Bacterial biofilms have the ability to infect almost any organ in the human body, posing a serious threat to human health. Especially for immunocompromised populations, severe chronic and persistent infections caused by bacterial biofilms can lead to fatal consequences. Currently, the treatment of biofilm infections often relies on intensified antibiotics, but long-term use can easily lead to drug resistance, which not only weakens the treatment effect but also may induce secondary infections. Accurate diagnosis of biofilm infection is crucial for effective treatment, and traditional diagnostic methods such as tissue biopsy are invasive, time-consuming, and may delay treatment. Therefore, the development of non-invasive diagnostic and therapeutic methods to achieve precise diagnosis and treatment of bacterial biofilm infections has become an urgent need in the medical field.
Recently, Lu Shan, Chen Xueyuan and other researchers from the Chinese Academy of Sciences Fujian Institute of Physical Structure have developed a new sunflower structured alginate lyase (Aly) - NaNdF4 nano hybrid diagnostic and therapeutic material. This nano hybrid material has achieved non-invasive optical diagnosis and treatment of pulmonary infection induced by Pseudomonas aeruginosa biofilm in a mouse model. Researchers used a unique enrichment encapsulation strategy to encapsulate hundreds of ultra small NaNdF4 nanoparticles in mesoporous silica cores, forming nano hybrid materials with uniform size, good monodispersity, and high mesoporous loading capacity（ NaNdF4@DMS-Aly ）. This nanomaterial has excellent photothermal conversion efficiency and near-infrared two zone emission performance, demonstrating good potential in in vivo therapy and imaging. In addition, a size of approximately 220 nm NaNdF4@DMS-Aly It is easier to deliver to the lungs, improving its bioavailability.
Research has found that in infected lungs, Aly enzyme is released in response to low pH environments, degrading alginate in biofilms; The surface of the material transforms into strong positivity, enhancing its interaction with Pseudomonas aeruginosa and prolonging its residence time in the lungs. By monitoring the luminescence intensity of pulmonary nanohybrid materials, the degree of biofilm infection can be evaluated in real-time. In addition, the synergistic effect of Aly enzymatic hydrolysis and photothermal sterilization can achieve strong removal of biofilms, with an in vitro sterilization rate of 5.3 log10, reaching the disinfection level; The clearance rate of bacteria in the lungs of mice reached 94%. The nano hybrid material is mainly metabolized by the liver and spleen, and is basically eliminated from the body after 8 days of intravenous injection, effectively avoiding the potential long-term toxicity of the nano material.
This work is based on the use of rare earth nano optical diagnostic and therapeutic materials to achieve in situ diagnosis, precise treatment, and real-time efficacy evaluation in a mouse model of biofilm induced lung infection. It is of great significance for promoting precision medicine research and clinical practice in treating biofilm related infections.
The related research results are titled Customized Lanthanide Nanobiofabrics for Noninvasive Precision Photosynthetics of Pulmonary Biofilm Infection and published in ACS Nano. The research work has received support from the National Key R&D Program and the National Natural Science Foundation of China.
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