Page 64 - ASME_NEMB_2016_Program

Technical Program TRACK 5

crobubble captures and immobilizes the biological particles on the substrate Jianhe Guo, University of Texas at Austin, Austin, TX, United States,
through coordinated actions of Marangoni convection, surface tension, Donglei Fan, The University of Texas At Austin, Austin, TX, United
gas pressure, and substrate adhesion. Through directing the laser beam to States
move the microbubble, we create arbitrary patterns of particles and cells
with different architectures. With the low-power operation, versatility, and Catalytic nanomotors, which are autonomous self-propelled nanoscale
biocompatibility, the bubble-pen lithography will find a wide range of appli- devices powered by the conversion of chemical energy into mechanical mo-
cations in biology and medicine. tion, have attracted keen interest due to their potential in the near future to
revolutionize emerging topics in multidisciplinary nanotechnology, medicine,
12:20pm Investigation Of Anodic Alumina-Based Biomaterials sensing, and environmental science. Recent efforts aimed at enhancing
For Improved Nerve-Material Interaction the performance of catalytic nanomotors resulted in an increased speed
and power along with a larger cargo-towing force. However, the movement
Technical Presentation. NEMB2016-5983 directions of these catalytic nanomotors are usually random and constantly
changing with time. It is highly desirable to control the transport directions
Sevde Altuntas, TOBB University of Economics and Technology, of the catalytic nanomotors for practical usage. The most widely used tech-
nique reported previously is the magnetic tweezers for guiding the moving
ANKARA,Turkey, Buket Altinok, Belma Aslim, Gazi University, AN- directions of catalytic nanomotors. The catalytic nanomotors with magnetic
KARA,Turkey, Necmi Biyikli, UNAM National Nanotechnology Re- components have a deterministic motion guided in an external magnetic
search Center, Bilkent University, ANKARA,Turkey, Fatih Buyukse- field, but also easily aggregate due to magnetic attraction.
rin, TOBB University of Economics and Technology, ANKARA,Turkey
In this study, for the first time, we demonstrated guided manipulation of cat-
Biomaterials that allow the utilization of electrical, chemical and topographic alytic nanomotors by electric tweezers for applications in cargo delivery to
cues for improved neuron-material interaction and neural regeneration hold designated microdocks and assembling of catalytic nanomotors for chemi-
great promise for nerve tissue engineering, neural implant as well as nerve cally powering rotary nanoelectromechanical system (NEMS) devices. With
recording applications. The nature of anodic aluminum oxide (AAO) mem- the electric tweezers based on the combined AC and DC electric fields, the
branes intrinsically provides delicate control over topographic and chemical motions of nanowire catalytic motors can be readily aligned along the direc-
cues for enhanced cell interaction, and hence they are widely studied in tion of AC electric fields and their speed can be readily modulated by the
bone tissue engineering applications. The use of AAO in nerve tissue en- DC electric fields. A large array of catalytic nanomotors can be transported
gineering is still very limited, however, and the related studies mainly focus along arbitrary trajectories with tunable speeds depending on the applied
on the role of topography on neural behavior. In this project, in addition to DC E-field. Assisted with the electric fields applied in the vertical (Z-) direc-
topographic factors, chemical and electrical cues are used for the first time tion in a three orthogonal microelectrodes setup, the transport of catalytic
to control neural behavior on AAO membranes. In this context, AAO films nanomotors can be instantly initiated and stopped in the 2-D X-Y plane and
with uniform 100 and 250 nm diameters were first synthesized in different moved in the vertical (Z-) direction at suitable electric voltage. With strate-
electrolytes, and a parafilm protecting layer was used to selectively dissolve gically designed microelectrodes, we further realized swamp behaviors of
metallic Al. This process yields free-standing AAO membranes with ~ 50 catalytic nanomotors, where a large group of nanomotors can be simultane-
cm2 areas. These substrates were then coated with a thin layer of C to ob- ously assembled and released on demand. Finally, the powerfulness of the
tain conducting carbon nanotube membranes (CNM). SEM, AFM, EDX, XPS manipulation of chemical motors by the electric tweezers is demonstrated
and I-V measurement were then carried out for the detailed morphological, in two applications: firstly, without any chemical/magnetic assistance, indis-
electrical and chemical characterizations of CNMs which was followed by pensable in previous work, we facilely employed catalytic nanomotors to
the cell studies. attach, transport, and release cargos to assemble on pre-patterned microdo-
cks with induced electric fields. Secondly, we precisely assembled a catalyt-
The cell studies were conducted by using PC12 cell line. The viability and ic nanomotor to a designed rotary NEMS device and successfully powered
adhesion data dictates that 100 and 250 nm pore-sized AAO samples are its rotation. The innovations demonstrated in this work open a new, facile,
more suitable for the cells compared to same pore-sized CNMs. In addition and rational route in realizing many promising applications of chemical nano-
to this surface chemistry factor, weaker cell adhesion were observed for flat motors in biomedical and NEMS/MEMS devices.
TCPS and alumina controls that shows the influence of topographical cues
on cell behavior. When the average neurite length and number were com-
pared between different substrates, electrically stimulated (E+) 100 and 250 5-4
nm-CNMs demonstrated the best results, and hence, illustrate the effective-
ness of electrical factors in this context. Two substrates was then chosen for NOVEL PRINTING AND SYNTHESIS TECHNIQUES FOR
NGF doping, namely, 100 nm-AAO that provides the best cell adhesion and BIOMATERIAL SCAFFOLDS
electrically stimulated 100 nm-CNM that provides the best neurite extension.
From these NGF-doped 100 nm-AAO, NGF-doped 100 nm-CNM-E+ and
standard 100 nm-CNM-E+ substrates, the former one provided the best cell Navarro 11:30am - 1:00pm
adhesion as well as comparable neurite extension to that of standard 100
nm-CNM-E+ which has provided the best neurite extension under standard 11:30am Nano and Microscale Rapid 3D Printing for Regenera-
experimental conditions. Overall, our studies demonstrate that the natural tive Medicine
topographic and chemical form of nanoporous 100 nm-AAO substrate pro-
vide an optimum surface for cell viability and adhesion. Upon NGF doping,
this nanomaterial further provides opportunities for neurite formation and Keynote. NEMB2016-5943
hence can have potential applications in neural implant and nerve-recording
electrodes. Shaochen Chen, UC San Diego, La Jolla, CA, United States

This project was supported by The Scientific and Technological Research The goal of our laboratory is to develop micro- and nano-scale bioprinting
Council of Turkey (TUBITAK) Grant No: 111M686. and 3D printing techniques to create 3D designer scaffolds for tissue engi-
neering and regenerative medicine. In this talk, I will present my laboratory’s
12:40pm Electric Fields Guided Manipulation of Catalytic Nano- recent research efforts in femtosecond laser nano-printing and projection
motors for Cargo Delivery and Assembly of Chemically Powered 3D bioprinting to create 3D scaffolds using a variety of biomaterials. These
64 NEMS 3D biomaterials are functionalized with precise control of micro-architecture,
mechanical (e.g. stiffness and Poisson’s ratio), chemical, and biological prop-
erties. Design, fabrication, and experimental results will be discussed. Such
Technical Presentation. NEMB2016-6017 functional biomaterials allow us to investigate cell-microenvironment inter-