Independent Blue and Red Light Triggered Narcissistic Self‐Sorting Self‐Assembly of Colloidal Particles

Abstract

The ability of living systems to self‐sort different cells into separate assemblies and the ability to independently regulate different structures are one ingredient that gives rise to their spatiotemporal complexity. Here, this self‐sorting behavior is replicated in a synthetic system with two types of colloidal particles; where each particle type independently self‐assembles either under blue or red light into distinct clusters, known as narcissistic self‐sorting. For this purpose, each particle type is functionalized either with the light‐switchable protein VVDHigh or Cph1, which homodimerize under blue and red light, respectively. The response to different wavelengths of light and the high specificity of the protein interactions allows for the independent self‐assembly of each particle type with blue or red light and narcissistic self‐sorting. Moreover, as both of the photoswitchable protein interactions are reversible in the dark; also, the self‐sorting is reversible and dynamic. Overall, the independent blue and red light controlled self‐sorting in a synthetic system opens new possibilities to assemble adaptable, smart, and advanced materials similar to the complexity observed in tissues.

Orthogonal Blue and Red Light Controlled Cell–Cell Adhesions Enable Sorting-out in Multicellular Structures

“…The parallels between colloidal and cellular self-assembly are also witnessed by in vitro bead aggregation assays with cadherin coated beads. 45 Transferring the recently reported sorting out behavior (known as narcissistic or asocial self-sorting in the colloidal self-assembly community) achieved with mixtures of VVDHigh and Cph1 coated polystyrene beads 29 to cells shows that not just concepts in colloidal self-assembly but self-sorting also apply to multicellular structures. The comparable self-assembly and self-sorting observed in synthetic colloidal systems and in multicellular mixtures shows that these photoswitchable proteins provide a transferable framework to produce higher order architectures and achieve self-sorting of micrometer sized objects.…”

“…This study was inspired by a concept established with mixtures of two types of colloidal polystyrene particles, which could self-sort into distinct groups (also known as narcissistic or asocial self-sorting in the colloidal self-assembly community) using different colors of light. 29 In this study, we extend the concept of asocial self-sorting established for nonliving colloidal particles to cells for the assembly of multicellular tissue-like structures in the context of bottom-up tissue engineering. In this respect, this study is a demonstration of how well-established concepts of self-assembly and self-sorting for colloidal particles can be extended to multicellular systems and the parallels between self-sorting in colloidal mixtures and sorting-out in multicellular mixtures.…”

The Many Ways to Assemble Nanoparticles Using Light

“…Alternating the exposure to UV and visible light led to reversible dissociation and reformation of the inclusion complexes, and therefore of the aggregates. In other recent notable examples of light‐controlled self‐assembly of microparticles, Wegner and co‐workers demonstrated light‐induced narcissistic and social self‐sorting of 2 µm polystyrene beads decorated with photoswitchable proteins, whereas Fan and co‐workers developed dual‐responsive colloids by coating magnetic Fe 3 O 4 particles with monolayers of spiropyran molecules …”

Wie Licht beim Aufbau von Geweben helfen kann

“…Manche dieser Proteine gehen unter Licht eine Bindung mit sich selbst ein -sie homodimerisieren -und sind somit geeignet, Zellen des gleichen Typs, die diese Proteine auf der Oberfl äche exprimieren, zusammenzubringen (Abb. 2A, [8]). Die andere Variante sind Proteinpaare, die bei Beleuchtung aneinanderbinden, also heterodimerisieren.…”

“…Um in einem Gemisch unterschiedliche Zell-Zell-Adhäsionen unabhängig voneinander zu steuern, bedarf es zweier Stimuli, die sich gegenseitig nicht beeinflussen. Hier bieten die lichtschaltbaren Adhäsionen die Möglichkeit, Proteine zu verwenden, die auf unterschiedliche Wellenlängen reagieren [8]. Bei unseren Versuchen arbeiten wir mit zwei unterschiedlichen Zelltypen: Der eine Zelltyp kontrolliert werden.…”