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Research Projects
Standardized 3D Cell Culture in
Well-Plate Platform for Drug Screening
Ex vivo cell
assays are a widespread means for preclinical research as well
as drug screening procedures. Currently, 2D monolayer culture
systems or 3D multi-cellular culture systems are most relied
upon. Great volume of research has shown that cells lose its
natural phenotype in monolayer configuration. However,
irregular topology and insufficient stromal components of the
currently available scaffolds for the 3D systems rendered skewed
cell signaling and migration and reproducibility lowering the
efficacy of their use in rapid drug screening. In an aim to
address these issues, a new type of scaffold has been developed
based on inverted colloidal crystal (ICC) topology and comprised
of poly(acrylamide) hydrogel. The ICC poly(acrylamide) hydrogel
scaffolds were shown to be biocompatible with numerous types of
cells ranging from monocytes to epithelial cells. The optical
transparency of the scaffolds allowed real time live imaging of
inoculated cells. The fabrication technology of the ICC hydrogel
scaffold was further enhanced by efficient production capability
which led to its subsequent integration into standard 48 and 96
multi-well plates. While currently available 3D scaffolds are
not well-plate formatted, the ICC poly(acrylamide) hydrogel
scaffolds can be fabricated to tightly fit into any type of
multi-well plates. Integration into a well-plate format in
conjuncture with structural regularities of the scaffold offers
standardization which is paramount to reproducibility in drug
screening assays. In addition, such format increases cell
seeding efficiency. Efficient production capability and
subsequent standardization may provide a powerful and efficient
drug screening platform at industrial scale.
Images: SEM images
of (A) colloidal crystal of microspheres with diameter of 170um
(B,C) 330um. SEM images of resulting inverted colloidal crystal
(ICC) scaffold from image B (D, E).
Images: Confocal
images of live (green) and dead (red) cells of 4 different cell
lines cultured in ICC scaffolds - K-562 human erythroleukemia
cell line, HS-5 human bone marrow stromal cell line, HS202 human
thymus epithelial cell line, and primary fetal human thymic
epithelial cells
Images: ICC
scaffolds are tightly conformed into 96 multi-well plates.
3D Scaffolds with Inverted
Colloidal Crystal Geometry from Expandable Cationic Hydrogel for
Well-Plate Format
Immensely diverse types of hydrogels
have been developed and deployed to biomedical applications
which can be utilized for preparation of 3D tissue scaffolds
mimicking living tissues. In this study, we introduce
positively charged hydrogel made by free radical
copolymerization of neutral and cationic monomer. The cationic
hydrogel was found to be biocompatible and its cationic surface
promoted adhesion and proliferation of anchorage-dependent cell
types on the surface for at least 3 to 6 weeks of culture.
Moreover, migration of adherent cells between the scaffold and
other interface had been observed. Swelling of the developed
cationic hydrogel was dependent on the contents of cross-linking
agent, charged monomer, and ionic strength of the external
environment. This property was utilized to 1) control the
physical dimensions of ICC geometry (cavity size and
interconnecting channels) significant for many tasks of ex-vivo
tissue engineering and 2) for tight fitting the ICC scaffolds,
which is critical for standardization of experiments in 3D
tissue replicas for drug discovery and other tasks.
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