Loss Of Fluorescence Research Articles

Validity assessment of a third-generation light-induced fluorescence device in detecting proximal and occlusal caries lesions: A cross-sectional study

ObjectivesThe objective of this study was to evaluate the efficacy of a quantitative light-induced fluorescence (QLF) device (QrayCam Pro, AIOBIO, Seoul, Republic of Korea) in detecting and differentiating the severity of posterior proximal and occlusal primary caries. Materials and methodsThe study included a total of 120 teeth in 60 patients (of both genders, aged between 21 and 38 years) between January and March 2024, one carious tooth and one sound tooth were selected at random in each patient. All occlusal surfaces were evaluated in accordance with the International Caries Detection and Assessment System (ICDAS) Nyvad Criteria, using the visual tactile method. The ICDAS employs a scoring system ranging from 0 to 6, while the Nyvad Criteria employs a similar scoring system. Addionally, the depth of the proximal lesions was scored (0–6) using bite-wing radiography. The quantitative values representing the maximum loss of fluorescence (∆Fmax) and the maximum change in the ratio of red and green fluorescence (∆Rmax) were obtained using the Q-ray Clinical software v 1.45. To assess the validity, the sensitivity, specificity, and area under the receiver operating characteristics curve (AUROC) were calculated. Spearman correlation coefficient was used to investigate the correlation between the findings of the traditional and QLF examination methods. ResultsThe AUROC values for both ∆Fmax and ∆Rmax were found to be excellent. The sensitivity of QrayCam Pro was found to be 84–88.6%, while the specificity was 100%. The correlation analysis demonstrated a strong correlation between scores obtained from the traditional examination and the QLF values. ConclusionsBased on the findings of this study, QrayCam Pro exhibits potential as a valuable additional tool for not only detecting caries but also for assessing their severity and activity. Clinical relevanceThis study revealed that QrayCam Pro might be suggested as a precise tool for enhancing caries detection and assessment compared to traditional methods. By providing quantitative data on caries severity and activity, it enables more informed treatment decisions, potentially optimizing outcomes for patients.

Evaluation of the Remineralization Potential of an Herbal Non-fluoridated Dentifrice on Carious Lesions: An In Vitro Study

Background: This in vitro study compared the remineralization potential of Dabur red (DR), a non-fluoridated herbal toothpaste, with Colgate Strong Teeth (CST), a fluoride-based toothpaste, on permanent teeth with artificially created white spot lesions. Vickers microhardness (VMH), quantitative light-induced fluorescence system (QLF), and scanning electron microscopy (SEM) were used for data analysis. Methods: Enamel samples were prepared from the buccal surface of forty-five extracted maxillary premolars and subjected to demineralization to achieve adequate fluorescence loss (ΔF). The samples were divided into DR, CST, and control groups (n=15) and underwent 21 days of pH cycling. VMH was measured at baseline and after 21 days. QLF imaging was performed on days 7, 14, and 21. One randomly selected sample from each group underwent SEM examination to compare morphological variations. The statistical analysis was conducted using SPSS 22.0. Intra-group comparisons were made with repeated measures of analysis of variance (ANOVA), and one-way ANOVA with Tukey’s post-hoc test was utilized for inter-group comparisons (P<0.05). Results: Mean VHN increased significantly in all three groups from baseline (DR=40.47, CST=41.91, control=36.42) to the 21st day (DR=119.47, CST=120.36, control=74.36) (P=0.00). Significant differences were found between the control and test groups, but not between DR and CST. No statistically significant difference was observed in ΔF at baseline and 7 days, but there were significant differences among the groups at 14 and 21 days. SEM images revealed dense mineralization for both DR and CST. Conclusion: After 21 days of in vitro remineralization, both DR and Colgate toothpaste demonstrated similar remineralizing potential as evaluated by surface MH and QLF.

The Alphabet Soup of Microscopy: An Introduction to Advanced Imaging Techniques. Part II: What the FLIP, FLAP, FRAP, FRET, and FLIM is Going On?

Abstract The use of fluorescence in imaging has been a pivotal factor in advancing our scientific understanding. As microscopy continues to evolve, the terminology used to describe these techniques becomes increasingly complex, often resulting in a bewildering array of acronyms that resemble alphabet soup. Among the most prominent acronyms are those associated with advanced fluorescence microscopy techniques: Fluorescence Loss in Photobleaching (FLIP), Fluorescence Localization after Photobleaching (FLAP), Fluorescence Recovery after Photobleaching (FRAP), Förster Resonance Energy Transfer (FRET), and Fluorescence Lifetime Imaging Microscopy (FLIM). Each of these methods provides invaluable insights into molecular dynamics and interactions within living cells and tissues. This article, Part 2 of the Alphabet Soup of Microscopy series, aims to clarify these widely used fluorescence microscopy techniques and to illuminate their contributions to our understanding of cellular processes.

The use of thermostable fluorescent proteins for live imaging in Sulfolobus acidocaldarius.

Among hyperthermophilic organisms, in vivo protein localization is challenging due to the high growth temperatures that can disrupt proper folding and function of mostly mesophilic-derived fluorescent proteins. While protein localization in the thermophilic model archaeon S. acidocaldarius has been achieved using antibodies with fluorescent probes in fixed cells, the use of thermostable fluorescent proteins for live imaging in thermophilic archaea has so far been unsuccessful. Given the significance of live protein localization in the field of archaeal cell biology, we aimed to identify fluorescent proteins for use in S. acidocaldarius. We expressed various previously published and optimized thermostable fluorescent proteins along with fusion proteins of interest and analyzed the cells using flow cytometry and (thermo-) fluorescent microscopy. Of the tested proteins, thermal green protein (TGP) exhibited the brightest fluorescence when expressed in Sulfolobus cells. By optimizing the linker between TGP and a protein of interest, we could additionally successfully fuse proteins with minimal loss of fluorescence. TGP-CdvB and TGP-PCNA1 fusions displayed localization patterns consistent with previous immunolocalization experiments. These initial results in live protein localization in S. acidocaldarius at high temperatures, combined with recent advancements in thermomicroscopy, open new avenues in the field of archaeal cell biology. This progress finally enables localization experiments in thermophilic archaea, which have so far been limited to mesophilic organisms.

Oxidative Modifications of Proteins and Lipids of Dried Semen, Urine, and Saliva Stains as a Function of Age in Forensic Context

Knowledge of the time of deposition is pivotal in forensic investigations. Recent studies show that changes in intrinsic fluorescence over time can be used to estimate the age of body fluids. These changes have been attributed to oxidative modifications caused by protein–lipid interactions. This pilot study aims to explore the impact of these modifications on body fluid fluorescence, enhancing the protein–lipid model system for age estimation. Lipid and protein oxidation markers, including protein carbonyls, dityrosine, advanced glycation end-products (AGEs), malondialdehyde (MDA), and 4-hydroxynonenal (HNE), were studied in aging semen, urine, and saliva over 21 days. Surface plasmon resonance imaging (SPRi), enzyme-linked immunosorbent assay (ELISA), and fluorescence spectroscopy were applied. Successful detection of AGE, dityrosine, MDA, and HNE occurred in semen and saliva via SPRi, while only dityrosine was detected in urine. Protein carbonyls were measured in all body fluids, but only in saliva was a significant increase observed over time. Additionally, protein fluorescence loss and fluorescent oxidation product formation were assessed, showing significant decreases in semen and saliva, but not in urine. Although optimization is needed for accurate quantification, this study reveals detectable markers for protein and lipid oxidation in aging body fluids, warranting further investigation.

Effectiveness of Fluoride Varnishes for White Spot Lesion Prevention and Remineralization during Orthodontic Treatment: A Randomized Controlled Trial.

This study investigated the effectiveness of titanium tetrafluoride (TiF4) varnish compared to sodium fluoride (NaF) varnish for preventing and remineralizing white spot lesions (WSLs) in individuals undergoing orthodontic treatment. This randomized, placebo-controlled, and double-blinded study was conducted with sixty-five adolescents who were selected based on caries activity and then randomized into three parallel groups: G1 (placebo varnish), G2 (5%-NaF varnish) and G3 (4%-TiF4 varnish). Volunteers received varnish application weekly for the first 4 weeks, after 6 (T1) and 12 (T2) months. The measured outcomes included: prevention of new WSLs, and reversal/progression of WSLs, assessed by Nyvad and ICDAS indices, as well as quantitative light-induced fluorescence (QLF). Chi-square, ANOVA, and Kruskall-Wallis tests were applied. The level of significance was set at 0.05, and post hoc Bonferroni test for p values were performed to correct for multiple comparisons. 1,274 teeth were included; 70.5% were Nyvad 0, and 29.5% were Nyvad 1, with no differences between the groups at baseline (T0). Regarding ICDAS, 70.5% were ICDAS 0, 21.6% were ICDAS 1, and 7.9% were ICDAS 2. G1 showed an increasing prevalence of WSLs at T1 and maintained stable at T2; G2 exhibited a decline at T2, while G3 experienced a decrease at T1 and T2 (p < 0.01). Incidence of WSLs at T2 was 10.2% (G1), 5.6% (G2) and 1.4% (G3). The percentage of teeth initially scored as Nyvad 0 that progressed to Nyvad 1 was 13%, 6.8%, and 1% for G1, G2, and G3, respectively. Conversely, the percentage of teeth initially scored as Nyvad 1 that regressed to Nyvad 0 or Nyvad 2 (T0-T2) was 14%, 49.3%, and 74.4%, respectively (p < 0.001). As for ICDAS index, regression was observed in 6.5%, 17.8% and 24%, while progression was observed in 14.9%, 7.7% and 0.9% for G1, G2 and G3, respectively (p < 0.001). Significant differences among the 3 groups for integrated fluorescence loss (mean±SD, G1: -14.28±9.47, G2: -11.10±11.49 and G3: -6.77±11.00) were found at T2 (p < 0.01). Both varnishes demonstrated the ability to prevent and remineralize WSLs. However, TiF4 varnish exhibited the most effective control over WSLs during the 12-month orthodontic treatment.

Orthogonal DNA Self-Assembly-Based Expansion Microscopy Platform for Amplified, Multiplexed Biomarker Imaging.

Expansion microscopy (ExM) facilitates nanoscale imaging under conventional microscopes, but it frequently encounters challenges such as fluorescence losses, low signal-to-noise ratio (SNR), and limited detection throughput. To address these issues, a method of orthogonal DNA self-assembly-based ExM (o-DAExM) platform is developed, which employs hybridization chain reaction instead of conventional fluorescence labeling units, showcasing signal amplification efficacy, enhancement of SNR, and expandable multiplexing capability at any stage of the ExM process. In this work, o-DAExM has been applied to compare with immunofluorescence-based ExM for cellular cytoskeleton imaging, and the resolved nanoscale spatial distributions of cytoskeleton show outstanding performance and reliability of o-DAExM. Furthermore, the study demonstrates the utility of o-DAExM in accurately revealing exosome heterogeneous information and multiplexed analysis of protein targets in single cells, which provides infinite possibilities in super-resolution imaging of cells and other samples. Therefore, o-DAExM offers a straightforward expansion and signal labeling method, highlighting future prospects to study nanoscale structures and functional networks in biological systems.

A new sol-gel fluorescent sensor to track carbonyl compounds

Carbonyl compounds are ubiquitous quality trackers that provide information about food product degradation as well as air and water pollution levels. In addition, they are used as biomarkers for medical diagnoses. With more user-friendly sensors, their fast detection and easy quantification are highly relevant. The synthesis, characterization, and performance assessment of a new sensor based on aniline fluorescence to monitor carbonyls in real time is reported. A cost-effective synthesis using a straightforward sol-gel process led to the construction of a nontoxic silica-based material with high porosity, which can be used with almost no sample preparation. The material exhibits a rapid (< 1 min) fluorescence decrease upon interaction with carbonyl groups. The limit of detection is as low as ca. 5 × 10−4 mol·L−1 for hexanal, while fluorescence extinction occurs at much higher concentrations (5 × 10−1·mol L−1), which enables the sensor to be used with a very broad range of detection. Real-time monitoring is possible since the fluorescence loss correlates with the concentration of carbonyl moieties. The performance was validated in simulating as well as in real media, making this sensor suitable for use in a wide range of applications.

Evaluation of a Novel Lateral Emitting Laser Fiber for Near-Infrared Photoimmunotherapy.

Near-infrared photoimmunotherapy (NIR-PIT) is a new cancer therapy that uses NIR light and conjugates of a tumor-targeting monoclonal antibody and phthalocyanine dye. In clinical practice, frontal and cylindrical diffusers are the only options for NIR illumination. However, illumination in a narrow space is technically difficult with such diffusers. Therefore, we evaluated a lateral illumination system using a lateral emitting laser (LEL) fiber. The LEL fiber illuminated a certain area in a lateral direction. NIR-PIT with an LEL fiber reduced luciferase activity in a light-dose-dependent manner in A431-GFP-luc cells in vitro and significantly suppressed tumor proliferation in a xenograft mouse model. To evaluate the usefulness of the LEL fiber in the illumination of a narrow space, a tumor was illuminated from the inside of a cylinder, mimicking a narrow space, and the fluorescence intensity in the tumor was monitored. In the frontal diffuser, NIR light was unevenly delivered and little light reached a distal tumor area from the illuminated side. By contrast, the LEL fiber allowed a uniform illumination of the entire tumor, and a loss of fluorescence was observed even in distal areas. These findings suggested that the LEL fiber can be used for NIR-PIT and is suitable for NIR light illumination in a narrow space.

Rhodamine B functionalized Titanium dioxide and Silver sulfide adorned Bismuth Ferrite Oxide as a Turn-Off fluorescent sensing probe to organochlorine pesticides

Rhodamine B(RhB) functionalized Bismuth Ferrite Oxide(BFO)/Titanium dioxide(TiO2)/Silver disulfide(AgS)nanoparticles were used to build a fluorescent turn-off sensor for the detection of Chlorpyrifos(CLP). The fluorescence was drastically quenched by the RhB fluorescence resonance energy transfer to the surface of BFO/TiO2/AgS NCs via electrostatic interactions. Then the addition of CLP to RhB@BFO/TiO2/AgSNCs initiates the loss of fluorescence by the adsorption of CLP molecules to the turn-off sensor probe. Under favorable conditions, the linearity between the fluorescence quenching and the concentrations was monitored and the limit of detection was estimated to be 0.006 ppm, 0.004 ppm for 2:1 and 3:1 ratio, with the fluorescence quenching efficiency ranges from 92.9 to 94 %.

Ampholytic Peptides Consisting of an Alternating Lysine/Glutamic Acid Sequence for the Simultaneous Formation of Polyion Complex Vesicles.

Nanoarchitectures such as micelles and vesicles that self-assemble via electrostatic interactions between their charged polymeric components have been widely used as material delivery platforms. In this work, ampholytic peptides with a sequence of alternating lysine and glutamic acid residues were designed and synthesized via chemoenzymatic polymerization. This alternating sequence was achieved by trypsin-catalyzed polymerization of a dipeptide monomer. Due to the electrostatic interaction between the anionic and cationic residues, the prepared ampholytic peptides spontaneously formed nanosized assemblies with a size of 100-200 nm in water. Modification with tetra(ethylene glycol) (TEG) at the N-terminus of these ampholytic alternating peptides resulted in the formation of stable nanosized assemblies, while peptides consisting of random sequences of lysine and glutamic acid formed large aggregates with deteriorated stability even with TEG modification. Morphological observations using a field-emission scanning electron microscope and an atomic force microscope revealed that the obtained assemblies were spherical and hollow, indicating the spontaneous formation of vesicles from the TEG-modified ampholytic alternating peptides. These vesicles were able to encapsulate a model fluorescent protein within their hollow structures without structural collapse causing loss of fluorescence, demonstrating the potential of these nanocarriers for use in material delivery systems.

Determination of surfactant secretion in precision-cut lung slices

Surfactant, secreted from type 2 (AT2) cells of the alveolar epithelium (AE), maintains alveolar stability. However, the variability of surfactant secretion, a possible cause of regional lung disease, remains unquantified. To address this, we cultured precision-cut lung slices (PCLS) of mouse lung explants, using low-melting point agarose as per reported protocols. For real-time confocal imaging (RCM), we loaded day-old PCLS with the cytosolic marker calcein green (CG) and the AT2 cell marker, lysotracker red (LTR). RCM revealed alveoli as CG-stained AE that circumscribed the non-fluorescent alveolar lumen. Each slice (n=3) contained &gt;300 alveoli, each with an LTR+ AT2 cell. Exposing the slice to ATPgamma-s (4 microM) induced progressive loss of LTR fluorescence, denoting induction of surfactant secretion. In 60% of AT2 cells, the fluorescence decreased to 40±2% of initial in 50 min (p&lt;0.01). In 11%, the decrease was to 59±1%. In 29%, there was no decrease. We conclude: (i) PCLS provide a robust platform for quantifying AT2 secretion; (ii) surfactant secretion rates vary considerably amongst AT2 cells. Mechanistic basis of the variation, hence its impact on lung function must be understood. HL36024. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Detection of pit and fissure sealant microleakage using quantitative light-induced fluorescence technology: an in vitro study.

This in vitro study aimed to evaluate the feasibility of quantitative light-induced fluorescence (QLF) technology for detecting the presence and severity of microleakage of pit and fissure sealants. The areas of interest (AOIs) were 160 pits and fissures of 40 extracted permanent teeth. Fluorescent images were acquired using a QLF device, and the maximum fluorescence loss ΔFmax of each AOI was analyzed. After staining and cross-sectioning of the teeth, histological dye penetration was scored on a scale of 0 to 3. The relationship between ΔFmax and microleakage depth was analyzed, and the areas under the curve (AUCs) were calculated. The │ΔFmax│ increased as microleakage depth increased. The ΔFmax values of microleakage areas showed a strong significant correlation with the histological scores of dye penetration (r = -0.72, P = 0.001). AUC analysis showed a high diagnostic accuracy for microleakage depth (AUC = 0.83-0.91). The highest AUC of 0.91 was found when differentiating the outer half microleakage of the sealant (histological score 0 vs. 1-3). QLF technology is effective in assessing the presence and severity of microleakage, suggesting its potential for noninvasive detection and monitoring of sealant microleakage in clinical settings.

Formation mechanism of quinoa protein hydrolysate-EGCG complexes at different pH conditions and its effect on the protein hydrolysate-lipid co-oxidation in emulsions

This study aimed to investigate the interaction, structure, antioxidant, and emulsification properties of quinoa protein hydrolysate (QPH) complexes formed with (−)-epigallocatechin gallate (EGCG) at pH 3.0 and 7.0. Additionally, the effect of pH conditions and EGCG complexation on protein hydrolysate-lipid co-oxidation in QPH emulsions was explored. The results indicated that QPH primarily interacted with EGCG through hydrophobic interactions and hydrogen bonds. This interaction led to alterations in the secondary structure of QPH, as well as a decrease in surface hydrophobicity and free SH content. Notably, the binding affinity between QPH and EGCG was observed to be higher at pH 7.0 compared to pH 3.0. Consequently, QPH-EGCG complexes exhibited more significant enhancement in antioxidant and emulsification properties at pH 7.0 than pH 3.0. The pH level also influenced the droplet size, ζ-potential, and interfacial composition of emulsions formed by QPH and QPH-EGCG complexes. Compared to QPH stabilized emulsions, QPH-EGCG stabilized emulsions were more capable of mitigating destabilization during storage and displayed fewer lipid oxidation products, carbonyl generation, and sulfhydryl groups and fluorescence loss, which implied better oxidative stability of the emulsions. Furthermore, the QPH-EGCG complexes formed at pH 7.0 exhibited better inhibition of protein hydrolysate-lipid co-oxidation. Overall, these findings provide valuable insights into the potential application of QPH and its complexes with EGCG in food processing systems.

Visual screening of CRISPR/Cas9 editing efficiency based on micropattern arrays for editing porcine cells.

CRISPR/Cas9 technology, combined with somatic cell nuclear transplantation (SCNT), represents the primary approach to generating gene-edited pigs. The inefficiency in acquiring gene-edited nuclear donors is attributed to low editing and delivery efficiency, both closely linked to the selection of CRISPR/Cas9 forms. However, there is currently no direct method to evaluate the efficiency of CRISPR/Cas9 editing in porcine genomes. A platform based on fluorescence reporting signals and micropattern arrays was developed in this study, to visually assess the efficiency of gene editing. The optimal specifications for culturing porcine cells, determined by the quantity and state of cells grown on micropattern arrays, were a diameter of 200µm and a spacing of 150µm. By visualizing the area of fluorescence loss and measuring the gray value of the micropattern arrays, it was quickly determined that the mRNA form targeting porcine cells exhibited the highest editing efficiency compared to DNA and Ribonucleoprotein (RNP) forms of CRISPR/Cas9. Subsequently, four homozygotes of the β4GalNT2 gene knockout were successfully obtained through the mRNA form, laying the groundwork for the subsequent generation of gene-edited pigs. This platform facilitates a quick, simple, and effective evaluation of gene knockout efficiency. Additionally, it holds significant potential for swiftly testing novel gene editing tools, assessing delivery methods, and tailoring evaluation platforms for various cell types.

Rational Design of a Circularly Permuted Flavin-Based Fluorescent Protein.

Flavin-based fluorescent proteins are oxygen-independent reporters that hold great promise for imaging anaerobic and hypoxic biological systems. In this study, we explored the feasibility of applying circular permutation, a valuable method for the creation of fluorescent sensors, to flavin-based fluorescent proteins. We used rational design and structural data to identify a suitable location for circular permutation in iLOV, a flavin-based reporter derived from A. thaliana. However, relocating the N- and C-termini to this position resulted in a significant reduction in fluorescence. This loss of fluorescence was reversible, however, by fusing dimerizing coiled coils at the new N- and C-termini to compensate for the increase in local chain entropy. Additionally, by inserting protease cleavage sites in circularly permuted iLOV, we developed two protease sensors and demonstrated their application in mammalian cells. In summary, our work establishes the first approach to engineer circularly permuted FbFPs optimized for high fluorescence and further showcases the utility of circularly permuted FbFPs to serve as a scaffold for sensor engineering.

Abstract 45: Driving AMPK signaling in CD4+ CART cells enhances metabolic capacity, memory formation, and anti-leukemia activity

Abstract Background: While Chimeric Antigen Receptor (CAR)T cell therapy has seen great success in pediatric and young adult acute lymphoblastic leukemia, up to 50% of patients will relapse following treatment. Increased memory formation and mitochondrial capacity, particularly in the CD4+ subset, have been linked to improved CART cell function and enhanced in vivo persistence, leading to long-term relapse-free survival. AMP-activated protein kinase (AMPK) is a cellular energy sensor responsible for promoting metabolic efficiency and T cell memory formation. We have previously demonstrated AMPK activity can be increased in human T cells via overexpression of the AMPKγ2 domain. We hypothesized that overexpression of AMPKγ2 in CART cells would enhance their metabolic capacity and improve their anti-leukemia function. Methods: Human CART cells bearing a CD19-CAR utilizing a 41BB costimulatory domain were generated from healthy human donors via lentiviral transduction and co-transduced with AMPKγ2 (AMPK) or an empty vector (EV) control. Flow sorting for the co-transduced populations yielded &amp;gt;95% CD4+ CART cells. CARTs were expanded in IL-2 for approximately 2 weeks, followed by overnight stimulation and subsequent metabolic analysis using the Seahorse Metabolic Analyzer. Memory status was assessed by CD62L and CCR7 co-expression. In vitro CART function was assessed using Zs-green+ NALM6 targets, with loss of green fluorescence over time measured on the Incucyte analyzer. Where indicated, tumor conditioned media was harvested from 72-hour NALM6 cultures. For in vivo experiments, immunodeficient NOD-scid IL2Rγnull (NSG) mice were injected with luciferase+ NALM6 targets, followed one week later by AMPK- or EV-CARTs. Leukemia burden, via IVIS imaging, and survival were followed over time. Results: CD4+ CARTs co-transduced with AMPKγ2 (AMPK-CARTs) increased oxygen consumption, maximal respiration, and spare respiratory capacity following overnight stimulation by ~20% compared to CARTs co-transduced with the EV (EV-CARTs) (p&amp;lt;0.05). Following expansion, CD62L+CCR7+ central memory cells were 4.5-fold more abundant in the AMPK-CART group (2.4-6.2-fold, p&amp;lt;0.01). In vitro, while AMPK-CARTs demonstrated similar cytotoxicity against NALM6 targets as EV-CARTs in standard media, they mediated faster killing of NALM6 targets when challenged in tumor conditioned media (p&amp;lt;0.001). In vivo, recipients of AMPK-CARTs showed a consistent decrease in tumor burden as measured by median radiance values, translating to a significant survival advantage (p&amp;lt;0.05). Conclusions: Increasing AMPK signaling in CD4+ CARTs via overexpression of AMPKγ2 improved metabolic profile, increased memory generation, and enhanced toxicity against leukemia targets both in vitro and in vivo. Together, these features make elevating AMPK signaling an attractive method to increase the efficacy of CART therapy. Citation Format: Erica Braverman, Herbert Schuler, Mengtao Qin, Craig Byersdorfer. Driving AMPK signaling in CD4+ CART cells enhances metabolic capacity, memory formation, and anti-leukemia activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 45.

Development of a novel in vitro model for non-cavitated carious lesion formation reflecting carious lesion activity

BackgroundOral biofilms are a critical component in dental caries formation. However, current remineralization studies often overlook the impact of microbial factors. Therefore, a comprehensive clinically relevant assessment of caries is needed. This study aimed to develop a novel in vitro model capable of generating non-cavitated carious lesions that incorporates both mineral loss and microbial activity using quantitative light-induced fluorescence-digital (QLF-D) technology. MethodsA total of 44 artificial early carious lesions were formed using bovine incisors. The extent of fluorescence loss (ΔF) was analyzed using a QLF-D camera. Oral microcosm biofilms were then employed to construct 22 active and 22 inactive carious lesions. The red fluorescence emission rate (ΔR) and bacterial viability (RatioG/G+R) was measured using QLF-D camera and a live-dead bacterial assay, respectively. Independent t-tests were performed to compare ΔF, ΔR, and bacterial viability of artificial carious lesions according to their activity status. ResultsNo significant difference in ΔF between the lesions was found based on activity status (p = 0.361). However, the ΔR of active lesions was 1.82 times higher than that of inactive lesions, and the RatioG/G+R was 1.49 times higher in active lesions than in inactive lesions (both p < 0.001). ConclusionsThe significant differences observed in ΔR and RatioG/G+R between active and inactive lesions emphasize the importance of considering lesion activity status when evaluating the potential efficacy of remineralization agents. This study presents a novel in vitro remineralization assessment model that reflects carious lesion activity while controlling baseline mineral distributions of lesions.

Red fluorescence intensity as a criterion for assessing remineralization efficacy in early carious lesions

ObjectivesEvaluating early carious lesion activity with an objective and clinically valid approach is crucial for developing effective treatment plans. Therefore, we here assessed the activity of non-cavitated carious lesions using a quantitative light-induced fluorescence-digital (QLF-D) camera and compared the remineralization efficiency after fluoride treatment according to the lesion's activity level. MethodsRed fluorescence emission rate (ΔR) and fluorescence loss (ΔF) were evaluated in 44 non-cavitated carious lesions by using a QLF-D camera. Based on the ΔR level, the lesions were classified into 22 active (ΔR ≥37.55) and 22 inactive carious lesions (ΔR <37.55). Each lesion was treated with 1.23 % fluoride gel for 60 s and then immersed into artificial saliva for 7 days. Subsequently, ΔR and ΔF changes in the lesions were measured. ResultsSignificant interactions between lesion activity and time were found for both ΔR and ΔF (p < 0.001). ΔR of active lesions declined faster and ΔF increased more steeply than did inactive lesions. Specifically, on day 7 post-fluoride treatment, the ΔR reduction rate was 1.40-times higher in active lesions, and the ΔF recovery rate was 2.50-times higher, indicating that active lesions respond more markedly to fluoride application. ConclusionsThis study highlighted the significance of ΔR in predicting remineralization efficiency in non-cavitated carious lesions after fluoride application. It underscored the importance of accurately assessing caries activity when formulating effective treatment plans. Lesion activity, as determined by ΔR, not only influences the outcome of remineralization treatments but also provides a more objective measure for tailoring caries management strategies.

A supramolecular host matrix for preserving fluorescence in the solid-state.

Fluorescent materials find numerous applications in light-based devices, but their utilization is severely affected by concentration caused quenching of fluorescence, the extreme form of which is the total loss of fluorescence in the solid state. Introduction of bulky substituents remains the most frequently applied fluorescence revival strategy, but requires multi-step synthetic modifications. We have demonstrated a simple one step supramolecular gel-based strategy to preserve the fluorescence in the solid state.