Degradable hollow shell particles for high-throughput screening and sorting of cells
Degradable hollow shell particles are disclosed that can encapsulate cells within the hollow inner cavity that allows for the high-throughput screening and sorting of the encapsulated cells based on their phenotypic properties. The solid-phase of the particle is porous such that solution exchange can occur between the external environment and the interior cavity. Further, the solid-phase contains degradable crosslinkers and can be degraded to release enclosed biological entities. An example embodiment consists of encapsulating a cell within the hollow shell particle, allowing the cell to accumulate biomass, selecting hollow shell particles based on accumulated biomass, and degrading the hollow shell particles to release the cells and develop hyper-producing cell lines. Exemplary cell types include microalgae, mammalian cells, bacteria, yeast, and fungi.
1 . A method of using a particle system comprising a plurality of hollow shell particles formed from a biocompatible and chemically or physically degradable crosslinked hydrogel, each hollow shell particle having a void or cavity formed therein and surrounded by a shell of crosslinked hydrogel, and one or more live cells contained in the void or cavity, the method comprising incubating the plurality of hollow shell particles in a growth medium for a period of time to obtain multicellular colonies contained in at least some of the plurality of hollow shell particles followed by subjecting the plurality of hollow shell particles to sorting by flow cytometry, wherein the sorting operation sorts hollow shell particles based on accumulated biomass of the multicellular colonies contained in respective hollow shell particles using a forward and/or side scatter signal obtained during flow cytometry.
2 . The method of claim 1 , further comprising releasing the multicellular colonies from the plurality of hollow shell particles that are sorted.
3 . The method of claim 2 , wherein the releasing is performed by the presence of cleaving molecules generated by the multicellular colonies or cleaving molecules exposed to the plurality of hollow shell particles.
4 . The method of claim 2 , wherein the releasing is caused by exposing the plurality of hollow shell particles to an environmental stimulus.
5 . The method of claim 2 , wherein the releasing is caused by one of pressure, shear stress, or mechanical stretching.
6 . A method of using a particle system comprising a plurality of hollow shell particles formed from a biocompatible and chemically or physically degradable crosslinked hydrogel, each hollow shell particle having a void or cavity formed therein and surrounded by a shell of crosslinked hydrogel, and one or more live cells contained in the void or cavity, the method, comprising:
incubating the plurality of hollow shell particles to grow the one or more cells contained therein, wherein at least some of the plurality of hollow shell particles expand in size in response to growing cell colonies within the respective hollow shell particles; and
filtering the hollow shell particles with a physical strainer or filter based on a diameter of the plurality of hollow shell particles.
7 . The method of using the particle system of claim 6 , comprising exposing the incubated plurality of hollow shell particles to a new solution to exchange the new solution into the void or cavity of the plurality of hollow shell particles.
8 . The method of using the particle system of claim 6 , comprising exposing the incubated plurality of hollow shell particles to a stain or fluorescent reporter.
9 . A method of using a particle system comprising:
providing plurality of hollow shell particles formed from a biocompatible and chemically or physically degradable crosslinked hydrogel, each hollow shell particle having a void or cavity formed therein and surrounded by a shell of crosslinked hydrogel and having a single cell contained in the void or cavity of at least some of the plurality of particles;
incubating the plurality of hollow shell particles in a growth medium for a time period to obtain multicellular colonies contained in the void or cavity of at least some of the plurality of hollow shell particles;
capturing secretions from the multicellular colonies within the hollow shell particles;
labeling the secretions with a fluorescent label or fluorogenic substrate; and
passing the plurality of hollow shell particles through a fluorescence activated cell sorter and sorting hollow shell particles containing multicellular colonies and labelled secretions based on a fluorescence and/or scatter signal of each hollow shell particle.
10 . The method of claim 9 , further comprising loading the sorted hollow shell particles into a plurality of separate sample volumes, wherein each sample volume contains a single hollow shell particle.
11 . The method of claim 10 , further comprising exposing the sorted hollow shell particles in the separate sample volumes to one or more reagents.
12 . The method of claim 11 , wherein the one or more reagents comprise a fluorogenic substrate.
13 . The method of claim 9 , wherein the growth medium is a selective growth medium that enables growth of a target population of cells.
14 . The method of claim 9 , wherein the plurality of hollow shell particles comprises greater than 10,000 hollow shell particles.