RESUMEN
Electrochemical in situ sensing of small signal molecules released from living cells has an increasing significance in early diagnosis, pathological analyses, and drug discovery. Here, a living cell-fixed sensing platform was built using the BC@DNA-Mn3(PO4)2 nanozyme, in which a highly biocompatible bacterial cellulose riveted with very tiny Mn3(PO4)2; it not only delivers high catalytic activity toward superoxide anions but possesses excellent biocompatibility for cell adsorption and growth. Additionally, the experimental results suggested that fixing the living cells on the surface of the sensing platform facilitates tiny Mn3(PO4)2 activity centers to capture and detect O2â¢- very quickly and simultaneously has great potential in miniaturization, cost reduction, and real-time monitoring.
Asunto(s)
Materiales Biocompatibles/química , Celulosa/química , ADN/química , Nanoestructuras/química , Compuestos Organometálicos/química , Superóxidos/análisis , Materiales Biocompatibles/síntesis química , Técnicas Biosensibles , Electrodos , Humanos , Tamaño de la Partícula , Superóxidos/metabolismo , Propiedades de Superficie , Factores de Tiempo , Células Tumorales CultivadasRESUMEN
The vast majority of early Paleozoic ecdysozoan worms are often resolved as stem-group Priapulida based on resemblances with the rare modern representatives of the group, such as the structure of the introvert and the number and distribution of scalids (a spiny cuticular outgrowth) and pharyngeal teeth. In Priapulida, both scalids and teeth create symmetry patterns, and three major diagnostic features are generally used to define the group: 25 longitudinal rows of scalids (five-fold symmetry), 8 scalids around the first introvert circle and the pentagonal arrangement of pharyngeal teeth. Here we describe Ercaivermis sparios gen. et sp. nov., a new priapulid from the early Cambrian Chengjiang Lagerstätte, characterized by an annulated trunk lacking a sclerotized ornament, four pairs of anal hooks and 16 longitudinal rows of scalids along its introvert and eight scalids around each introvert circle, giving the animal an unusual octoradial symmetry. Cladistic analyses resolve Ercaivermis as a stem-group priapulid. Ercaivermis also suggests that several biradial symmetry patterns (e.g., pentagonal, octagonal) expressed in the cuticular ornament, may have co-existed among early Cambrian priapulids and that the pentaradial mode may have become rapidly dominant during the course of evolution, possibly via the standardization of patterning, i.e., the natural selection of one symmetry type over others.
RESUMEN
Current macrocapsules with semipermeable but immunoprotective polymeric membranes are attractive devices to achieve the purpose of immunoisolation, however, their ability to allow diffusion of essential nutrients and oxygen is limited, which leads to a low survival rate of encapsulated cells. Here, a novel method is reported by taking advantage of thermotropic liquid crystals, sodium laurylsulfonate (SDS) liquid crystals (LCs), and rod-like crystal fragments (LCFs) to develop engineered alginate hydrogels with rod-like channels. This cell-isolation capsule with an engineered alginate hydrogel-wall allows small molecules, large molecules, and bacteria to diffuse out from the capsules freely but immobilizes the encapsulated cells inside and prevents cells in the microenvironment from moving in. The encapsulated cells show a high survival rate with isolation of host immune cells and long-term growth with adequate nutrients and oxygen supply. In addition, by sharing and responding to the normal molecular and vesicular microenvironment (NMV microenvironment), encapsulated cancer cells display a transition from tumorous phenotypes to ductal features of normal epithelial cells. Thus, this device will be potentially useful for clinical application in cell therapy by secreting molecules and for establishment of patient-derived xenograft (PDX) models that are often difficult to achieve for certain types of tumors, such as prostate cancer.
Asunto(s)
Hidrogeles , Neoplasias , Alginatos/química , Cápsulas/química , Difusión , Humanos , Hidrogeles/química , Masculino , Neoplasias/tratamiento farmacológico , PolímerosRESUMEN
Square-planar polypyridine platinum(II) complexes have been introduced into a silica/polymer matrix by covalent ligand modification. The photophysical properties of the supported matrices are well retained as their model complexes, and the quantum yields for singlet oxygen ((1)O(2)) generation are comparable with that of TPP (tetraphenylporphyrin) under similar conditions. A preliminary application in photosensitized oxidation indicates the silica/polymer-supported matrices are promising, which can be reused without loss of reactivity by a simple filtration. Moreover, the polymer-supported matrix exhibits excellent compatibility in various solvents.