Constrictive Pericarditis and Cardiac Tamponade Due to Tuberculosis as Presentation of Human Immunodeficiency Virus/Syndrome of Acquired Immunodeficiency: Case Report / Pericarditis constrictiva y taponamiento cardíaco por tuberculosis como presentación de virus de inmunodeficiencia humana/síndrome de inmunodeficiencia adquirida: presentación de caso / Pericardite constritiva e tamponamento cardíaco devido à tuberculose com uma apre-sentação do vírus da imunodeficiência adquirida: relato de cas

We report a case of constrictive pericarditis due to extrapulmonary tuberculosis associated with Human Immuno-deficiency Virus, complicated by cardiac tamponade that required surgical intervention in a drug user patient. The importance of early diagnosis and management is widely highlighted

El artículo presenta un caso de pericarditis constrictiva secundaria a tuberculosis extrapulmonar en un paciente con prueba positiva para virus de inmunodeficiencia humana (VIH) consumidor de sustancias psicoactivas, quien durante la hospitalización desarrolló un taponamiento cardíaco con requerimiento de intervención quirúrgica. Se plantea la discusión de la importancia de cada una de las pruebas solicitadas y el manejo adecuado en pacientes con dichas patologías

O artigo apresenta um caso de pericardite constritiva secundária à tuberculose extrapulmonar em paciente com teste positiva para vírus da imunodeficiência humana (HIV) e usuário de substâncias psicoativas que, durante a internação, desenvolveu tamponamento cardíaco com necessidade de intervenção cirúrgica. Discute-se a importância de cada um dos exames solicitados e o manejo ade-quado de pacientes com essas patologias

Albumin-based nanostructures for uveal melanoma treatment.

Uveal melanoma (UM) is an intraocular tumor which is almost lethal at the metastatic stage due to the lack of effective treatments. In this regard, we have developed an albumin-based nanostructure (ABN) containing AZD8055 (ABN-AZD), which is a potent mTOR kinase inhibitor, for its efficient delivery to the tumors. The drug has been conjugated to ABN using tailored linkers that have a disulfide moiety, allowing its release selectively and effectively in the presence of an elevated concentration of glutathione, such as inside the tumoral cells. Our therapeutic approach induced significant cellular toxicity in uveal melanoma cells, but not in non-tumoral keratinocytes, highlighting the excellent selectivity of the system. In addition, these nanostructures showed excellent activity in vivo, decreasing the tumor surface compared to the free AZD8055 in mice models. Remarkably, the results obtained were achieved employing a dose 23 times lower than those used in previous reports.

Desenlaces asociados con solución salina normal versus lactato de ringer en sepsis y choque séptico o hipovolémico / Outcomes associated with normal saline solution vs lactated ringer´s solution in sepsis and septic or hypovelemic shock

Introducción: los cristaloides son medicamentos usados en pacientes críticamente enfermos, con resultados ambiguos cuando se utilizan soluciones balanceadas versus solución salina normal. Objetivo: conocer si existen diferencias al usar solución salina 0.9% vs. lactato de Ringer en pacientes críticamente enfermos con sepsis y choque séptico o hipovolémico, en cuanto a mortalidad, lesión renal aguda y tiempo de estancia hospitalaria. Métodos: estudio observacional de tipo cohorte retrospectiva en mayores de 18 años con diagnóstico de sepsis, choque séptico o hipovolémico. Se excluyeron aquellos con enfermedad renal crónica en diálisis, las hospitalizadas por ginecología/obstetricia y aquellos con diagnóstico de muerte encefálica o donantes de órganos. Se evaluaron los desenlaces primarios de mortalidad, lesión renal aguda y estancia hospitalaria. Resultados y discusión: se incluyeron 314 pacientes, 158 en el grupo expuesto a solución salina al 0.9% y 156 con lactato de Ringer. Se presentó lesión renal aguda en 22.7% con solución salina y 25.8% con lactato de Ringer (OR 1.18 IC 95%:0.7-2). La mortalidad con solución salina fue de 49%, y en lactato 49% (OR 1.01 IC 95%:0.63-1.63). Los factores de riesgo identificados para mortalidad fueron uso de soporte vasopresor (OR 35 IC 95% 12-83) y lesión renal aguda (1.3 IC 95% 1.01-1.69). Conclusiones: en el paciente críticamente enfermo con sepsis, choque séptico o hipovolémico el uso desolución salina 0.9% no representa diferencias al compararlo con lactato de Ringer en cuanto a mortalidad, lesión renal aguda o estancia hospitalaria. La elección de un cristaloide debe ser individualizada, teniendo en cuenta las comorbilidades, la presencia de hipercloremia o hiperpotasemia.

Objective: crystalloids are drugs used in critically ill patients, with ambiguous results when balanced solutions versus normal saline solution (NS) are used. The objective of this study is to determine if there are differences when NS (0.9%) vs. lactated Ringer ́s (LR) solution are given to critically ill patients in sepsis or septic or hypovolemic shock, in terms of mortality, acute renal injury and length of hospital stay. Methods: a retrospective observational cohort study in patients over 18 years old with sepsis or septic or hypovolemic shock. Patients with chronic renal disease on dialysis, those hospitalized by gynecology/obstetrics and those diagnosed with brain death or organ donors were excluded. The primary mortality outcomes, acute renal injury and hospital stay were evaluated. Results: 314 patients were included, 158 in the NS group and 156 in the LR group. Acute renal injury occurred in 22.7% in the NS group and 25.8% in the LR group (OR 1.18 IC 95%:0.7-2). Mortality rate was 49% in the NS group and 49% in the LR group (OR 1.01 95%: CI 0.63-1.63). Mortality risk factors included the use of vasopressor support (OR 35 95% CI 12-83) and acute renal injury (1.3 95% CI 1.01-1.69). Conclusions: no difference was found with the use of NS in critically ill patients with sepsis or septic or hypovolemic shock when compared with LR in terms of mortality, acute renal injury or hospital stay. The choice of which crystalloid to administer should be individualized, based on the comorbidities and the presence of hyperchloremia or hyperkalemia.

Tailored Functionalized Magnetic Nanoparticles to Target Breast Cancer Cells Including Cancer Stem-Like Cells.

Nanotechnology-based approaches hold substantial potential to avoid chemoresistance and minimize side effects. In this work, we have used biocompatible iron oxide magnetic nanoparticles (MNPs) called MF66 and functionalized with the antineoplastic drug doxorubicin (DOX) against MDA-MB-231 cells. Electrostatically functionalized MNPs showed effective uptake and DOX linked to MNPs was more efficiently retained inside the cells than free DOX, leading to cell inactivation by mitotic catastrophe, senescence and apoptosis. Both effects, uptake and cytotoxicity, were demonstrated by different assays and videomicroscopy techniques. Likewise, covalently functionalized MNPs using three different linkers-disulfide (DOX-S-S-Pyr, called MF66-S-S-DOX), imine (DOX-I-Mal, called MF66-I-DOX) or both (DOX-I-S-S-Pyr, called MF66-S-S-I-DOX)-were also analysed. The highest cell death was detected using a linker sensitive to both pH and reducing environment (DOX-I-S-S-Pyr). The greatest success of this study was to detect also their activity against breast cancer stem-like cells (CSC) from MDA-MB-231 and primary breast cancer cells derived from a patient with a similar genetic profile (triple-negative breast cancer). In summary, these nanoformulations are promising tools as therapeutic agent vehicles, due to their ability to produce efficient internalization, drug delivery, and cancer cell inactivation, even in cancer stem-like cells (CSCs) from patients.

Iron Oxide Nanoparticles as Carriers for DOX and Magnetic Hyperthermia after Intratumoral Application into Breast Cancer in Mice: Impact and Future Perspectives.

There is still a need for improving the treatment of breast cancer with doxorubicin (DOX). In this paper, we functionalized magnetic nanoparticles (MNPs) with DOX and studied the DOX-induced antitumor effects in breast cancer cells (BT474) in the presence of magnetic hyperthermia (43 °C, 1 h). We show that i) intratumoral application of DOX-functionalized MNPs (at least at a concentration of 9.6 nmol DOX/100 mm3 tumor volume) combined with magnetic hyperthermia favors tumor regression in vivo, and there is evidence for an increased effect compared to magnetic hyperthermia alone or to the intratumoral application of free DOX and ii) the presence of the pseudopeptide NucAnt (N6L) on the MNP surface might well be beneficial in its function as carrier for MNP internalization into breast cancer cells in vitro, which could further augment the possibility of the induction of intracellular heating spots and cell death in the future.

Multifunctional Albumin-Stabilized Gold Nanoclusters for the Reduction of Cancer Stem Cells.

Controlled delivery of multiple chemotherapeutics can improve the effectiveness of treatments and reduce side effects and relapses. Here in, we used albumin-stabilized gold nanoclusters modified with doxorubicin and SN38 (AuNCs-DS) as combined therapy for cancer. The chemotherapeutics are conjugated to the nanostructures using linkers that release them when exposed to different internal stimuli (Glutathione and pH). This system has shown potent antitumor activity against breast and pancreatic cancer cells. Our studies indicate that the antineoplastic activity observed may be related to the reinforced DNA damage generated by the combination of the drugs. Moreover, this system presented antineoplastic activity against mammospheres, a culturing model for cancer stem cells, leading to an efficient reduction of the number of oncospheres and their size. In summary, the nanostructures reported here are promising carriers for combination therapy against cancer and particularly to cancer stem cells.

The phenotype of target pancreatic cancer cells influences cell death by magnetic hyperthermia with nanoparticles carrying gemicitabine and the pseudo-peptide NucAnt.

In this paper we show that conjugation of magnetic nanoparticles (MNPs) with Gemcitabine and/or NucAnt (N6L) fostered their internalization into pancreatic tumor cells and that the coupling procedure did not alter the cytotoxic potential of the drugs. By treating tumor cells (BxPC3 and PANC-1) with the conjugated MNPs and magnetic hyperthermia (43 °C, 60 min), cell death was observed. The two pancreatic tumor cell lines showed different reactions against the combined therapy according to their intrinsic sensitivity against Gemcitabine (cell death, ROS production, ability to activate ERK 1/2 and JNK). Finally, tumors (e.g. 3 mL) could be effectively treated by using almost 4.2 × 105 times lower Gemcitabine doses compared to conventional therapies. Our data show that this combinatorial therapy might well play an important role in certain cell phenotypes with low readiness of ROS production. This would be of great significance in distinctly optimizing local pancreatic tumor treatments.

Research on heart failure in Colombia 1980-2015: a systematic review / La investigación en falla cardíaca en Colombia 1980-2015: una revisión sistemática

Abstract Introduction: Heart failure is one of the most prevalent diseases worldwide. In Colombia, the state of research on the subject is unknown. Objective: To describe the original publications on heart failure in Colombia. Materials and methods: Systematic review. Digital search in Embase, PubMed, LILACS and Scielo, using the MeSH terms: "heart failure", "Colombian", "Colombia", "Latin America", "developing countries". Manual search of 58 journals identified in Publindex. Original research that evaluated adult Colombians with heart failure and published between 1980 and 2015 were included. Results: 2 684 articles were identified, of which 35 met the inclusion criteria. 30 (85.7%) were published since 2009, 30 (85.7%) were conducted in Bogotá and Medellín, 11 (31.4%) had n>200, 19 (54.2%) were descriptive and 5 (14.2%) quasi-experimental. Moreover, 9 (25.7%) described general populations, 9 (25.7%) addressed the issue of self-care, 3 (8.8%) cardiac rehabilitation, 3 (8.8%) perception of the disease and 3 (8.8%) prognostic factors. Conclusions: The amount of published original research on heart failure is low, and most of them were carried out recently. Descriptive design was the most frequent, while the most frequently addressed topics were self-care and population descriptions.

Resumen Introducción. La falla cardíaca es una de las enfermedades con mayor prevalencia a nivel mundial. En Colombia no se conoce con certeza el estado de la investigación en torno al tema. Objetivo. Describir las publicaciones originales en falla cardíaca en Colombia. Materiales y métodos. Revisión sistemática. Búsqueda electrónica en Embase, PubMed, LILACS Y SciELO, con términos MeSH: "heart failure", "colombian", "Colombia", "Latin America", "developing countries". Búsqueda manual en 58 revistas identificadas en Publindex. Se incluyeron investigaciones originales, publicadas entre 1980 y 2015, que evaluaron población adulta colombiana con falla cardíaca. Resultados. Se identificaron 2 684 artículos: 35 cumplieron criterios de inclusión; 30 (85.7%) fueron publicados a partir del 2009; 30 (85.7%) se realizaron en Bogotá y Medellín; 11 (31.4%) tuvieron n>200; 19 (54.2%) fueron descriptivos y 5 (14.2%) cuasiexperimentales; 9 (25.7%) describieron poblaciones generales; 9 (25.7%) abordaron el tema del autocuidado, 3 (8.8%), la rehabilitación cardíaca, 3 (8.8%), la percepción de enfermedad y 3 (8.8%), los factores pronósticos. Conclusión. El número de investigaciones originales publicadas sobre falla cardíaca es escaso; la mayoría se realizó en los últimos años. El diseño descriptivo fue el más común. Los temas abordados con mayor frecuencia fueron el autocuidado y las descripciones poblacionales.

Reprogramming Cells for Synergistic Combination Therapy with Nanotherapeutics against Uveal Melanoma.

Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults and around half of the patients develop metastasis and die shortly after because of the lack of effective therapies for metastatic UM. Consequently, new therapeutic approaches to this disease are welcome. In this regard, microRNAs have been shown to have a key role in neoplasia progression and have the potential to be used as therapeutic tools. In addition, in different cancers including UM, a particular microRNA signature appears that is different from healthy cells. Thus, restoring the regular levels of microRNAs could restore the normal behavior of cells. In this study, four microRNAs downregulated in UM have been chosen to reprogram cancer cells, to promote cell death or increase their sensitivity to the chemotherapeutic SN38. Furthermore, to improve the internalization, stability and/or solubility of the therapeutic molecules employed in this approach, gold nanoparticles (AuNPs) were used as carriers. Remarkably, this study found a synergistic effect when the four oligonucleotides were employed and when the chemotherapeutic drug was added.

Mechanical measurement of hydrogen bonded host-guest systems under non-equilibrium, near-physiological conditions.

Decades after the birth of supramolecular chemistry, there are many techniques to measure noncovalent interactions, such as hydrogen bonding, under equilibrium conditions. As ensembles of molecules rapidly lose coherence, we cannot extrapolate bulk data to single-molecule events under non-equilibrium conditions, more relevant to the dynamics of biological systems. We present a new method that exploits the high force resolution of optical tweezers to measure at the single molecule level the mechanical strength of a hydrogen bonded host-guest pair out of equilibrium and under near-physiological conditions. We utilize a DNA reporter to unambiguously isolate single binding events. The Hamilton receptor-cyanuric acid host-guest system is used as a test bed. The force required to dissociate the host-guest system is ∼17 pN and increases with the pulling rate as expected for a system under non-equilibrium conditions. Blocking one of the hydrogen bonding sites results in a significant decrease of the force-to-break by 1-2 pN, pointing out the ability of the method to resolve subtle changes in the mechanical strength of the binding due to the individual H-bonding components. We believe the method will prove to be a versatile tool to address important questions in supramolecular chemistry.

Recent advances in uveal melanoma treatment.

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Recent advances in the understanding of molecular characteristics helped to determine which tumors are most likely to progress. About 50% of patients carrying genetic alterations such as chromosomal aberrations and mutations are at significant risk for metastatic disease of which the majority will succumb to UM within few months. Currently, there is no effective treatment for metastatic uveal melanoma, and we hope this review will encourage researchers and clinicians to work to find a better standard of care. In this article we provide a comprehensive overview of the molecular framework of UM, highlighting the most common mutations involved in this kind of cancer. It also covers the most recent treatments from basic research to clinical trials, including small molecules, nucleic acids or immunotherapy, among others. It is intended to serve as a key reference for clinicians and researchers working in this field.

Oligonucleotide Sensor Based on Selective Capture of Upconversion Nanoparticles Triggered by Target-Induced DNA Interstrand Ligand Reaction.

We present a sensor that exploits the phenomenon of upconversion luminescence to detect the presence of specific sequences of small oligonucleotides such as miRNAs among others. The sensor is based on NaYF4:Yb,Er@SiO2 nanoparticles functionalized with ssDNA that contain azide groups on the 3' ends. In the presence of a target sequence, interstrand ligation is possible via the click-reaction between one azide of the upconversion probe and a DBCO-ssDNA-biotin probe present in the solution. As a result of this specific and selective process, biotin is covalently attached to the surface of the upconversion nanoparticles. The presence of biotin on the surface of the nanoparticles allows their selective capture on a streptavidin-coated support, giving a luminescent signal proportional to the amount of target strands present in the test samples. With the aim of studying the analytical properties of the sensor, total RNA samples were extracted from healthy mosquitoes and were spiked-in with a specific target sequence at different concentrations. The result of these experiments revealed that the sensor was able to detect 10-17 moles per well (100 fM) of the target sequence in mixtures containing 100 ng of total RNA per well. A similar limit of detection was found for spiked human serum samples, demonstrating the suitability of the sensor for detecting specific sequences of small oligonucleotides under real conditions. In contrast, in the presence of noncomplementary sequences or sequences having mismatches, the luminescent signal was negligible or conspicuously reduced.

Antibacterial Activity of DNA-Stabilized Silver Nanoclusters Tuned by Oligonucleotide Sequence.

Silver nanoclusters (AgNCs) stabilized by DNA are promising materials with tunable fluorescent properties, which have been employed in a plethora of sensing systems. In this report, we explore their antimicrobial properties in Gram-positive and Gram-negative bacteria. After testing 9 oligonucleotides with different sequence and length, we found that the antibacterial activity depends on the sequence of the oligonucleotide employed. The sequences tested yielded fluorescent AgNCs, which can be grouped in blue, yellow, and red emitters. Interestingly, blue emitters yielded poor antibacterial activity, whereas yellow and red emitters afforded an activity similar to silver nitrate. Furthermore, structural studies using circular dichroism indicate the formation of complexes with different stability and structure, which might be one of the factors that modulate their activity. Finally, we prepared a trimeric structure containing the sequence that afforded the best antimicrobial activity, which inhibited the growth of Gram-positive and negative bacteria in the submicromolar range.

Modified RNAs in CRISPR/Cas9: An Old Trick Works Again.

Old tricks, new dog: CRISPR/Cas9 is a powerful tool for gene editing that requires an endonuclease (Cas9) and RNA strands. It has been shown that chemical modification of the RNA structures, an approach that has been used to improve the efficiency of RNA interference, can also be applied to enhance the activity of CRISPR/Cas9 and reduce its off-target effects.

Multifunctionalized iron oxide nanoparticles for selective drug delivery to CD44-positive cancer cells.

Nanomedicine nowadays offers novel solutions in cancer therapy and diagnosis by introducing multimodal treatments and imaging tools in one single formulation. Nanoparticles acting as nanocarriers change the solubility, biodistribution and efficiency of therapeutic molecules, reducing their side effects. In order to successfully  apply these novel therapeutic approaches, efforts are focused on the biological functionalization of the nanoparticles to improve the selectivity towards cancer cells. In this work, we present the synthesis and characterization of novel multifunctionalized iron oxide magnetic nanoparticles (MNPs) with antiCD44 antibody and gemcitabine derivatives, and their application for the selective treatment of CD44-positive cancer cells. The lymphocyte homing receptor CD44 is overexpressed in a large variety of cancer cells, but also in cancer stem cells (CSCs) and circulating tumor cells (CTCs). Therefore, targeting CD44-overexpressing cells is a challenging and promising anticancer strategy. Firstly, we demonstrate the targeting of antiCD44 functionalized MNPs to different CD44-positive cancer cell lines using a CD44-negative non-tumorigenic cell line as a control, and verify the specificity by ultrastructural characterization and downregulation of CD44 expression. Finally, we show the selective drug delivery potential of the MNPs by the killing of CD44-positive cancer cells using a CD44-negative non-tumorigenic cell line as a control. In conclusion, the proposed multifunctionalized MNPs represent an excellent biocompatible nanoplatform for selective CD44-positive cancer therapy in vitro.

Gold-Coated Superparamagnetic Nanoparticles for Single Methyl Discrimination in DNA Aptamers.

Au- and iron-based magnetic nanoparticles (NPs) are promising NPs for biomedical applications due to their unique properties. The combination of a gold coating over a magnetic core puts together the benefits from adding the magnetic properties to the robust chemistry provided by the thiol functionalization of gold. Here, the use of Au-coated magnetic NPs for molecular detection of a single methylation in DNA aptamer is described. Binding of α-thrombin to two aptamers conjugated to these NPs causes aggregation, a phenomenon that can be observed by UV, DLS and MRI. These techniques discriminate a single methylation in one of the aptamers, preventing aggregation due to the inability of α-thrombin to recognize it. A parallel study with gold and ferromagnetic NPs is detailed, concluding that the Au coating of FexOy NP does not affect their performance and that they are suitable as complex biosensors. These results prove the high detection potency of Au-coated SPIONs for biomedical applications especially for DNA repair detection.

Efficient treatment of breast cancer xenografts with multifunctionalized iron oxide nanoparticles combining magnetic hyperthermia and anti-cancer drug delivery.

INTRODUCTION: Tumor cells can effectively be killed by heat, e.g. by using magnetic hyperthermia. The main challenge in the field, however, is the generation of therapeutic temperatures selectively in the whole tumor region. We aimed to improve magnetic hyperthermia of breast cancer by using innovative nanoparticles which display a high heating potential and are functionalized with a cell internalization and a chemotherapeutic agent to increase cell death. METHODS: The superparamagnetic iron oxide nanoparticles (MF66) were electrostatically functionalized with either Nucant multivalent pseudopeptide (N6L; MF66-N6L), doxorubicin (DOX; MF66-DOX) or both (MF66-N6LDOX). Their cytotoxic potential was assessed in a breast adenocarcinoma cell line MDA-MB-231. Therapeutic efficacy was analyzed on subcutaneous MDA-MB-231 tumor bearing female athymic nude mice. RESULTS: All nanoparticle variants showed an excellent heating potential around 500 W/g Fe in the alternating magnetic field (AMF, conditions: H=15.4 kA/m, f=435 kHz). We could show a gradual inter- and intracellular release of the ligands, and nanoparticle uptake in cells was increased by the N6L functionalization. MF66-DOX and MF66-N6LDOX in combination with hyperthermia were more cytotoxic to breast cancer cells than the respective free ligands. We observed a substantial tumor growth inhibition (to 40% of the initial tumor volume, complete tumor regression in many cases) after intratumoral injection of the nanoparticles in vivo. The proliferative activity of the remaining tumor tissue was distinctly reduced. CONCLUSION: The therapeutic effects of breast cancer magnetic hyperthermia could be strongly enhanced by the combination of MF66 functionalized with N6L and DOX and magnetic hyperthermia. Our approach combines two ways of tumor cell killing (magnetic hyperthermia and chemotherapy) and represents a straightforward strategy for translation into the clinical practice when injecting nanoparticles intratumorally.

Detection of GNAQ mutations and reduction of cell viability in uveal melanoma cells with functionalized gold nanoparticles.

BACKGROUND: Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Early treatment may improve any chances of preventing metastatic disease, but diagnosis of small UM is challenging. Up to 95 % of all UMs carry somatic mutations in the G-coupled proteins GNAQ and GNA11 promoting anchorage-independent growth and proliferation. About 50 % of UMs are fatal. Once metastatic, patients have limited options for successful therapy. METHODS: We have developed functionalized gold nanoparticles (AuNPs) to visualize transcripts of mutant GNAQ mRNA in living cells. In addition to their suitability as a specific tool for GNAQ mutation detection, we have developed a novel linker that enables conjugation of siRNAs to AuNPs allowing for greater and more rapid intracellular release of siRNAs compared to previously described approaches. RESULTS: Binding of modified AuNPs to matching target mRNA leads to conformational changes, resulting in a detectable fluorescent signal that can be used for mutation detection in living cells. Knockdown of GNAQ with siRNA-AuNPs effectively reduced downstream signals and decreased cell viability in GNAQ mutant uveal melanoma cells. CONCLUSION: AuNPs may in future be developed to serve as sensors for mutations of vital importance. The new release system for siRNA-AuNP improves previous systems, which conceivably will be useful for future therapeutic gene regulatory approaches.

Glutathione-triggered drug release from nanostructures.

The delivery of drugs can be improved with the use of different carriers, such as those based on nanoparticles. The nanostructures loaded with the therapeutic molecules should be able to reach the target cells and, what is more, release the drugs efficiently. Ideally, the drugs should be delivered only in the target cells, and not along their way to the cells. For these reasons several approaches have been developed to control the release of the drugs at the desired sites. In this review article we have summarized the reports that describe the use of glutathione to trigger the release of the therapeutic molecules from different nanostructures.

Multifunctionalization of magnetic nanoparticles for controlled drug release: a general approach.

In this study, a general approach for the multifunctionalization of magnetic nanoparticles (MNPs) with drugs (Doxorubicin and Gemcitabine) and targeting moieties (Nucant pseudopeptide) for controlled and selective release is described. The functionalization is achieved by the formation of disulfide bonds between MNPs and drugs derivatives synthesized in this work. Our strategy consists in the introduction of a pyridyldisulfide moiety to the drugs that react efficiently with sulfhydryl groups of pre-activated MNPs. This approach also allows the quantification of the covalently immobilized drug by measuring the amount of the 2-pyridinethione released during the process. The linkers developed here allow the release of drugs without any chemical modification. This process is triggered under highly reducing environment, such as that present inside the cells. Complete release of drugs is achieved within 5-8 h under intracellular conditions whereas negligible percentage of release is observed in extracellular conditions. We propose here a modular general approach for the functionalization of nanoparticles that can be used for different types of drugs and targeting agents.