RESUMO
Biohybrid microswimmers, which are realized through the integration of motile microscopic organisms with artificial cargo carriers, have a significant potential to revolutionize autonomous targeted cargo delivery applications in medicine. Nonetheless, there are many open challenges, such as motility performance and immunogenicity of the biological segment of the microswimmers, which should be overcome before their successful transition to the clinic. Here, we present the design and characterization of a biohybrid microswimmer, which is composed of a genetically engineered peritrichously flagellated Escherichia coli species integrated with red blood cell-derived nanoliposomes, also known as nanoerythrosomes. Initially, we demonstrated nanoerythrosome fabrication using the cell extrusion technique and characterization of their size and functional cell membrane proteins with dynamic light scattering and flow cytometry analyses, respectively. Then, we showed the construction of biohybrid microswimmers through the conjugation of streptavidin-modified bacteria with biotin-modified nanoerythrosomes by using non-covalent streptavidin interaction. Finally, we investigated the motility performance of the nanoerythrosome-functionalized biohybrid microswimmers and compared it with the free-swimming bacteria. The microswimmer design approach presented here could lead to the fabrication of personalized biohybrid microswimmers from patients' own cells with high fabrication efficiencies and motility performances.
RESUMO
This article explores the use of the postrotary nystagmus (PRN) test for children younger than current norms (children 4.0 yr-8.11 yr). In the first study, 37 children ages 4-9 yr were examined in the standard testing position and in an adult-held adapted position to determine whether holding a child affected the reflex. Because the position did not affect the reflex, in the second study, PRN in 44 children ages 2 mo-47 mo was compared with published normative mean raw scores for 44 children age 5 yr to determine whether norms for older children were applicable to younger children. No statistically significant differences were found between <4-yr-old and 5-yr-old children, suggesting that the PRN test can be used in infants and toddlers with valid comparison to current norms for 4-yr-olds on the Sensory Integration and Praxis Tests (4.0 yr-8.11 yr). Future research exploring the predictive value of this measure is warranted.
