Near-infrared PbS quantum dots functionalized with affibodies and ZnPP for targeted imaging and therapeutic applications

We report a new theranostic device based on lead sulfide quantum dots (PbS QDs) with optical emission in the near infrared wavelength range decorated with affibodies (small 6.5 kDa protein-based antibody replacements) specific to the cancer biomarker human epidermal growth factor receptor 2 (HER2), and zinc(II) protoporphyrin IX (ZnPP) to combine imaging, targeting and therapy within one nanostructure. Colloidal PbS QDs were synthesized in aqueous solution with a nanocrystal diameter of ~ 5 nm and photoluminescence emission in the near infrared wavelength range. The ZHER2:432 affibody, mutated through the introduction of two cysteine residues at the C-terminus (Afb2C), was used as capping ligand to form Afb2C-PbS QDs which have a high binding affinity for HER2 which is overexpressed in several types of cancer including breast cancer. Afb2C-PbS QDs were further modified by conjugation with ZnPP, which acts as an anticancer agent. The biological activity of these QDs was tested against SKBR3 (HER2-positive) and MDA-MB-231 (HER2-normal) breast cancer cells, with results showing that ZnPP-Afb2C-functionalized PbS QDs were successfully targeted to the HER2-overexpressing cancer cells and induced cell apoptosis thanks to the conjugation with ZnPP. These results expand the use of the QD nanoplatform with the formulation of novel nanomaterials for targeted delivery and combined imaging and therapy via direct surface-protein interaction

Impact of a participatory program to reduce noise in a Neonatal Unit Impacto de un programa participativo de reducción de ruido en una unidad neonatal Impacto de um programa participativo de redução do ruído em unidade neonatal

This study evaluated the impact of a participatory program to reduce noise in a neonatal intermediate care unit of a university hospital. A time-series quasi-experimental design was used, in which sound pressure levels were measured before and after the intervention was implemented using the Quest-400 dosimeter. Non-parametric statistical tests were used to compare noise with the level of significance fixed at 5%. Results showed significant reduction of sound pressure levels in the neonatal unit after the intervention program was implemented (p<0.0001). The average Leq before the intervention was 62.5dBA and was reduced to 58.8dBA after the intervention. A reduction of 7.1dBA in the average Lmax(from 104.8 to 87.7dBA) and of 30.6dBA in the average Lpeak(from 138.1 to 107.5dBA) was observed. The program was proven to be effective in significantly reducing noise levels in the neonatal unit, although levels were still more intense than recommended.<br>El objetivo fue evaluar el impacto de un programa participativo en la reducción del ruido ambiente en una unidad neonatal de un hospital universitario. Se utilizó delineamiento casi-experimental del tipo tiempo-serie, en el cual los niveles de presión sonora fueron mensurados antes y después de la implantación del programa de intervención, utilizando el dosímetro Quest-400. Para el análisis comparativo del ruido, se utilizaron las pruebas estadísticas no paramétricas (&#945;=0,05). Se constató reducción significativa de los niveles de presión sonora de la unidad neonatal después de la implantación del programa de intervención (p<0,0001). El Leq medio fue de 62,5dBA antes de la intervención y se redujo para 58,8dBA después de la intervención. Hubo reducción de 7,1dBA en el Lmax medio (de 104,8 para 87,7dBA) y de 30,6dBA en el Lpeak medio (de 138,1 para 107,5dBA). Se concluye que el programa fue efectivo en la reducción del nivel sonoro de la unidad neonatal, a pesar de que todavía se mantiene más intenso que lo recomendable.<br>O objetivo deste estudo foi avaliar o impacto de um programa participativo na redução do ruído ambiente em uma unidade neonatal, de um hospital universitário. Utilizou-se delineamento quase-experimental do tipo tempo-série, no qual os níveis de pressão sonora foram dimensionados antes e após a implantação do programa de intervenção, utilizando o dosímetro Quest-400. Para a análise comparativa do ruído, utilizaram-se os testes estatísticos não-paramétricos (&#945;=0,05). Constatou-se redução significativa dos níveis de pressão sonora da unidade neonatal, após a implantação do programa de intervenção (p<0,0001). O Leq médio foi de 62,5dBA antes da intervenção e reduziu para 58,8dBA após a intervenção. Houve redução de 7,1dBA no Lmax médio (de 104,8 para 87,7dBA) e de 30,6dBA no Lpeak médio (de 138,1 para 107,5dBA). Concluiu-se que o programa foi efetivo na redução do nível sonoro da unidade neonatal, embora ainda se mantenha mais intenso que o recomendável