Search bioRxiv⌕ Search

Biology subjects

Sander, A.

Publications and source records attributed to Sander, A..

2 recordsLinked to original sources

Comparison of musculoskeletal robot biomechanical properties to human participants using motion study

Advanced robotic systems that replicate musculoskeletal structure and function have significant potential for a wide range of applications. Although they are proposed to be better platforms for biomedical applications, little is known about how well current musculoskeletal humanoid systems mimic the motion and force profiles of humans. This is particularly relevant to the field of tendon tissue engineering, where engineered grafts require advanced bioreactor systems that accurately replicate the kinetic and kinematic profiles experienced by the humans in vivo. A motion study was conducted comparing the kinetic and kinematic profiles produced by a musculoskeletal humanoid robot shoulder to a group of human participants completing abduction/adduction tasks. Results from the study indicate that the humanoid arm can be programed to either replicate the kinematic profile or the kinetic profile of human participants during task completion, but not both simultaneously. This study supports the use of humanoid robots for applications such as tissue engineering and highlights suggestions to further enhance the physiologic relevance of musculoskeletal humanoid robotic platforms.

bioengineering↗

OCT4 interprets and enhances nucleosome flexibility

Pioneer transcription factors are proteins that induce cellular identity transitions by binding to inaccessible regions of DNA in nuclear chromatin. They contribute to chromatin opening and recruit other factors to regulatory DNA elements. The structural features and dynamics modulating their interaction with nucleosomes are still unresolved. From a combination of experiments and molecular simulations, we reveal here how the pioneer factor and master regulator of pluripotency, Oct4, interprets and enhances nucleosome structural flexibility. The magnitude of Oct4s impact on nucleosome dynamics depends on the binding site position and the mobility of the unstructured tails of nucleosomal histone proteins. Oct4 propagates and stabilizes open nucleosome conformations by specific sequence recognition and nonspecific DNA exploration. Our findings provide a structural basis for the versatility of transcription factors in engaging with nucleosomes and have implications for understanding how pioneer factors induce chromatin dynamics.

biophysics↗