Chemists create the microspine with shape-transforming properties for
targeted cargo delivery at microscale

Date:
July 7, 2023
Source:
The University of Hong Kong
Summary:
With the goal of advancing biomimetic microscale materials, the
research team has developed a new method to create microscale
superstructures, called MicroSpine, that possess both soft
and hard materials which mimic the spine structure and can
act as microactuators with shape-transforming properties. This
breakthrough was achieved through colloidal assembly, a simple
process in which nano- and microparticles spontaneously organize
into ordered spatial patterns.


Facebook Twitter Pinterest LinkedIN Email

==========================================================================
FULL STORY ==========================================================================
In nature, it is common to find structures that combine both soft and
hard material. These structures are responsible for diverse mechanical properties and functions of biological systems. As a typical example,
the human spine possesses alternating stacks of hard bones and soft intervertebral discs, which is an essential architecture that supports the human body while maintaining body flexibility. Mimicking the soft-hard structure in nature can, in principle, inspire the design of artificial materials and devices, such as actuators and robots. However, the
realisation has been extremely challenging, especially at the microscale,
where material integration and manipulation become exceedingly less
practical.

With the goal of advancing biomimetic microscale materials, the
research team led by Dr Yufeng WANG from the Department of Chemistry
of The University of Hong Kong (HKU) has developed a new method to
create microscale superstructures, called MicroSpine, that possess
both soft and hard materials which mimic the spine structure and
can act as microactuators with shape- transforming properties. This breakthrough, published in the top scientific journal Science Advances,
was achieved through colloidal assembly, a simple process in which nano-
and microparticles spontaneously organise into ordered spatial patterns.

Many biological organisms, ranging from mammals to arthropods and microorganisms, contain structures of synergistically integrated soft
and hard components. These structures exist in different lengths,
from micrometres to centimetres, and account for the characteristic
mechanical functions of biological systems. They have also stimulated
the creation of artificial materials and devices, such as actuators and
robots, which change shape, move, or actuate according to external cues.

Although soft-hard structures are easy to fabricate at the macroscale (millimetre and above), they are much harder to realise at the microscale (micrometre and below). This is because it becomes increasingly
challenging to integrate and manipulate mechanically distinct components
at smaller scale.

Traditional manufacturing methods, such as lithography, face several limitations when attempting to create small-scale components using
top-down strategies. For example, low yield can occur because small-scale manufacturing processes are more complex and require greater precision,
which can increase the risk of defects and errors in the final product.

To tackle the challenge, Dr Wang and his team took a different approach,
called colloidal assembly. Colloids are tiny particles 1/100 the size
of human hair and can be made from various materials. When properly
engineered, the particles can interact with one another, spontaneously assembling into ordered superstructures. As a bottom-up method,
colloidal assembly is advantageous for making microscale structures
because it allows for precise control over the creation of the desired structures from various building blocks, possessing a higher yield. Yet,
the difficulty is how to guide the particles to assemble to the desired soft-hard structure.

By using the spine as a basis for design, the team has invented new
particles derived from metal-organic frameworks (MOFs), an emerging
material that can assemble with high directionality and specificity. Being
also the hard component, these MOF particles can combine with soft
liquid droplets to form linear chains. The hard and soft components
take alternating positions in the chain, mimicking the spine structure,
that is, the MicroSpine.

'We also introduce a mechanism by which the soft component of the chain
can expand and shrink when MicroSpine is heated or cooled, so it can
change shape reversibly,' explained Ms Dengping LYU, the first author of
the paper, as well as the PhD Candidate in the Department of Chemistry
at HKU.

Using the MicroSpine system, the team also demonstrated various precise actuation modes when the soft parts of the chain are selectively
modified. In addition, the chains have been used for encapsulation and
release of guest objects, solely controlled by temperature.

The realisation of these functions is significant for the future
development of the system, as it could lead to the creation of intelligent microrobots capable of performing sophisticated microscale tasks, such
as drug delivery, localised sensing and other applications. The highly
uniform and precisely structured microscale components could be used to
create more effective drug delivery systems or sensors that can detect
specific molecules with high sensitivity and accuracy.

The research team believes this technology represents an important step
towards creating complex microscale devices and machines. According to
Dr Wang, 'If you think about modern machinery such as cars, they are
assembled by tens of thousands of different parts. We aim to achieve
the same level of complexity using different colloidal parts.' By taking inspiration from nature, the research team hopes to design more biomimetic systems that can perform complex tasks at the microscale and beyond.

The research is funded by the Research Grants Council (RGC).

* RELATED_TOPICS
o Plants_&_Animals
# Biotechnology_and_Bioengineering # Biotechnology #
Nature # Evolutionary_Biology
o Matter_&_Energy
# Materials_Science # Chemistry # Nanotechnology #
Civil_Engineering
* RELATED_TERMS
o Materials_science o Nanoparticle o Nanotechnology o Metallurgy
o Artificial_reef o Hygroscopy o Triboelectric_effect o
Carbon_nanotube

==========================================================================

Print

Email

Share ========================================================================== ****** 1 ****** ***** 2 ***** **** 3 ****
*** 4 *** ** 5 ** Breaking this hour ==========================================================================
* Six_Foods_to_Boost_Cardiovascular_Health
* Cystic_Fibrosis:_Lasting_Improvement *
Artificial_Cells_Demonstrate_That_'Life_...

* Advice_to_Limit_High-Fat_Dairy_Foods_Challenged
* First_Snapshots_of_Fermion_Pairs *
Why_No_Kangaroos_in_Bali;_No_Tigers_in_Australia
* New_Route_for_Treating_Cancer:_Chromosomes *
Giant_Stone_Artefacts_Found:_Prehistoric_Tools
* Astonishing_Secrets_of_Tunicate_Origins *
Most_Distant_Active_Supermassive_Black_Hole

Trending Topics this week ========================================================================== SPACE_&_TIME Asteroids,_Comets_and_Meteors Big_Bang Jupiter
MATTER_&_ENERGY Construction Materials_Science Civil_Engineering COMPUTERS_&_MATH Educational_Technology Communications
Mathematical_Modeling


==========================================================================

Strange & Offbeat ========================================================================== SPACE_&_TIME Quasar_'Clocks'_Show_Universe_Was_Five_Times_Slower_Soon_After_the_Big_Bang First_'Ghost_Particle'_Image_of_Milky_Way Gullies_on_Mars_Could_Have_Been_Formed_by_Recent_Periods_of_Liquid_Meltwater, Study_Suggests MATTER_&_ENERGY Holograms_for_Life:_Improving_IVF_Success Researchers_Create_Highly_Conductive_Metallic_Gel_for_3D_Printing Artificial_Cells_Demonstrate_That_'Life_Finds_a_Way' COMPUTERS_&_MATH Number_Cruncher_Calculates_Whether_Whales_Are_Acting_Weirdly AI_Tests_Into_Top_1%_for_Original_Creative_Thinking Growing_Bio-Inspired_Polymer_Brains_for_Artificial_Neural_Networks
Story Source: Materials provided by The_University_of_Hong_Kong. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Dengping Lyu, Wei Xu, Nansen Zhou, Wendi Duan, Zhisheng Wang,
Yijiang Mu,
Renjie Zhou, Yufeng Wang. Biomimetic thermoresponsive
superstructures by colloidal soft-and-hard co-assembly. Science
Advances, 2023; 9 (26) DOI: 10.1126/sciadv.adh2250 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2023/07/230707111635.htm

--- up 1 year, 18 weeks, 4 days, 10 hours, 50 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)