Emergence of Quantum Dots as Innovative Tools for Early Diagnosis and Advanced Treatment of Breast Cancer.

Quantum dots (QDs) semiconducting nanomaterials, have garnered attention due to their distinctive properties, including small size, high luminescence, and biocompatibility. In the context of triple-negative breast cancer (TNBC), notorious for its resistance to conventional treatments, QDs exhibit promising potential for enhancing diagnostic imaging and providing targeted therapies. This review underscores recent advancements in the utilization of QDs in imaging techniques, such as fluorescence tomography and magnetic resonance imaging, aiming at the early and precise detection of tumors. Emphasis is placed on the significance of QD design, synthesis and functionalization processes as well as their use in innovative strategies for targeted drug delivery, capitalizing on their ability to selectively deliver therapeutic agents to cancer cells. As the research in this field advances rapidly, this review covers a classification of QDs according to their composition, the characterization techniques than can be used to determine their properties and, subsequently, emphasizes recent findings in the field of TNBC-targeting, highlighting the imperative need to address challenges, like potential toxicity or methodologies standardization. Collectively, the findings explored thus far suggest that QDs could pave the way for early diagnosis and effective therapy of TNBC, representing a significant stride toward precise and personalized strategies in treating TNBC.

Vanadocene-functionalized mesoporous silica nanoparticles: platforms for the development of theranostic materials against breast cancer.

Nanoscale materials have demonstrated a very high potential in anticancer therapy by properly adjusting their functionalization and physicochemical properties. Herein, we report the synthesis of some novel vanadocene-loaded silica-based nanomaterials incorporating four different S-containing amino acids (penicillamine, methionine, captopril, and cysteine) and different fluorophores (rhodamine B, coumarin 343 or Alexa Fluor™ 647), which have been characterized by diverse solid-state spectroscopic techniques viz; FTIR, diffuse reflectance spectroscopies,13C and51V solid-state NMR spectroscopy, thermogravimetry and TEM. The analysis of the biological activity of the novel vanadocene-based nanostructured silicas showed that the materials containing cysteine and captopril aminoacids demonstrated high cytotoxicity and selectivity against triple negative breast cancer cells, making them very promising antineoplastic drug candidates. According to the biological results it seems that vanadium activity is connected to its incorporation through the amino acid, resulting in synergy that increases the cytotoxic activity against cancer cells of the studied materials presumably by increasing cell internalization. The results presented herein hold significant potential for future developments in mesoporous silica-supported metallodrugs, which exhibit strong cytotoxicity while maintaining low metal loading. They also show potential for theranostic applications highlighted by the analysis of the optical properties of the studied systems after incorporating rhodamine B, coumarin 343 (possible)in vitroanticancer analysis, or Alexa Fluor™ 647 (in vivostudies of cancer models).

Melatonin Derivative-Conjugated Formulations of Pd(II) and Pt(II) Thiazoline Complexes on Mesoporous Silica to Enhance Cytotoxicity and Apoptosis against HeLa Cells.

The search for alternatives to cisplatin has led to the development of new metal complexes where thiazoline derivatives based on platinum(II) and palladium(II) stand out. In this sense, the Pt(II) and Pd(II) complexes coordinated with the thiazoline derivative ligand 2-(3,4-dichlorophenyl)imino-N-(2-thiazolin-2-yl)thiazolidine (TdTn), with formula [PtCl2(TdTn)] and [PdCl2(TdTn)], have previously shown good results against several cancer lines; however, in this work, we have managed to improve their activity by supporting them on mesoporous silica nanoparticles (MSN). The incorporation of metal compounds with a melatonin derivative (5-methoxytryptamine, 5MT), which is a well-known antioxidant and apoptosis inducer in different types of cancer, has been able to increase the cytotoxic activity of both MSN-supported and isolated complexes with only a very low amount (0.35% w/w) of this antioxidant. The covalently functionalized systems that have been synthesized are able to increase selectivity as well as accumulation in HeLa cells. The final materials containing the metal complexes and 5MT (MSN-5MT-PtTdTn and MSN-5MT-PdTdTn) required up to nine times less metal to achieve the same cytotoxic activity than their corresponding non-formulated counterparts did, thus reducing the potential side effects caused by the use of the free metal complexes.

First-Row Transition 7-Oxo-5-phenyl-1,2,4-triazolo[1,5-a]pyrimidine Metal Complexes: Antiparasitic Activity and Release Studies.

Leishmaniasis and Chagas disease are still considered neglected illnesses due to the lack of investment in research, despite the fact that almost one million new cases are reported every year. Four 7-oxo-5-phenyl-1,2,4-triazolo[1,5-a]pyrimidine (HftpO) first-row transition complexes (Cu, Co, Ni, Zn) have been studied for the first time in vitro against five different species of Leishmania spp. (L. infantum, L. braziliensis, L. donovani, L. peruviana and L. mexicana) as well as Trypanosoma cruzi, showing higher efficacy than the reference commercial drugs. UV and luminescence properties were also evaluated. As a proof of concept, anchoring of a model high-effective-metal complex as an antiparasitic agent on silica nanoparticles was carried out for the first time, and drug-release behaviour was evaluated, assessing this new approach for drug vehiculation.

Organotin(IV)-Decorated Graphene Quantum Dots as Dual Platform for Molecular Imaging and Treatment of Triple Negative Breast Cancer.

The pharmacological activity of organotin(IV) complexes in cancer therapy is well recognized but their large applicability is hampered by their poor water solubility. Hence, carbon dots, in particular nitrogen-doped graphene quantum dots (NGQDs), may be a promising alternative for the efficient delivery of organotin(IV) compounds as they have a substantial aqueous solubility, a good chemical stability, and non-toxicity as well as a bright photoluminescence that make them ideal for theranostic applications against cancer. Two different multifunctional nanosystems have been synthesized and fully characterized based on two fragments of organotin-based cytotoxic compounds and 4-formylbenzoic acid (FBA), covalently grafted onto the NGQDs surface. Subsequently, an in vitro determination of the therapeutic and theranostic potential of the achieved multifunctional systems was carried out. The results showed a high cytotoxic potential of the NGQDs-FBA-Sn materials against breast cancer cell line (MDA-MB-231) and a lower effect on a non-cancer cell line (kidney cells, HEK293T). Besides, thanks to their optical properties, the dots enabled their fluorescence molecular imaging in the cytoplasmatic region of the cells pointing towards a successful cellular uptake and a release of the metallodrug inside cancer cells (NGQDs-FBA-Sn).

Antibacterial Properties of Mesoporous Silica Nanoparticles Modified with Fluoroquinolones and Copper or Silver Species.

Antibiotic resistance is a global problem and bacterial biofilms contribute to its development. In this context, this study aimed to perform the synthesis and characterization of seven materials based on silica mesoporous nanoparticles functionalized with three types of fluoroquinolones, along with Cu2+ or Ag+ species to evaluate the antibacterial properties against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa, including clinical and multi-drug-resistant strains of S. aureus and P. aeruginosa. In addition, in order to obtain an effective material to promote wound healing, a well-known proliferative agent, phenytoin sodium, was adsorbed onto one of the silver-functionalized materials. Furthermore, biofilm studies and the generation of reactive oxygen species (ROS) were also carried out to determine the antibacterial potential of the synthesized materials. In this sense, the Cu2+ materials showed antibacterial activity against S. aureus and E. coli, potentially due to increased ROS generation (up to 3 times), whereas the Ag+ materials exhibited a broader spectrum of activity, even inhibiting clinical strains of MRSA and P. aeruginosa. In particular, the Ag+ material with phenytoin sodium showed the ability to reduce biofilm development by up to 55% and inhibit bacterial growth in a "wound-like medium" by up to 89.33%.

Cytotoxic and DNA-binding Capacity of Titanocene Functionalized Mesoporous Nanoparticles in Breast Cancer Cell Lines MCF-7 and MDA-MB-231.

AIMS: The fight against cancer is an active research topic that combines several disciplines to find suitable agents to treat various tumours. BACKGROUND: Following cisplatin, organometallic compounds, including titanocene derivatives, have been tested as antitumoral agents. However, key issues still need to be addressed in metallodrug chemotherapy relating to solubility, stability, and dosage. Mesoporous silica nanoparticles, being low toxic biocompatible materials with high loading capacity, are ideal candidates to overcome these problems. OBJECTIVE: This study aimed to prepare and structurally characterize titanocene functionalized mesoporous silica nanoparticles and evaluate their cytotoxic activity against cancer cells. METHODS: The preparation of titanocene functionalized mesoporous silica nanoparticles was achieved by synthetic protocols, involving either grafting or tethering. Characterization was carried out using standard techniques, FT-IR, XRD, XRF, TEM, and BET. The titanocene functionalized materials were studied as antitumoral agents in the breast cancer lines MCF-7 and MDA-MB-231. RESULTS: The functionalized MSN showed promising antitumoral activity against cells lines MCF-7 and MDAMB- 231 up to 9 times more than titanocene alone. CONCLUSION: This study reported the potential of titanocene-functionalized mesoporous silica nanoparticles in future chemotherapeutic actions.

New Carbonate-Based Materials and Study of Cytotoxic Capacity in Cancer Cells.

Calcium carbonate, one of the most commonly found biominerals produced by organisms, has shown great potential for the development of systems with biological applications due to its excellent biocompatibility, biodegradability, and simple chemical composition. Here, we focus on the synthesis of various carbonate-based materials with vaterite phase control and their subsequent functionalization for applications in treating glioblastoma, one of the most limiting tumors currently without effective treatments. The incorporation of l-cysteine into the systems increased cell selectivity while the incorporation of manganese supplied the materials with cytotoxic capacity. Extensive characterization of the systems by infrared spectroscopy, ultraviolet-visible spectroscopy, X-ray diffraction, X-ray fluorescence, and transmission electron microscopy confirmed the incorporation of the different fragments causing selectivity and cytotoxicity to the systems. To verify their therapeutic activity, the vaterite-based materials were tested in the CT2A cell line (murine glioma) and compared to SKBR3 (breast cancer) and HEK-293T (human kidney) cell lines. These studies on the cytotoxicity of the materials have shown promising results that can encourage future in vivo studies in glioblastoma models.

Dual Anticancer and Antibacterial Properties of Silica-Based Theranostic Nanomaterials Functionalized with Coumarin343, Folic Acid and a Cytotoxic Organotin(IV) Metallodrug.

Five different silica nanoparticles functionalized with vitamin B12, a derivative of coumarin found in green plants and a minimum content of an organotin(IV) fragment (1-MSN-Sn, 2-MSN-Sn, 2-SBA-Sn, 2-FSPm-Sn and 2-FSPs-Sn), were identified as excellent anticancer agents against triple negative breast cancer, one of the most diagnosed and aggressive cancerous tumors, with very poor prognosis. Notably, compound 2-MSN-Sn shows selectivity for cancer cells and excellent luminescent properties detectable by imaging techniques once internalized. The same compound is also able to interact with and nearly eradicate biofilms of Staphylococcus aureus, the most common bacteria isolated from chronic wounds and burns, whose treatment is a clinical challenge. 2-MSN-Sn is efficiently internalized by bacteria in a biofilm state and destroys the latter through reactive oxygen species (ROS) generation. Its internalization by bacteria was also efficiently monitored by fluorescence imaging. Since silica nanoparticles are particularly suitable for oral or topical administration, and considering both its anticancer and antibacterial activity, 2-MSN-Sn represents a new dual-condition theranostic agent, based primarily on natural products or their derivatives and with only a minimum amount of a novel metallodrug.

Biological Use of Nanostructured Silica-Based Materials Functionalized with Metallodrugs: The Spanish Perspective.

Since the pioneering work of Vallet-Regí's group on the design and synthesis of mesoporous silica-based materials with therapeutic applications, during the last 15 years, the potential use of mesoporous silica nanostructured materials as drug delivery vehicles has been extensively explored. The versatility of these materials allows the design of a wide variety of platforms that can incorporate numerous agents of interest (fluorophores, proteins, drugs, etc.) in a single scaffold. However, the use of these systems loaded with metallodrugs as cytotoxic agents against different diseases and with distinct therapeutic targets has been studied to a much lesser extent. This review will focus on the work carried out in this field, highlighting both the pioneering and recent contributions of Spanish groups that have synthesized a wide variety of systems based on titanium, tin, ruthenium, copper and silver complexes supported onto nanostructured silica. In addition, this article will also discuss the importance of the structural features of the systems for evaluating and modulating their therapeutic properties. Finally, the most interesting results obtained in the study of the potential therapeutic application of these metallodrug-functionalized silica-based materials against cancer and bacteria will be described, paying special attention to preclinical trials in vivo.

Design of Mesoporous Silica Nanoparticles for the Treatment of Amyotrophic Lateral Sclerosis (ALS) with a Therapeutic Cocktail Based on Leptin and Pioglitazone.

Amyotrophic lateral sclerosis (ALS) is a devasting neurodegenerative disease with no cure to date. Therapeutic agents used to treat ALS are very limited, although combined therapies may offer a more effective treatment strategy. Herein, we have studied the potential of nanomedicine to prepare a single platform based on mesoporous silica nanoparticles (MSNs) for the treatment of an ALS animal model with a cocktail of agents such as leptin (neuroprotective) and pioglitazone (anti-inflammatory), which have already demonstrated promising therapeutic ability in other neurodegenerative diseases. Our goal is to study the potential of functionalized mesoporous materials as therapeutic agents against ALS using MSNs as nanocarriers for the proposed drug cocktail leptin/pioglitazone (MSN-LEP-PIO). The nanostructured materials have been characterized by different techniques, which confirmed the incorporation of both agents in the nanosystem. Subsequently, the effect, in vivo, of the proposed drug cocktail, MSN-LEP-PIO, was used in the murine model of TDP-43 proteinopathy (TDP-43A315T mice). Body weight loss was studied, and using the rotarod test, motor performance was assessed, observing a continuous reduction in body weight and motor coordination in TDP-43A315T mice and wild-type (WT) mice. Nevertheless, the disease progression was slower and showed significant improvements in motor performance, indicating that TDP-43A315T mice treated with MSN-LEP-PIO seem to have less energy demand in the late stage of the symptoms of ALS. Collectively, these results seem to indicate the efficiency of the systems in vivo and the usefulness of their use in neurodegenerative models, including ALS.

Effect of chain length on the cytotoxic activity of (alkyl-ω-ol)triphenyltin(IV) loaded into SBA-15 nanostructured silica and in vivo study of SBA-15~Cl|Ph3Sn(CH2)8OH.

A series of nanostructured SBA-15-based materials functionalized with the tetraorganotin(IV) metallodrugs Ph3Sn(CH2)nOH (n = 3, 4, 6, 8 and 11) are synthesized and structurally characterized by different techniques used in solid-state chemistry. The cytotoxicity of both the organotin(IV) compounds and the tin-functionalized SBA-15 materials are studied against different cancer cell lines observing that the materials have similar cytotoxic activity in comparison with the free organotin compounds in terms of mass. However, considering that the percentage of active metal compound loaded into material is low, the utilization of mesoporous silica as drug vehicle clearly improves the cytotoxic effectiveness of metal-based drugs against cancer cells. One of the most potent between all tested systems is material SBA-15~Cl|Ph3Sn(CH2)8OH. Its cytotoxicity seems to come from additional mechanisms apart from apoptosis provoking cell reprogram in B16 melanoma into more mature and less aggressive phenotype. Moderated production of ROS/RNS is probably in the background of observed phenomenon. Obtained results are further confirmed in syngeneic mouse model of melanoma in C57BL6 mice. The in vivo results show that SBA-15 do not disturb tumor growth, while both Ph3Sn(CH2)8OH and SBA-15~Cl|Ph3Sn(CH2)8OH significantly decreases tumor volume with an enhancement of the antitumor potential of the tetraorganotin(IV) compound upon immobilization in SBA-15.

Synthesis of a theranostic platform based on fibrous silica nanoparticles for the enhanced treatment of triple-negative breast cancer promoted by a combination of chemotherapeutic agents.

A new series of theranostic silica materials based on fibrous silica particles acting as nanocarriers of two different cytotoxic agents, namely, chlorambucil and an organotin metallodrug have been prepared and structurally characterized. Besides the combined therapeutic activity, these platforms have been decorated with a targeting molecule (folic acid, to selectively target triple negative breast cancer) and a molecular imaging agent (Alexa Fluor 647, to enable their tracking both in vitro and in vivo). The in vitro behaviour of the multifunctional silica systems showed a synergistic activity of the two chemotherapeutic agents in the form of an enhanced cytotoxicity against MDA-MB-231 cells (triple negative breast cancer) as well as by a higher cell migration inhibition. Subsequently, the in vivo applicability of the siliceous nanotheranostics was successfully assessed by observing with in vivo optical imaging techniques a selective tumour accumulation (targeting ability), a marked inhibition of tumour growth paired to a marked antiangiogenic ability after 13 days of systemic administration, thus, confirming the enhanced theranostic activity. The systemic nanotoxicity was also evaluated by analyzing specific biochemical markers. The results showed a positive effect in form of reduced cytotoxicity when both chemotherapeutics are administered in combination thanks to the fibrous silica nanoparticles. Overall, our results confirm the promising applicability of these novel silica-based nanoplatforms as advanced drug-delivery systems for the synergistic theranosis of triple negative breast cancer.

Tin-loaded mesoporous silica nanoparticles: Antineoplastic properties and genotoxicity assessment.

Nanotechnology has immensely advanced the field of cancer diagnostics and treatment by introducing potential delivery vehicles as carriers for drugs or therapeutic agents. In due course, mesoporous silica nanoparticles (MSNs) have emerged as excellent vehicles for delivering drugs, biomolecules, and biomaterials, attributed to their solid framework and porosity providing a higher surface area for decorating with various functional ligands. Recently, the metal tin (Sn) has gained huge importance in cancer research owing to its excellent cytotoxicity and ability to kill cancer cells. In the present work, we synthesized MSNs, conjugated them with organotin compounds, and characterized them using various physicochemical techniques. Subsequently, the biological evaluation of MSN (S1), MSN-MP (S2) and tin-conjugated MSNs (S3: MSN-MP-SnPh3) (MP = 3-mercaptopropyltriethoxysilane) revealed that these nanoconjugates induced cytotoxicity, necrosis, and apoptosis in MCF-7 cells. Moreover, these nanoconjugates exhibited anti-angiogenic properties as demonstrated in the chick embryo model. The increase of reactive oxygen species (ROS) was found as a one of the plausible mechanisms underlying cancer cell cytotoxicity induced by these nanoconjugates, encouraging their application for the treatment of cancer. The tin-conjugated MSNs demonstrated less toxicity to normal cells compared to cancer cells. Furthermore, the genotoxicity studies revealed the clastogenic and aneugenic effects of these nanoconjugates in CHO cells mostly at high concentrations. These interesting observations are behind the idea of developing tin-conjugated MSNs as prospective candidates for anticancer therapy.

Hybrid Nanosystems Based on Nicotinate-Functionalized Mesoporous Silica and Silver Chloride Nanoparticles Loaded with Phenytoin for Preventing Pseudomonas aeruginosa Biofilm Development.

Pseudomonas aeruginosa (PA) is one of the most common bacteria isolated from chronic wounds and burns. Its treatment is a challenge due to antimicrobial drug resistance and biofilm formation. In this context, this study aimed to perform the synthesis and full characterization of hybrid nanosystems based on mesoporous silica nanoparticles (MSNs) functionalized with a nicotinic ligand and silver chloride nanoparticles, both phenytoin sodium (Ph)-loaded and unloaded, to evaluate the antibacterial properties against three different strains of PA (including two clinical strains) in a planktonic state and as biofilms. Ph is a well-known proliferative agent, which was incorporated into the hybrid nanomaterials to obtain an effective material for tissue healing and prevention of infection caused by PA. The Ph-loaded materials promoted a quasi-complete inhibition of bacterial growth in wound-like medium and biofilm development, with values of 99% and 96%, respectively, with selectivity indices above the requirements for drugs to become promising agents for the topic preventive treatment of chronic wounds and burns.

Structure elucidation, in vitro binding studies and ROS-dependent anti-cancer activity of Cu(II) and Zn(II) phthaloylglycinate(phen) complexes against MDA-MB-231 cells.

New mononuclear Cu(II) and Zn(II)-based complexes 1 [Cu(L)2(diimine)HOCH3] and 2 [Zn(L)2(diimine)] have been synthesized as anti-cancer chemotherapeutics targeted to tRNA. The structure elucidation of complexes 1 and 2 was carried out by spectroscopic and single X-ray diffraction studies. In vitro interaction studies of complexes 1 and 2 with ct-DNA/tRNA were performed by employing various biophysical techniques to evaluate and predict their interaction behavior and preferential selectivity at biomolecular therapeutic targets. The corroborative results of the interaction studies demonstrated that complexes 1 and 2 exhibited avid binding propensity via intercalative mode of binding toward ct-DNA/tRNA. Electrophoretic assay revealed that the complexes 1 and 2 were able to promote single- and double-strand cleavage of the plasmid DNA at low micromolar concentrations under physiological conditions in the absence of an additional oxidizing or reducing agent. RNA hydrolysis studies revealed that the complexes 1 and 2 could promote tRNA cleavage in a concentration and time-dependent manner. The cytotoxic potential of complexes 1 and 2 was evaluated against the MDA-MB-231 cell line, which showed that the complexes were able to inhibit the cell growth in a dose-dependent manner. The intracellular ROS production and mitochondrial superoxide anion assay revealed that the complexes 1 and 2 induce a dose-dependent activity, suggesting the involvement of ROS-mediated mitochondrial apoptotic pathway leading to cell death.

Ru(II) Polypyridine Complex-Functionalized Mesoporous Silica Nanoparticles as Photosensitizers for Cancer Targeted Photodynamic Therapy.

Cancer is the leading cause of death in the developed world. In the last few decades, photodynamic therapy (PDT) has augmented the number of medical techniques to treat this disease in the clinics. As the pharmacological active species to kill cancer cells are only generated upon light irradiation, PDT is associated with an intrinsic first level of selectivity. However, since PDT agents also accumulate in the surrounding, healthy tissue and since it is practically very challenging to only expose the tumor site to light, some side effects can be observed. Consequently, there is a need for a selective drug delivery system, which would give a second level of selectivity. In this work, a dual tumor targeting approach is presented based on mesoporous silica nanoparticles, which act by the enhanced permeability and retention effect, and the conjugation to folic acid, which acts as a targeting moiety for folate receptor-overexpressed cancer cells. The conjugates were found to be nontoxic in noncancerous human normal lung fibroblast cells while showing a phototoxic effect upon irradiation at 480 or 540 nm in the low nanomolar range in folate receptor overexpressing cancerous human ovarian carcinoma cells, demonstrating their potential for cancer targeted treatment.

Water soluble ionic Co(II), Cu(II) and Zn(II) diimine-glycinate complexes targeted to tRNA: structural description, in vitro comparative binding, cleavage and cytotoxic studies towards chemoresistant prostate cancer cells.

Four new water soluble Co(ii), Cu(ii) and Zn(ii) ionic metal complexes (1-4) [Cu(diimine)(H2O)2(glycinate)]+[glycinate]-, [Co(diimine)(H2O)4]+[glycinate]- and [Zn(diimine) (H2O)4]+[glycinate]-, where diimine = 2,2'-bipyridine (1-3) and 1,10-phenanthroline (4) were synthesized and thoroughly characterized by spectroscopic and single X-ray crystallographic studies. Complex 1 possesses a triclinic crystal system with a penta-coordinated geometry whereas complexes 2-4 crystallized in an isostructural monoclinic system having distorted octahedral geometry. Density functional theory (DFT) studies for complexes 1-4 were performed to correlate their geometrical parameters and to calculate the energy of frontier molecular orbitals. The corroborative results of spectroscopic and voltammetric studies with ct-DNA and tRNA revealed that the complexes bind noncovalently via an electrostatic mode of binding with specificity for tRNA as compared to ct-DNA. Gel electrophoresis experiments revealed that all the complexes unwind the plasmid pBR322 DNA at low micromolar concentrations (2-9 µM) following an oxidative mechanism for Cu(ii) and Co(ii) complexes (1, 2 and 4) whereas the Zn(ii) complex (3) mediates DNA cleavage by the hydrolytic pathway. The tRNA cleavage showed concentration and time dependent activity of the complexes to promote RNA hydrolysis. Furthermore, the BSA binding ability of complexes 1-4 was monitored, which revealed that the complexes could quench the intrinsic fluorescence in a static manner. Complexes 1-4 were found to be non-toxic towards normal prostate epithelial cells, PNT2, but were potent against chemoresistant metastatic prostate cancer cells, Du145, with GI50 values ranging from 12.75-37 µM. Complexes 1 and 2 also showed cytotoxic activity against cancer stem cells having GI50 values of 14.70 and 14.90 µM, respectively. Molecular docking studies were performed with DNA and tRNA which further validated the spectroscopic analysis demonstrating the higher binding affinity of the complexes towards tRNA.

Role of Folic Acid in the Therapeutic Action of Nanostructured Porous Silica Functionalized with Organotin(IV) Compounds Against Different Cancer Cell Lines.

The synthesis, characterization and cytotoxic activity against different cancer cell lines of various mesoporous silica-based materials containing folate targeting moieties and a cytotoxic fragment based on a triphenyltin(IV) derivative have been studied. Two different mesoporous nanostructured silica systems have been used: firstly, micronic silica particles of the MSU-2 type and, secondly, mesoporous silica nanoparticles (MSNs) of about 80 nm. Both series of materials have been characterized by different methods, such as powder X-ray diffraction, X-ray fluorescence, absorption spectroscopy and microscopy. In addition, these systems have been tested against four different cancer cell lines, namely, OVCAR-3, DLD-1, A2780 and A431, in order to observe if the size of the silica-based systems and the quantity of incorporated folic acid influence their cytotoxic action. The results show that the materials are more active when the quantity of folic acid is higher, especially in those cells that overexpress folate receptors such as OVCAR-3 and DLD-1. In addition, the study of the potential modulation of the soluble folate receptor alpha (FOLR1) by treatment with the synthesized materials has been carried out using OVCAR-3, DLD-1, A2780 and A431 tumour cell lines. The results show that a relatively high concentration of folic acid functionalization of the nanostructured silica together with the incorporation of the cytotoxic tin fragment leads to an increase in the quantity of the soluble FOLR1 secreted by the tumour cells. In addition, the studies reported here show that this increase of the soluble FOLR1 occurs presumably by cutting the glycosyl-phosphatidylinositol anchor of membrane FR-α and by the release of intracellular FR-α. This study validates the potential use of a combination of mesoporous silica materials co-functionalized with folate targeting molecules and an organotin(IV) drug as a strategy for the therapeutic treatment of several cancer cells overexpressing folate receptors.

5-Aminopyridine-2-carboxylic acid as appropriate ligand for constructing coordination polymers with luminescence, slow magnetic relaxation and anti-cancer properties.

Five new coordination polymers (CPs) constructed of aminopyridine-2-carboxylate (ampy) ligand have been synthesized and fully characterized. Three of them correspond to metal-organic chains built from the coordination of ampy to sodium and lanthanides with formulae [MNa(ampy)4]n (M = terbium (2), erbium (1) and ytterbium (3)) resembling a previously reported dysprosium material which shows anticancer activity. On another level, the reaction of Hampy with cobalt and copper ions ({[CoK(ampy)3(H2O)3](H2O)3}n (4) and [Cu(ampy)2]n (5)) lead to CPs with variable dimensionalities, which gives the opportunity of analyzing the structural properties of this new family. Lanthanide materials display solid state intense photoluminescent emissions in both the visible and near-infrared region and exhibit slow relaxation of magnetization with frequency dependence of the out-of-phase susceptibility. More interestingly, in our search for multifunctional materials, we have carried out antitumor measurements of these compounds. These multidisciplinary studies of metal complexes open up the possibility for further exploring the applications in the fields of metal-based drugs.