Advances in surface design and biomedical applications of magnetic nanoparticles.

Despite significant efforts by scientists in the development of advanced nanotechnology materials for smart diagnosis devices and drug delivery systems, the success of clinical trials remains largely elusive. In order to address this biomedical challenge, magnetic nanoparticles (MNPs) have gained attention as a promising candidate due to their theranostic properties, which allow the simultaneous treatment and diagnosis of a disease. Moreover, MNPs have advantageous characteristics such as a larger surface area, high surface-to-volume ratio, enhanced mobility, mass transference and, more notably, easy manipulation under external magnetic fields. Besides, certain magnetic particle types based on the magnetite (Fe3O4) phase have already been FDA-approved, demonstrating biocompatible and low toxicity. Typically, surface modification and/or functional group conjugation are required to prevent oxidation and particle aggregation. A wide range of inorganic and organic molecules have been utilized to coat the surface of MNPs, including surfactants, antibodies, synthetic and natural polymers, silica, metals, and various other substances. Furthermore, various strategies have been developed for the synthesis and surface functionalization of MNPs to enhance their colloidal stability, biocompatibility, good response to an external magnetic field, etc. Both uncoated MNPs and those coated with inorganic and organic compounds exhibit versatility, making them suitable for a range of applications such as drug delivery systems (DDS), magnetic hyperthermia, fluorescent biological labels, biodetection and magnetic resonance imaging (MRI). Thus, this review provides an update of recently published MNPs works, providing a current discussion regarding their strategies of synthesis and surface modifications, biomedical applications, and perspectives.

Wolbachia, Cardinium and climate: an analysis of global data.

Bacterial endosymbionts are very common in terrestrial arthropods, but infection levels vary widely among populations. Experiments and within-species comparisons suggest that environmental temperature might be important in explaining this variation. To investigate the importance of temperature, at broad geographical and taxonomic scales, we extended a global database of terrestrial arthropods screened for Wolbachia and Cardinium. Our final dataset contained data from more than 117 000 arthropods (over 2500 species) screened for Wolbachia and more than 18 000 arthropods (over 800 species) screened for Cardinium, including samples from 137 different countries, with mean temperatures varying from -6.5 to 29.2°C. In insects and relatives, Cardinium infection showed a clear and consistent tendency to increase with temperature. For Wolbachia, a tendency to increase with temperature in temperate climates is counteracted by reduced prevalence in the tropics, resulting in a weak negative trend overall. We discuss the implications of these results for natural and introduced symbionts in regions affected by climate change.

[Study of 176 HIV-seropositive children in Santa Catarina State]. / Estudo de 176 crianças soropositivas para o HIV em Santa Catarina.

OBJECTIVE: The incidence of the acquired immunodeficiency syndrome (AIDS) has increased in Santa Catarina State in Brazil over the last years, with a high number of infected women and children. The purpose of this study was to establish the main characteristics of the children from this State whose HIV serologic tests were positive. METHODS: This was a descriptive study of 176 children with positive serologic tests to HIV, conducted in the Hospital Infantil Joana de Gusmão, Florianópolis City, Santa Catarina State, Brazil. RESULTS: Most of the children (105 cases, 59.6%) were born in Florianópolis, Capital of Santa Catarina State, and Itajaí (22 cases, 12.5%). Vertical transmission of HIV was observed in 167 patients (94.9%). Among 167 HIV-positive mothers, 77 (46.1%) of them acquired the virus by sexual transmission and 35 (21.0%) by use of injectable drugs. However, among 89 HIV-positive fathers, 63 (70.7%) of them used to take drugs. The average age of the HIV-positive children whose serologic tests became negative was 10.5 months. Among 103 symptomatic patients, 87 (84.5%) presented hepatomegaly, 81 (78.6%) lymphadenopathy, 66 (64.0%) splenomegaly, 59 (57.3%) skin bruises, 54 (52.4%) recurrent bronchopneumonia and 50 cases (48.5%) recurrent diarrhea. The most frequent opportunistic infection was mucocutaneous candidiasis that occurred in 41 children (39.8%). CONCLUSIONS: The characteristics were similar to those reported in the literature. A great concentration of HIV infected persons was observed in the coast area where there are three harbor towns, an elevated number of injectable drug users and presence of many tourists.