Recently, professor Hao Zhihui from the School of Chemistry and Pharmacy of Qingdao Agricultural University(QAU) published her research results on the mechanism of antibacterial pharmacodynamics of targeted preparations in Drug Delivery, a famous international journal of pharmacy. The article is titled"Cefquinome-loaded Microsphere Supplies Against Klebsiella Pneumonia Infection During Experimental Infections" (influencing factor 6.402). The research was funded by National Natural and Science Foundation Project, and the 13th Five-Year Plan for Research and Development Project. Graduate student Qu Shaoqi is the first author; professor Hao Zhihui is the correspondent author;QAU is the sole signing unit. The research results are the latest reports on the pharmacodynamic mechanism of veterinary drug targeted preparations to date, providing methods for the application of targeted microsphere preparations, and reflecting the leading level of research in this field.

Professor Hao Zhizhi's research group unilized the K. pneumoniae-infected rats to establish a model of pneumonia infection, and conducted related research on the mechanism of pharmacodynamic enhancement after different drug treatments. The study found that after rats is infected with Klebsiella pneumoniae, the content of bacteria in the lung tissue reaches 105 CFU/g, and the phagocytic capacity of macrophages is significantly decreased. There is a strong inflammatory reaction, and the mortality rate is about 50%. however, no death is found in the rats treated with the targeted preparations. A further study of its mechanism found that targeted preparations significantly increased the phagocytic capacity of macrophages and bacterial-elimination rate. The increase of IL-4, IL-10, IL-13, TNF-α, IL-1β and IL-8 activates the inflammatory response pathway, with changes in cytokine levels and types as secondary manifestations of drug bactericidal effects. Then pulmonary interstitial is broadening, inflammatory fluid infiltration is significantly improved, and lung tissue structure is basically restored to normal.

Professor Hao Zhihui's research group has been committed to the key technology research on the acquisition of pharmaceutical active ingredients and the improvement of drug efficacy. In 2017, he published the research results of the targeting mechanism of targeted agents in animals in Drug Delivery, entitled "Preparation and Testing of Cefquinome Loaded Poly Lactic co Glycolic Acid Microspheres For Lung Targeting", clarifying the lung targeting distribution and mechanism of cefquinome-targeted microspheres. It provides clinical and theoretical basis for the application of targeted microsphere preparations in veterinary clinics.

As shown in the above figure: using different carrier materials and different preparation methods, the influencing factors of cephalosporin-targeted microspheres were studied. On the basis of successful preparation of cefquinome lung-targeted microspheres, and with rats used as experimental animals, it shows that the targeted preparation is significantly lung-targeted and there are no obvious histopathological changes; the targeted preparation significantly improved the lung tissue damage of the bacterial-infected rats; and the curative effect was significantly improved compared with the control drug.