Väitös (kemia): MSc Jinghui Yang

MSc Jinghui Yang esittää väitöskirjansa ”Amphiphile-Templated Dynamic Combinatorial Libraries” julkisesti tarkastettavaksi Turun yliopistossa perjantaina 10.4.2026 klo 12.00 (Turun yliopisto, Medisiina C, Osmo Järvi -sali, Kiinamyllynkatu 10, Turku).

Vastaväittäjänä toimii professori Kari Rissanen (Jyväskylän yliopisto) ja kustoksena professori Pasi Virta (Turun yliopisto). Tilaisuus on englanninkielinen. Väitöksen alana on kemia.

Tiivistelmä väitöstutkimuksesta:

How can simple molecules be guided to build complex and useful structures?

In my doctoral dissertation at the University of Turku, I studied how small molecules can form different structures depending on their surroundings. A simple way to think about this is Lego: the same bricks can be used to build many different shapes. In a similar way, small molecules can join together, come apart, and reconnect. This allows the same molecular building blocks to form different structures under different conditions.

My research focused on dynamic chemical systems in water. Unlike fixed chemical products, these systems can change over time and respond to their environment. I was especially interested in amphiphilic environments, which contain parts that interact well with water and parts that do not. Such environments are common in nature and can strongly affect how molecules behave. In my work, I asked whether these environments could help guide molecules to organize themselves, select certain structures, and even retain traces of earlier conditions.

The first part of my research showed that dynamic molecular systems can function inside living cells. I developed a system in which small molecular building blocks connect with each other under certain cellular conditions. As they connect and assemble into larger structures, their fluorescence becomes stronger, which makes the process visible. When the conditions change, the structures can break apart again and the signal becomes weaker. This showed that reversible molecular assembly is possible even in the complex environment of living cells.

The second part of my research showed that a specially designed molecule can guide a dynamic mixture toward one preferred product. In simple terms, this molecule helps the building blocks come together in a favorable way, so that one ring-shaped structure forms more easily than others. I also showed that this system could be combined with the anticancer drug doxorubicin. Changes in fluorescence made it possible to follow the release of the drug. This means the same system can both control molecular assembly and report what is happening.

The third part of my research showed that even a temporary environment can leave a lasting effect on a molecular system. By changing the amount of a surfactant, I was able to guide the system to form different ring sizes. In one case, the selected structure kept its special organization even after the original environment had been removed. This suggests that the system could retain a kind of memory of earlier conditions.

What are the key findings of your dissertation research?

The key finding of my dissertation is that the environment around molecules does not simply surround them. It can actively guide what they do. It can influence how molecules assemble, which structures are formed, and how stable those structures become. My work shows that relatively simple molecular building blocks can be turned into systems that respond to change, give visible signals, and sometimes retain information about past conditions.

What new information does this research provide?

This research provides new knowledge about how special chemical environments can direct dynamic molecular systems in different ways. It shows that reversible molecular networks can operate inside living cells, that one molecular product can be favored over others through molecular guidance, and that even short-lived environments can leave persistent effects on molecular organization. Together, these findings improve our understanding of how structure, environment, and function are connected in adaptive chemical systems.

What is the impact of your research on the surrounding world?

This research helps lay the foundation for smarter chemical systems in the future. Such systems could be useful in areas such as biological imaging, sensing, and drug delivery, because they can respond to their surroundings and provide a visible signal of change. More broadly, this work helps us understand how complex behavior can emerge from simple molecules. That is important not only for developing new functional materials, but also for understanding how life-like properties such as adaptation, selection, and memory may arise in non-living chemical systems.