Functionalized Platinum Nanoparticles with Biomedical Applications.

Functionalized platinum nanoparticles have been of considerable interest in recent research due to their properties and applications, among which they stand out as therapeutic agents. The functionalization of the surfaces of nanoparticles can overcome the limits of medicine by increasing selectivity and thereby reducing the side effects of conventional drugs. With the constant development of nanotechnology in the biomedical field, functionalized platinum nanoparticles have been used to diagnose and treat diseases such as cancer and infections caused by pathogens. This review reports on physical, chemical, and biological methods of obtaining platinum nanoparticles and the advantages and disadvantages of their synthesis. Additionally, applications in the biomedical field that can be utilized once the surfaces of nanoparticles have been functionalized with different bioactive molecules are discussed, among which antibodies, biodegradable polymers, and biomolecules stand out.

Resiniferatoxin promotes adult worm expulsion in Trichinella spiralis-infected rats by Th2 immune response modulation.

BACKGROUND: The immune response during T spiralis infection is characterized by an increase in eosinophils and mast cells, as well as Th2 cytokine production, such as interleukin (IL)-4, IL-10 and IL-13, promoting T spiralis expulsion from the host. However, this response damages the host, favouring the parasite survival. In the search for new pharmacological strategies that protect against T spiralis infection, a recent study showed that treatment with resiniferatoxin (RTX) modulates the Th1 cytokines production, reducing muscle parasite burden. OBJECTIVE: To evaluate the effect of RTX treatment on the Th2 cytokines production, the number of eosinophils, mast cells and the intestinal expulsion of T spiralis. METHODS: Serum levels of IL-4, IL-10 and IL-13 were quantified by ELISA; the number of eosinophils, mast cells and the adult worms of T spiralis in the small intestine was quantified. RESULTS: RTX treatment increased serum levels of IL-4, IL-10 and IL-13, and it decreases intestinal eosinophilia, however, favours the mastocytosis, promoting T spiralis intestinal expulsion. CONCLUSIONS: These findings suggest that RTX is capable to modulate the Th2 immune response, promoting T spiralis expulsion, which contributes to the defence against T spiralis infection, placing the RTX as a potential immunomodulatory drug.

Effect of treatment with resiniferatoxin in an experimental model of pulpal inflammatory in mice.

AIM: To evaluate whether treatment with resiniferatoxin (RTX) is capable of lowering the plasma levels of PGE2 and TNF-α, as well as histopathological parameters in inflammation of pulp tissue in a mouse experimental model. METHODOLOGY: Ten groups of six BALB/c mice were formed as follows: healthy group (HC ), healthy group treated with RTX (HRTX ), two groups with pulp inflammation at 14 and 18 hours (PI14 /PI18 ), six groups with pulpal inflammation plus treatment with Ibuprofen (IBU14 /IBU18 ), dexamethasone (DEX14 /DEX18 ) and resiniferatoxin (RTX14 /RTX18 ) at 14 and 18 hours, respectively. Pulpal inflammation was induced through occlusal exposure of the pulp of the maxillary first molar. The plasma levels of PGE2 and TNF-α and the histological parameters of the pulp tissue of the HC and HRTX groups were evaluated at the time of acquiring the animals. In the other groups, the plasma levels of PGE2 and TNF-α and the histopathological parameters were evaluated at 14 and 18 hours after pulp damage. Plasma levels of PGE2 and TNF-α were quantified by ELISA, and the histopathological parameters were evaluated by H/E staining. Statistical significance was determined by one-way analysis of variance (ANOVA) to test for overall differences between group means. RESULTS: A significant increase (*p < .05) in plasma levels of PGE2 and TNF-α occurred 14 and 18 hours after pulp damage. In addition, treatment with RTX significantly decreased (*p < .05) the plasma levels of PGE2 and TNF-α at 14 and 18 hours after pulp damage, as well as the infiltrate of inflammatory cells at 18 hours after pulp damage, similarly to treatment with ibuprofen and dexamethasone. CONCLUSION: It was possible to detect systemic levels of PGE2 and TNF-α at 14 and 18 hours after pulp damage. Likewise, treatment with RTX was associated with an anti-inflammatory effect similar to treatment with ibuprofen and dexamethasone. These findings place resiniferatoxin as a therapeutic alternative in the treatment of inflammatory diseases in Dentistry.

Therapeutic Effects of Resiniferatoxin Related with Immunological Responses for Intestinal Inflammation in Trichinellosis.

The immune response against Trichinella spiralis at the intestinal level depends on the CD4+ T cells, which can both suppress or promote the inflammatory response through the synthesis of diverse cytokines. During the intestinal phase, the immune response is mixed (Th1/Th2) with the initial predominance of the Th1 response and the subsequent domination of Th2 response, which favor the development of intestinal pathology. In this context, the glucocorticoids (GC) are the pharmacotherapy for the intestinal inflammatory response in trichinellosis. However, its therapeutic use is limited, since studies have shown that treatment with GC suppresses the host immune system, favoring T. spiralis infection. In the search for novel pharmacological strategies that inhibit the Th1 immune response (proinflammatory) and assist the host against T. spiralis infection, recent studies showed that resiniferatoxin (RTX) had anti-inflammatory activity, which decreased the serum levels of IL-12, INF-γ, IL-1ß, TNF-α, NO, and PGE2, as well the number of eosinophils in the blood, associated with decreased intestinal pathology and muscle parasite burden. These researches demonstrate that RTX is capable to inhibit the production of Th1 cytokines, contributing to the defense against T. spiralis infection, which places it as a new potential drug modulator of the immune response.

Functionalized Metal Nanoparticles in Cancer Therapy.

Currently, there are many studies on the application of nanotechnology in therapy. Metallic nanoparticles are promising nanomaterials in cancer therapy; however, functionalization of these nanoparticles with biomolecules has become relevant as their effect on cancer cells is considerably increased by photothermal and photodynamic therapies, drug nanocarriers, and specificity by antibodies, resulting in new therapies that are more specific against different types of cancer. This review describes studies on the effect of functionalized palladium, gold, silver and platinum nanoparticles in the treatment of cancer, these nanoparticles themselves show an anticancer effect. This effect is further enhanced when the NPs are functionalized with either antibodies, DNA, RNA, peptides, proteins, or folic acid and other molecules. These NPs can penetrate the cell and accumulate in the tumor tissue, resulting in a cytotoxic effect through the generation of ROS, the induction of apoptosis, cell cycle arrest, DNA fragmentation, and a photothermal effect. NP-based therapy is a new strategy that can be used synergistically with chemotherapy and radiotherapy to achieve more effective therapies and reduce side effects.

Two-Step Triethylamine-Based Synthesis of MgO Nanoparticles and Their Antibacterial Effect against Pathogenic Bacteria.

Magnesium oxide nanoparticles (MgO NPs) were obtained by the calcination of precursor microparticles (PM) synthesized by a novel triethylamine-based precipitation method. Scanning electron microscopy (SEM) revealed a mean size of 120 nm for the MgO NPs. The results of the characterizations for MgO NPs support the suggestion that our material has the capacity to attack, and have an antibacterial effect against, Gram-negative and Gram-positive bacteria strains. The ability of the MgO NPs to produce reactive oxygen species (ROS), such as superoxide anion radicals (O2•-) or hydrogen peroxide (H2O2), was demonstrated by the corresponding quantitative assays. The MgO antibacterial activity was evaluated against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria, with minimum inhibitory concentrations (MICs) of 250 and 500 ppm on the microdilution assays, respectively. Structural changes in the bacteria, such as membrane collapse; surface changes, such as vesicular formation; and changes in the longitudinal and horizontal sizes, as well as the circumference, were observed using atomic force microscopy (AFM). The lipidic peroxidation of the bacterial membranes was quantified, and finally, a bactericidal mechanism for the MgO NPs was also proposed.

Dysregulation of the Th1/Th2 cytokine profile is associated with immunosuppression induced by hypothalamic-pituitary-adrenal axis activation in mice.

Hypothalamic-pituitary-adrenal (HPA) axis activation-induced immunosuppression is associated with increased concentration of circulating corticosterone and impaired cellular immune responses. The purpose of this study was to investigate the effect of chronic HPA axis activation on the cellular immune response, Th1/Th2 cytokine profile, and concentration of corticosterone. Mice were divided into two groups: a control group comprised of healthy, untreated mice that received no stress, and an HPA axis-activated group that received stress through electric shock (ES). The delayed-type hypersensitivity reaction to dinitrofluorobenzene, splenocyte proliferative response to mitogens Concanavalin A and lipopolysaccharide, Th1 and Th2 profile, and TGF-beta1 production were measured in plasma and in culture supernatants. The corticosterone concentration was also measured in plasma. In the ES group, elevated plasma corticosterone concentration was associated with immunosuppression and a significant decrease in plasma concentrations of IL-2, IL-4, and TGF-beta1. In vitro IL-2 production in response to Con A was significantly lower in the ES group than in the control group. TGF-beta1 production in nonstimulated and stimulated cultures in response to either mitogen was significantly lower in the ES group than in the control group. Plasma concentrations of IFN-gamma and IL-10 did not differ significantly between groups. The concentrations of IFN-gamma, IL-4, and IL-10 in the supernatants of splenocytes stimulated with either mitogen and IL-4 production by nonstimulated cells were significantly higher in the ES group than in the control group. These results suggest that corticosterone mediates the immunosuppression induced by HPA axis activation, and induces dysregulation of the Th1/Th2 cytokine profile.

Correlación del factor neurotrófico derivado del cerebro con los componentes que integran el síndrome metabólico infantil / Correlation of brain derived neurotrophic factor with the components that integrate the child metabolic syndrome

La obesidad infantil representa un factor importante en el desarrollo del síndrome metabólico (SM). En este sentido el factor neurotrófico derivado del cerebro (BDNF: Brain Derived Neurotrophic Factor) interviene en el metabolismo energético así como en vías que controlan el peso corporal y desórdenes metabólicos. El objetivo de este estudio fue determinar si hay una correlación entre el BDNF con los marcadores que definen al síndrome metabólico en una población infantil de México. Se integraron al estudio 100 niños con un rango de edad de 5-13 años, se estratificaron en tres grupos, normo peso, sobrepeso y obesidad, a los cuales se les determinaron las variables antropométricas, percentil de la tensión arterial sistólica y diastólica, concentraciones séricas de glucosa, triglicéridos, colesterol de alta densidad (HDL) y BDNF. Se aplicó ANOVA y una correlación de Pearson. Los resultados muestran que la prevalencia de SM utilizando los criterios de Cook y Weiss fue del 14%, mientras que por la Federación Internacional de Diabetes (IDF) es del 11%. La circunferencia de cintura, triglicéridos, colesterol HDL, presión arterial sistólica/diastólica y glucosa, mostraron diferencias significativas entre los grupos estudiados (*p<0,001). El BDNF se correlacionó positivamente con la desviación estándar del índice de masa corporal de acuerdo con la edad (DE-IMCE) (p=0,01), el percentil del perímetro de la cintura (p=0,00), la presión arterial sistólica (p=0,01) y las concentraciones plasmáticas de glucosa (p=0,02). Estos datos muestran que existe una correlación entre el BDNF con la DE-IMCE, la circunferencia de la cintura, la presión arterial sistólica y glucosa(AU)

Childhood obesity represents an important factor in the development of metabolic syndrome (MS). In this sense, the brain derived neurotrophic factor (BDNF) is involved in energy metabolism as well as in pathways that control body weight and metabolic disorders. The objective of this study was to determine if there is a correlation between BDNF with the markers that define the metabolic syndrome in a child population in Mexico. The study included 100 children with an age range of 5-13 years, stratified into three groups, normal weight, overweight and obesity, which were determined anthropometric variables, percentile of systolic and diastolic blood pressure, concentrations serum glucose, triglycerides, high density cholesterol (HDL) and BDNF. ANOVA and Pearson correlation were applied. The results show that the prevalence of MS using the Cook and Weiss criteria was 14%, while for the International Diabetes Federation (IDF) it is 11%. Waist circumference, triglycerides, HDL cholesterol, systolic/diastolic blood pressure and glucose showed significant differences between the groups studied (*p<0.001). The BDNF was positively correlated with the standard deviation of the body mass index according to age (DE-IMCE) (p=0.01), the percentile of the waist circumference (p=0.00), systolic blood pressure (p=0.01) and plasma glucose concentrations (p=0.02). These data show that there is a correlation between BDNF with DE-IMCE, waist circumference, systolic blood pressure and glucose(AU)