posted on 2021-06-11, 09:43authored byChangyu Wang, Cuiling Lin, Rui Ming, Xiangxin Li, Pascal Jonkheijm, Mengjiao Cheng, Feng Shi
Three-dimensional
(3D) scaffolds with chemical diversity are significant
to direct cell adhesion onto targeted surfaces, which provides solutions
to further control over cell fates and even tissue formation. However,
the site-specific modification of specific biomolecules to realize
selective cell adhesion has been a challenge with the current methods
when building 3D scaffolds. Conventional methods of immersing as-prepared
structures in solutions of biomolecules lead to nonselective adsorption;
recent printing methods have to address the problem of switching multiple
nozzles containing different biomolecules. The recently developed
concept of macroscopic supramolecular assembly (MSA) based on the
idea of “modular assembly” is promising to fabricate
such 3D scaffolds with advantages of flexible design and combination
of diverse modules with different surface chemistry. Herein we report
an MSA method to fabricate 3D ordered structures with internal chemical
diversity for site-selective cell adhesion. The 3D structure is prepared
via 3D alignment of polydimethylsiloxane (PDMS) building blocks with
magnetic pick-and-place operation and subsequent interfacial bindings
between PDMS based on host/guest molecular recognition. The site-specific
cell affinity is realized by distributing targeted building blocks
that are modified with polylysine molecules of opposite chiralities:
PDMS modified with films containing poly-l-lysine (PLL) show
higher cell density than those with poly-d-lysine (PDL).
This principle of selective cell adhesion directed simply by spatial
distribution of chiral molecules has been proven effective for five
different cell lines. This facile MSA strategy holds promise to build
complex 3D microenvironment with on-demand chemical/biological diversities,
which is meaningful to study cell/material interactions and even tissue
formation.