Scientists develop phagocytic protocells capable of the targeted delivery of enzymes

June 13, 2017, University of Bristol
Scientists develop phagocytic protocells capable of the targeted delivery of enzymes
Time sequence of optical microscopy images showing spontaneous transfer of a dye-loaded cross-linked silica colloidosome (red object, dotted line) into a magnetic emulsion droplet through a fatty acid stabilized aperture. Scale bar = 100 µm. Credit: University of Bristol

Researchers at the University of Bristol have designed a community of artificial cell-like droplets that collectively displays a simple form of phagocytosis behavior. The work provides a new approach to designing complex life-like properties in non-living materials.

The chemists have made a major advance in the construction of synthetic communities of artificial cells capable of mimicking phagocytosis—a complex biological process seen in living cells that enables the ingestion of foreign material by certain cell types. The work, published in Nature Materials, has potential applications ranging from microfluidics to delivering enzymes for spatially controlled reactions or for the removal of hazardous pollutants.

In the new work, the researchers led by Professor Stephen Mann together with colleagues Dr Mei Li, Dr Laura Rodriquez-Arco at Bristol's School of Chemistry and Bristol Centre for Protolife Research, designed a protocell community consisting of a mixture of two different types of nanoparticle-coated aqueous micro- that collectively exhibit a simple form of artificial phagocytosis. The droplets are either small and surrounded by a semi-permeable crosslinked silica membrane (colloidosomes), or large and enclosed by a porous non-crosslinked shell (magnetic emulsion droplets). When the two types of protocells are mixed together in oil, they undergo collisions but do not interact. However, if a fatty acid is added to the oil then the magnetic emulsion droplets develop an aperture in their iron oxide shell through which the smaller colloidosomes are ingested when the protocells come into contact. As a result, the colloidosomes are captured and remain trapped within the water-filled interior of the larger protocells.

Using this spontaneous engulfment process, enzymes trapped within the colloidosomes can be transferred into the magnetic emulsion droplets to trigger specific chemical reactions even though the enzymes remain located within the ingested colloidosomes. Alternatively, by using non-crosslinked colloidosomes, enzymes and other payloads such as polymer beads can be released into the larger emulsion droplets after phagocytosis by spontaneous disassembly of the silica nanoparticle membrane.

Professor Stephen Mann said: "Our long-term aim is to build on this latest work by developing a portfolio of protocell behaviours that mimic complex life-like properties ranging from artificial phagocytosis, predation and chemical communication with applications that can be used to clean up pollutants, store and release drugs, monitor chemical reactions, and serve as models for the origin of life."

Explore further: Protocells on the hunt

More information: Laura Rodriguez-Arco et al. Phagocytosis-inspired behaviour in synthetic protocell communities of compartmentalized colloidal objects, Nature Materials (2017). DOI: 10.1038/nmat4916

Related Stories

Protocells on the hunt

October 4, 2016

Researchers at the University of Bristol have designed a synthetic community of artificial cells that collectively displays a simple form of predatory behaviour.

Coated droplets hint at formation of early cells

April 25, 2014

(Phys.org) —Researchers at the University of Bristol have designed a chemical system that brings together alternative ideas on how primitive cells were formed on the early Earth to produce a new model of protocell organization. ...

Building protocells from inorganic nanoparticles

May 10, 2013

(Phys.org) —Researchers at the University of Bristol have led a new enquiry into how extremely small particles of silica (sand) can be used to design and construct artificial protocells in the laboratory. The work is described ...

Small droplets feel the vibe

October 6, 2016

A team of researchers at the University of Bristol have used ultrasonic forces to accurately pattern thousands of microscopic water-based droplets. Each droplet can be designed to perform a biochemical experiment, which could ...

Sensing light with 'liquid Lego'

June 14, 2007

Scientists at Oxford University and Duke University in the United States have used tiny water droplets to build a unique microscopic light sensor.

Recommended for you

Biologists' new peptide could fight many cancers

January 16, 2018

MIT biologists have designed a new peptide that can disrupt a key protein that many types of cancers, including some forms of lymphoma, leukemia, and breast cancer, need to survive.

Insulating bricks with microscopic bubbles

January 16, 2018

The better a building is insulated, the less heat is lost in winter—and the less energy is needed to achieve a comfortable room temperature. The Swiss Federal Office of Energy (SFOE) regularly raises the requirements for ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.