Search Results (422)

Phthalocyanines (Pcs) are well-established photosensitizers in photodynamic therapy, valued for their strong light absorption, high singlet oxygen generation, and photostability. Recent advances have focused on covalently conjugating Pcs, particularly zinc phthalocyanines (ZnPcs), with a wide range of small bioactive molecules to improve selectivity, efficacy, and multifunctionality. These conjugates combine light-activated reactive oxygen species (ROS) production with targeted delivery and controlled release, offering enhanced treatment precision and reduced off-target toxicity. Chemotherapeutic agent conjugates, including those with erlotinib, doxorubicin, tamoxifen, and camptothecin, demonstrate receptor-mediated uptake, pH-responsive release, and synergistic anticancer effects, even overcoming multidrug resistance. Beyond oncology, ZnPc conjugates with antibiotics, anti-inflammatory drugs, antiparasitics, and antidepressants extend photodynamic therapy’s scope to antimicrobial and site-specific therapies. Targeting moieties such as folic acid, biotin, arginylglycylaspartic acid (RGD) and epidermal growth factor (EGF) peptides, carbohydrates, and amino acids have been employed to exploit overexpressed receptors in tumors, enhancing cellular uptake and tumor accumulation. Fluorescent dye and porphyrinoid conjugates further enrich these systems by enabling imaging-guided therapy, efficient energy transfer, and dual-mode activation through pH or enzyme-sensitive linkers. Despite these promising strategies, key challenges remain, including aggregation-induced quenching, poor aqueous solubility, synthetic complexity, and interference with ROS generation. In this review, the examples of Pc-based conjugates were described with particular interest on the synthetic procedures and optical properties of targeted compounds. Full article

Ovarian cancer is a deadly gynecological malignancy that will affect about 21,000 women and result in almost 153,000 deaths in the United States in 2025. New clinical tools that facilitate early diagnosis and treatment of ovarian malignancies will significantly help reduce mortality and improve current long-term survival rates. We utilized a previously identified single-strand DNA aptamer RLA01 that binds and internalizes into target epithelial ovarian cancer cells to label PLGA-based nanoparticles and determine their ability to selectively target EOC cells and deliver payloads for cellular internalization. Nanoparticles labeled with RLA01 significantly enhanced cellular uptake 20–85% by receptor-mediated endocytosis into target EOC Caov-3 cells and inhibited cellular uptake in non-target HOSE 6-3 cells. Further, labeling of paclitaxel-loaded nanoparticles with RLA01 significantly decreased cell proliferation and induced apoptosis. A preliminary pilot study looking at the in vivo stability of aptamers demonstrated their ability to promote retention and honing of nanoparticles at tumors. These data demonstrate the effective combinatorial use of aptamer RLA01 and nanoparticle technologies for the direct targeting of tumor cell populations both in vitro and in vivo. Full article

The biological effects of nanoparticles are closely related to their intracellular content and location, both of which are influenced by various factors. This study investigates the effects of surface charge on the uptake, intracellular distribution, and exocytosis of CdSe/ZnS quantum dots (QDs) in Raw264.7 macrophages. Negatively charged 3-mercaptopropanoic acid functionalized QDs (QDs-MPA) show higher cellular uptake than positively charged 2-mercaptoethylamine functionalized QDs (QDs-MEA), and serum enhances the uptake of both types of QDs via protein corona-mediated receptor endocytosis. QDs-MEA primarily enter the cells through clathrin/caveolae-mediated pathways and predominantly accumulate in lysosomes, while QDs-MPA are mainly internalized through clathrin-mediated endocytosis and localize to both lysosomes and mitochondria. Exocytosis of QDs-MPA is faster and more efficient than that of QDs-MEA, though both exhibit limited excretion. In addition to endocytosis and exocytosis, cell division influences intracellular QD content over time. These results reveal the charge-dependent interactions between QDs and macrophages, providing a basis for designing biocompatible nanomaterials. Full article

Familial hypercholesterolemia (FH) is a genetic disorder marked by significantly elevated levels of low-density lipoprotein cholesterol (LDL-C) since childhood, substantially increasing the risk of premature atherosclerosis and cardiovascular disease. While dysfunction of hepatic LDL-C receptors is the main underlying cause, the gastrointestinal tract plays a key role in cholesterol homeostasis and represents an important therapeutic target. Inhibition of intestinal cholesterol absorption has emerged as an effective strategy in the management of pediatric FH, particularly in patients for whom statins may not be the ideal first-line treatment. Ezetimibe, an inhibitor of the Niemann-Pick C1-like 1 (NPC1L1) protein, has been shown to reduce LDL-C levels in children with FH, with a greater efficacy observed when used in combination with statins. Bile acid sequestrants also enhance cholesterol excretion but are often limited by gastrointestinal side effects, while dietary interventions, such as phytosterol supplementation and fiber-enriched diets, provide additional benefits in lowering LDL-C and are generally well tolerated. Emerging therapies, including microbiota-targeted strategies and novel cholesterol absorption inhibitors, show promise for expanding future treatment options. This review explores the mechanisms of intestinal cholesterol absorption and their relevance to pediatric FH. We examine key pathways, including dietary cholesterol uptake through NPC1L1, bile acid reabsorption, and cholesterol efflux mediated by ATP-binding cassette transporters, while also discussing clinical and experimental evidence on pharmacological and dietary interventions that modulate these pathways. A deeper understanding of cholesterol metabolism, the emerging role of the gut microbiota, and innovative therapeutic agents can support the development of more effective and personalized approaches to the treatment of children with FH. Full article

Background and Purpose: Glioblastoma remains a therapeutic challenge with a poor prognosis despite multimodal treatments. Reporter-based magnetic resonance imaging (MRI) offers a promising approach for tumor visualization, but its efficacy depends on sufficient reporter gene expression. This study aimed to develop a chimeric element-regulated ferritin heavy chain 1 (FTH1) reporter system to enhance MRI-based glioma detection while enabling targeted therapy via transferrin receptor (TfR)-mediated drug delivery. Methods: Using gene cloning techniques, we constructed a chimeric FTH1 expression system comprising tumor-specific PEG3 promoter (transcriptional control), bFGF-2 5′UTR (translational enhancement), and WPRE (mRNA stabilization). Lentiviral vectors delivered constructs to U251 glioblastoma cells and xenografts. FTH1/TfR expression was validated by Western blot and immunofluorescence. Iron accumulation was assessed via Prussian blue staining and TEM. MRI evaluated T2 signal changes. Transferrin-modified doxorubicin liposomes (Tf-LPD) were characterized for size and drug loading and tested for cellular uptake and cytotoxicity in vitro. In vivo therapeutic efficacy was assessed in nude mouse models through tumor volume measurement, MR imaging, and histopathology. Results: The chimeric system increased FTH1 expression significantly over PEG3-only controls (p < 0.01), with an increase of nearly 1.5-fold compared to the negative and blank groups and approximately a two-fold increase relative to the single promoter group, with corresponding TfR upregulation. Enhanced iron accumulation reduced T2 relaxation times significantly (p < 0.01), improving MR contrast. Tf-LPD (115 nm, 70% encapsulation) showed TfR-dependent uptake, inducing obvious apoptosis in high-TfR cells compared with that in controls. In vivo, Tf-LPD reduced tumor growth markedly in chimeric-system xenografts versus controls, with concurrent MR signal attenuation. Conclusions: The chimeric regulatory strategy overcomes limitations of single-element systems, demonstrating significant potential for integrated glioma theranostics. Its modular design may be adaptable to other reporter genes and malignancies. Full article

L-asparaginase (L-ASNase) remains a vital chemotherapeutic agent for acute lymphoblastic leukemia (ALL), primarily due to its mechanism of depleting circulating asparagine essential for leukemic cell proliferation. However, existing ASNases (including pegylated ones) face limitations including immunogenicity, rapid clearance, and off-target toxicities. Earlier, we have shown that the conjugation of L-ASNase with the polyamines and their copolymers results in significant enhancement of the antiproliferative activity due to accumulation in tumor cells. We suggested that this effect is probably mediated by polyamine transport system (PTS) receptors that are overexpressed in ALL cells. Here, we investigated the effect of competitive inhibitors of PTS receptors to the L-ASNase interaction with cancer cells (L5178Y, K562 and A549). L-ASNase from Rhodospirillum rubrum (RrA), Erwinia carotovora (EwA), and Escherichia coli (EcA) were conjugated with natural polyamines (spermine—spm, spermidine—spd, putrescine—put) and a synthetic branched polymer, polyethyleneimine 2 kDa (PEI2 ), using carbodiimide chemistry. Polyamine conjugation with L-ASNase significantly increased enzyme binding and cellular uptake, as quantified by fluorimetry and confocal microscopy. This increased cellular uptake translated into increased cytotoxicity of L-ASNase conjugates. The presence of competitive ligands to PTS receptors decreased the uptake of polyamine-conjugated enzymes-fatty acid derivatives of polyamines produced the strongest suppression. Simultaneously with this suppression, in some cases, competitive ligands to PTS significantly promoted the uptake of the native unconjugated enzymes, “equalizing” the cellular access for native vs conjugated ASNase. The screening for competing inhibitors of PTS receptor-mediated endocytosis revealed spermine and caproate/lipoate derivatives as the most potent inhibitors or antagonists, significantly reducing the cytostatic efficacy of polyamine-conjugated ASNases. The results obtained emphasize the complex, cell-type-dependent and inhibitor-specific nature of these interactions, which highlights the profound involvement of PTS in L-ASNase internalization and cytotoxic activity. These findings support the viability of polyamine conjugation as a strategy to enhance L-ASNase delivery and therapeutic efficacy by targeting the PTS. Full article

Tracking T cells in vivo using MRI is a major challenge due to the difficulty of labeling these non-phagocytic cells with a sufficient contrast agent to generate a detectable signal change. In this study, we explored CD4-Superparamagnetic iron oxide nanoparticles (SPION), which is commonly used in magnetic cell sorting, as a potential receptor-mediated, specific CD4⁺ T cell MRI labeling agent. We optimized the labeling protocol for maximal CD4⁺ cell labeling and viability. Cell health was confirmed with trypan blue assay, and labeling efficacy was confirmed with Prussian blue staining, transmission electron microscopy, and MRI of labeled cell pellets. Key cell functionality was assessed by flow cytometry. Next, CD4-SPION-labeled T cells or unlabeled T cells were delivered via intravenous injection in naïve mice. Liver MRIs pre-, 24 h, and 72 h post-T cell injection were performed to determine in vivo tracking ability. Our results show that CD4-SPION induces significant attenuation of T2 signals in a concentration-dependent manner, confirming their potential as an effective MRI contrast agent. In vitro, analyses showed that CD4⁺ T cells were able to uptake CD4-SPION without affecting cellular activity and key functions, as evidenced by Prussian blue staining and flow cytometric analysis of IL-2 receptor and the IL-7 receptor α-chains, CD69 upregulation, and IFN-γ secretion. In vivo, systemically distributed CD4-SPION-labeled T cells could be tracked in the liver at 24 and 72 h after injection, contrary to controls. Histological staining of tissue sections validated the findings. Our results showed that SPION CD4⁺ T cell sorting coupled with longitudinal MR imaging is a valid method to track CD4⁺ T cells in vivo. This safe, specific, and sensitive approach will facilitate the use of SPION as an MRI contrast agent in clinical practice, allowing for non-invasive tracking of adoptive cell therapies in multiple disease conditions. Full article

Plasma non-transferrin-bound iron (NTBI) comprises multiple subspecies, classified by their composition, chemical reactivity, and susceptibility to chelation. The redox-active and chelatable fraction of NTBI is referred to as labile plasma iron (LPI). The pathophysiological significance of NTBI and LPI lies in their ability to enter cells via alternative transport pathways that are not regulated by the transferrin receptor system or by cellular iron levels. Several mechanisms have been proposed for their cellular entry, including the hijacking of divalent metal transporters and passive diffusion. This unregulated uptake can lead to iron accumulation in vulnerable tissues such as the liver and the heart. NTBI and LPI bypassing normal cellular control mechanisms can rapidly exceed the cell’s capacity to safely store excess iron, leading to toxicity. Both NTBI and LPI contribute to oxidative stress by participating in free-radical-generating reactions. However, LPI concentration in the bloodstream may be differentially affected by the mode and extent of iron overload, the presence of residual serum iron-binding activity, and the antioxidant capacity of individual sera. In summary, both NTBI and LPI contribute to iron-mediated toxicity but differ in terms of reactivity, availability, and pathogenic potential depending on the pathophysiological conditions that influence the degree of toxicity. Full article

Background: Vaccines have revolutionized disease prevention, yet their effectiveness is challenged by variable immunogenicity, individual response differences, and emerging variants. Biomimetic strategies, inspired by natural immune processes, offer new avenues to enhance vaccine performance. Objectives: This narrative review examines how bioinspired approaches—grounded in evolutionary medicine, immunology, and host–microbiota interactions—can improve vaccine immunogenicity and long-term protection. We further examine the evolutionary foundations of immune responses, highlighting how an evolutionary perspective can inform the development of durable, broadly protective, and personalized vaccines. Furthermore, mechanistic insights at the molecular and cellular level are explored, including Toll-like receptor (TLR) engagement, dendritic cell activation pathways, and MHC-I/MHC-II-mediated antigen presentation. These mechanisms are often mimicked in biomimetic systems to enhance uptake, processing, and adaptive immune activation. Results: The review highlights how immunosenescence, maternal immunity, genetic variation, and gut microbiota composition influence vaccine responses. Biomimetic platforms—such as nanoparticle carriers and novel adjuvants—enhance antigen presentation, boost adaptive immunity, and may overcome limitations in traditional vaccine approaches. Additionally, co-administration strategies, delivery systems, and microbiota-derived immunomodulators show promise in improving vaccine responsiveness. Conclusions: Integrating biomimetic and evolutionary principles into vaccine design represents a promising path toward safer, longer-lasting, and more effective immunizations Full article

Glucagon-like peptide-1 (GLP-1) has emerged as a pivotal regulator in the management of glucose homeostasis, glycogen metabolism, and energy balance, positioning it as a critical therapeutic target for addressing obesity, metabolic syndrome, and type 2 diabetes mellitus (T2DM). GLP-1 receptor agonists (GLP-1RAs) have shown promise for improving glycemic control and reducing weight through appetite regulation, delayed gastric emptying, and energy expenditure modulation. This narrative review explores the mechanisms of GLP-1-mediated glycogen metabolism and energy expenditure, particularly in key tissues—pancreas, liver, skeletal muscle, and adipose tissue. In the pancreas, GLP-1 enhances insulin secretion and beta-cell function. In the liver, it promotes glycogen synthesis via insulin-dependent and potential insulin-independent pathways, involving protein kinase B (AKT) and AMP-activated protein kinase (AMPK) signaling. Skeletal muscle benefits from GLP-1 through increased glucose uptake, AMPK activation, and mitochondrial function, facilitating glycogen storage. In adipose tissue, GLP-1 stimulates brown adipose tissue (BAT) thermogenesis and energy expenditure, contributing to weight loss. This increase in energy expenditure, along with enhanced glycogen metabolism, is a plausible mechanism for the weight loss observed with GLP-1RAs. Despite these advances, significant knowledge gaps remain, particularly regarding the direct hepatic effects of GLP-1, the extent to which it modulates glycogen metabolism in vivo, and its impact on thermogenesis in humans. Future research focusing on both the tissue-specific actions of GLP-1 and its systemic role in energy homeostasis and metabolic regulation will be essential for optimizing its therapeutic potential. Full article

Glutamate is an excitatory neurotransmitter in the central nervous system (CNS) that mediates synaptic transmission. However, glutamate homeostasis among neural cells is broken in cerebral ischemia. Excessive glutamate triggers N-methyl-d-aspartate receptors (NMDARs) in postsynaptic neurons, leading to intracellular calcium (Ca²⁺) overload and excitoneurotoxicity. At this moment, L-lactate may affect NMDARs and play a protective role in cerebral ischemia. This work proposes that L-lactate regulates glutamate signaling among neural cells. But, dysregulation of L-lactate in glutamate signaling cascades contributes to glutamate excitotoxicity in cerebral ischemia. In detail, L-lactate regulates the glutamine(Gln)-glutamate cycle between astrocytes and presynaptic neurons, which triggers the astroglial L-lactate-sensitive receptor (LLR)-cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway, coordinating astroglial glutamate uptake and neuronal glutamate transmission. L-lactate mediates glutamate signaling and synaptic transmission among neural cells. In addition, L-lactate promotes the function of mitochondrial calcium uniporter complex (MCUC), which quickly depletes intracellular Ca²⁺ in postsynaptic neurons. In addition, L-lactate can promote the conversion of microglia from the pro-inflammatory (M1) to anti-inflammatory (M2) phenotype. Therefore, regulation of L-lactate in glutamate signaling in the CNS might become a preventive target for cerebral ischemia. Full article

Alzheimer’s disease (AD), a progressive neurodegenerative disorder, is marked by the pathological accumulation of amyloid-β plaques and tau neurofibrillary tangles, both of which disrupt neuronal communication and function. Emerging evidence highlights the role of extracellular vesicles (EVs) as key mediators of intercellular communication, particularly in the propagation of pathological proteins in AD. Among the regulatory factors influencing EV composition and function, neuraminidase 1 (NEU1), a lysosomal sialidase responsible for desialylating glycoproteins has gained attention for its involvement in EV glycosylation. This review explores the role of NEU1 in modulating EV glycosylation, with particular emphasis on its influence on immune modulation and intracellular trafficking pathways and the subsequent impact on intercellular signaling and neurodegenerative progression. Altered NEU1 activity has been associated with abnormal glycan profiles on EVs, which may facilitate the enhanced spread of amyloid-β and tau proteins across neural networks. By regulating glycosylation, NEU1 influences EV stability, targeting and uptake by recipient cells, primarily through the desialylation of surface glycoproteins and glycolipids, which alters the EV charge, recognition and receptor-mediated interactions. Targeting NEU1 offers a promising therapeutic avenue to restore EV homeostasis and reduces pathological protein dissemination. However, challenges persist in developing selective NEU1 inhibitors and effective delivery methods to the brain. Furthermore, altered EV glycosylation patterns may serve as potential biomarkers for early AD diagnosis and monitoring. Overall, this review highlights the importance of NEU1 in AD pathogenesis and advocates for deeper investigation into its regulatory functions, with the aim of advancing therapeutic strategies and biomarker development for AD and related neurological disabilities. Full article

Background: Silicone breast implants have been linked to autoimmune/inflammatory syndrome induced by adjuvants (ASIA). This study evaluates the role of ^99mTc-HYNIC-TOC somatostatin receptor scintigraphy in assessing somatostatin-mediated inflammation and the impact of explantation on inflammatory activity. Methods: Fifty patients with silicone breast implants and symptoms suggestive of ASIA were evaluated. Pre- and postexplantation imaging was performed using ^99mTc-HYNIC-TOC scintigraphy. Matthews correlation coefficients quantified associations between clinical symptoms and imaging findings, and autoantibody profiles were analysed. Results: Scintigraphy identified a significant uptake in organs associated with autoimmune symptoms, particularly joints and salivary glands. Strong correlations were found between imaging findings and symptoms, including knee pain (MCC = 0.81) and sicca syndrome (MCC = 0.96). Explantation resolved abnormal uptake in the surgical bed, though variable uptake persisted in other organs, reflecting systemic inflammatory heterogeneity. Autoantibody analysis revealed positivity in 66% of patients, with antinuclear antibodies being most frequent (30%). Conclusions: ^99mTc-HYNIC-TOC scintigraphy effectively evaluates organ-specific inflammation in ASIA. Explantation reduces localized inflammation but does not consistently address systemic autoimmune responses. Larger prospective studies are needed to validate these findings and improve management strategies for ASIA. Full article

Atherosclerosis is a chronic condition marked by lipid accumulation, inflammation, and endothelial dysfunction, leading to narrowed arteries and an increased risk of heart attacks and strokes. Key proteins involved in this process include PCSK9, LOX-1, ROS, CD36, and ABCA1. PCSK9 degrades LDL receptors, raising blood LDL levels, while LOX-1 and CD36 promote the uptake of oxidized LDL by macrophages, enhancing foam cell formation. ABCA1, on the other hand, facilitates cholesterol efflux to HDL, reducing atherosclerosis risk. Red watermelon (Citrullus lanatus), rich in lycopene, citrulline, and vitamins A, C, and E, has antioxidant and cardioprotective properties. This study aimed to explore the effects of red watermelon extract on the expression of PCSK9, LOX-1, ROS, TNFα, CD36, and ABCA1 in a Wistar rat model of atherosclerosis. In a randomized control trial, male Wistar rats were induced with a high-fat diet (margarine) and treated with red watermelon extract for four weeks. The findings showed that red watermelon extract reduced the expression of PCSK9, LOX-1, CD36, ROS, and TNFα, leading to lower LDL levels, and inhibited foam cell formation. It also increased ABCA1 expression, thus promoting cholesterol efflux and higher HDL levels. Path analysis confirmed that the anti-atherogenic effect of C. lanatus was primarily mediated through the PCSK9-ABCA1-FC axis. This suggests that red watermelon may serve as a natural agent for atherosclerosis prevention by regulating lipid metabolism pathways. Full article

The activation of immunosuppressed antigen-presenting cells (APCs) in the tumor microenvironment is a key goal in modern cancer immunotherapy. Our laboratory utilizes a liposome-based immunotherapy platform that binds endogenous complement to deliver antigen, adjuvant, and therapeutic agents to APCs in vivo. The liposomes contain external linker groups, which readily bind complement protein C3, and mediate liposomal uptake via complement receptor 3 into APCs. To test the ability of a model antigen to bind to these external linker groups on C3-liposomes and elicit a robust adaptive immune response, we conjugated a modified ovalbumin peptide (OVA-C) to the liposomes and incorporated a toll-like receptor (TLR) 4 agonist, monophosphoryl lipid A (MPLA), in the liposomal membrane. Adaptive immune responses from C57BL/6 mice were analyzed by ELISA and ELISpot. Mice vaccinated with OVA-C liposomes elicited significantly greater humoral and cellular adaptive responses relative to controls. Furthermore, female mice vaccinated with MPLA + OVA-C liposomes produced significantly more IgG antibodies than males vaccinated with the same liposomes. In conclusion, antigen binding on the exterior of C3-liposomes markedly improves antigen loading efficiency and still allows for complement C3-targeted delivery to APCs. These data demonstrate the initiation of a robust cellular and humoral immune response using a new liposomal delivery platform. Full article