Anticancer Drug 5-fluorouracil Research Articles

Metal organic framework-based polymeric hydrogel: A promising drug delivery vehicle for the treatment of breast cancer

The constraints associated with current cancer therapies have inspired scientists to develop advanced, precise, and safe drug delivery methods. These delivery systems boost treatment effectiveness, minimize harm to healthy cells, and combat cancer recurrence. To design advanced drug delivery vehicle with these character, in the present manuscript, we have designed a self-healing and injectable hybrid hydrogel through synergistically interacting metal organic framework, CuBTC with the poly(vinyl alcohol) (PVA). This hybrid hydrogel acts as a localized drug delivery system and was used to encapsulate and release the anticancer drug 5-Fluorouracil selectively at the targeted site in response to the physiological pH. The hydrogel was formed through transforming the gaussian coil like matrix of PVA-CuBTC into a three-dimensional network of hydrogel upon the addition of crosslinker; borax. The biocompatible character of the hydrogel was confirmed through cell viability test. The biocompatible hybrid hydrogel then was used to encapsulate and studied for the pH responsive release behavior of the anti-cancer drug, 5-FU. The in vitro cytotoxicity of the drug-loaded hydrogel was evaluated against MCF-7 and HeLa cells. The study confirms that the hybrid hydrogel is effective for targeted and sustained release of anticancer drugs at cancer sites.

Germline cis variant determines epigenetic regulation of the anti-cancer drug metabolism gene dihydropyrimidine dehydrogenase (DPYD)

Enhancers are critical for regulating tissue-specific gene expression, and genetic variants within enhancer regions have been suggested to contribute to various cancer-related processes, including therapeutic resistance. However, the precise mechanisms remain elusive. Using a well-defined drug-gene pair, we identified an enhancer region for dihydropyrimidine dehydrogenase (DPD, DPYD gene) expression that is relevant to the metabolism of the anti-cancer drug 5-fluorouracil (5-FU). Using reporter systems, CRISPR genome-edited cell models, and human liver specimens, we demonstrated in vitro and vivo that genotype status for the common germline variant (rs4294451; 27% global minor allele frequency) located within this novel enhancer controls DPYD transcription and alters resistance to 5-FU. The variant genotype increases recruitment of the transcription factor CEBPB to the enhancer and alters the level of direct interactions between the enhancer and DPYD promoter. Our data provide insight into the regulatory mechanisms controlling sensitivity and resistance to 5-FU.

Germline cis variant determines epigenetic regulation of the anti-cancer drug metabolism gene dihydropyrimidine dehydrogenase (DPYD).

Enhancers are critical for regulating tissue-specific gene expression, and genetic variants within enhancer regions have been suggested to contribute to various cancer-related processes, including therapeutic resistance. However, the precise mechanisms remain elusive. Using a well-defined drug-gene pair, we identified an enhancer region for dihydropyrimidine dehydrogenase (DPD, DPYD gene) expression that is relevant to the metabolism of the anti-cancer drug 5-fluorouracil (5-FU). Using reporter systems, CRISPR genome-edited cell models, and human liver specimens, we demonstrated in vitro and vivo that genotype status for the common germline variant (rs4294451; 27% global minor allele frequency) located within this novel enhancer controls DPYD transcription and alters resistance to 5-FU. The variant genotype increases recruitment of the transcription factor CEBPB to the enhancer and alters the level of direct interactions between the enhancer and DPYD promoter. Our data provide insight into the regulatory mechanisms controlling sensitivity and resistance to 5-FU.

Tackling Antibiotic Resistance: Exploring 5-Fluorouracil as a Promising Antimicrobial Strategy for the Treatment of Streptococcus suis Infection.

Streptococcus suis (S. suis) is a zoonotic pathogen with a global distribution, which causes serious diseases in both humans and animals and economic losses in the swine industry. As antibiotic resistance increases, there is an urgent imperative to explore novel antibacterial alternatives. In the present study, we selected the anticancer drug 5-fluorouracil (5-FU) approved by the Food and Drug Administration (FDA) as a candidate drug to treat S. suis infections. The results showed that various pathogens, especially S. suis, are more sensitive to 5-FU. Moreover, the cytotoxicity of 5-FU is relatively low. Extensive in vitro assays demonstrated the pronounced bacteriostatic and bactericidal efficacy of 5-FU against susceptible and multidrug-resistant S. suis strains. Its mechanisms of action include damage to the bacterial cell walls and membranes, resulting in the leakage of intracellular components, and the inhibition of thymidylate synthase (TS), leading to a depletion of deoxythymidine triphosphate (dTTP) pools, ultimately causing thymine-less death and lethal DNA damage in bacteria. Gene-knockout experiments further showed that 5-FU played a role by inhibiting the thyA gene-encoding thymidine synthase. Finally, we determined that S. suis infections can be alleviated by 5-FU in the mouse infection model. This study emphasizes the antibacterial potential of 5-FU against S. suis and provides evidence for its targeting of bacterial membrane damage and DNA damage. In summary, 5-FU can control S. suis infection and is expected to become a new alternative to antibiotics.

Combinatorial Therapy: Targeting CD133+ Glioma Stem-like Cells with a Polysaccharide-Prodrug Complex Functionalised Gold Nanocages.

Cancer treatments are advancing to harness the body's immune system against tumours, aiming for lasting effects. This progress involves combining potent chemotherapy drugs with immunogens to kill cancer cells and trigger lasting immunity. Developing new prodrugs that integrate both chemotherapy and immune-boosting elements could significantly improve anticancer outcomes by activating multiple mechanisms to kill cancer cells. While bacterial polysaccharides are typically not used in therapy due to their immune-stimulating properties, we propose a safe application of an extremophilic bacterial polysaccharide, Mauran (MR), modified with the anticancer drug 5-fluorouracil (5FU) to create a novel prodrug. This obtained prodrug, chloracetyl-MR-5FU, is specifically targeted using gold nanocages to CD133+ glioma cells. Test results have shown a high encapsulation efficiency of the drug during the polysaccharide modification process; its anticancer activity was demonstrated in vitro and the release of the prodrug was demonstrated in ex vivo studies.

An Experimental Study on the Addition of Bacteria to Residual Anticancer Drugs: Evaluation of the Effect on Bacterial Growth.

Using anticancer drugs as examples, we examined the possibility of reusing residual drugs. The use of residual drugs is not widespread owing to concerns regarding bacterial contamination. We combined anticancer drugs and bacteria to investigate their effects on bacterial growth. The anticancer drugs carboplatin, paclitaxel, etoposide, irinotecan, methotrexate, and 5-fluorouracil (5-FU) were mixed with Staphylococcus aureus, Enterococcus faecalis, Serratia marcescens, and Escherichia coli. After a certain period, the bacteria were counted. Irinotecan showed no antibacterial activity, whereas 5-FU exhibited high antibacterial activity against the tested bacteria. The 5-FU also showed a minimum inhibitory concentration value in the range of 8-80 μg/mL, depending on the bacterial species. 5-FU dose-dependently inhibited S. aureus growth at more than 0.8 µg/mL. Because protein synthesis systems are reportedly antibiotic targets, we used a cell-free protein synthesis system to confirm the mechanism of the antibacterial activity of the anticancer agent. 5-FU and methotrexate had direct inhibitory effects on protein synthesis. It has been suggested that even if residual drugs are contaminated with bacteria, there will be no microbial growth, or the microbes will be killed by the drug. With careful monitoring, 5-FU can potentially be used for antimicrobial purposes.

Deep eutectic solvent based self-healable, stretchable and injectable eutectogels: A versatile platform for breast cancer treatment

Recent focus is on developing cancer treatments that overcome challenges of high-dose chemotherapy, providing improved safety, effectiveness, and site-specific targeting through responsive mechanisms. In our quest for an advanced drug delivery vehicle, herein we have developed a self-healable and injectable polymeric eutectogels that responds to intracellular biological stimuli i.e., pH and temperature. The eutectogels made through interacting imidazolium based deep eutectic solvents with polyvinyl alcohol serve as a local drug delivery system for cancer therapeutics, releasing the anti-cancer drug 5-fluorouracil (5-FU) to the targeted site through intracellular pH, i.e. pH 5.0. Rheology experiments showed strong mechanical strength (>7.3 % strain) for the studied eutectogels that have hierarchical and porous 3D network morphology formed by thick fibers. It exhibits crucial qualities- swelling, injectability, and self-healing- essential for an effective drug delivery vehicle. Additionally, eutectogels demonstrates outstanding biocompatibility, with hemolysis below 2 %, ensuring blood compatibility and sustained viability in HaCaT cells. Leveraging these properties, 5-FU-loaded eutectogels were studied for in vitro cytotoxicity (MCF-7 and HeLa) and drug release that revealed that the eutectogels can be used for targeted delivery under physiological conditions and can more efficiently kill cancerous cells.

Binding Pattern and Structural Interactome of the Anticancer Drug 5-Fluorouracil: A Critical Review.

5-Fluorouracil (5-FU) stands as one of the most widely prescribed chemotherapeutics. Despite over 60 years of study, a systematic synopsis of how 5-FU binds to proteins has been lacking. Investigating the specific binding patterns of 5-FU to proteins is essential for identifying additional interacting proteins and comprehending their medical implications. In this review, an analysis of the 5-FU binding environment was conducted based on available complex structures. From the earliest complex structure in 2001 to the present, two groups of residues emerged upon 5-FU binding, classified as P- and R-type residues. These high-frequency interactive residues with 5-FU include positively charged residues Arg and Lys (P type) and ring residues Phe, Tyr, Trp, and His (R type). Due to their high occurrence, 5-FU binding modes were simplistically classified into three types, based on interactive residues (within <4 Å) with 5-FU: Type 1 (P-R type), Type 2 (P type), and Type 3 (R type). In summary, among 14 selected complex structures, 8 conform to Type 1, 2 conform to Type 2, and 4 conform to Type 3. Residues with high interaction frequencies involving the N1, N3, O4, and F5 atoms of 5-FU were also examined. Collectively, these interaction analyses offer a structural perspective on the specific binding patterns of 5-FU within protein pockets and contribute to the construction of a structural interactome delineating the associations of the anticancer drug 5-FU.

Chitosan/montmorillonite nanocomposite film as anticancer drug carrier: A promising biomaterial to treat skin cancers

The solvent-evaporation approach was used to produce a chitosan (CS)/montmorillonite (MMT) nanocomposite film containing the anticancer drug 5-fluorouracil (5-FU). The physicochemical and morphological characteristics, drug release profile, cytotoxic and microbiological properties of the nanocomposite films were evaluated to verify their potential as a biomaterial for the treatment of tumors. X-ray diffraction (XRD) confirmed the formation of a CS-MMT/5-FU intercalated nanocomposite and Fourier transform infrared (FTIR) detected the characteristic 5- FU bonds in the CS/5-FU and CS-MMT/5-FU nanocomposite films, suggesting successful incorporation of the drug. The addition of 5-FU to chitosan increased the contact angle from 60.5° to 65.2°, which was compensated by the incorporation of MMT, resulting in a minimum contact angle of 42.7° (maximum hydrophilicity) for CS-MMT/5-FU. This result influenced the swelling degree and the in vitro release of 5-FU. The higher hydrophilicity of CS-MMT/5-FU promoted an increase in the swelling ratio compared to the CS/5-FU nanocomposite. CS-MMT/5-FU also showed a sustained, lower 5-FU release rate with antimicrobial activity against S. aureus, E. coli and C. albicans without inducing cytotoxicity or cell death. These results can be explained by the accommodation of the drug between the MMT lamellae, which maintains the 5-FU release without affecting its microbiological activity and reducing its toxicological effects. This work demonstrates that combining montmorillonite and chitosan in a nanocomposite film has the technological potential to control the release of 5-FU, resulting in a non-toxic antimicrobial drug carrier with promising potential for the treatment of skin malignancies.

Uridine triacetate: the saviour in waiting, finally arrives

Cancer of the gastrointestinal tract is one of the very common solid cancers. Colorectal cancer is one of the types in which the anticancer drug 5-fluorouracil (5-FU) or its prodrug capecitabine is used. Toxicity to 5-FU or capecitabine is a common occurrence in patients receiving it. In such conditions, dose reduction or drug discontinuation for some time was the only way out apart from some supportive measures. An exhaustive search was always on to find a suitable antidote for the toxicity. The molecule uridine triacetate was studied for a long to be used in this condition. A systematic search of the existing literature about uridine triacetate was done with available sources like PubMed, Google Scholar, etc. Information about uridine triacetate was assembled and processed from these sources. Uridine triacetate was given orphan drug status for this indication a few years back. After a clinical trial, the drug was finally approved by the US FDA on December 11, 2015, for use in case of toxicity to 5- 5-FU or capecitabine. Well, stat Therapeutics has been marketing the drug under the trade name of Vistogard. Uridine triacetate works by preventing the toxic metabolite of 5-FU from entering and establishing itself in the RNA framework, by competing with the toxic metabolites. It is a relatively safe drug with minimal side effects. This article discusses the molecule uridine triacetate, its structure, metabolism, and kinetics in the body, the why and how of its action, and finally the results and findings of the clinical trial done with it.

Pharmaceutical Formulations Containing Graphene and 5-Fluorouracil for Light-Emitting Diode-Based Photochemotherapy of Skin Cancer.

Nonmelanoma skin cancer (NMSC) is the most common cancer worldwide, among which 80% is basal cell carcinoma (BCC). Current therapies' low efficacy, side effects, and high recurrence highlight the need for alternative treatments. In this work, a partially reduced nanographene oxide (p-rGOn) developed in our laboratory was used. It has been achieved through a controlled reduction of nanographene oxide via UV-C irradiation that yields small nanometric particles (below 200 nm) that preserve the original water stability while acquiring high light-to-heat conversion efficiency. The latter is explained by a loss of carbon-oxygen single bonds (C-O) and the re-establishment of sp2 carbon bonds. p-rGOn was incorporated into a Carbopol hydrogel together with the anticancer drug 5-fluorouracil (5-FU) to evaluate a possible combined PTT and chemotherapeutic effect. Carbopol/p-rGOn/5-FU hydrogels were considered noncytotoxic toward normal skin cells (HFF-1). However, when A-431 skin cancer cells were exposed to NIR irradiation for 30 min in the presence of Carbopol/p-rGOn/5-FU hydrogels, almost complete eradication was achieved after 72 h, with a 90% reduction in cell number and 80% cell death of the remaining cells after a single treatment. NIR irradiation was performed with a light-emitting diode (LED) system, developed in our laboratory, which allows adjustment of applied light doses to achieve a safe and selective treatment, instead of the standard laser systems that are associated with damages in the healthy tissues in the tumor surroundings. Those are the first graphene-based materials containing pharmaceutical formulations developed for BCC phototherapy.

Preparation of pH-sensitive nanogels bioconjugated with shark antibodies (VNAR) for targeted drug delivery with potential applications in colon cancer therapies.

Cancer is the second leading cause of death worldwide. To combat this disease, novel and specialized therapeutic systems are urgently needed. This is the first study to explore a system that combines shark variable domain (Fv) of new antigen receptor (VNAR) antibodies (hereinafter VNARs), PEGylated nanogels (pH-sensitive poly(N,N-diethylaminoethyl methacrylate, PDEAEM), and the anticancer drug 5-fluorouracil (5-FU) to explore its potential applications in colon cancer therapies. Nanogels were functionalized in a scalable reaction with an N-hydroxysuccinimide (NHS)-terminated polyethylene glycol derivative and bioconjugated with shark antibodies. Dynamic light scattering measurements indicated the presence of monodispersed nanogels (74 to 236 nm). All systems maintained the pH-sensitive capacity to increase in size as pH decreased. This has direct implications for the release kinetics of 5-FU, which was released faster at pH 5 than at pH 7.4. After bioconjugation, the ELISA results indicated VNAR presence and carcinoembryonic antigen (CEA) recognition. In vitro evaluations of HCT-116 colon cancer cells indicated that functionalized empty nanogels are not cytotoxic and when loaded with 5-FU, the cytotoxic effect of the drug is preserved. A 15% reduction in cell viability was observed after two hours of contact with bioconjugated nanogels when compared to what was observed with non-bioconjugated nanogels. The prepared nanogel system shows potential as an effective and site-specific nanocarrier with promising applications in in vivo studies of colon cancer therapies.

Titanium-based metal-organic frameworks as pH-responsive drug delivery carriers of 5-Fluorouracil

In this study, we synthesized two titanium-based metal-organic frameworks (Ti-MOFs), namely MIL-125 and MIL-125-NH2, known for their excellent biocompatibility, as potential carriers for the anti-cancer drug 5-Fluorouracil (5-FU). We conducted comprehensive examinations of their morphologies, particle size distributions using SEM, stability, permanent porosity, and in vitro drug loading and release behaviors. Both materials demonstrated significant advantages due to their excellent stability, large surface area, and nanoscale sizes, which resulted in a high capacity for loading 5-FU. Significantly, both MIL-125 and MIL-125-NH2 consistently displayed pH-responsive release of 5-FU. This result may not only help to enhance the therapeutic efficacy of 5-FU but is also expected to improve its targeting potential. Our current research suggests that Ti-MOFs hold great promise as carriers for 5-FU in cancer treatment, offering guidance for the design and development of new customized and responsive drug delivery system.

Electrochemical investigation of an anticancer drug 5-Fluorouracil in the presence of Theophylline using low-cost and disposable poly(GLY) modified pencil graphite electrode

Herein this study, a facile, efficient and disposable electrochemical sensor has been prepared by electropolymerization of glycine (poly(GLY)) on the surface of pencil graphite electrode (PGE). The surface topology of the equipped poly(GLY) modified pencil graphite electrode (poly(GLY)/PGE) and bare pencil graphite electrode (BPGE) has been characterized by the scanning electron microscopy (SEM) combined with energy dispersive x-ray analysis (EDX) and charge transfer behaviour was measured by electron impedance spectroscopy (EIS) method. The voltammetric behaviour of anticancer, 5-fluorouracil (5-FU) in the presence of theophylline (THP) has been carried out in 0.1 M phosphate buffer solution (PBS) of physiological pH 7.0 using different techniques such as cyclic voltammetry (CV), linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV). The proposed poly(GLY)/PGE shows augmented peak current for 5-FU at lower potential side over the BPGE due to the electrocatalytic behaviour of modifier layers wrapped on the electrode surface. The kinetic behaviour of 5-FU at modified electrode surface was studied by varying different parameters such as pH, scan rate and concentration study in 0.1 M PBS used as a supporting electrolyte. The limit of detection (LOD) for 5-FU was attained using DPV method with different concentrations (1.0–13.0 μM) and it was found to be 0.012 μM. The possible electrochemical reaction of 5-FU was proposed and it was incorporated by two electrons and two protons mechanism at modified electrode surface. The voltammetric response of poly(GLY)/PGE towards the determination of 5-FU was unaffected in the presence of some excipients in addition to the remarkable stability and reproducibility. The applicability of the proposed sensor has been performed by real sample investigation of 5-FU with a substantial percentage of recovery results in all optimized conditions.

BN-biphenyl nanosheet as a potential drug carrier for 5-Fluorouracil: A DFT investigation

Thus far, numerous pieces of research have been undertaken into developing new drug delivery systems. Within the current piece of research, the BN-biphenyl nanosheet (BN-bNS) was employed as a BN-analog of biphenyl. The DFT estimations were undertaken to explore the interaction between the anti-cancer drug 5-fluorouracil (5-FU) and BN-bNS. Moreover, the results demonstrated the chemical reactivity of the complex of 5-FU/ BN-bNS, which demonstrated its suitability for 5-FU bonding with the adsorptive site. Moreover, for the better understanding of the complexes of 5-FU BN-bNS, we performed the noncovalent interaction analysis, and the interaction between 5-FU and BN-bNS was found to be strong. So, BN-bNS can be used a promising nanocarrier for 5-FU for drug delivery purposes.

Release studies of the anticancer drug 5-fluorouracil from chitosan-banana peel extract films

5-F-lourouracil is an anticancer drug used for the treatment of different types of cancers. 5-flourouracil loaded chitosan-banana peel extract films were prepared for the in vitro drug release studies. Solvent casting technique was employed to prepare the films. The structure and morphology of the prepared films were analysed by FTIR, XRD and SEM methods and confirmed the presence of drug in the films. The drug loaded films show excellent thermal stability and good shelf life. Studies revealed that the percentage of banana peel extract influences the swelling properties of the film, thickness of the films and release of the drug from the films. Increase in the concentration of chitosan and banana peel extract decreases the swelling properties of the film and rate of release of the drug from the film. The release rate of 5-fluorouracil from the drug loaded chitosan-banana peel extract films were followed spectrophotometrically at λmax 266 nm and the film derived from 1 % chitosan solution and 1 mL aqueous banana peel extract (saturated) exhibited maximum drug release. Cytotoxicity studies proved that the films are non-toxic in nature and augurs well for their applications as excellent drug delivery systems. Antimicrobial studies show that the drug loaded chitosan-banana peel extract films were found to be active against microbes E. coli, Streptococcus mutans, Staphylococcus aureus, Candida albicans and Aspergillus niger and inactive against Pseudomonas aeruginosa.

Folic acid-coupled bovine serum albumin-modified magnetic nanocomposites from quantum-sized Fe3O4 and layered double hydroxide for actively targeted delivery of 5-fluorouracil

The development of multifunctional magnetic nanocomposites as a drug delivery system for cancer therapy is highly desirable in current nanomedicine. Herein, folic acid-bovine serum albumin conjugate (FA-BSA) was modified on nanocomposites by combining quantum-sized Fe3O4 and layered double hydroxide (LDH) to obtain a novel FA-BSA/Fe3O4@LDH for the delivery of the anticancer drug 5-Fluorouracil (5-Fu). The prepared nanocomposites showed good dispersibility, colloidal stability, magnetic property and erythrocyte compatibility. FA-BSA/Fe3O4@LDH/5-Fu showed pH responsiveness, with both the amount and duration of release of FA-BSA/Fe3O4@LDH/5-Fu being significantly higher in pH 5.0 release medium than in pH 7.4 release medium. The cellular experiments implied that no significant cytotoxicity of FA-BSA/Fe3O4@LDH, particularly due to the presence of FA-BSA, which further enhanced the biocompatibility of the nanocomposite. Furthermore, FA-BSA/Fe3O4@LDH/5-Fu could specifically target the 2D HepG2 cells model and 3D hepatoma cell microspheres model in vitro, and efficient internalization through folate receptor-mediated endocytosis, showing excellent anti-cancer cell activity in a concentration-dependent manner. Therefore, the constructed FA-BSA/Fe3O4@LDH was able to provide a potential novel multifunctional nanocomposite for magnetic-targeting drug delivery and pH-responsive release of drugs to enhance the efficiency of cancer therapy.

Targeted Delivery of 5-Fluorouracil and Sonidegib via Surface-Modified ZIF-8 MOFs for Effective Basal Cell Carcinoma Therapy.

The therapeutic effectiveness of the most widely used anticancer drug 5-fluorouracil (5-FU) is constrained by its high metabolism, short half-life, and rapid drug resistance after chemotherapy. Although various nanodrug delivery systems have been reported for skin cancer therapy, their retention, penetration and targeting are still a matter of concern. Hence, in the current study, a topical gel formulation that contains a metal-organic framework (zeolitic imidazole framework; ZIF-8) loaded with 5-FU and a surface modified with sonidegib (SDG; acting as a therapeutic agent as well as a targeting ligand) (5-FU@ZIF-8 MOFs) is developed against DMBA-UV-induced BCC skin cancer in rats. The MOFs were prepared using one-pot synthesis followed by post drug loading and SDG conjugation. The optimized MOFs were incorporated into hyaluronic acid-hydroxypropyl methyl cellulose gel and further subjected to characterization. Enhanced skin deposition of the 5-FU@ZIF-8-SDG MOFs was observed using ex vivo skin permeation studies. Confocal laser microscopy studies showed that 5-FU@ZIF-8-SDG MOFs permeated the skin via the transfollicular pathway. The 5-FU@ZIF-8-SDG MOFs showed stronger cell growth inhibition in A431 cells and good biocompatibility with HaCaT cells. Histopathological studies showed that the efficacy of the optimized MOF gels improved as the epithelial cells manifested modest hyperplasia, nuclear pleomorphism, and dyskeratosis. Additionally, immunohistochemistry and protein expression studies demonstrated the improved effectiveness of the 5-FU@ZIF-8-SDG MOFs, which displayed a considerable reduction in the expression of Bcl-2 protein. Overall, the developed MOF gels showed good potential for the targeted delivery of multifunctional MOFs in topical formulations for treating BCC cancer.

Nanocomposite based on Gd2O3 nanoparticles and drug 5-fluorouracil as potential theranostic nano-cargo system

We have prepared silica matrix with hexagonal symmetry of pores (SBA-15) and loaded it with anticancer drug 5-Fluorouracil (5-FU) to promote it as a drug delivery system. Gd2O3 nanoparticles were incorporated into the matrix to enhance nanosystems applicability as contrast agent for MRI, thus enabled this nanocomposite to be used as multifunctional nano-based therapeutic agent. Drug release profile was obtained by UV-VIS spectroscopy, and it indicates the prolongated release of 5-FU during the first hours and the total release after 5 h. The cytotoxicity tests using MTT-assay, fluorescent microscopy, bright-field microscopy, and flow cytometry were carried out using human glioma U87 MG cells and SK BR 3 cells. The nanocomposite with anticancer drug (Gd2O3/SBA-15/5FU) showed toxic behaviour towards studied cells, unlike nanocomposite without drug (Gd2O3/SBA-15) that was non-toxic. Our drug delivery system was designed to minimalize negative effect of Gd3+ ions at magnetic resonance imaging and drug 5-FU on healthy cells due to their encapsulation into biocompatible silica matrix, so the Gd3+ ions are more stable (in comparison to chelates), lower therapeutic dose of 5-FU is needed and its prolongated release from silica pores was confirmed. Very good T1 contrast in MR images was observed even at low concentrations, thus this nanosystem can be potentially used as contrast imaging agent.

Crystal Structure of DNA Replication Protein SsbA Complexed with the Anticancer Drug 5-Fluorouracil.

Single-stranded DNA-binding proteins (SSBs) play a crucial role in DNA metabolism by binding and stabilizing single-stranded DNA (ssDNA) intermediates. Through their multifaceted roles in DNA replication, recombination, repair, replication restart, and other cellular processes, SSB emerges as a central player in maintaining genomic integrity. These attributes collectively position SSBs as essential guardians of genomic integrity, establishing interactions with an array of distinct proteins. Unlike Escherichia coli, which contains only one type of SSB, some bacteria have two paralogous SSBs, referred to as SsbA and SsbB. In this study, we identified Staphylococcus aureus SsbA (SaSsbA) as a fresh addition to the roster of the anticancer drug 5-fluorouracil (5-FU) binding proteins, thereby expanding the ambit of the 5-FU interactome to encompass this DNA replication protein. To investigate the binding mode, we solved the complexed crystal structure with 5-FU at 2.3 Å (PDB ID 7YM1). The structure of glycerol-bound SaSsbA was also determined at 1.8 Å (PDB ID 8GW5). The interaction between 5-FU and SaSsbA was found to involve R18, P21, V52, F54, Q78, R80, E94, and V96. Based on the collective results from mutational and structural analyses, it became evident that SaSsbA's mode of binding with 5-FU diverges from that of SaSsbB. This complexed structure also holds the potential to furnish valuable comprehension regarding how 5-FU might bind to and impede analogous proteins in humans, particularly within cancer-related signaling pathways. Leveraging the information furnished by the glycerol and 5-FU binding sites, the complexed structures of SaSsbA bring to the forefront the potential viability of several interactive residues as potential targets for therapeutic interventions aimed at curtailing SaSsbA activity. Acknowledging the capacity of microbiota to influence the host's response to 5-FU, there emerges a pressing need for further research to revisit the roles that bacterial and human SSBs play in the realm of anticancer therapy.