3 research outputs found
Stretchable and Micropatterned Membrane for Osteogenic Differentation of Stem Cells
Stem cells have emerged as potentially
useful cells for regenerative
medicine applications. To fully harness this potential, it is important
to develop in vitro cell culture platforms with spatially regulated
mechanical, chemical, and biological cues to induce the differentiation
of stem cells. In this study, a cell culture platform was constructed
that used polydopamine (PDA)-coated parafilm. The modified parafilm
supports cell attachment and proliferation. In addition, because of
the superb plasticity and ductility of the parafilm, it can be easily
micropatterned to regulate the spatial arrangements of cells, and
can exert different mechanical tensions. Specifically, we constructed
a PDA-coated parafilm with grooved micropatterns to induce the osteogenic
differentiation of stem cells. Adipose-derived mesenchymal stem cells
that were cultured on the PDA-coated parafilm exhibited significantly
higher osteogenic commitment in response to mechanical and spatial
cues compared to the ones without stretch. Our findings may open new
opportunities for inducing osteogenesis of stem cells in vitro using
the platform that combines mechanical and spatial cues
Microfluidic Generation of Polydopamine Gradients on Hydrophobic Surfaces
Engineered surface-bound molecular
gradients are of great importance
for a range of biological applications. In this paper, we fabricated
a polydopamine gradient on a hydrophobic surface. A microfluidic device
was used to generate a covalently conjugated gradient of polydopamine
(PDA), which changed the wettabilty and the surface energy of the
substrate. The gradient was subsequently used to enable the spatial
deposition of adhesive proteins on the surface. When seeded with human
adipose mesenchymal stem cells, the PDA-graded surface induced a gradient
of cell adhesion and spreading. The PDA gradient developed in this
study is a promising tool for controlling cellular behavior and may
be useful in various biological applications
Simple, Cost-Effective 3D Printed Microfluidic Components for Disposable, Point-of-Care Colorimetric Analysis
The
fabrication of microfluidic chips can be simplified and accelerated
by three-dimensional (3D) printing. However, all of the current designs
of 3D printed microchips require off-chip bulky equipment to operate,
which hindered their applications in the point-of-care (POC) setting.
In this work, we demonstrate a new class of movable 3D printed microfluidic
chip components, including torque-actuated pump and valve, rotary
valve, and pushing valve, which can be operated manually without any
off-chip bulky equipment such as syringe pump and gas pressure source.
By integrating these components, we developed a user-friendly 3D printed
chip that can perform general colorimetric assays. Protein quantification
was performed on artificial urine samples as a proof-of-concept model
with a smartphone used as the imaging platform. The protein was quantified
linearly and was within the physiologically relevant range for humans.
We believe that the demonstrated components and designs can expand
the functionalities and potential applications of 3D printed microfluidic
chip and thus provoke more investigation on manufacturing lab-on-a-chip
devices by 3D printers