Controlled local presentation of matrix proteins in microparticle–laden cell aggregates

Abstract

Multi-cellular aggregates are found in healthy and diseased tissues, and while cell-cell contact is important for regulating many cell functions, cells also interact, to varying degrees, with extra-cellular matrix (ECM) proteins. Islets of Langerhans are one such example of cell aggregates in contact with ECM, both at the periphery of the cluster and dispersed throughout. While several studies have investigated the effect of reintroducing contact with ECM proteins on islet cell survival and function, the majority of these experiments only allow contact with the exterior cells. Thus, cell-culture platforms that enable the study of ECM-cell interactions throughout multi-cellular aggregates are of interest. Here, local presentation of ECM proteins was achieved using hydrogel microwell arrays to incorporate protein-laden microparticles during formation of MIN6 β-cell aggregates. Varying the microparticle seeding density reproducibly controlled the number of microparticles incorporated within three-dimensional aggregates (i.e., total amount of protein). Further, a relatively uniform spatial distribution of laminin- and fibronectin-coated microparticles was achieved throughout the x-, y-, and z-directions. Multiple ECM proteins were presented to β-cells in concert by incorporating two distinct populations of microparticles throughout the aggregates. Finally, scaling the microwell device dimensions allowed for the formation of two different sized cell-particle aggregates, ~80 and 160 μm in diameter. While the total number of microparticles incorporated per aggregate varied with size, the fraction of the aggregate occupied by microparticles was affected only by the microparticle seeding density, indicating that uniform local concentrations of proteins can be preserved while changing the overall aggregate dimensions.

Mineral particles modulate osteo-chondrogenic differentiation of embryonic stem cell aggregates

“…Several proof-of-concept studies have demonstrated the possibility of using biomaterial-based microparticles to modulate the 3D microenvironment of stem cell aggregates [40, 41]. However, successful induction of PSC aggregate differentiation toward specific lineages through this strategy has yet to be reported.…”

Advancing biomaterials of human origin for tissue engineering

“…Based on this principle, by introducing specific structural and molecular elements in varying geometries and at different concentrations, a range of biomaterials with tissue-specific structural properties and bioinspired polymeric surface close to those of the native ECM can be created [687,688]. Upon application, penetrating cells may be surrounded by a dynamic pericellular matrix, similar to a native matrix, that possesses considerable regulatory potential [689–692]. This approach is spurring interest in the use of natural ECM proteins for scaffolding production.…”

Unraveling Comparative Anti-Amyloidogenic Behavior of Pyrazinamide and D-Cycloserine: A Mechanistic Biophysical Insight

“…However, the mechanism that leads to protein misfolding and aggregation is not common for all proteins [ 8 ]. In recent years, studies have revealed several ways to suppress the aggregation processes by different group of molecules or compounds which include metal ions, acridine and its derivatives, polyphenols, plant derivatives, drug molecules and various chemical agents [ 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. In all these studies, research has mainly been directed to develop the anti-amyloidogenic or anti-aggregating compounds by studying their effect either on proteins directly involved in neurological and non-neurological disorders [ 16 ] or on model proteins having similarity with the them [ 17 , 18 ].…”