Fluorescent Self-Assembled Complexes Based on Glyco-Functionalized G-Quadruplexes as a Targeted Delivery Platform.

Targeted delivery systems combined with the stimuli-responsive release of drug molecules hold noteworthy promise for precision medicine, enabling treatments with enhanced effectiveness and reduced adverse effects. An ideal drug delivery platform with versatile targeting moieties, the capability of combinational payloads, and simple preparation is highly desirable. Herein, we developed pH-sensitive fluorescent self-assembled complexes (SACs) of a galactose-functionalized G-quadruplex (G4) and a coumarin carboxamidine derivative as a targeted delivery platform through the nanoprecipitation method. These SACs selectively targeted hepatocellular carcinoma (HepG2) cells in fluorescence imaging after a short incubation and exerted specific anticancer effects in an appropriate dose range. Co-delivery of 1 µM prodrug floxuridine oligomers and 16 µg/mL SACs (minimal hemolytic effect) significantly reduced the cytotoxicity of the nucleoside anticancer drug on normal cells (NIH/3T3), kept up to 70% alive after 72-h incubation, and improved anticancer efficacy compared to SACs alone. This strategy can be extended to ratiometric multidrug delivery through self-assembly for targeted combinational therapy.

Esterase-Responsive Floxuridine-Tethered Multifunctional Nanoparticles for Targeted Cancer Therapy.

Floxuridine is a potential clinical anticancer drug for the treatment of various cancers. However, floxuridine typically causes unfavorable side effects due to its very poor tumor selectivity, and, hence, there is a high demand for the development of novel approaches that permit the targeted delivery of floxuridine into cancerous cells. Herein, the design and synthesis of an esterase-responsive multifunctional nanoformulation for the targeted delivery of floxuridine in esterase-overexpressed cancer cells is reported. Photopolymerization of floxuridine-tethered lipoic acid results in the formation of amphiphilic floxuridine-tethered poly(disulfide). Self-assembly of the amphiphilic polymer results in the formation of nanoparticles with floxuridine decorated on the surfaces of the particles. Integration of aptamer DNA for nucleolin onto the surface of the nanoparticle is demonstrated by exploring the base-pairing interaction of floxuridine with adenine. Targeted internalization of the aptamer-decorated nanoparticle into nucleolin-expressed cancer cells is demonstrated. Esterase triggered cleavage of the ester bond connecting floxuridine with the polymer backbone, and the subsequent targeted delivery of floxuridine into cancer cells is also shown. Excellent therapeutic efficacy is observed both in vitro and also in the 3D tumor spheroid model. This noncovalent strategy provides a simple yet effective strategy for the targeted delivery of floxuridine into cancer cells in a less laborious fashion.

REV3 promotes cellular tolerance to 5-fluorodeoxyuridine by activating translesion DNA synthesis and intra-S checkpoint.

The drug floxuridine (5-fluorodeoxyuridine, FUdR) is an active metabolite of 5-Fluorouracil (5-FU). It converts to 5-fluorodeoxyuridine monophosphate (FdUMP) and 5-fluorodeoxyuridine triphosphate (FdUTP), which on incorporation into the genome inhibits DNA replication. Additionally, it inhibits thymidylate synthase, causing dTMP shortage while increasing dUMP availability, which induces uracil incorporation into the genome. However, the mechanisms underlying cellular tolerance to FUdR are yet to be fully elucidated. In this study, we explored the mechanisms underlying cellular resistance to FUdR by screening for FUdR hypersensitive mutants from a collection of DT40 mutants deficient in each genomic maintenance system. We identified REV3, which is involved in translesion DNA synthesis (TLS), to be a critical factor in FUdR tolerance. Replication using a FUdR-damaged template was attenuated in REV3-/- cells, indicating that the TLS function of REV3 is required to maintain replication on the FUdR-damaged template. Notably, FUdR-exposed REV3-/- cells exhibited defective cell cycle arrest in the early S phase, suggesting that REV3 is involved in intra-S checkpoint activation. Furthermore, REV3-/- cells showed defects in Chk1 phosphorylation, which is required for checkpoint activation, but the survival of FUdR-exposed REV3-/- cells was further reduced by the inhibition of Chk1 or ATR. These data indicate that REV3 mediates DNA checkpoint activation at least through Chk1 phosphorylation, but this signal acts in parallel with ATR-Chk1 DNA damage checkpoint pathway. Collectively, we reveal a previously unappreciated role of REV3 in FUdR tolerance.

A Modified Floxuridine Reduced-Dose Protocol for Patients with Unresectable Colorectal Liver Metastases Treated with Hepatic Arterial Infusion.

BACKGROUND: Most patients treated with the standard dosing protocol (SDP) of hepatic arterial infusion (HAI) floxuridine require dose holds and reductions, thereby limiting their HAI therapy. We hypothesized that a modified dosing protocol (MDP) with a reduced floxuridine starting dose would decrease dose holds, dose reductions, and have similar potential to convert patients with unresectable colorectal liver metastases (uCRLM) to resection. PATIENTS AND METHODS: We reviewed our institutional database of patients with uCRLM treated with HAI between 2016 and 2022. In 2019, we modified the floxuridine starting dose to 50% (0.06 mg/kg) of the SDP (0.12 mg/kg). We compared treatment related outcomes between the SDP and MDP cohorts. RESULTS: Of n = 33 patients, 15 (45%) were treated on the SDP and 18 (55%) with our new institutional MDP. The MDP cohort completed more cycles before a dose reduction (mean 4.2 vs. 2), received more overall cycles (median 7.5 vs. 5), and averaged 39 more days of treatment (all P < 0.05). The SDP experienced more dose reductions (1.4 vs. 0.61) and dose holds (1.2 vs. 0.2; both P < 0.01). Of the patients in each group potentially convertible to hepatic resection, three patients (23%) in the SDP and six patients (35%) in the MDP group converted to resection (P = 0.691). Overall, four patients (27%) in the SDP developed treatment ending biliary toxicity compared with one patient (6%) in the MDP. CONCLUSIONS: A 50% starting dose of HAI floxuridine provides fewer treatment disruptions, more consecutive floxuridine cycles, and a similar potential to convert patients with initially uCRLM for disease clearance.

Floxuridine supports UPS independent of germline signaling and proteostasis regulators via involvement of detoxification in C. elegans.

The ubiquitin-proteasome system (UPS) is critical for maintaining proteostasis, influencing stress resilience, lifespan, and thermal adaptability in organisms. In Caenorhabditis elegans, specific proteasome subunits and activators, such as RPN-6, PBS-6, and PSME-3, are associated with heat resistance, survival at cold (4°C), and enhanced longevity at moderate temperatures (15°C). Previously linked to improving proteostasis, we investigated the impact of sterility-inducing floxuridine (FUdR) on UPS functionality under proteasome dysfunction and its potential to improve cold survival. Our findings reveal that FUdR significantly enhances UPS activity and resilience during proteasome inhibition or subunit deficiency, supporting worms' normal lifespan and adaptation to cold. Importantly, FUdR effect on UPS activity occurs independently of major proteostasis regulators and does not rely on the germ cells proliferation or spermatogenesis. Instead, FUdR activates a distinct detoxification pathway that supports UPS function, with GST-24 appearing to be one of the factors contributing to the enhanced activity of the UPS upon knockdown of the SKN-1-mediated proteasome surveillance pathway. Our study highlights FUdR unique role in the UPS modulation and its crucial contribution to enhancing survival under low-temperature stress, providing new insights into its mechanisms of action and potential therapeutic applications.

High-load nanoparticles with a chemotherapeutic SN-38/FdUMP drug cocktail.

[Gd(OH)]2+[(SN-38)0.5(FdUMP)0.5]2- inorganic-organic hybrid nanoparticles (IOH-NPs) with a chemotherapeutic cocktail of ethyl-10-hydroxycamptothecin (SN-38, active form of irinotecan) and 5-fluoro-2'-deoxyuridine-5'-phosphate (FdUMP, active form of 5'-fluoruracil), 40 nm in size, are prepared in water. The IOH-NPs contain a total drug load of 63 wt% with 33 wt% of SN-38 and 30 wt% of FdUMP. Cell-based assays show efficient cellular uptake and promising anti-tumour activity on two pancreatic cancer cell lines of murine origin (KPC, Panc02). Beside the high-load drug cocktail, especially the option to use SN-38, which - although 100- to 1000-times more potent than irinotecan - is usually unsuitable for systemic administration due to poor solubility, low stability, and high toxicity upon non-selective delivery. The [Gd(OH)]2+[(SN-38)0.5(FdUMP)0.5]2- IOH-NPs are a new concept to deliver a drug cocktail with SN-38 and FdUMP directly to the tumour, shielded in a nanoparticle, to reduce side effects.

Development of a Supermolecular Radionuclide-Drug Conjugate System for Integrated Radiotheranostics for Non-small Cell Lung Cancer.

Radionuclide-drug conjugates (RDCs) designed from small molecule or nanoplatform shows complementary characteristics. We constructed a new RDC system with integrated merits of small molecule and nanoplatform-based RDCs. Erlotinib was labeled with 131I to construct the bulk of RDC (131I-ER). Floxuridine was mixed with 131I-ER to develop a hydrogen bond-driving supermolecular RDC system (131I-ER-Fu NPs). The carrier-free 131I-ER-Fu NPs supermolecule not only demonstrated integrated merits of small molecule and nanoplatform-based RDC, including clear structure definition, stable quality control, prolonged circulation lifetime, enhanced tumor specificity and retention, and rapidly nontarget clearance, but also exhibited low biological toxicity and stronger antitumor effects. In vivo imaging also revealed its application for tumor localization of nonsmall cell lung cancer (NSCLC) and screening of patients suitable for epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. We considered that 131I-ER-Fu NPs showed potentials as an integrated platform for the radiotheranostics of NSCLC.

Tumor-penetrating iRGD facilitates penetration of poly(floxuridine-ketal)-based nanomedicine for enhanced pancreatic cancer therapy.

Efficient intratumoral penetration is essential for nanomedicine to eradicate pancreatic tumors. Although nanomedicine can enter the perivascular space of pancreatic tumors, their access to distal tumor cells, aloof from the vessels, remains a formidable challenge. Here, we synthesized an acid-activatable macromolecular prodrug of floxuridine (FUDR)-poly(FUDR-ketal), engineered a micellar nanomedicine of FUDR, and intravenously co-administered the nanomedicine with the tumor-penetrating peptide iRGD for enhanced treatment of pancreatic tumor. A FUDR-derived mono-isopropenyl ether was synthesized and underwent self-addition polymerization to afford the hydrophobic poly(FUDR-ketal), which was subsequently co-assembled with amphiphilic DSPE-mPEG into the micellar nanomedicine with size of 12 nm and drug content of 56.8 wt% using nanoprecipitation technique. The acetone-based ketal-linked poly(FUDR-ketal) was triggered by acid to release FUDR to inhibit cell proliferation. In an orthotopic pancreatic tumor model derived from KPC (KrasLSL-G12D/+; Trp53LSL-R172H/+; Pdx1-Cre) cells that overexpress neuropilin-1 (NRP-1) receptor, iRGD improved penetration of FUDR nanomedicine into tumor parenchyma and potentiated the therapeutic efficacy. Our nanoplatform, along with iRGD, thus appears to be promising for efficient penetration and activation of acid-responsive nanomedicines for enhanced pancreatic cancer therapy.

A phase I open-label, dose-escalation study of NUC-3373, a targeted thymidylate synthase inhibitor, in patients with advanced cancer (NuTide:301).

PURPOSE: 5-fluorouracil (5-FU) is inefficiently converted to the active anti-cancer metabolite, fluorodeoxyuridine-monophosphate (FUDR-MP), is associated with dose-limiting toxicities and challenging administration schedules. NUC-3373 is a phosphoramidate nucleotide analog of fluorodeoxyuridine (FUDR) designed to overcome these limitations and replace fluoropyrimidines such as 5-FU. PATIENTS AND METHODS: NUC-3373 was administered as monotherapy to patients with advanced solid tumors refractory to standard therapy via intravenous infusion either on Days 1, 8, 15 and 22 (Part 1) or on Days 1 and 15 (Part 2) of 28-day cycles until disease progression or unacceptable toxicity. Primary objectives were maximum tolerated dose (MTD) and recommended Phase II dose (RP2D) and schedule of NUC-3373. Secondary objectives included pharmacokinetics (PK), and anti-tumor activity. RESULTS: Fifty-nine patients received weekly NUC-3373 in 9 cohorts in Part 1 (n = 43) and 3 alternate-weekly dosing cohorts in Part 2 (n = 16). They had received a median of 3 prior lines of treatment (range: 0-11) and 74% were exposed to prior fluoropyrimidines. Four experienced dose-limiting toxicities: two Grade (G) 3 transaminitis; one G2 headache; and one G3 transient hypotension. Commonest treatment-related G3 adverse event of raised transaminases occurred in < 10% of patients. NUC-3373 showed a favorable PK profile, with dose-proportionality and a prolonged half-life compared to 5-FU. A best overall response of stable disease was observed, with prolonged progression-free survival. CONCLUSION: NUC-3373 was well-tolerated in a heavily pre-treated solid tumor patient population, including those who had relapsed on prior 5-FU. The MTD and RP2D was defined as 2500 mg/m2 NUC-3373 weekly. NUC-3373 is currently in combination treatment studies. TRIAL REGISTRATION: Clinicaltrials.gov registry number NCT02723240. Trial registered on 8th December 2015. https://clinicaltrials.gov/study/NCT02723240 .

Robotic Biliary Stricturoplasty and Roux-en-Y Hepaticojejunostomy After Hepatic Artery Infusion Pump Injury.

BACKGROUND: Hepatic artery infusion pump (HAIP) with floxuridine/dexamethasone and systemic chemotherapy is an established treatment regimen, which had been reported about converting 47% of patients with stage 4 colorectal liver metastasis from unresectable to resectable.1,2 To this effect, HAIP chemotherapy contributes to prolonged survival of many patients, which otherwise may not have other treatment options. Biliary sclerosis, however, is a known complication of the HAIP treatment, which occurs in approximately 5.5% of patients receiving this modality as an adjuvant therapy after hepatectomy and in 2% of patients receiving HAIP treatment for unresectable disease.3 While biliary sclerosis diffusely affects the perihilar and intrahepatic biliary tree, a dominant stricture maybe found in select cases, which gives an opportunity for a local surgical treatment after failure of endoscopic stenting/dilations. While the use of minimally invasive approach to biliary surgery is gradually increasing,4 there have been no descriptions of its application in this scenario. In this video, we demonstrate the use of minimally invasive robotic technique for biliary stricturoplasty and Roux-en-Y (RY) hepaticojejunostomy to treat persistent right hepatic duct stricture after HAIP chemotherapy. PATIENT: A 68-year-old woman with history of multifocal bilobar stage 4 colorectal liver metastasis presented to our office with obstructive jaundice and recurrent cholangitis that required nine endoscopic retrograde cholangiopancreatographies (ERCPs) and a placement of internal-external percutaneous transhepatic biliary drain (PTBD) by interventional radiology within the past 2 years. Her past surgical history was consistent with laparoscopic right hemicolectomy 3 years prior, followed by a left lateral sectorectomy with placement of an HAIP for adjuvant treatment. The patient had more than ten metastatic liver lesions within the right and left lobe, ranging from 2 to 3 cm in size at the time of HAIP placement. The patient had a histologically normal background liver parenchyma before the HAIP chemotherapy treatment. The patient did not have any history of alcohol use, diabetes mellitus, metabolic syndrome, nonalcoholic steatohepatitis, or other underlying intrinsic liver disorders, which are known to contribute to the development of hepatic fibrosis. Despite a radiologically disease-free status, the patient started to have episodes of acute cholangitis 1 year after the placement of HAIP that required multiple admissions to a local hospital. The HAIP was subsequently removed once the diagnosis of biliary sclerosis was made despite dose reductions and treatment with intrahepatic dexamethasone for almost 1 year. In addition to this finding, the known liver metastases have shown complete radiological resolution. Therefore further treatment with HAIP was deemed unnecessary, and pump removal was undertaken. Magnetic resonance imaging showed a dominant stricture at the junction of the right anterior and right posterior sectoral hepatic duct. The location of the dominant stricture was confirmed by an ERCP and cholangioscopy. Absence of neoplasia was confirmed with multiple cholangioscopic biopsies. Multiple endoscopic and percutaneous attempts with stent placement failed to dilate the area of stricture. Postprocedural cholangiographies showed a persistent significant narrowing, which led to multiple recurrent obstructive jaundice and severe cholangitis. While the use of surgical approach is rarely needed in the treatment of biliary sclerosis, a decision was made after extensive multidisciplinary discussions to perform a robotic stricturoplasty and RY hepaticojejunostomy with preservation of the native common bile duct. TECHNIQUE: The operation began with a laparoscopic adhesiolysis to allow for identification of HAIP tubing (which was later removed) and placement of robotic ports. A peripheral liver biopsy was obtained to evaluate the degree of hepatic parenchymal fibrosis. Porta hepatic area was carefully exposed without causing an inadvertent injury to the surrounding hollow organs. Biopsy of perihepatic soft tissues was taken as appropriate to rule out any extrahepatic disease. The common bile duct and common hepatic duct with ERCP stents within it were identified with the use of ultrasonography. Anterior wall of the common hepatic duct was then opened, exposing the two plastic stents. Cephalad extension of the choledochotomy was made toward the biliary bifurcation and the right hepatic duct. The distal common bile duct was preserved for future endoscopic access to the biliary tree. After lowering the right-sided hilar plate, dense fibrosis around the right hepatic duct was divided sharply with robotic scissors, achieving a mechanical release of the dominant stricture. An intraoperative cholangioscopy was performed to confirm adequate openings of the right hepatic duct secondary and tertiary radicles, as well as patency of the left hepatic duct. A 4-Fr Fogarty catheter was used to sweep the potential biliary debris from within the right and left hepatic lobe. Finally, a confirmatory choledochoscopy was performed to ensure patency and clearance of the right-sided intrahepatic biliary ducts and the left hepatic duct before fashioning the hepaticojejunostomy. A 40-cm antecolic roux limb was next prepared for the RY hepaticojejunostomy. A side-to-side double staple technique was utilized to create the jejunojejunostomy. The common enterotomy was closed in a running watertight fashion. Once the roux limb was transposed to the porta hepatic in a tension-free manner, a side-to-side hepaticojejunostomy was constructed in a running fashion by using absorbable barbed sutures. The index suture was placed at 9 o'clock location, and the posterior wall of the anastomosis was run toward 3 o'clock location. This stabilized the roux limb to the bile duct. The anterior wall of the anastomosis was next fashioned by using a running technique from both corners of the anastomosis toward the middle (12 o'clock), where both sutures were tied together. This completed a wide side-to-side hepaticojejunostomy anastomosis encompassing the upper common hepatic duct, biliary bifurcation, and the right hepatic duct. A closed suction drain was placed before closing.5 RESULTS: The operative time was approximately 4 hr with 60 ml of blood loss. The postoperative course was uneventful. The patient was discharged home on postoperative Day 5 after removal of the closed suction drain, confirming the absence of bile leak. The patient had developed periportal/periductal fibrosis, cholestasis, and moderate-severe parenchymal fibrosis (F3-F4) based on liver biopsy, often seen in patients treated with a long course of floxuridine HAIP chemotherapy. The patient is clinically doing well at 1 year outpatient follow-up without any evidence of recurrent cholangitis at the time of this manuscript preparation. CONCLUSIONS: Robotic biliary stricturoplasty with RY hepaticojejunostomy for treatment of biliary sclerosis after HAIP chemotherapy is safe and feasible. Appropriate experience in minimally invasive hepatobiliary surgery is necessary to achieve this goal.

High OXPHOS efficiency in RA-FUdr-differentiated SH-SY5Y cells: involvement of cAMP signalling and respiratory supercomplexes.

Neurons are highly dependent on mitochondria to meet their bioenergetic needs and understanding the metabolic changes during the differentiation process is crucial in the neurodegeneration context. Several in vitro approaches have been developed to study neuronal differentiation and bioenergetic changes. The human SH-SY5Y cell line is a widely used cellular model and several differentiation protocols have been developed to induce a neuron-like phenotype including retinoic acid (RA) treatment. In this work we obtained a homogeneous functional population of neuron-like cells by a two-step differentiation protocol in which SH-SY5Y cells were treated with RA plus the mitotic inhibitor 2-deoxy-5-fluorouridine (FUdr). RA-FUdr treatment induced a neuronal phenotype characterized by increased expression of neuronal markers and electrical properties specific to excitable cells. In addition, the RA-FUdr differentiated cells showed an enrichment of long chain and unsaturated fatty acids (FA) in the acyl chain composition of cardiolipin (CL) and the bioenergetic analysis evidences a high coupled and maximal respiration associated with high mitochondrial ATP levels. Our results suggest that the observed high oxidative phosphorylation (OXPHOS) capacity may be related to the activation of the cyclic adenosine monophosphate (cAMP) pathway and the assembly of respiratory supercomplexes (SCs), highlighting the change in mitochondrial phenotype during neuronal differentiation.

Feeding on lactic acid bacteria isolated from food extends the lifespan of Caenorhabditis elegans.

Lactic acid bacteria (LAB) contribute to human health, and LAB functionality has been studied using Caenorhabditis elegans as an alternative host. However, many studies have focused on the efficacy of a single strain of LAB, and few reports have compared various LAB strains. In this study, we examined the effects of 15 strains of LAB isolated from vegetables, meat, and fermented foods on nematode longevity and healthy lifespan. To reduce the frequency of laborious survival observations, we performed a lifespan assay on agar plates containing 2'-deoxy-5-fluorouridine (FUdR), which inhibits egg hatching and prevents generation mixing. Four beneficial strains showed significant lifespan extension and increased spontaneous nematode mobility, regardless of treatment with or without FUdR and the frequency of survival observation. These results suggested increased longevity and an extended healthy lifespan, confirming the reliability of our method. The four strains are expected to show anti-ageing effects besides longevity and have effects on age-related degenerative diseases. Our labor-saving method can be used as an alternative to conventional methods and enable simultaneous screening of multiple strains. Future research could explore factors contributing to lifespan regulation by comparing and verifying differential strain effects on lifespan.

Deciphering the binding mode and structural perturbations in floxuridine-human serum albumin complexation with spectroscopic, microscopic, and computational techniques.

The binding mode of antineoplastic antimetabolite, floxuridine (FUDR), with human serum albumin (HSA), the leading carrier in blood circulation, was ascertained using multi-spectroscopic, microscopic, and computational techniques. A static fluorescence quenching was established due to decreased Ksv values with rising temperatures, suggesting FUDR-HSA complexation. UV-vis absorption spectral results also supported this conclusion. The binding constant, Ka values, were found within 9.7-7.9 × 103 M-1 at 290, 300, and 310 K, demonstrating a moderate binding affinity for the FUDR-HSA system. Thermodynamic data (ΔS = +46.35 J.mol-1.K-1 and ΔH = -8.77 kJ.mol-1) predicted the nature of stabilizing forces (hydrogen-bonds, hydrophobic, and van der Waals interactions) for the FUDR-HSA complex. Circular dichroism spectra displayed a minor disruption in the protein's 2° and 3° structures. At the same time, atomic force microscopy images proved variations in the FUDR-HSA surface morphology, confirming its complex formation. The protein's microenvironment around Trp/Tyr residues was also modified, as judged by 3-D fluorescence spectra. FUDR-bound HSA showed better resistance against thermal stress. As disclosed from ligand displacement studies, the FUDR binding site was placed in subdomain IIA (Site I). Further, the molecular docking analysis corroborated the competing displacement studies. Molecular dynamics evaluations revealed that the complex achieved equilibrium during simulations, confirming the FUDR-HSA complex's stability.

Case-Based Clinical Guidance on Dosing and Management of the Hepatic Artery Infusion Chemotherapy Pump.

Hepatic artery infusion (HAI) delivers localized high-dose floxuridine directly to liver tumors through an implanted pump. While patients are undergoing active treatment, the pump is refilled with chemotherapy alternating with saline every 2 weeks using a specialized noncoring needle. Numerous clinical scenarios influence the dosing of floxuridine, which do not conform to the usual dose modification schema for systemic chemotherapy. This article aims to provide practical clinical management solutions to overcome the common challenges faced by oncologists in the real-world management of HAI pump therapy.

Enhancing or Quenching of a Mitochondria-Targeted AIEgens-Floxuridine Sensor by the Regulation of pH-Dependent Self-assembly, Efficient Recognition of Hg2+, and Stimulated Response of GSH.

Biocompatible fluorescent probes have emerged as essential tools in life sciences for visualizing subcellular structures and detecting specific analytes. Herein, we report the synthesis and characterization of a novel fluorescent probe (TPE-FdU), incorporated with hydrophilic 2'-fluoro-substituted deoxyuridine and hydrophobic ethynyl tetraphenylethene moieties, which possessed typical aggregation-induced emission (AIE) behavior. In comparison to the TPE-FdU (pKa 7.68) treated in neutral conditions, it performed well at pH 4, exhibiting an enhanced 450 nm emission signal of approximately four times stronger. As the pH value was increased to 10, the fluorescence intensity was completely quenched. The TEM images of TPE-FdU in an acidic environment (nanospherical morphology, AIE enhance, pH = 4) and in a basic environment (microrods, fluorescence quenching, pH = 9) revealed that it was a pH-dependent self-assembled probe, which was also illustrated by the interpretation of the NMR spectrum. Furthermore, the TPE-FdU probe exhibited a specific response to trace Hg2+ ions. Interestingly, the quenched fluorescence of the TPE-FdU probe caused by Hg2+ can be recovered by the addition of GSH due to the formation of the Hg-S bond being released away. MTT assay and CLSM images demonstrated that TPE-FdU was nontoxic and selectively visualized in the intracellular mitochondria. These results contributed to the development of advanced fluorescent probes with diverse applications in cell imaging, environment protection, and biomedical research.

Effects of six pyrimidine analogs on the growth of Tetrahymena thermophila and their implications in pyrimidine metabolism.

Tetrahymena are ciliated protists that have been used to study the effects of toxic chemicals, including anticancer drugs. In this study, we tested the inhibitory effects of six pyrimidine analogs (5-fluorouracil, floxuridine, 5'-deoxy-5-fluorouridine, 5-fluorouridine, gemcitabine, and cytarabine) on wild-type CU428 and conditional mutant NP1 Tetrahymena thermophila at room temperature and the restrictive temperature (37°C) where NP1 does not form the oral apparatus. We found that phagocytosis was not required for pyrimidine analog entry and that all tested pyrimidine analogs inhibited growth except for cytarabine. IC50 values did not significantly differ between CU428 and NP1 for the same analog at either room temperature or 37°C. To investigate the mechanism of inhibition, we used two pyrimidine bases (uracil and thymine) and three nucleosides (uridine, thymidine, and 5-methyluridine) to determine whether the inhibitory effects from the pyrimidine analogs were reversible. We found that the inhibitory effects from 5-fluorouracil could be reversed by uracil and thymine, from floxuridine could be reversed by thymidine, and from 5'-deoxy-5-fluorouridine could be reversed by uracil. None of the tested nucleobases or nucleosides could reverse the inhibitory effects of gemcitabine or 5-fluorouridine. Our results suggest that the five pyrimidine analogs act on different sites to inhibit T. thermophila growth and that nucleobases and nucleosides are metabolized differently in Tetrahymena.

Starting a successful hepatic artery infusion pump program: A practical guide.

Implementation of a successful hepatic artery infusion pump program requires numerous factors to be in place, and the lack of any of these may lead to program failure. First and foremost, hepatic artery infusion pump programs must have adequate surgical expertise in the complex technical aspects of hepatic artery infusion pump implantation and postoperative management. Most new hepatic artery infusion pump programs are initiated by a surgeon and led in conjunction with a medical oncologist. Medical oncology experience in floxuridine dosing is critical in maximizing the treatment doses and the number of cycles administered while avoiding biliary toxicity. This is facilitated by collaboration with an engaged pharmacy team. To have adequate patient volume for a successful program, internal and external stakeholders must have buy-in, including surgical and medical oncology colleagues unfamiliar with hepatic artery infusion pumps, colorectal surgery, and other referring providers. Programmatic support must be obtained from the hospital, cancer center, and department administration. Day-to-day pump access for chemotherapy and maintenance saline fills must be performed by appropriately trained infusion nurses to avoid complications. Nuclear and diagnostic radiology experience is key to identifying extrahepatic perfusion and hepatic artery infusion pump-specific complications. Additionally, skilled interventional radiologists and gastroenterologists are necessary to identify and treat rare complications rapidly. Finally, given the current rapid expansion of hepatic artery infusion pump programs, new programs must identify engaged mentors to help guide patient selection, navigate the nuanced issues that may arise, and provide advice in the case of complications. Although hepatic artery infusion pump dissemination outside of several major tertiary centers previously had stalled, establishing a successful and active hepatic artery infusion pump is feasible with appropriate training, mentorship, and thoughtful assembly of a dedicated multidisciplinary team.

Systemic exposure of floxuridine after hepatic arterial infusion pump chemotherapy with floxuridine in patients with resected colorectal liver metastases.

BACKGROUND: Floxuridine's high hepatic extraction ratio and short elimination half-life allows maximum liver exposure with minimal systemic side-effects. This study attempts to quantify the systemic exposure of floxuridine. METHODS: Patients undergoing continuous hepatic arterial infusion pump (HAIP) floxuridine after resection of colorectal liver metastases (CRLM) in two centres underwent six cycles of floxuridine at start dose 0.12 mg/kg/day. No concomitant systemic chemotherapy was administered. Peripheral venous blood samples were drawn during the first two cycles: pre-dose (only in the second cycle), 30 min, 1 h, 2 h, 7 h, and 15 days after floxuridine infusion. Foxuridine concentration in the residual pump reservoir was measured on day 15 of both cycles. A floxuridine assay with a lower boundary of detection of 0.250 ng/mL was developed. RESULTS: 265 blood samples were collected in the 25 patient included in this study. Floxuridine was mostly measurable at day 7 and day 15 (86 % and 88 % of patients respectively). The median dose corrected concentrations were 0.607 ng/mL [IQR: 0.472-0.747] for cycle 1 day 7, 0.579 ng/mL [IQR: 0.470-0.693] for cycle 1 day 15, 0.646 ng/mL [IQR: 0.463-0.8546] for cycle 2 day 7, and 0.534 ng/mL [IQR: 0.4257-0.7075] for cycle 2 day 15. One patient had remarkably high floxuridine concentrations reaching up to 44 ng/mL during the second cycle, without a clear explanation. The floxuridine concentration in the pump decreased by 14.7 % (range 0.5 %-37.8 %) over a period of 15 days (n = 18). CONCLUSION: Overall, negligible systemic concentrations of floxuridine were detected. However, remarkably increased levels were detected in one patient. Floxuridine concentration in the pump decreases over time.