CHO-K1 Cell Line Research Articles

In vitro Cytotoxicity, Apoptosis, Effects on Cell Cycle Kinetics and Schedule-Dependent Effects Induced by Paclitaxel on C6 and CHO-K1 Cell Lines

Exposure of C6 and CHO-K1 cells to different concentrations of the antineoplastic drug paclitaxel resulted in a loss of cellular viability. The percentage of surviving cells fell significantly after 48 hours of treatment and IC50 values observed were between 0.5 to 0.75 and 0.25 to 0.75 µg/ml in C6 and CHO-K1 cells, respectively. No significant cytotoxicity was observed after 24 hours of treatment and cells incubated at higher concentrations of paclitaxel showed increased survivability. Paclitaxel induced apoptosis by caspase 3/7 activation and caused accumulation of cells in the G2/M phase of the cell cycle. Upon fluorescent microscopy, both the cell lines lost the morphology, confluence and adherence at 24 hours but effects were much more pronounced at 48 hours of treatment. The in vitro data suggested that paclitaxel is highly effective when there is prolonged exposure of tumor to the drug rather than increasing the intratumoral or biophasic concentration of the drug.

Biological Properties of Yeast-based Mannoprotein for Prospective Biomedical Applications.

Natural products constitute more than half of all biomolecules lately being used in clinical settings. Mannoprotein derived from the yeast cell wall has found full biotechnological applications. This study was intended to investigate the antioxidant, anticancer, and toxicological properties of Kluyveromyces marxianus mannoprotein (KM). The KM extract was obtained through a sequence of operations, including centrifugation for cell isolation, precipitation with potassium citrate/sodium metabisulfite, and recovery and purification. Its antioxidant, growth inhibition, macrophage mitogenic, and toxic activities were evaluated for its future use in the biomedical field. Significant inhibitory effects of KM were obtained on reactive species. It showed antiproliferative activity against HeLa (human cervical adenocarcinoma) and MCF-7 (human breast cancer) cell lines with no toxic effects on HUVECs (human umbilical vein endothelial cells). The in vitro model of CHO-K1 (Chinese hamster ovary) cell lines did not show the cytotoxic and genotoxic of KM. Moreover, it enhanced macrophage activity in terms of nitric oxide (NO) production and viability. No sign of acute toxicity was found in BALB/c mice, and body weight remained unchanged in guinea pigs over three months. Comprehensive biological evaluations in this study are expected to expand the potential of KM as a natural material.

LC-MS/MS-based quantitative proteomic and phosphoproteomic analysis of CHO-K1 cells adapted to growth in glutamine-free media.

This study aims to provide insights into the molecular mechanisms underlying adaptation of CHO-K1 cells to growth in glutamine-free media and potentially identifying critical signalling proteins and pathways involved in this phenotype. A CHO-K1 cell line adapted to growth in glutamine-free media was established using a straightforward one-step glutamine reduction strategy. The adapted cell line had a comparable phenotype to the parental cells in terms of cell growth and viability. Global quantitative proteomic and phosphoproteomic analysis was carried out to compare the cells adapted to growth in glutamine-free media to parental cells grown in media containing 8 mM L-glutamine. The adaptation process was accompanied by changes in proteins associated with cytoskeleton rearrangement and mRNA splicing as evidenced via functional analysis of 194 differentially expressed proteins between the two cell lines. 434 phosphoproteins with altered abundance were also identified as a result of adaptation to L-glutamine-free conditions with an associated enrichment of pathways associated with MAPK and calcium signalling. This work provides a comprehensive proteomic and phosphoproteomic analysis of protein expression changes after adaptation to glutamine-free growth conditions highlighting critical pathways to consider in the rational design of improved feeding strategies or in cell line engineering to improve bioprocess phenotypes.

Assessing the Biological Safety of Atmospheric Cold Plasma Treated Wheat Using Cell and Insect Models.

Atmospheric cold plasma (ACP) is under investigation for an extensive range of biocontrol applications in food biosystems. However, the development of a novel intervention technology requires a thorough evaluation of the potential for negative effects and the implications for the human and animal food chains’ safety. The evaluations were performed using a contained, high-voltage, dielectric barrier discharge plasma system. The cytotoxicity of two types of food models—a liquid model (wheat model medium (WMM)) vs. a solid model (wheat grain extract (WGE)) was compared in vitro using the mammalian cell line CHO-K1. The residual toxicity of ACP treatment of grains for food purposes was assessed using the invertebrate model Tribolium castaneum, by feeding the beetles with flour produced from ACP-treated wheat grains. The cytotoxic effects and changes in the chemistry of the ACP-treated samples were more pronounced in samples treated in a liquid form as opposed to actual wheat grains. The feeding trial using T. castaneum demonstrated no negative impacts on the survivability or weight profiles of insects. Investigations into the interactions of plasma-generated species with secondary metabolites in the food matrices are necessary to ensure the safety of plasma for food applications.

Establishment of C20Mab-11, a novel anti-CD20 monoclonal antibody, for the detection of B cells.

CD20 is one of several B-lymphocyte antigens that has been shown to be an effective target for the detection and treatment of B-cell lymphomas. Sensitive and specific monoclonal antibodies (mAbs) are required for every application used for the diagnosis of B-cell lymphoma. Although many anti-CD20 mAbs have been established, the types of applications, those anti-CD20 can be used in, are limited. In this study, we aimed to establish novel anti-CD20 mAbs to be used for broad applications, such as flow cytometry, western blot, and immunohistochemical analyses, using the Cell-Based Immunization and Screening (CBIS) method. One of the established mAbs, C20Mab-11 (IgM, kappa), detected overexpression of CD20 in CHO-K1 or LN229 cell lines, indicating that C20Mab-11 is specific for CD20. In western blot analyses, C20Mab-11 detected not only overexpression of CD20 in CHO-K1 or LN229 cell lines, but also CD20 of BALL-1 and Raji cells with both sensitivity and specificity. Furthermore, C20Mab-11 strongly stained B cells of the lymph follicle and B cell lymphomas in immunohistochemical analyses. These results indicate that C20Mab-11 develped by CBIS method, is useful for the detection of CD20 in lymphoma tissues by flow cytometry, western blot, and immunohistochemical analyses and potentially could be beneficial for the treatment of B cell lymphomas.

Gene editing in CHO cells to prevent proteolysis and enhance glycosylation: Production of HIV envelope proteins as vaccine immunogens.

Several candidate HIV subunit vaccines based on recombinant envelope (Env) glycoproteins have been advanced into human clinical trials. To facilitate biopharmaceutical production, it is necessary to produce these in CHO (Chinese Hamster Ovary) cells, the cellular substrate used for the manufacturing of most recombinant protein therapeutics. However, previous studies have shown that when recombinant Env proteins from clade B viruses, the major subtype represented in North America, Europe, and other parts of the world, are expressed in CHO cells, they are proteolyzed and lack important glycan-dependent epitopes present on virions. Previously, we identified C1s, a serine protease in the complement pathway, as the endogenous CHO protease responsible for the cleavage of clade B laboratory isolates of -recombinant gp120s (rgp120s) expressed in stable CHO-S cell lines. In this paper, we describe the development of two novel CHOK1 cell lines with the C1s gene inactivated by gene editing, that are suitable for the production of any protein susceptible to C1s proteolysis. One cell line, C1s-/- CHOK1 2.E7, contains a deletion in the C1s gene. The other cell line, C1s-/- MGAT1- CHOK1 1.A1, contains a deletion in both the C1s gene and the MGAT1 gene, which limits glycosylation to mannose-5 or earlier intermediates in the N-linked glycosylation pathway. In addition, we compare the substrate specificity of C1s with thrombin on the cleavage of both rgp120 and human Factor VIII, two recombinant proteins known to undergo unintended proteolysis (clipping) when expressed in CHO cells. Finally, we demonstrate the utility and practicality of the C1s-/- MGAT1- CHOK1 1.A1 cell line for the expression of clinical isolates of clade B Envs from rare individuals that possess broadly neutralizing antibodies and are able to control virus replication without anti-retroviral drugs (elite neutralizer/controller phenotypes). The Envs represent unique HIV vaccine immunogens suitable for further immunogenicity and efficacy studies.

A doubly auxotrophic CHO-K1 cell line for the production of recombinant monoclonal antibodies.

Chinese hamster ovary (CHO) cells are the most widely used mammalian hosts for recombinant protein production due to their hardiness, ease of transfection, and production of glycan structures similar to those in natural human monoclonal antibodies. To enhance the usefulness of CHO-K1 cells we developed a new selection system based on double auxotrophy. We used CRISPR-Cas9 to knockout the genes that encode the bifunctional enzymes catalyzing the last two steps in the de novo synthesis of pyrimidines and purines (uridine monophosphate synthase and 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase [ATIC], respectively). Survival of these doubly auxotrophic cells depends on the provision of sources of purines and pyrimidines or on the transfection and integration of open reading frames encoding these two enzymes. We successfully used one such double auxotroph (UA10) to select for stable transfectants carrying (a) the recombinant tumor necrosis factor-α receptor fusion protein etanercept and (b) the heavy and light chains of the anti-Her2 monoclonal antibody trastuzumab. Transfectant clones produced these recombinant proteins in a stable manner and in substantial amounts. The availability of this double auxotroph provides a rapid and efficient selection method for the serial or simultaneous transfer of genes for multiple polypeptides of choice into CHO cells using readily available purine- and pyrimidine-free commercial media.

Green Propolis: Cytotoxic and Leishmanicidal Activities of Artepillin C, p-Coumaric Acid, and Their Degradation Products

Brazilian green propolis is a bee product which displays many biological activities, such as antiparasitic, antimicrobial, and cytotoxic. Artepillin C and p-coumaric acid are two of its major compounds that contribute to these activities. Both compounds were submitted to degradation under light, oxygen, and heating, furnishing four and one degradation products, respectively. Artepillin C, p-coumaric acid, and their degradation products were evaluated against seven strains of oral bacteria, cancer cell lines (AGP-01 and He-La), and Leishmania amazonensis (promastigotes and amastigotes). The Z-isomer artifact of artepillin C displayed significant activity against both gastric cancer cell line AGP-01 (IC50 9.09 μM) and L. amazonensis, especially against the amastigote forms of the parasite (IC50 3.49 μM). p-Coumaric acid also displayed a promising activity against L. amazonensis amastigotes (IC50 3.12 μM), while its Z-isomer artifact was more effective against the promastigotes (IC50 9.35 μM). The obtained compounds were not cytotoxic against the normal cell line CHO-k1. The present study shows that Brazilian green propolis is an important source of bioactive compounds and that Z-artepillin C and Z-p-coumaric acid display antiparasitic and cytotoxic activities.

Engineered transient and stable overexpression of translation factors eIF3i and eIF3c in CHOK1 and HEK293 cells gives enhanced cell growth associated with increased c-Myc expression and increased recombinant protein synthesis

There is a desire to engineer mammalian host cell lines to improve cell growth/biomass accumulation and recombinant biopharmaceutical protein production in industrially relevant cell lines such as the CHOK1 and HEK293 cell lines. The over-expression of individual subunits of the eukaryotic translation factor eIF3 in mammalian cells has previously been shown to result in oncogenic properties being imparted on cells, including increased cell proliferation and growth and enhanced global protein synthesis rates. Here we report on the engineering of CHOK1 and HEK cells to over-express the eIF3i and eIF3c subunits of the eIF3 complex and the resultant impact on cell growth and a reporter of exogenous recombinant protein production. Transient over-expression of eIF3i in HEK293 and CHOK1 cells resulted in a modest increase in total eIF3i amounts (maximum 40% increase above control) and an approximate 10% increase in global protein synthesis rates in CHOK1 cells. Stable over-expression of eIF3i in CHOK1 cells was not achievable, most likely due to the already high levels of eIF3i in CHO cells compared to HEK293 cells, but was achieved in HEK293 cells. HEK293 cells engineered to over-express eIF3i had faster growth that was associated with increased c-Myc expression, achieved higher cell biomass and gave enhanced yields of a reporter of recombinant protein production. Whilst CHOK1 cells could not be engineered to over-express eIF3i directly, they could be engineered to over-express eIF3c, which resulted in a subsequent increase in eIF3i amounts and c-Myc expression. The CHOK1 eIF3c engineered cells grew to higher cell numbers and had enhanced cap- and IRES-dependent recombinant protein synthesis. Collectively these data show that engineering of subunits of the eIF3 complex can enhance cell growth and recombinant protein synthesis in mammalian cells in a cell specific manner that has implications for the engineering or selection of fast growing or high producing cells for production of recombinant proteins.

Experimental Substantiation of the Possibility to Use Finite Cell Line CHO-K1 for Determination of Specific Activity of Components of Chemical Cholera Vaccine

Objective was to experimentally substantiate the possibility to use the finite cell line CHO-K1 for measuring specific activity of cholera toxin and component of the vaccine choleragen-anatoxin in the process of chemical cholera vaccine manufacturing. Materials and methods . The studies involved the finite cell line CHO-K. The registration of results of bio-indication method was performed visually with the help of inverted microscope and photometrically - in colorimetric test for the assessment of metabolic activity of the cells at the wave length of 595 nm. Results and discussion . The proposed method allows for determining the toxin-production activity of Vibrio cholerae 569B strain during submerged cultivation in bioreactor and specific activity of choleragen-anatoxin by anatoxin binding measuring using cell cultures. The results correlate with the data obtained using intradermal Craig’s technique, GM1-ELISA and radial passive immune hemolysis (RPIH). Introduction of cell culture method into practice will provide for significant decrease in the volumes of usage of animals at the stages of manufacturing of chemical bivalent cholera vaccine.

Effects of polydopamine-passivation on the optical properties of carbon dots and its potential use in vivo.

Passivation of carbon dots via heteroatom doping has been shown to enhance their optical properties and tune their fluorescence signature. Additionally, the incorporation of polymeric precursors in carbon dot synthesis has gained considerable interest with benefits to biological applications namely bioimaging, drug delivery and sensing, among others. In order to combine the desirable attributes of both, fluorescence enhancement and increased biocompatibility, polymers composed of high aromaticity and nitrogen content can be used as efficient carbon dot passivating agents. Here, the synthesis of fluorescent polymer-passivated carbon dots was developed through a microwave-assisted pyrolysis reaction of galactose, citric acid and polydopamine. Passivation of the dots with polydopamine induces a 90 nm red-shift in the fluorescence maxima from 420 to 510 nm. Moreover, passivation results in excitation-independent fluorescence and a 3.5-fold increase in fluorescence quantum yield, which increases from 1.3 to 4.6%. The application of the carbon dots as imaging probes was investigated in in vitro and in vivo model systems. Cytotoxicity studies in J774 and CHO-K1 cell lines revealed reduced cell toxicity for the polydopamine-passivated carbon dots in comparison to their unpassivated counterpart. In BALB/c mice, biodistribution studies demonstrated that regardless of surface passivation, the dots predominantly remained in the circulatory system 90 minutes post inoculation suggesting their potential use for cardiovascular therapies.

The Envelope-Based Fusion Antigen GP120C14K Forming Hexamer-Like Structures Triggers T Cell and Neutralizing Antibody Responses Against HIV-1.

There is an urgent need for the development of potent vaccination regimens that are able to induce specific T and B cell responses against human immunodeficiency virus type 1 (HIV-1). Here, we describe the generation and characterization of a fusion antigen comprised of the HIV-1 envelope GP120 glycoprotein from clade C (GP120C) fused at its C-terminus, with the modified vaccinia virus (VACV) 14K protein (A27L gene) (termed GP120C14K). The design is directed toward improving the immunogenicity of the GP120C protein through its oligomerization facilitated by the fused VACV 14K protein that results in hexamer-like structures. Two different immunogens were generated: a recombinant GP120C14K fusion protein (purified from a stable CHO-K1 cell line) and a recombinant modified vaccinia virus Ankara (MVA) poxvirus vector expressing the GP120C14K fusion protein (termed MVA-GP120C14K). The GP120C14K fusion protein is recognized by broadly neutralizing antibodies (bNAbs) against HIV-1. In a murine model, a heterologous prime/boost immunization regimen with MVA-GP120C14K prime followed by adjuvanted GP120C14K protein boost generated stronger and polyfunctional HIV-1 Env-specific CD8 T cell responses when compared with the delivery of the monomeric GP120C form. Furthermore, the immunization protocol MVA-GP120C14K/GP120C14K elicited higher HIV-1 Env-specific T follicular helper cells, germinal center B cells and antibody responses than monomeric GP120. In addition, a similar MVA-GP120C14K prime/GP120C14K protein boost regimen performed in rabbits triggered high HIV-1-Env-specific IgG binding antibody titers that were capable of neutralizing HIV-1 pseudoviruses. The extent of HIV-1 neutralization was comparable to that elicited by the current standard GP140 SOSIP trimers from clades B and C when immunized as MVA-SOSIP prime/SOSIP protein boost regimen. Overall, the novel fusion antigen and the corresponding immunization scheme provided in this report can therefore be considered as potential vaccine strategies against HIV-1.

Antibody-induced crosslinking and cholesterol-sensitive, anomalous diffusion of nicotinic acetylcholine receptors.

Synaptic strength depends on the number of cell-surface neurotransmitter receptors in dynamic equilibrium with intracellular pools. Dysregulation of this homeostatic balance occurs, for example in myasthenia gravis, an autoimmune disease characterized by a decrease in the number of postsynaptic nicotinic acetylcholine receptors (nAChRs). Monoclonal antibody mAb35 mimics this effect. Here we use STORM nanoscopy to characterize the individual and ensemble dynamics of monoclonal antibody-crosslinked receptors in the clonal cell line CHO-K1/A5, which robustly expresses adult muscle-type nAChRs. Antibody labeling of live cells results in 80% receptor immobilization. The remaining mobile fraction exhibits a heterogeneous combination of Brownian and anomalous diffusion. Single-molecule trajectories exhibit a two-state switching behavior between free Brownian walks and anticorrelated walks within confinement areas. The latter act as permeable fences (~34nm radius, ~400ms lifetime). Dynamic clustering, trapping, and immobilization also occur in larger nanocluster zones (120-180nm radius) with longer lifetimes (11±1s), in a strongly cholesterol-sensitive manner. Cholesterol depletion increases the size of the clustering phenomenon; cholesterol enrichment has the opposite effect. The disclosed high proportion of monoclonal antibody-crosslinked immobile receptors, together with their anomalous, cholesterol-sensitive diffusion and clustering, provides new insights into the antibody-enhanced antigenic modulation that leads to physiopathological internalization and degradation of receptors in myasthenia.

Calcium signalling in mammalian cell lines expressing wild type and mutant human \u03b11-Antitrypsin

A possible role for calcium signalling in the autosomal dominant form of dementia, familial encephalopathy with neuroserpin inclusion bodies (FENIB), has been proposed, which may point towards a mechanism by which cells could sense and respond to the accumulation of mutant serpin polymers in the endoplasmic reticulum (ER). We therefore explored possible defects in Ca2+-signalling, which may contribute to the pathology associated with another serpinopathy, α1-antitrypsin (AAT) deficiency. Using CHO K1 cell lines stably expressing a wild type human AAT (MAAT) and a disease-causing polymer-forming variant (ZAAT) and the truncated variant (NHK AAT), we measured basal intracellular free Ca2+, its responses to thapsigargin (TG), an ER Ca2+-ATPase blocker, and store-operated Ca2+-entry (SOCE). Our fura2 based Ca2+ measurements detected no differences between these 3 parameters in cell lines expressing MAAT and cell lines expressing ZAAT and NHK AAT mutants. Thus, in our cell-based models of α1-antitrypsin (AAT) deficiency, unlike the case for FENIB, we were unable to detect defects in calcium signalling.

Influence of geometry on cell proliferation of PLA and alumina scaffolds constructed by additive manufacturing

Abstract

In vitro assessment of corticosteroid effects of eight chiral herbicides

Information regarding the enantioselective endocrine disruption of chiral herbicides is scarce. This study assessed the disrupting effects of eight typical chiral herbicides on corticosteroids (including glucocorticoids and mineralocorticoids). Enantioselectivity of eight chiral herbicides were evaluated for their agonistic/antagonistic effects on glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) with CHOK1 cell line using reporter gene assay. Their influence on the production of corticosteroids were further investigated in H295R cell line using enzyme-linked immunosorbent assay (ELISA). None of the racemates or enantiomers of eight chiral herbicides exhibited GR or MR agonistic activity at non-cytotoxic concentrations. However, rac-propisochlor and S-imazamox antagonized cortisol-induced transactivation of GR by 21.79% and 38.73% at the concentration of 1.0 × 10−7 M and 1.0 × 10−6 M, respectively, and R-napropamide remarkably attenuated aldosterone-induced MR transactivation by 68.78% at 1.0 × 10−6 M. The secretion of cortisol was significantly restrained after treated with 1.0 × 10−6 M rac-propisochlor and rac-/R-napropamide at the concentration of 1.0 × 10−6 M by 26.49%, 30.10% and 35.27%, respectively, while this glucocorticoid was remarkably induced by 1.0 × 10−5 M rac-diclofop-methyl and its two enantiomers at the concentration of 1.0 × 10−5 M by 75.60%, 100.1% and 68.78%, respectively. Exposure to rac-propisochlor (1.0 × 10−6 M), S-diclofop-methyl (1.0 × 10−5 M) or rac-/S-/R- acetochlor (1.0 × 10−6 M) and rac-/S-/R-lactofen (1.0 × 10−6 M) inhibited the secretion of aldosterone by approximately 40%. Our findings suggested that chiral herbicides disrupted corticosteroid homeostasis in an enantioselective way. Therefore, more comprehensive screening is required to better understand the ecological and health risks of chiral pesticides.

Comparative studies of pure cultures and a consortium of white-rot fungi to degrade a binary mixture of dyes by solid-state fermentation and performance at different scales

White-rot fungi have been widely used in pure culture and consortia for treating recalcitrant compounds, such as synthetic dyes, since they are able to cleave and mineralize lignin using ligninolytic enzymes. Moreover, solid-state fermentation stands out in the treatment of dyes due to its low environmental impact. In this study we evaluated the degradation of allura red and tartrazine adsorbed onto corncob by either pure cultures or binary consortia of Trametes versicolor and Pleurotus pulmonarius. We performed a comparative study in terms of culture conditions optimization, degradation, activity of ligninolytic enzymes kinetics, and cytotoxicity assessment to unravel the differences between using individual cultures or consortium of white-rot fungi. 94% of the dye mixture was degraded in pure cultures, but only 64.3% was broken-down by the consortium. Enzymatic activity and degradation kinetics showed that T. versicolor maximum laccase activity corresponded to the plateau phase of degradation whilst for P. pulmonarius and consortium no match between both profiles was found. Also, T. versicolor extracts were not cytotoxic to CHO–K1 cell line. The process was therefore magnified using T. versicolor in pure culture. The degradation efficiency was maintained in all the sizes, allowing an increase of 20 times the amount of treated dyes.

Nanoemulsion Structural Design in Co-Encapsulation of Hybrid Multifunctional Agents: Influence of the Smart PLGA Polymers on the Nanosystem-Enhanced Delivery and Electro-Photodynamic Treatment.

In the present study, we examined properties of poly(lactide-co-glycolide) (PLGA)-based nanocarriers (NCs) with various functional or “smart” properties, i.e., coated with PLGA, polyethylene glycolated PLGA (PEG-PLGA), or folic acid-functionalized PLGA (FA-PLGA). NCs were obtained by double emulsion (water-in-oil-in-water) evaporation process, which is one of the most suitable approaches in nanoemulsion structural design. Nanoemulsion surface engineering allowed us to co-encapsulate a hydrophobic porphyrin photosensitizing dye—verteporfin (VP) in combination with low-dose cisplatin (CisPt)—a hydrophilic cytostatic drug. The composition was tested as a multifunctional and synergistic hybrid agent for bioimaging and anticancer treatment assisted by electroporation on human ovarian cancer SKOV-3 and control hamster ovarian fibroblastoid CHO-K1 cell lines. The diameter of PLGA NCs with different coatings was on average 200 nm, as shown by dynamic light scattering, transmission electron microscopy, and atomic force microscopy. We analyzed the effect of the nanocarrier charge and the polymeric shield variation on the colloidal stability using microelectrophoretic and turbidimetric methods. The cellular internalization and anticancer activity following the electro-photodynamic treatment (EP-PDT) were assessed with confocal microscopy and flow cytometry. Our data show that functionalized PLGA NCs are biocompatible and enable efficient delivery of the hybrid cargo to cancer cells, followed by enhanced killing of cells when supported by EP-PDT.

Photodegradable MEH-PPV in a natural rubber matrix: Toward a biocompatible colorimetric film for real-time light dosimetry

Abstract This paper reports an interesting strategy of incorporating a photodegradable polymeric luminophore, the poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] - OC10C6-PPV (MEH-PPV), in an inert natural rubber (Hevea brasiliensisis) - C5H8 (NR) matrix for monitoring and recording the radiation dose administered to patients under phototherapy, particularly in the treatment for jaundice newborns. A time-trend spectrofluorimetric study has been carried out to characterize the luminescent changes of the MEH-PPV/NR luminophore system upon photodegradation by realistic conditions of phototherapy treatment, and the dependence between color and dose was used to determine the dose-response relationships of this color film dosimeter. Cytotoxicity tests (CHO-K1 cell line) have also been conducted on extracts of the OC10C6-PPV/C5H8 before and after photolysis. The experimental results reported here highlight the potential application of photodegradable polymer/natural rubber as a biocompatible skin-mountable patch to monitor light exposure to improve patient care in phototherapy, photodynamic, lasers and radiation therapies.

Synthesis and in-vitro Evaluation of S-allyl Cysteine Ester - Caffeic Acid Amide Hybrids as Potential Anticancer Agents.

We have synthesized a series of S-allyl cysteine ester-caffeic acid amide hybrids and evaluated them in order to determine their possible anticancer activity and selectivity in colorectal cancer, which is still one of the leading causes of morbidity and mortality worldwide. All compounds were tested against SW480 human colon adenocarcinoma cells and the non-malignant CHO-K1 cell line. Among the tested compounds, hybrids 6e, 9a, 9b, 9c, and 9e exhibited the highest effect on viability (IC50 SW480-48h= 0.18, 0.12, 0.12, 0.11, and 0.12 mM, respectively) and selectivity (SI = 10.3, 1.5, >83.33, >90.91 and >83.33, respectively) in a time- and concentration-dependent manner. Besides, our results were even better as regards lead compounds (S-allyl cysteine and caffeic acid) and the standard drug (5-FU). Additionally, these five compounds induced mitochondrial depolarization that could be related with an apoptotic process. Moreover, hybrids 6e, 9a, and 9e induced cell cycle arrest in G2/M phase, and compound 9c in S- phase, which suggests that these hybrid compounds could have also a cytostatic effect in SW480 cell line. The SAR analysis showed that hydroxyl groups increased the activity. Besides, there was not a clear relationship between the antitumor properties and the length of the alkyl chain. Since hybrid compounds were much more selective than the conventional drug (5-FU), this makes them promising candidates for further studies against colorectal cancer.