A fluorescent gemcitabine prodrug that follows a nucleoside transporter-independent internalization and bears enhanced therapeutic efficacy with respect to gemcitabine.

The multiplexity of cancer has rendered it the second leading cause of mortality worldwide and theragnostic prodrugs have gained popularity in recent years as a means of treatment. Theragnostic prodrugs enable the simultaneous diagnosis and therapy of tumors via high-precision real-time drug release monitoring. Herein, we report the development of the small theragnostic prodrug GF, based on the nucleoside anticancer agent gemcitabine and the fluorescent dye 5(6)-carboxyfluorescein. We have successfully demonstrated its efficient internalization in tumor cells, showing localization throughout both the early and late endocytic pathways. Its mechanism of cell internalization was evaluated, confirming its independence from nucleoside transporters. Its cellular localization via confocal microscopy revealed a clathrin-mediated endocytosis mechanism, distinguishing it from analogous compounds studied previously. Furthermore, GF exhibited stability across various pH values and in human blood plasma. Subsequently, its in vitro cytotoxicity was assessed in three human cancer cell lines (A549, U87 and T98). Additionally, its pharmacokinetic profile in mice was investigated and the consequent drug release was monitored. Finally, its in vivo visualization was accomplished in zebrafish xenotransplantation models and its in vivo efficacy was evaluated in A549 xenografts. The results unveiled an intriguing efficacy profile, positioning GF as a compelling candidate warranting further investigation.

Pediatric Hemophilic Arthropathy of the Knee: Treatment With Circular External Fixator and Intra-articular Injection of Platelet-Rich Plasma.

There are limited reports about managing knee flexion contracture (KFC) due to hemophilic hemarthrosis with the Ilizarov technique and platelet-rich plasma intraarticular injection administration. This article aims to describe a case of KFC treated with a circular external fixator and intraarticular administration of platelet-rich plasma in a pediatric patient. A 12-year-old male patient suffering from hemophilia A was being monitored by our department due to knee effusions. Extensive knee flexion contracture of the left knee was seen. The Ilizarov technique was chosen for surgical management of the worsening knee flexion contracture. The duration of distraction was six weeks. Due to localized pain and functional impairment, intra-articular administration of platelet-rich plasma (PRP) was applied twice, on the first month after the circular frame removal and at a six-month follow-up, with clinical and functional improvement. Our clinical case report demonstrates that PRP intra-articular injections are likely to provide an improvement in pain and knee joint function, as well as joint hyperemia, even in the case of already established knee flexion contracture, which was managed with a circular distraction device. However, more studies regarding the Ilizarov technique and the PRP intraarticular administration are needed for a protocol to be established for the management of the hemophilic knee joint in the pediatric population.

Antitumor activity of 5-hydroxy-3',4',6,7-tetramethoxyflavone in glioblastoma cell lines and its antagonism with radiotherapy.

5-Hydroxy-3',4',6,7-tetramethoxyflavone (TMF) is a plant-origin flavone known for its anti-cancer properties. In the present study, the cytotoxic effect of TMF was evaluated in the U87MG and T98G glioblastoma (GBM) cell lines. The effect of TMF on cell viability was assessed with trypan blue exclusion assay and crystal violet staining. In addition, flow cytometry was performed to examine its effect on the different phases of the cell cycle, and in vitro scratch wound assay assessed the migratory capacity of the treated cells. Furthermore, the effect of in vitro radiotherapy was also evaluated with a combination of TMF and radiation. In both cell lines, TMF treatment resulted in G0/G1 cell cycle arrest, reduced cell viability, and reduced cell migratory capacity. In contrast, there was an antagonistic property of TMF treatment with radiotherapy. These results demonstrated the antineoplastic effect of TMF in GBM cells in vitro, but the antagonistic effect with radiotherapy indicated that TMF should be further evaluated for its possible antitumor role post-radiotherapy.

Nuclear Medicine and Cancer Theragnostics: Basic Concepts.

Cancer theragnostics is a novel approach that combines diagnostic imaging and radionuclide therapy. It is based on the use of a pair of radiopharmaceuticals, one optimized for positron emission tomography imaging through linkage to a proper radionuclide, and the other bearing an alpha- or beta-emitter isotope that can induce significant damage to cancer cells. In recent years, the use of theragnostics in nuclear medicine clinical practice has increased considerably, and thus investigation has focused on the identification of novel radionuclides that can bind to molecular targets that are typically dysregulated in different cancers. The major advantages of the theragnostic approach include the elimination of multi-step procedures, reduced adverse effects to normal tissues, early diagnosis, better predictive responses, and personalized patient care. This review aims to discuss emerging theragnostic molecules that have been investigated in a series of human malignancies, including gliomas, thyroid cancer, neuroendocrine tumors, cholangiocarcinoma, and prostate cancer, as well as potent and recently introduced molecular targets, like cell-surface receptors, kinases, and cell adhesion proteins. Furthermore, special reference has been made to copper radionuclides as theragnostic agents and their radiopharmaceutical applications since they present promising alternatives to the well-studied gallium-68 and lutetium-177.

Humoral and Cellular Response and Associated Variables Nine Months following BNT162b2 Vaccination in Healthcare Workers.

In this study, we aimed to illustrate the trajectory of humoral and cellular immunity nine months after primary vaccination with the BNT162b2 mRNA vaccine among 189 healthcare workers (HCWs). Additionally, we endeavored to identify correlations between immunity parameters and a number of common variables and comorbidities. A total of 189 healthcare workers (HCWs), vaccinated against COVID-19, were finally included in the study. All of the subjects had received two doses of the BNT162b2 vaccine; had undergone antibody tests one, four and nine months post-vaccination; and had completed a medical questionnaire. Further samples taken at nine months were tested for cellular immunity. No participants had evidence of COVID-19 infection pre- or post-vaccination. An anti-S1 receptor binding domain (RBD) antibody assay was used to assess humoral response, and cellular immunity was estimated with an INF-γ release assay (IGRA). Statistical analysis was performed using STATA. We report a statistically significant antibody drop over time. Being above the age of 40 or a smoker reduces the rise of antibodies by 37% and 28%, respectively. More than half of the participants did not demonstrate T-cell activation at nine months. Female gender and antibody levels at four months predispose detection of cellular immunity at nine months post-immunization. This study furthers the qualitative, quantitative, and temporal understanding of the immune response to the BNT162b2 mRNA vaccine and the effect of correlated factors.

Therapeutic Potential of Linearol in Combination with Radiotherapy for the Treatment of Glioblastoma In Vitro.

Glioblastoma is one of the most malignant and lethal forms of primary brain tumors in adults. Linearol, a kaurane diterpene isolated from different medicinal plants, including those of the genus Sideritis, has been found to possess significant anti-oxidant, anti-inflammatory and anti-microbial properties. In this study, we aimed to determine whether linearol could exhibit anti-glioma effects when given alone or in combination with radiotherapy in two human glioma cell lines, U87 and T98. Cell viability was examined with the Trypan Blue Exclusion assay, cell cycle distribution was tested with flow cytometry, and the synergistic effects of the combination treatment were analyzed with CompuSyn software. Linearol significantly suppressed cell proliferation and blocked cell cycle at the S phase. Furthermore, pretreatment of T98 cells with increasing linearol concentrations before exposure to 2 Gy irradiation decreased cell viability to a higher extent than linearol or radiation treatment alone, whereas in the U87 cells, an antagonistic relationship was observed between radiation and linearol. Moreover, linearol inhibited cell migration in both tested cell lines. Our results demonstrate for the first time that linearol is a promising anti-glioma agent and further studies are needed to fully understand the underlying mechanism of this effect.

Siderol Inhibits Proliferation of Glioblastoma Cells and Acts Synergistically with Temozolomide.

Glioblastoma (GBM) is the most aggressive primary central nervous system (CNS) tumor in adults with dismal prognosis. Currently, the therapeutic interventions include gross total resection, when possible, followed by radiotherapy and chemotherapy. However, despite treatment, tumor usually recurs within 7-9 months. The presence of glioma cells with stem-like properties and tumor's heterogeneity have been identified as the most important factors driving recurrence. Recently, research efforts have been focused on the use of natural substances as treatment for GBM. Siderol is an ent-kaurane diterpenoid, isolated from the genus Sideritis. Sideritis extracts have already been investigated for their anti-inflammatory, antioxidant, and anticancer effects. In this study, we investigated the antitumoral effects of siderol in GBM T98 and U87 cell lines, as well as the effects of combined treatment with temozolomide (TMZ). Cell viability was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and trypan blue exclusion assay. Different concentrations of siderol were used in order to calculate the IC50 values at 72 h after treatment. Flow cytometry used for the DNA cell cycle analysis after treatment with siderol in concentrations of IC50 and twice the IC50 values for 72 h. Furthermore, the effect of siderol in cell's migratory ability was tested using wound healing assay. Cell viability and proliferation, after combined treatment with siderol and TMZ, also were evaluated with the trypan blue exclusion assay and the effects of the combination treatment were analyzed with CompuSyn software. Treatment with siderol significantly reduced cell viability in T98 and U87 cell lines in a dose-dependent manner and IC50 values were calculated, 18 µM and 13 µM, respectively. Moreover, siderol induced G0/G1 cell cycle arrest in a dose-dependent manner and inhibited the migration in both cell lines. In addition, siderol and TMZ seem to have synergistic action in the majority of tested concentrations in both T98 and U87 cells. In conclusion, siderol may represent an innovative strategy for the treatment of GBM, and further studies are needed on siderol's efficacy and mode of action.