Page 55 - Plastics News August 2018

TECHNOLOGY

Creation and functionalization of Bacteria-fighting polymers

virus-like polymer particles created with light

esearchers at Tohoku University in Japan have esearchers from the Department of Chemistry
Rcollaborated with others to develop a simple way to RDQG :DUZLFN 0HGLFDO 6FKRRO GHYHORSHG D ZD\ WR
create and functionalize virus-like polymer particles that synthesise large libraries of polymers, in such a way
have various nanostructures. The collaboration includes to make their screening for antimicrobial activity
researchers from Michigan University in the USA and faster, and without the need to use sealed vials. By
Karlsruhe Institute of Technology (KIT) in Germany. The XVLQJ PXOWLSOH EXLOGLQJ EORFNV LQ WKHLU SRO\PHUV QHZ
geometrical control of enzymes, antibodies and other DQWLPLFURELDOV ZHUH LGHQWLÀHG VRPH RI ZKLFK DSSHDU
proteins over polymer particles is essential for realizing to inhibit bacteria growth, contrary to predictions.
FDVFDGH UHDFWLRQV REVHUYHG LQ D OLYLQJ ERG\ KLJKO\ 7KH EHQHÀW RI WKH PHWKRG LV WKDW LW DOORZV VFUHHQLQJ
VHQVLWLYH LPPXQRDVVD\ V\VWHPV DQG KLJKO\ HIÀFLHQW GUXJ of hundreds of different structures, enabling the
delivery systems. Given enzymatic reactions occur step- UHVHDUFKHUV WR JR ÀVKLQJ IRU QHZ SURSHUWLHV ZKLFK LQ
by-step along aligned enzymes, the formations of such this case was antibiotic activity.
enzyme arrays are crucial
for realizing the particles. There is growing awareness of antimicrobial resistance
In immunoassay systems and the need to develop innovative solutions to tackle
and drug delivery systems microbial infection. Traditional anti-microbials (such as
using polymer particles, the penicillin) work by inhibiting key cellular processes. The
density and alignment of :DUZLFN WHDP OHG E\ 3URIHVVRU 0DWWKHZ *LEVRQ ZHUH
antibodies on the particles instead inspired by host-defence peptides which are
are very important factors in broad spectrum antimicrobials and function by breaking
achieving high sensitivities. apart the membrane of bacteria.Professor Matthew
A virus is an ideal particle *LEVRQ IURP :DUZLFN V 'HSDUWPHQW RI &KHPLVWU\ DQG
given its nanostructures and :DUZLFN 0HGLFDO 6FKRRO DOVR OHDG DXWKRU RI WKH SDSHU
geometrically controlled functional groups.
However, structural control and selective chemical
PRGLÀFDWLRQ RI V\QWKHWLF SRO\PHU SDUWLFOHV KDYH XQWLO
now been inaccessible due to their complicated synthetic
routes. Diblock copolymers form nanoscale phase-
separated structures, and macromolecular compositions
can control structures and periodicities. In the present
study, Guillaume Delaittre and co-workers at KIT have
succeeded in synthesizing hydrophobic diblock copolymers
that have functionalized blocks. Divya Varadharajan at KIT VDLG :KLOVW PDQ\ SHRSOH KDYH VXFFHVVIXOO\ PLPLFNHG
antimicrobial peptides with polymers, the limiting step
and Hiroshi Yabu at Tohoku University have converted those was the number of different combinations of building
diblock copolymers to nanostructured particles by using a
EORFNV \RX FDQ XVH :H XVHG VLPSOH URERWLFV DQG D
nanoprecipitation method they developed. Changing the light controlled polymerisation, which lets us do the
preparation conditions, sizes and morphologies of particles chemistry open to air, without any sealed vials which
led to core-shell, stacked lamellae, and other morphologies are essential for most polymer syntheses" Dr Sarah-Jane
being found. The stacked lamellae structure, in which both Richards, from the Gibson Group at the University of
polymer phases are exposed to the particle surfaces, was :DUZLFN DQG WKH OHDG DXWKRU RI WKH ZRUN VDLG :H
FKRVHQ IRU VHOHFWLYH FKHPLFDO PRGLÀFDWLRQ 7R YLVXDOL]H prepared the polymers in such a way that at the end
WKH VLWH VHOHFWLYH FKHPLFDO PRGLÀFDWLRQ RI SDUWLFOHV of the reaction, we use the robotics to mix polymers
ÁXRUHVFHQW G\HV ZHUH À[HG RQ WKH RQH SRO\PHU SKDVH directly with bacteria."

55 August 2018 Plastics News