Porous Gelatin Microspheres For Controlled Drug Delivery With High Hemostatic Efficacy

Effective hemostasis and antibacterial efficacy for extensive trauma in a warzone and civilian accidents are important for reducing mortalities and serious complications.Gelatin has been widely used as a hemostatic agent and has the potential for use in drug delivery systems.To enhance its hemostatic efficiency and create conducive conditions for sustained drug release,we developed Vancomycin-impregnated porous gelatin microspheres（Van-MS）by introducing the porous structure into gelatin.Results showed that Van-MS can be successfully developed via the ice crystal pore-making method combined with hydration maintaining its stability.We also explored the use of biodegradable porous materials for treatment of infections and bleeding in soft tissue,and analyzed Van-MS via scanning electron microscopy（SEM）,scanning electron microscopy and energy dispersive X-ray spectrometry（SEM-EDS）,Fourier Transform infrared spectroscopy（FTIR）and High-Performance Liquid Chromatography（HPLC）.Results from Van-MS showed high hemostatic both efficacies in vivo and in vitro.Moreover,muscle lesions treated by Van-MS showed formation of fibrous connective tissue and were nearly sealed after 10 days in a rabbit traumatic infection model.This antibacterial performance was attributed to absorption of exudates and sustained drug release.Hemostatic effects were due to:（1）particles water swelling form a physical barrier that led to physical hemostasis;（2）activation of the endogenous coagulation pathway which resulted in physiological hemostasis;（3）aggregation of platelets and erythrocytes after absorbing water;and（4）stronger hemostatic properties owing to their porous structure with high specific surface area.