Preparation, thermoresponsive behavior, and preliminary biological study of functionalized poly(N-isopropylacrylamide-co-dopamine methacrylamide) copolymers with an organotin(IV) compound

Recent advances focused on smart polymers have demonstrated the numerous advantages regarding other structures because they can adapt the behavior depending on physicochemical properties. In this way, functionalized thermoresponsive polymers with organometallic complexes were profoundly analyzed. Consequently, novel catalytic systems or biomedical devices could be developed. This publication focuses on the facile preparation of poly(N-isopropylacrylamide-co-dopamine methacrylamide) copolymers functionalized with triphenyltin chloride by protonolysis through the -OH of catechol groups. The presence of hydrophobic organotin(IV) derivatives could modify the solubility, thermoresponsive behavior, and other properties regarding pure copolymers. Also, sensitive analysis of the microstructure could help to understand the changes associated with the lower critical solution temperature by rheology, UV-vis spectroscopy, and calorimetry. In addition, a preliminary biological study against MDA-MB-231 cancer cells and peripheral blood mononuclear cells showed that the functionalized copolymers could be a potential platform to be explored in the future in the fight against cancer.The financial support obtained from the National Science Foundation of China (21574086), Shenzhen Fundamental Research Funds (No. KC2014ZDZJ0001A), Shenzhen Sci & Tech research grant (ZDSYS201507141105130) and China Postdoctoral Science Foundation Grant (2018M633119) are acknowledged. Also, these researchers would like to thank the former Ministerio de Ciencia, Innovación y Universidades of Spain (current Ministerio de Ciencia e Innovación of Spain) for the grant RTI2018-094322-B-I00 and the Dirección General de Investigación e Innovación, Consejería de Educación e Investigación de la Comunidad de Madrid for the predoctoral grant PEJD-2017-PRE/BMD-3512 (I. M.-P.)

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.We would like to thank the funding of the Ministerio de Ciencia e Innovación of Spain (former Ministerio de Ciencia Innovación y Universidades of Spain) and FEDER, Una manera de hacer Europa for the grant number RTI2018-094322-B-I00. We would also like to thank Comunidad de Madrid for the predoctoral grant PEJD-2017-PRE/BMD3512 (I.M.-P.). M.M, Y.L.M., and M.F. are grateful to the Comunidad Autónoma de Madrid and FEDER for the I + D collaborative Programme in Biomedicine NIETO-CM (Project reference B2017-BMD3731). M.F. and K.O.P. thank the Comunidad Autonoma ´ de Madrid for research project No. 2017-T1/BIO-4992 (“Atraccion ´ de Talento” Action) cofunded by Universidad Complutense de Madrid. M.F is grateful to Instituto de Salud Carlos III (ISCIII) for project No DTS20/00109 (AES-ISCIII). M. M., M.F. and L.L.C would also like to thank Comunidad de Madrid for the predoctoral grant IND2020/BIO-17523. M.F. and K.O.P. acknowledge the support of Microscopy & Dynamic Imaging Unit of CNIC, Madrid, Spain. The Unit is part of the ReDiB-ICTS and has the support of FEDER, “Una manera de hacer Europa.” The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovacion ´ (MCIN) and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (grant CEX2020-001041-S funded by MICIN/AEI/10.13039/ 501100011033).S

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.Spanish Government RTI2018-094322-B-I00 CTQ2017-90802-REDTMinistry of Research and Innovation, CNCS-UEFISCDI within PNCDI III PN-III-P4-ID-PCCF-2016-014

EBV dUTPase: A Novel Modulator of Inflammation and the Tumor Microenvironment in EBV-Associated Malignancies

There is increasing evidence that put into question the classical dogma that the Epstein–Barr virus (EBV) exists in cells as either a lytic virus in which new progeny is produced or in a latent state in which no progeny is produced. Notably, a third state has now been described, known as the abortive-lytic phase, which is characterized by the expression of some immediate early (IE) and early (E) genes, but no new virus progeny is produced. While the function of these IE and E gene products is not well understood, several recent studies support the concept they may contribute to tumor promotion by altering the tumor microenvironment (TME). The mechanisms by which these viral gene products may contribute to tumorigenesis remain unclear; however, it has been proposed that some of them promote cellular growth, immune evasion, and/or inhibit apoptosis. One of these EBV early gene products is the deoxyuridine triphosphate nucleotidohydrolase (dUTPase) encoded by BLLF3, which not only contributes to the establishment of latency through the production of activin A and IL-21, but it may also alter the TME, thus promoting oncogenesis

Viral dUTPases: Modulators of Innate Immunity

Most free-living organisms encode for a deoxyuridine triphosphate nucleotidohydrolase (dUTPase; EC 3.6.1.23). dUTPases represent a family of metalloenzymes that catalyze the hydrolysis of dUTP to dUMP and pyrophosphate, preventing dUTP from being incorporated into DNA by DNA polymerases, maintaining a low dUTP/dTTP pool ratio and providing a necessary precursor for dTTP biosynthesis. Thus, dUTPases are involved in maintaining genomic integrity by preventing the uracilation of DNA. Many DNA-containing viruses, which infect mammals also encode for a dUTPase. This review will summarize studies demonstrating that, in addition to their classical enzymatic activity, some dUTPases possess novel functions that modulate the host innate immune response

Copper-functionalized nanostructured silica-based systems: Study of the antimicrobial applications and ROS generation against gram positive and gram negative bacteria

A series of copper-functionalized SBA-15 (Santa Barbara Amorphous) materials containing the ligands triethoxysilylpropylmaleamic acid (maleamic) or triethoxy-3-(2-imidazolin-1-yl)propylsilane (imidazoline) have been prepared. The nanostructured silica-based systems SBA-maleamic, SBA-imidazoline, SBA-maleamic-Cu and SBA-imidazoline-Cu were characterized by several methods observing that the functionalization took place mainly inside the pores of the mesoporous system. The antimicrobial behaviour of the synthesized materials against Staphylococcus aureus and Escherichia coli was tested observing a very potent activity of the copper-functionalized systems (minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values for SBA-maleamic-Cu of ca. 31.25 μg/mL, which correspond with ca. 1.13 μg/mL of Cu). A study of the oxidative stress promoted by the synthesized materials showed that the SBA-maleamic-Cu and the SBA-imidazoline-Cu were able to increase the reactive oxygen species (ROS) production in S. aureus by 427% and 373%, respectively, while this increase was slightly lower in E. coli (387 and 324%, respectively). Furthermore, an electrochemical study was carried out in order to determine if these materials interact with lysine or alanine to validate a potential antimicrobial mechanism based on the inhibition of the synthesis of the peptidoglycan of the bacterial wall. Finally, these studies were also performed to determine the potential interaction of the copper-containing materials with glutathione in order to assess if they are able to perturb the metabolism of this tripeptide.Fil: Díaz-García, Diana. Universidad Rey Juan Carlos; EspañaFil: Ardiles, Perla R.. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Díaz-Sánchez, Miguel. Universidad Rey Juan Carlos; EspañaFil: Mena-Palomo, Irene. Universidad Rey Juan Carlos; EspañaFil: del Hierro, Isabel. Universidad Rey Juan Carlos; EspañaFil: Prashar, Sanjiv. Universidad Rey Juan Carlos; EspañaFil: Rodríguez-Diéguez, Antonio. Universidad Rey Juan Carlos; EspañaFil: Páez, Paulina Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: Gómez Ruiz, Santiago. Universidad Rey Juan Carlos; Españ