Scientists from China and the United States have examined how biology triggers morphological changes in certain types of nanoparticles. These types of particles are called smart transformable nanoparticles because they can alter their size and shape upon stimulation from their surrounding environment.
The particles are particularly promising for tumor theranostics because their physical properties will adapt to the physiology. These adaptations improve particle circulation, biodistribution, tumor penetration, tumor retention, and subcellular distribution for targeted therapy.
The team published its study (“Smart transformable nanoparticles for enhanced tumor theranostics”) in Applied Physics Reviews.
“The physical morphologies of nanoparticles, especially size and shape, always significantly influence their biological behaviors. In the past, nanoparticles with constant physical morphologies have been widely investigated and applied in tumor theranostics,” the investigators wrote.
“With the increased in-depth knowledge of tumors and physiological microenvironments, nanoparticles are required to self-adjust their physical morphologies during their circulation in varying physiological microenvironments and when reaching tumor site that possess distinct microenvironments. Therefore, smart transformable nanomaterials, which can alter their morphologies under different physiological conditions, show great potential in advanced tumor theranostics.
“This review summarizes the influence of nanoparticles’ physical morphologies on their biological behaviors under different physiological conditions, highlights the designs of transformable nanoparticles serving as a guideline for their construction, intensively discusses the recent biomedical applications of these smart transformable nanoparticles for tumor theranostics, and also proposes future challenges and perspectives in the development of smart transformable nanoparticles for tumor theranostics.”
“Smart transformable nanoparticles can alter their morphologies under different physiological conditions as the therapeutic demands,” said co-author Jianxun Ding, PhD, from the Chinese Academy of Sciences. “In our study, we reveal the structural designs for these smart systems as well as the in-depth mechanisms of the transformations.”
The researchers present the designs of transformable nanoparticles as a guideline for their construction and discuss the biomedical applications in the realm of theranostics. Ding and his colleagues developed novel classifications for nanoparticle transformation design and the mechanisms contributing to the change.
For instance, the researchers divide the design transformation into two broad categories: size and shape. For size-transformable nanoparticles, the alterations are further divided into small-to-large and large-to-small transformations. The study discloses detailed and rational designs of transformable nanoparticles based on their structures.
As for the mechanisms contributing to nanoparticle transformation, “we believed the structure and stimuli both made a great contribution,” noted Ding. “For example, different pH values decided the accurate site for the transformation, which correlate to varying physiological, extracellular, and endo/lysosomal conditions.”
Nanoparticles with constant physical morphologies have been widely investigated and applied in tumor theranostics in the past, while more recent studies of nanoparticle transformation phenomena have focused primarily on the response to stimuli. Until now, however, there has not been an in-depth discussion on the designs and applications of morphology-transformable nanoparticles.
“Our review covers the structure design, mechanism for transformation, and biomedical application of smart transformable nanoparticles, and includes perspectives on their limitations as well,” explained Ding. “We believe this review will shed light on this important field.”
