Search Results (642)

Albumin-binding agents enhance tumor uptake of radiopharmaceuticals targeting prostate-specific membrane antigens (PSMAs) in radiotherapy. We synthesized PSMA-NARI-56, a molecule with both PSMA targeting activity and albumin-binding moiety, labeled with ¹⁷⁷Lu as the therapeutic agent. The aim of this study was to determine the specific binding of ¹⁷⁷Lu-PSMA-NARI-56 towards PSMA, assess its biodistribution, and evaluate therapeutic effectiveness by tumor-bearing mice. The effect of ¹⁷⁷Lu-PSMA-NARI-56 viability of PSMA-positive cell (LNCaP) was evaluated. Biodistribution and endoradiotherapy studies were utilized to determine the distribution, targeting, and anti-tumor efficacy by tumor-bearing mice identified by ¹¹¹In-PSMA-NARI-56. ¹⁷⁷Lu-PSMA-NARI-56 exhibited a significant impact on the viability of the LNCaP cell. Biodistribution results revealed the maximum tumor uptake of ¹⁷⁷Lu-PSMA-NARI-56 occurring within 24 h, reaching 40.56 ± 10.01%ID/g. In radionuclide therapy, at 58 days post-injection (p.i.), ¹⁷⁷Lu-PSMA-NARI-56 demonstrated superior tumor inhibition (98%) compared to ¹⁷⁷Lu-PSMA-617 (58%), and the mouse survival rate after 90 days of radiotherapy (90%) was also higher than that of ¹⁷⁷Lu-PSMA-617 (30%) in LNCaP tumor-bearing mice. In the PSMA-positive animal model, ¹⁷⁷Lu-PSMA-NARI-56 shows higher potential radiotheranostic and prolonged accumulation (identify by ¹¹¹In-PSMA-NARI-56/nanoSPECT/CT image), offering the potential for improved treatment effectiveness and increased survival rates when compared to ¹⁷⁷Lu-PSMA-617. Full article

Extracellular vesicles (EVs), nanoscale membrane-enclosed particles, are natural carriers of proteins and nucleic acids. Microalgae are widely used as a source of bioactive substances in the food and cosmetic industries and definitely have a potential to be used as the producers of EVs for biomedical applications. In this study, the extracellular vesicles isolated from the culture medium of two unicellular microalgae, Chlamydomonas reinhardtii (Chlamy-EVs) and Parachlorella kessleri (Chlore-EVs), were characterized by atomic force microscopy (AFM), cryo-electronic microscopy (cryo-EM), and nanoparticle tracking analysis (NTA). The biocompatibility with human cells in vitro (HEK-293T, DF-2 and A172) and biodistribution in mouse organs and tissues in vivo were tested for both microalgal EVs. An exogenous therapeutic protein, human heat shock protein 70 (HSP70), was successfully loaded to Chlamy- and Chlore-EVs, and its efficient delivery to human glioma and colon carcinoma cell lines has been confirmed. Additionally, in order to search for potential therapeutic biomolecules within the EVs, their proteomes have been characterized. A total of 105 proteins were identified for Chlamy-EVs and 33 for Chlore-EVs. The presence of superoxide dismutase and catalase in the Chlamy-EV constituents allows for considering them as antioxidant agents. The effective delivery of exogenous cargo to human cells and the possibility of the particle yield optimization by varying the microalgae growth conditions make them favorable producers of EVs for biotechnology and biomedical application. Full article

Background: Lysosomal-associated membrane protein 1 (LAMP1), typically localized to the lysosomal membrane, is increasingly implicated as a marker of cancer aggressiveness and metastasis when expressed on the cell surface. This study aimed to develop a LAMP1-targeted antibody-based PET tracer and assess its efficacy in mouse models of human breast and colon adenocarcinoma. Methods: To determine the source of LAMP1 expression, we utilized human single-cell RNA sequencing and spatial transcriptomics, complemented by in-house flow cytometry on xenografted mouse models. Tissue microarrays of multiple epithelial cancers and normal tissue were stained for LAMP-1, and staining was quantified. An anti-LAMP1 monoclonal antibody was conjugated with desferrioxamine (DFO) and labeled with zirconium-89 (⁸⁹Zr). Human triple-negative breast cancer (MDA-MB-231) and colon cancer (Caco-2) cell lines were implanted in nude mice. PET/CT imaging was conducted at 24, 72, and 168 h post-intravenous injection of ⁸⁹Zr-DFO-anti-LAMP1 and ⁸⁹Zr-DFO-IgG (negative control), followed by organ-specific biodistribution analyses at the final imaging time point. Results: Integrated single-cell and spatial RNA sequencing demonstrated that LAMP1 expression was localized to myeloid-derived suppressor cells (MDSCs) and cancer-associated fibroblasts (CAFs) in addition to the cancer cells. Tissue microarray showed significantly higher staining for LAMP-1 in tumor tissue compared to normal tissue (3986 ± 2635 vs. 1299 ± 1291, p < 0.001). Additionally, xenograft models showed a significantly higher contribution of cancer cells than the immune cells to cell surface LAMP1 expression. In vivo, PET imaging with ⁸⁹Zr-DFO-anti-LAMP1 PET/CT revealed detectable tumor uptake as early as 24 h post-injection. The ⁸⁹Zr-DFO-anti-LAMP1 tracer demonstrated significantly higher uptake than the control ⁸⁹Zr-DFO-IgG in both models across all time points (MDA-MB-231 SUV_max at 168 h: 12.9 ± 5.7 vs. 4.4 ± 2.4, p = 0.003; Caco-2 SUV_max at 168 h: 8.53 ± 3.03 vs. 3.38 ± 1.25, p < 0.01). Conclusions: Imaging of cell surface LAMP-1 in breast and colon adenocarcinoma is feasible by immuno-PET. LAMP-1 imaging can be expanded to adenocarcinomas of other origins, such as prostate and pancreas. Full article

Background: We have previously shown the remarkable impact of a single infusion of supercharged NK cells (sNK) in preventing and eliminating oral, pancreatic, and uterine cancers implanted in humanized BLT (hu-BLT) mice. Objective: In this report, we extended the studies to melanoma tumors to observe whether there were differences in response to sNK cells. Methods: We investigated the safety and tissue biodistribution profile of sNK cells in hu-BLT mice. This included the effect of sNK cell therapy on the peripheral blood-derived PBMCs, bone marrow, and spleen of hu-BLT mice. Results: Our investigation showed promising outcomes, as sNK cell infusions effectively inhibited melanoma tumor growth in hu-BLT mice. These potent cells not only traversed through the peripheral blood, spleen, and bone marrow but also infiltrated the tumor site, triggering in vivo differentiation of melanoma tumors. Moreover, the infusion of sNK cells increased the percentages of NK cells in the peripheral blood of hu-BLT mice, restoring cytotoxicity and IFN-γ secretion within the peripheral blood, spleen, and bone marrow of melanoma-bearing mice. Conclusions: This therapeutic approach not only reversed tumor progression but also revitalized the functionality of endogenous NK cells, potentially reversing the immunosuppressive effects induced by tumor cells in cancer patients. Full article

Background: Lipid nanoparticles (LNPs) represent one of the most effective non-viral vectors for nucleic acid delivery and have demonstrated clinical success in siRNA therapies and mRNA vaccines. While considerable research has focused on optimizing ionizable lipids and helper lipids, the impact of PEGylated lipid content on LNP-mediated mRNA delivery, especially in terms of in vitro transfection efficiency and in vivo performance, remains insufficiently understood. Methods: In this study, LNPs were formulated using a self-synthesized ionizable lipid and varying molar ratios of DMG-PEG2000. Nanoparticles were prepared via nanoprecipitation, and their physicochemical properties, mRNA encapsulation efficiency, cellular uptake, and transfection efficiency were evaluated in HeLa and DC2.4 cells. In vivo delivery efficiency and organ distribution were assessed in mice following intravenous administration. Results: The PEGylated lipid content exerted a significant influence on both the in vitro and in vivo performance of LNPs. A bell-shaped relationship between PEG content and transfection efficiency was observed: 1.5% DMG-PEG2000 yielded optimal mRNA transfection in vitro, while 5% DMG-PEG2000 resulted in the highest transgene expression in vivo. This discrepancy in optimal PEG content may be attributed to the trade-off between cellular uptake and systemic circulation: lower PEG levels enhance cellular internalization, whereas higher PEG levels improve stability and in vivo bioavailability at the expense of cellular entry. Furthermore, varying the PEG-lipid content enabled the partial modulation of organ distribution, offering a formulation-based strategy to influence biodistribution without altering the ionizable lipid structure. Conclusions: This study highlights the critical role of PEGylated lipid content in balancing nanoparticle stability, cellular uptake, and in vivo delivery performance. Our findings provide valuable mechanistic insights and suggest a straightforward formulation-based strategy to optimize LNP/mRNA systems for therapeutic applications. Full article

Background/Objective: Programmed cell death ligand-1 (PD-L1), which is overexpressed in certain tumors, inhibits the body’s natural immune response by providing an “off” signal that enables cancer cells to evade the immune system. It has been demonstrated that [¹⁷⁷Lu]Lu-DOTA-iPD-L1 (PD-L1 inhibitor cyclic peptide) promotes immune responses. This study aimed to synthesize and evaluate [¹⁸F]AlF-NOTA-iPD-L1 as a novel radiotracer for PD-L1 positron emission tomography (PET) imaging and as a potential theranostic pair for [¹⁷⁷Lu]Lu-DOTA-iPD-L1. Methods: The NOTA-iPD-L1 peptide conjugate was synthesized and characterized by U.V.-vis, I.R.-FT, and UPLC-mass spectroscopies. Radiolabeling was performed using [¹⁸F]AlF as the precursor, and the radiochemical purity (HPLC), partition coefficient, and serum stability were assessed. Cellular uptake and internalization (in 4T1 triple-negative breast cancer cells), binding competition, immunofluorescence, and Western blot assays were applied for the radiotracer in vitro characterization. Biodistribution in mice bearing 4T1 tumors was performed, and molecular imaging (Cerenkov images) of [¹⁸F]AlF-NOTA-iPD-L1 and [¹⁷⁷Lu]Lu-DOTA-iPD-L1 in the same mouse was obtained. Results: [¹⁸F]AlF-NOTA-iPD-L1 was prepared with a radiochemical purity greater than 97%, and it demonstrated high in vitro and in vivo stability, as well as specific recognition by the PD-L1 protein (IC₅₀ = 9.27 ± 2.69 nM). Biodistribution studies indicated a tumor uptake of 6.4% ± 0.9% ID/g at 1-hour post-administration, and Cerenkov images showed a high tumor uptake of both [¹⁸F]AlF-NOTA-iPD-L1 and ¹⁷⁷Lu-iPD-L1 in the same mouse. Conclusions: These results warrant further studies to evaluate the clinical usefulness of [¹⁸F]AlF-NOTA-iPD-L1/[¹⁷⁷Lu]Lu-DOTA-iPD-L1 as a radiotheranostic pair in combination with anti-PD-L1/PD1 immunotherapy. Full article

Umbilical cord mesenchymal stem cells (UCMSCs)-derived small extracellular vehicles (sEVs) are reported to offer therapeutic effects in regenerative medicine, but they lack safety and biodistribution profiles to support smooth translation at the clinical stage and regulatory requirements. Our study aimed to determine the safety and biodistribution profile in a healthy animal model before application in the metabolic syndrome model. Method: Healthy male Sprague Dawley (SD) rats were given an intravenous (IV) injection of normal saline (control group) or pooled fetal UCMSCs-derived sEVs (treated group) every three weeks for 90 days. Morbidity and mortality observation (daily), physical measurements (weekly), selected serum biochemistry (every three weeks), and hematology (every three weeks) were performed for 90 days. Acute toxicity (on day 14) and sub-chronic toxicity (on day 90) were assessed for gross necropsy, relative organ weight, and histopathological assessment of lungs, liver, spleen, kidney, and lymph nodes. Separately, a biodistribution study was conducted with the sEVs preparations labeled with PKH26 fluorescent dye, given intravenously to the rats. The organs were harvested 24 h post-injection. There were no drastic changes in either group’s morbidity or mortality, physical, hematological, and biochemistry evaluation. The histopathological assessment concluded moderate (focal) inflammation in the treated group’s kidneys and signs of recovery from the inflammation and vascular congestion in the liver. A biodistribution study revealed a higher accumulation of sEVs in the spleen. Multiple IV injections of the pooled fetal UCMSCs-derived sEVs in healthy male SD rats were deemed safe. The sEVs were abundantly distributed in the spleen 24 h post-injection. Full article

Atherosclerosis, a chronic inflammatory disease, remains a leading cause of cardiovascular mortality worldwide. Despite standard treatments like statins and percutaneous coronary intervention (PCI), significant residual risk and therapeutic limitations underscore the need for innovative strategies. This review summarizes recent advances in nanoparticle-based therapies for atherosclerosis, focusing on key developments from the last five years. We discuss various nanoplatforms designed to selectively target key cellular players in plaque pathogenesis, including macrophages, endothelial cells, and vascular smooth muscle cells (VSMCs), to inhibit inflammation, modulate cellular phenotypes, and stabilize plaques. A significant focus is placed on the emerging field of biomimetic nanoparticles, where therapeutic cores are camouflaged with cell membranes derived from macrophages, platelets, neutrophils, or erythrocytes. This approach leverages the natural biological functions of the source cells to achieve enhanced immune evasion, prolonged circulation, and precise targeting of atherosclerotic lesions. Furthermore, the review covers nanoparticles engineered for specific functional interventions, such as lowering LDL levels and exerting direct anti-inflammatory and anti-oxidative effects. Finally, we address the critical challenges hindering clinical translation, including nanotoxicity, biodistribution, and manufacturing scalability. In conclusion, nanotechnology offers a versatile and powerful platform for atherosclerosis therapy, with targeted and biomimetic strategies holding immense promise to revolutionize future cardiovascular medicine. Full article

Mucopolysaccharidosis IVA (MPS IVA) is a lysosomal storage disorder causing systemic skeletal dysplasia due to a deficiency of N-acetyl-galactosamine-6-sulfate sulfatase (GALNS) enzyme activity, leading to the impaired degradation and accumulation of glycosaminoglycans (GAGs), keratan sulfate (KS) and chondroitin-6-sulfate. While treatments such as enzyme replacement therapy (ERT) and hematopoietic stem cell transplantation (HSCT) are available, they have significant limitations regarding efficacy in skeletal tissues and long-term safety, highlighting the need for more effective therapies. We evaluated a novel gene therapy approach using a dual Integrase-deficient lentiviral vector (IDLV) to deliver an expression cassette that includes human GALNS cDNA and Cas9 sgRNA, targeting the upstream region of the mouse Galns initial codon. This approach leverages the endogenous promoter to drive transgene expression. We assessed in vitro transduction, editing, and functional correction in NIH3T3 and MPS IVA mouse fibroblasts. In vivo efficacy was successfully evaluated via the facial vein injection in MPS IVA newborn mice. In vitro, this IDLV platform demonstrated supraphysiological GALNS activity in cell lysate, resulting in the normalization of KS levels. In vivo direct IDLV platform in newborn MPS IVA mice led to sustained plasma GALNS activity, reduced plasma KS, and favorable biodistribution. Partial correction of heart and bone pathology was observed, with no vector toxicity and minimal antibody responses. This dual IDLV-CRISPR/Cas9 approach effectively mediated targeted GALNS knock-in, yielding sustained enzyme activity, reduced KS storage, and partial pathological amelioration in MPS IVA mice. In conclusion, IDLVs represent an efficient, safe platform for delivering the CRISPR/Cas9 gene editing system for MPS IVA. Full article

Treatment of malignant diseases using oncolytic viruses (OVs) is currently considered a promising therapeutic approach. Initial encouraging results fueled a large number of clinical trials, showcasing favorable safety profiles of OVs—but therapeutic outcomes remain far from perfect. The efficacy of systemically administered OVs is limited due to rapid immune clearance and suboptimal biodistribution, while locally administered OVs encounter an additional barrier of poor bioavailability. Cell-based carriers that can shield viral particles and provide tumor-targeted OV delivery, represent one of the potential ways to address these challenges. The feasibility of this approach was demonstrated using a broad range of cell types, including mesenchymal stem cells (MSCs), neural stem cells (NSCs), different subsets of immune cells, and cancer cell lines. The resulting spectrum of carriers can be viewed as a multifaceted tool, taking into account the specific properties, advantages, and limitations of each cell carrier type discussed in this review. Careful consideration of these features will provide the basis for successful development of cell-based OV delivery platforms. Full article

Triple-negative breast cancer (TNBC) frequently evades immune recognition and elimination, resulting in an immunosuppressive microenvironment. The phagocytic activity of tumor-associated macrophages underscores the development of nanomaterials as a promising strategy to target these macrophages and modulate their polarization, thereby advancing immunotherapy against TNBC. This research developed functional polymers that are complexed with therapeutic molecules as a coating strategy for iron oxide nanoparticles. An arginine-based poly (ester urea urethane) polymer complexed with a macrophage-polarizing molecule (APU-R848) could provide a synergistic effect with iron oxide nanoparticles (IONPs) to stimulate the M1-polarization of macrophages at the tumor site, resulting in a versatile nano-platform for immune regulation of TNBC. In the 4T1 in vivo breast tumor model, the APU-R848-IONPs demonstrated an improved intratumoral biodistribution compared to IONPs without a polymer coating. APU-R848-IONPs significantly reversed the immune-suppressive tumor environment by reducing the M2/M1 macrophage phenotype ratio by 51%, associated with an elevated population of cytotoxic T cells and a significantly enhanced production of tumoricidal cytokines. The activated immune response induced by APU-R848-IONP resulted in a significant anti-tumor effect, demonstrating an efficacy that was more than 3.2-fold more efficient compared to the controls. These immune-regulatory pseudo-protein-coated iron oxide nanoparticles represent an effective nano-strategy for macrophages’ regulation and the activation of anti-tumor immunity, providing a new treatment modality for triple-negative breast cancer. Full article

Background: Cell-penetrating peptides cross cell membrane barriers while carrying cargoes in a functional form. Our work identified two novel lung-targeting peptides, S7A and R11A. Here, we present studies on biodistribution, the cell types targeted, and an in vitro proof of application. Methods: Studies were performed in human bronchial epithelial cells (HBECs) with and without various endocytic inhibitors, and coincubation with fluorescently labeled transferrin or endocytic markers. Cyclic R11A (cR11A) was conjugated to siRNA duplexes and anti-viral activity against SARS-CoV-2 was tested. Biodistribution studies were performed by injecting wild-type mice with fluorescently labeled peptides, and various circulation times were allowed for, as well as cross-staining of lung sections or isolated single cells with various cellular markers, followed by fluorescence-activated cell sorting or confocal microscopy. Results: cR11A showed peak uptake in 15 min, with the highest uptake in airway epithelial type II (ATII) cells, followed by p63+ basal cells and ionocytes. Cyclization increased transduction efficiencies ~100-fold. Endocytosis studies showed a decrease in peptide uptake by pre-treatment with Pitstop2 but not Amiloride or Nystatin. Endocytic marker Lamp1 showed colocalization at the earliest time point, with the escape of the peptide from endocytic vesicles later. cR11A conjugated to ant-spike and anti-envelop proteins showed anti-viral effects with an EC₉₀ of 0.6 μM and 1.0 µM, respectively. Conclusions: We have identified a novel peptide, cR11A, that targets ATII, basal cells, and ionocytes, the cyclization of which increased transduction efficiency in vitro and in vivo. The uptake mechanism appears to be via clathrin-mediated endocytosis with escape from endocytic vesicles. cR11A can act as a vector to deliver anti-viral siRNA to epithelial cells. Full article

We have previously reported on a novel monoclonal antibody (mAb) we designated F5, which was raised against a glycopeptide derived from the tandem repeat (TR) region of Mucin-4 (MUC4), a heavily O-glycosylated protein that is overexpressed in many pancreatic cancer cells. This mAb was highly specific for the MUC4 glycopeptide antigen in glycan microarrays, ELISA and SPR assays, selectively stained tissue derived from advanced-stage tumors, and bound MUC4⁺ tumor cells in flow cytometry assays. The mAb was also unique in that it did not cross-react with other commercial anti-MUC4 mAbs that were raised in a similar but non-glycosylated TR sequence. Here we describe the selective conjugation of a novel near-infrared dye to this mAb and in vivo biodistribution of this labeled mAb to various MUC4-expressing tumors in mice. The labeled mAb were selectively distributed to both cell-derived xenograft (CDX) flank tumors and patient-derived xenograft (PDX) tumors that expressed MUC4 compared to those that were MUC4-negative. Organ distribution analysis showed high uptake in MUC4⁺ relative to MUC4⁻ tumors. These results suggest that mAb F5 may be used to develop MUC4-targeted, passive antibody-based immunotherapies against Pancreatic Ductal Adenocarcinomas (PDACs) which are notorious for being refractory to many chemo- and radiotherapies Full article

Prostate cancer is the second leading cause of cancer-related death in men, with metastatic castration-resistant prostate cancer (mCRPC) and bone metastases representing a critical clinical challenge. Although radium-223 (Ra-223) is approved for treating mCRPC with bone metastases, its efficacy remains limited, necessitating the development of more effective therapies. This study investigates the therapeutic potential of ¹⁷⁷Lu-PSMA-617, a PSMA-targeted radiopharmaceutical, in a murine model of prostate cancer bone metastases. To our knowledge, this is the first study to systematically evaluate ¹⁷⁷Lu-PSMA-617 in an orthotopic bone metastatic prostate cancer model, providing a clinically relevant preclinical platform to assess both imaging and therapeutic performance. We conducted comprehensive preclinical evaluations, including synthesis, stability analysis, cell binding assays, nuclear imaging, in vivo biodistribution, pharmacokinetics, and antitumor efficacy. The synthesis of ¹⁷⁷Lu-PSMA-617 demonstrated high radiochemical yield (99.2%), molar activity (25.5 GBq/μmol), and purity (>98%), indicating high product quality. Stability studies confirmed minimal release of free Lutetium-177, maintaining the compound’s integrity under physiological conditions. In vitro assays showed selective binding and internalization in PSMA-positive LNCaP prostate cancer cells, with negligible uptake in PSMA-negative PC-3 cells. In vivo biodistribution studies demonstrated efficient tumor targeting, with peak uptake in LNCaP tumors (23.31 ± 0.94 %IA/g) at 4 h post-injection. The radiopharmaceutical exhibited favorable pharmacokinetics, with high tumor-to-background ratios (tumor-to-blood, 434.4; tumor-to-muscle, 857.4). Therapeutic efficacy was confirmed by significant survival extension in treated mice (30.7% for 37 MBq and 53.8% for 111 MBq), with median survival times of 34 and 40 days, respectively, compared to 26 days in the control group. Radiation dosimetry analysis indicated a favorable safety profile with a calculated effective dose of 0.127 mSv/MBq. These findings highlight the novelty and translational relevance of using ¹⁷⁷Lu-PSMA-617 in a clinically relevant bone metastasis model, reinforcing its potential as a dual-purpose agent for both targeted therapy and molecular imaging in advanced prostate cancer. Full article

The rapid development of nanotechnology has led to increased human exposure to metal-based nanoparticles (MNPs) through inhalation, ingestion, and dermal contact, raising growing concerns on their potential health effects. Due to their nanoscale size and unique physicochemical properties, the MNPs can translocate from the initial exposure sites to the circulatory system and accumulate in the body. This review focuses on MNP-induced cardiovascular toxicity, highlighting its biodistribution, cytotoxic mechanisms, and pathological impact associated with various cardiovascular diseases. MNPs disrupt endothelial function, promote oxidative stress, and induce apoptosis and ferroptosis in cardiovascular cells. Furthermore, MNPs increase endothelial permeability, impair blood–brain barrier integrity, and enhance procoagulant activity, thereby contributing to vascular and cardiac dysfunction. The particles and their released metal ions play a synergistic role in mediating these toxic effects. Here, we focused on the effects of nano-sized particles while incorporating recent in vitro and in vivo studies that address the cardiovascular impacts and mechanisms of MNP-induced toxicity. This comprehensive review will help understand and explain the potentially toxic effects of MNPs on the cardiovascular system. Full article