Groupe Badia

Titre: The Impact of Antibacterial Carbon Dots on the Biophysical Properties of Pulmonary Surfactant

RESUME

One of the most common types of pulmonary infection diseases is bacterial pneumonia which can cause mild to life-threatening illness in people of all ages. Presently, antibiotics are used as first-line drugs to treat pneumonia. Due to the limitations of systemic administration methods, inhalation, as a targeted administration route, can deliver the drug directly to infected cells. [1]

Inhaled nebulized nanomedicines (NMs) are gaining attention among researchers due to being transported into the deep lung deposition at the alveoli region. However, the pulmonary fate of inhaled NMs is affected by the bio-nano interactions with pulmonary surfactant (PS) at the air/alveoli fluid interface, which alters the fate of inhaled therapeutic NMs and the lung's physiological function. Since the role of PS is reducing the surface tension at the air/alveoli interface to ease the breathing process, whatever affects the standard functionality of PS could cause respiratory problems. Therefore, the interaction of NMs with PS can cause changing surface tension, PS phase structure, and reservoir formation. The consequences of each alteration have a diverse impact on the breathing system. [2]

Recently, the antibacterial cysteine-carbon dots (cys-CDs) have been successfully developed [3]. Antibacterial properties of these cys-CDs against different strains of bacteria show promising results toward generating new ideas in the field of antibiotics.

In this research project, the effects of different concentrations of antibacterial cys-CDs on the phase behavior and lateral structure of lung surfactant binary mixture model (DPPC:POPG) were investigated at the air/water interface using surface pressure−area isotherms and Brewster angle microscopy, respectively. Additionally, atomic force microscopy was used to image the morphology of films transferred onto a mica substrate with nanometer resolution. The results revealed that the presence of cys-CDs resulted in hindering lipid packing and loss of material resulting in shifts to higher molecular area during early compression for monolayer isotherms. However, further studies are aimed at looking over the more complex lung lining memetics.

References

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• _{Victoria, J. Manioudakis, L. Zaroubi, B. Findlay, and R. Naccache, “Tuning residual chirality in carbon dots with antimicrobial properties” RSC Advances, vol. 10, no. 53, 32202-32210, 2020.}