent magnetic property were characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, and vibrating sample magnetometer, respectively. The adsorption capacity of DUMIPs was 8.1 mg g-1, 2.6-fold over its corresponding non-imprinted polymers (DUNIPs). The adsorption in DUMIPs was considered as multilayer adsorption and posed high affinity to diuron, due to the better fitting to Freundilich isotherm. Competitive recognition study demonstrated DUMIPs had highly selective binding diuron. DUMIPs, as an influential sorbent has been used for selective extraction of diuron from environmental samples (paddy field water, paddy soil and grain seedlings) and the elution was determined by high efficiency liquid chromatography (HPLC). In this analytical method, various factors affecting the extraction efficiency such as pH, sorbent dosage, utilization efficiency and volumes of eluent were simultaneously investigated. Under the optimal conditions, the linearity of the method obtained is in the range of 0.02-10.0 mg L-1. The limit of detection is 0.012 mg L-1. In four spiked levels (0.04, 0.2, 1.0, and 4.0 mg kg-1), the recoveries of diuron in real samples are in the range of 83.56%-116.10% with relative standard deviations in the range of 1.21-6.81%. Importantly, compared to C18-SPE column, the MMIPs exhibited convenient separation by external magnetic field, strong clean-up capacity, and selective enrichment for diuron. Thus, the DUMIPs-based method is great potential for efficient sample preparation in the determination of trace amounts of diuron residues in complex matrices.

A cone-beam computed tomography study of C-shaped root canal systems in mandibular second premolars in a Taiwan Chinese subpopulation.

BACKGROUND/PURPOSE: The purpose of this study is to investigate the prevalence and the morphologic characteristics of the radicular groove and root canal system in human mandibular second premolars with C-shaped root in a Taiwan Chinese subpopulation using cone-beam computed tomographic (CBCT) imaging. METHODS: CBCT images of 580 mandibular second premolars were collected from 317 patients. All of the mandibular second premolars were examined in serial axial sections to identify the presence of any C-shaped root and C-shaped canal systems. The morphologic characteristics of mandibular second premolars with C-shaped roots were studied by performing measurements of serial axial sections. RESULTS: The prevalence rate of mandibular second premolars with a C-shaped root was 3.45% (20/580 teeth) and the rate of those with a C-shaped canal system was 2.24% (13/580 teeth). It was found that 69% of the radicular grooves were located on the lingual half of the root (9/13 teeth) in mandibular second premolars with a C-shaped canal system. In those teeth with a lingual radicular groove, the main canal was toward the buccal side. Frequently, the first C-shaped canal image was found at the mid-root level. The deepest part of the radicular groove was located at about 2.5 mm apical to the first C-shaped canal image. CONCLUSION: There was a 2-3% morphologic variation of the mandibular second premolar with a C-shaped root canal system among the Taiwan Chinese subpopulation investigated in this study. Detailed knowledge of the morphological characteristics of teeth may be valuable when choosing clinical treatments.

The Effect of Implant-Induced Artifacts on Interpreting Adjacent Bone Structures on Cone-Beam Computed Tomography Scans.

INTRODUCTION: Cone-beam computed tomography (CBCT) imaging can be used to visualize anatomical structures before implant placement. The aim of this study is to evaluate the impact of implant artifacts on the accuracy of measuring periimplant bone dimensions. MATERIALS AND METHODS: Nineteen implants were placed into 9 fresh, frozen cadavers. A CBCT scan was taken, the implants were removed, and a second scan was taken. Implant dimensions and periimplant bone measurements were calculated. The mean differences were compared with paired t tests. Pearson's correlation coefficients were calculated for bone thickness measurements. DISCUSSION: No significant differences were found between the implant dimension or bone thickness measurements on each scan. Bone thickness at the implant platform and apex were significantly correlated (P < 0.001). CONCLUSION: The presence of dental implants did not impact the accuracy of cone-beam computed tomography (CBCT) measurements of bone thickness by metallic artifacts.

Medical costs of a low skeletal muscle mass are modulated by dietary diversity and physical activity in community-dwelling older Taiwanese: a longitudinal study.

BACKGROUND: Age-related loss of skeletal muscle mass (SMM) and function (sarcopenia) are associated with poor health outcomes and an economic burden on health care services. An appropriate diet and physical activity have been proposed for prevention and treatment of sarcopenia. Nevertheless, the effects on medical service utilization and costs remain unclear. This study determined the effects of SMM in conjunction with diet quality and physical activity on medical service utilization and expenditure in community-dwelling older Taiwanese. METHODS: In total, 1337 participants from the Elderly Nutrition and Health Survey in Taiwan (1999-2000) were enrolled. An SMM index [SMMI, calculated by dividing SMM (kg) by height (m2)] was used as the marker of sarcopenia. Participants with the lowest SMMI quartiles (<11.4 kg/m2 for men and 8.50 kg/m2 for women) comprised the high-risk group, and the remainder comprised the low-risk group. Dietary information (dietary diversity: low and high) and physical activity (low and moderate) were obtained at baseline. Annual medical service utilization and expenditure were calculated from National Health Insurance claims until December 31, 2006. Generalized linear models were used to determine the association between the SMMI and annual medical service utilization and costs in conjunction with dietary diversity or physical activity. RESULTS: After 8 follow-up years, regardless of gender, participants in the high-risk group reported significantly more hospitalization (days and expenditure) and total medical expenditure. Participants in the high-risk group who had low dietary diversity made fewer annual outpatient (14%), preventive care (19%), and dental (40%) visits, but exhibited longer hospitalization (102%) than did those who had a low SMMI and high dietary diversity. Similar patterns were observed in the corresponding medical expenditures. The findings were similar when considering physical activity. Being in the low-risk group in conjunction with having high dietary diversity or more physical activity was associated with the lowest annual adjusted mean hospitalization days with expenditure, and also total expenditure. CONCLUSIONS: A lower SMMI was associated with more hospitalization days and costs. However, high dietary diversity and more physical activity can attenuate the effects of lower SMMI on medical service utilization and expenditure.

Citrus polyphenol for oral wound healing in oral ulcers and periodontal diseases.

BACKGROUND/PURPOSE: Various polyphenolic compounds from plants have been confirmed to have different pharmaceutical functions. The purpose of this study was to evaluate citrus polyphenol (CP) for dental applications. A medium with CP was developed to improve oral wound healing. The CP could be used as a supplemental compound in mouthwash for periodontal diseases. METHOD: In this study, the metabolic activity and cell toxicity of CP (1%, 0.1%, and 0.01%) for fibroblasts were investigated by MTT and lactate dehydrogenase assays (n = 6). The effect of CP on motility of fibroblast was also evaluated via a wound healing model. RESULTS: The growth of Hs68 cells on TCPS was greatly increased in the presence of 0.01% CP. In addition, the significant difference (p<0.01) of cell toxicity of fibroblast was observed after 6 days in 0.01% CP medium. Using the wound healing model, it was also found that CP could enhance the migratory ability of fibroblasts. CONCLUSION: The results confirm the feasibility of CP be a supplemental compound in mouthwash for treatment of periodontal diseases in dental application to improve wound healing in the mouth.

Novel microinjector for carrying bone substitutes for bone regeneration in periodontal diseases.

BACKGROUND/PURPOSE: Traditionally, guide bone regeneration (GBR) was a widely used method for repairing bone lost from periodontal disease. There were some disadvantages associated with the GBR method, such as the need for a stable barrier membrane and a new creative cavity during the surgical process. To address these disadvantages, the purpose of this study was to evaluate a novel microinjector developed for dental applications. The microinjector was designed to carry bone graft substitutes to restore bone defects for bone regeneration in periodontal diseases. The device would be used to replace the GBR method. METHODS: In this study, the injected force and ejected volume of substitutes (including air, water, and ethanol) were defined by Hooke's law (n = 3). The optimal particle size of bone graft substitutes was determined by measuring the recycle ratio of bone graft substitutes from the microinjector (n = 3). Furthermore, a novel agarose gel model was used to evaluate the feasibility of the microinjector. RESULTS: The current study found that the injected force was less than 0.4 N for obtaining the ejected volume of approximately 2 mL, and when the particle size of tricalcium phosphate (TCP) was smaller than 0.5 mm, 80% TCP could be ejected from the microinjector. Furthermore, by using an agarose model to simulate the periodontal soft tissue, it was also found that bone graft substitutes could be easily injected into the gel. CONCLUSION: The results confirmed the feasibility of this novel microinjector for dental applications to carry bone graft substitutes for the restoration of bone defects of periodontal disease.

Inhibition of growth and migration of oral and cervical cancer cells by citrus polyphenol.

BACKGROUND/PURPOSE: It has been confirmed that polyphenolic compounds present in food have various pharmaceutical functions. The purpose of this study was to evaluate citrus polyphenol (CP) for dental applications. The culture medium with CP was developed to inhibit the proliferation of oral cancer cells. CP could be used as a supplemental compound for topical application for oral cancer patients. METHODS: In this study, the metabolic activity and cell toxicity of CP (at concentrations of 1%, 0.1%, and 0.01%) for oral and cervical cancer cells were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase assays (n = 6). Furthermore, the effects of CP on motilities of oral and cervical cancer cells were also evaluated using a scratch assay model. RESULTS: We found that the growth of Ca9-22 and HeLa cells on tissue culture polystyrene was greatly inhibited when 1% CP was added to the medium. In addition, significant differences (p < 0.01) in cytotoxicities of oral and cervical cancer cells were observed after 6 days in the culture medium to which 1% CP was added. Furthermore, using a scratch assay model to evaluate the migratory abilities of oral and cervical cancer cells, it was also found that CP could inhibit the migratory abilities of cancer cells. CONCLUSION: The results confirmed the feasibility of the topical application of CP as a supplemental compound for inhibition of cancer cell proliferation and migration.

Modified novel technique for improving the success rate of applying seprafilm by using laparoscopy.

STUDY OBJECTIVE: To describe a modified surgical procedure for applying the adhesion barrier Seprafilm laparoscopically. DESIGN: Retrospective analysis with videos and illustrations showing laparoscopic application of Seprafilm. SETTING: University hospital. PATIENTS: Women undergoing fertility-sparing laparoscopic surgery (myomectomy, endometriotic ovarian cyst or dermoid cyst enucleation, and tuboplasty) via a modified technique. INTERVENTION: Two layers of Seprafilm with plastic covering were rolled together and delivered through a 10-mm trocar, and an irrigation tube was used to moisten the Seprafilm and cover the irregular postoperative rough surface of the organ. After application of Seprafilm, the patient was placed in a reverse Trendelenburg position to check whether the Seprafilm remained in situ on the target surgical surface to act as a physical barrier to adhesion development. MEASUREMENTS AND MAIN RESULTS: After changing the patient's position, illustrations and videos showed that the Seprafilm remained on the postoperative surgical surface, creating a site-specific physical barrier. On day 4 after myomectomy, second-look laparoscopy in 2 patients showed that the Seprafilm had become gel-like and remained between the intestine and posterior rough surface of the uterus. There were no systemic second-look laparoscopic data. CONCLUSION: It is feasible and easier to apply Seprafilm adhesion barrier laparoscopically using the modified technique. Further studies are warranted to prove its efficacy after such use.

[Determination of ochratoxin A in human urine by HPLC-FLD after cleaned-up by molecularly imprinted polymer solid phase extraction column].

A method was developed for the determination of ochratoxin A (OTA) in human urine by HPLC-FLD after molecularly imprinted polymer solid phase extraction (MIP-SPE) column. After the pH being adjusted to 2.5 with 0.1 mol x L(-1) HC1, sample was cleaned up with MIP-SPE column for ochratoxin A, the analyte was analyzed by high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD), and finally all the positive results were confirmed by LC-MS/MS. Recoveries from urine samples spiked with OTA at levels ranging from 2 to 20 ng x mL(-1) were 90.6%-101.9%, and RSDs were 0.1%-1.6%. Sixty-five volunteers living in Beijing took part in the study, of which 5 were found containing OTA in their urine and the highest value was 0.091 ng x mL(-1). The MIP-SPE column was firstly applied to purify and concentrate OTA in human urine, this method is simple, rapid and reliable and can be used to determine the contents of OTA in human urine.

Liposomes with Low Levels of Grafted Poly(ethylene glycol) Remain Susceptible to Destabilization by Anti-Poly(ethylene glycol) Antibodies.

Binding of anti-PEG antibodies to poly(ethylene glycol) (PEG) on the surface of PEGylated liposomal doxorubicin (PLD) in vitro and in rats can activate complement and cause the rapid release of doxorubicin from the liposome interior. Here, we find that irinotecan liposomes (IL) and L-PLD, which have 16-fold lower levels of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE)-PEG2000 in their liposome membrane as compared to PLD, generate less complement activation but remain sensitive to destabilization and drug release by anti-PEG antibodies. Complement activation and liposome destabilization correlated with the theoretically estimated number of antibody molecules bound per liposome. Drug release from liposomes proceeded through the alternative complement pathway but was accelerated by the classical complement pathway. In contrast to PLD destabilization by anti-PEG immunoglobulin G (IgG), which proceeded by the insertion of membrane attack complexes in the lipid bilayer of otherwise intact PLD, anti-PEG IgG promoted the fusion of L-PLD, and IL to form unilamellar and oligo-vesicular liposomes. Anti-PEG immunoglobulin M (IgM) induced drug release from all liposomes (PLD, L-PLD, and IL) via the formation of unilamellar and oligo-vesicular liposomes. Anti-PEG IgG destabilized both PLD and L-PLD in rats, indicating that the reduction of PEG levels on liposomes is not an effective approach to prevent liposome destabilization by anti-PEG antibodies.

Dual crosslinking silk fibroin/pectin-based bioink development and the application on neural stem/progenitor cells spheroid laden 3D bioprinting.

The human nervous system is an incredibly intricate physiological network, and neural cells lack the ability to repair and regenerate after a brain injury. 3-dimensional (3D) bioprinting technology offers a promising strategy for constructing biomimetic organ constructs and in vitro brain/disease models. The bioink serves as a pivotal component that emulates the microenvironment of biomimetic construct and exerts a profound influence on cellular behaviors. In this study, a series of mechanically adjustable and dual crosslinking bioinks were developed using photocrosslinkable methacrylated silk fibroin (SilMA) in combination with the ionic crosslinking material, pectin, or pectin methacryloyl (PecMA) with silk fibroin (SF) supplementation. SilMA/pectin exhibited superior properties, with SilMA providing biocompatibility and adjustable mechanical properties, while the addition of pectin enhanced printability. The porous structure supported neural cell growth, and 15 % SilMA/0.5 % pectin bioinks displayed excellent printability and shape fidelity. Neural stem/progenitor cells (NSPCs)-loaded bioinks were used to construct a 3D brain model, demonstrating sustained vitality and high neuronal differentiation without the need for growth factors. The SilMA/pectin bioinks demonstrated adjustable mechanical properties, favorable biocompatibility, and an environment highly conducive to neural induction, offering an alternative approach for neural tissue engineering applications or in vitro brain models.

Single-cell transcriptomics reveals cell atlas and identifies cycling tumor cells responsible for recurrence in ameloblastoma.

Ameloblastoma is a benign tumor characterized by locally invasive phenotypes, leading to facial bone destruction and a high recurrence rate. However, the mechanisms governing tumor initiation and recurrence are poorly understood. Here, we uncovered cellular landscapes and mechanisms that underlie tumor recurrence in ameloblastoma at single-cell resolution. Our results revealed that ameloblastoma exhibits five tumor subpopulations varying with respect to immune response (IR), bone remodeling (BR), tooth development (TD), epithelial development (ED), and cell cycle (CC) signatures. Of note, we found that CC ameloblastoma cells were endowed with stemness and contributed to tumor recurrence, which was dominated by the EZH2-mediated program. Targeting EZH2 effectively eliminated CC ameloblastoma cells and inhibited tumor growth in ameloblastoma patient-derived organoids. These data described the tumor subpopulation and clarified the identity, function, and regulatory mechanism of CC ameloblastoma cells, providing a potential therapeutic target for ameloblastoma.