micromanipulation, magnetic guidance, magnetic microrobot, dot-matrix magnetic flux density, tissue engineering, Mechanical engineering and machinery, and TJ1-1570
In this paper, a magnetically guided micromanipulation method is proposed to accurately create artistic patterns with magnetic microrobots in a liquid environment for tissue engineering. A magnetically guided device is developed depend on symmetrical combination of square permanent magnets and array layout of soft magnetic wires, which changed the space distribution of magnetic field of conventional permanent magnet and generated powerful magnetic flux density and high magnetic field gradient. Furthermore, the morphological structure of the magnetic microrobot is flexibly adjusted via precise control of the volumetric flow rates inside the microfluidic device and the magnetic nanoparticles are taken along to enable its controllability by rapid magnetic response. And then, the spatial posture of the magnetic microrobot is contactless controlled by the magnetically guided manipulator and it is released under the influence of surface tension and gravity. Subsequently, the artistic fashions of the magnetic microrobots are precisely distributed via the dot-matrix magnetic flux density of the magnetically guided device. Finally, the experimental results herein demonstrate the accuracy and diversity of the pattern structures in the water and the developed method will be providing a new way for personalized functional scaffold construction.
Masaru Takeuchi, Taro Kozuka, Eunhye Kim, Akihiko Ichikawa, Yasuhisa Hasegawa, Qiang Huang, and Toshio Fukuda
Journal of Functional Biomaterials, Vol 11, Iss 1, p 18 (2020)
microfabrication, cell culture, microfluidics, biodegradable material, photo cross-linkable material, Biotechnology, TP248.13-248.65, Medicine (General), and R5-920
We developed a procedure for fabricating movable biological cell structures using biodegradable materials on a microfluidic chip. A photo-cross-linkable biodegradable hydrogel gelatin methacrylate (GelMA) was used to fabricate arbitrary microstructure shapes under a microscope using patterned ultraviolet light. The GelMA microstructures were movable inside the microfluidic channel after applying a hydrophobic coating material. The fabricated microstructures were self-assembled inside the microfluidic chip using our method of fluid forcing. The synthesis procedure of GelMA was optimized by changing the dialysis temperature, which kept the GelMA at a suitable pH for cell culture. RLC-18 rat liver cells (Riken BioResource Research Center, Tsukuba, Japan) were cultured inside the GelMA and on the GelMA microstructures to check cell growth. The cells were then stretched for 1 day in the cell culture and grew well on the GelMA microstructures. However, they did not grow well inside the GelMA microstructures. The GelMA microstructures were partially dissolved after 4 days of cell culture because of their biodegradability after the cells were placed on the microstructures. The results indicated that the proposed procedure used to fabricate cell structures using GelMA can be used as a building block to assemble three-dimensional tissue-like cell structures in vitro inside microfluidic devices.
International Journal of Infectious Diseases, Vol 77, Iss , Pp 8-13 (2018)
Infectious and parasitic diseases and RC109-216
Objectives: Few studies on human papillomavirus (HPV) have been conducted in Mongolia. This study was performed to evaluate the prevalent HPV genotypes and their associations with cytology and demographic and behavioral characteristics in Mongolian women with cervical abnormalities. Methods: Exfoliated cell samples of 100 women who had a previous history of cervical abnormality were collected. Cytological interpretation was conducted microscopically and HPV genotyping was performed using the Roche Linear Array test. Study questionnaires were completed. Results: Overall, 25 HPV genotypes were detected in 47% of participants, and the most prevalent were HPV 16, 52, 58, and 33. Cytological examination revealed 12% of participants had atypical squamous cells of undetermined significance (ASC-US), 8% had low-grade squamous intraepithelial lesions (LSIL), 7% had high-grade squamous intraepithelial lesions (HSIL), and 14% had squamous cell carcinoma (SCC), while 59% of women had a normal cytology. HPV 16 was the most common type among women with a normal cytology and cervical cancer. However, women with cervical abnormalities including LSIL and HSIL were predominantly infected with HPV 52. Moreover, women aged
Haojian Lu, Mei Zhang, Yuanyuan Yang, Qiang Huang, Toshio Fukuda, Zuankai Wang, and Yajing Shen
Nature Communications, Vol 9, Iss 1, Pp 1-7 (2018)
Despite the enormous potential of magnetically-guided soft robots for various applications, challenges related to inefficient locomotion in harsh environments hinder its development. Here, the authors demonstrate a multi-legged millirobot with excellent locomotion capability in harsh environments.