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International Journal of Bioprinting 3D-printed microstructure for bacteriostasis

the core features of the shark skin structure; second, the range and strain types. Moreover, the characteristics of
simplified structure is very regular, with three parameters microstructures such as morphology, parameters, and
that can be finely adjusted, including the width, height, the corresponding bacterial inhibitory effect are easy to
and spacing of the rectangular columns, which facilitates quantify. The data gathered can then be used to construct
the subsequent exploration of the mechanism; third, the independent databases, as well as simulation models
simplified structure is relatively simple and intuitive, equipped with the excellent data processing capability of
which is conducive to the generalization, extension, and artificial intelligence, which provides a powerful tool for the
improvement of the model as a research model; finally, the screening of microstructures in terms of their morphology,
simplified structure is convenient for fabrication, reducing parameters, and mechanism delineation. Taken together,
the cost and time of fabrication. Notably, the simplified the current research not only deepens our understanding
microstructures had significant bacterial inhibitory of bacteriostatic mechanisms in micro-nanostructures but
property compared to the simulated structures. Our also paves the way for the development of next-generation
subsequent studies confirmed the parametric sensitivity bacteriostatic surfaces with applications in biomedical
of the inhibitory capacity of simplified microstructures. devices, implants, and healthcare/industrial products. 53–55
Previous studies, such as the one described above, have
found that microstructures can achieve bacterial inhibition 5. Conclusion
by disrupting the cell membranes of bacteria through In this paper, we demonstrate that parameter and
stretching or cutting. However, this phenomenon was morphology variations affect the physical inhibition of
52
not detected in our experiments using SEM images. In microstructures formed on the surface of an object using
addition, the size change of the micron-scale structures two-photon polymerization 3D printing technology. First,
had a negligible effect on the hydrophobicity of the the simplified shark skin structures were able to inhibit the
microstructures. The parametric sensitivity of the proliferation of more than 90% of S. mutans within 8 h and
52
bacterial inhibitory ability is likely attributed to the retained the same inhibitory effect at more than 70% after
following two factors: (i) the spatial restriction effect of 24 h. Second, the height of the nanopillar had the greatest
the microstructure on the bacteria, and (ii) the effect effect on the inhibitory ability of the microstructure against
of microstructure-bacteria contact mode on bacterial S. mutans compared to the spacing and width. This effect
proliferation. This also explains the significantly enhanced was also observed in other microstructures. In conclusion,
inhibitory ability of the simplified microstructures, we propose a novel strategy for exploring the mechanism of
because they are far less smooth and continuous than the bacterial inhibition, i.e., to utilize the high-resolution and
simulated ones, and the spatial restriction ability of the precise morphology control capability of two-photon 3D
spaces between the rectangular columns is stronger than printing technology to precisely control the morphology
those of the simulated ones. Subsequently, we switched of microstructures, so as to understand the underlying
to a microporous structure and adopted an incremental mechanism of bacterial inhibitory ability and the key
diameter parameter design. The microporous structure influencing factors. This strategy is expected to fill the gap
is a model of a single parameter controlling the role of in the mechanism of physical bacterial inhibition, thereby
spatial restriction compared to the simplified structure of improving the bacterial inhibitory effect and accelerating
shark skin. From the results, the inhibitory ability of the the application of this technology in industry, medicine,
microporous structure shows similar parametric sensitivity, and daily life.
and the effect of the parameter is dual. Therefore, we
recommend enhancing the bacterial inhibitory capacity of Acknowledgments
both models by adjusting bacteria’s spatial restriction and
mode of contact with the microstructures. None.
The findings suggest that certain specialized
microstructures exhibit a bacteriostatic effect, which Funding
becomes significant only when specific geometric This study was supported by Postdoctoral Science
parameters are met. One major limitation of the present Foundation of China (2018M630883 and 2019T120688),
study is that the fully delineated mechanism of bacterial Hubei Province Chinese Medicine Research Project
inhibition remains uncovered, however, capitalizing on (ZY2023Q015), Natural Science Foundation of Hubei
the advantages of two-photon polymerization 3D printing, Province (2023AFB665), Central Universities (Wuhan
such as high accuracy, efficiency, simplicity, and low cost, University) Clinical Medicine + X (2042024YXB017), the
future studies can attempt on large-scale exploration Medical Young Talents Program of Hubei Province, and
of the mechanism, while expanding the parameter Wuhan Young Medical Talents Training Project to L.-L. Bu,

Volume X Issue X (2025) 161 doi: 10.36922/IJB025150135