DESIGN OF EXPERIMENTS MODEL FOR THE OPTIMIZATION OF SILK FIBROIN BASED NANOPARTICLES

Objective: Silk fibroin based nanoparticles have been utilized extensively in biomedical fields. Amongst many preparation methods, desolvation is a favorable one. However, this method yields nanoparticles with unpredictable parameters. Thus, this investigation aimed to systematically study the effects of three independent variables including fibroin concentration (% w/v, X1), volume ratio between fibroin solution and ethanol (X2), formulation time (h, X3) on three main responses, particle size (nm, Y1), polydispersity index (Y2), zeta potential (mV, Y3).Methods: Fibroin was extracted from degummed Bombyx mori silk. The fibroin calibration curve was constructed by UV-spectrophotometer at 276 nm. The nanoparticles were prepared using the desolvation method of aqueous fibroin solution in ethanol. Design Expert® software was used to design the model. The mean particle size, polydispersity index and zeta potential were determined using ZetaPALS®analyzer.Results: By using D-optimal design with the quadratic model, the results showed that all X1, X2, and X3 variables had significant impacts on the fibroin nanoparticles characteristics Y1, Y2, and Y3. The generated model was also validated and demonstrated to be solid and reliable. The obtained optimal nanoparticles possessed Y1 of 238.1 nm, Y2 of 0.12, and Y3of-21.78 mV, which were in agreement with the predicted values, 224.8 nm, 0.13 and-19.31 mV, respectively. The optimal actual and theoretical particle characteristics were correlated with a desirable value of R2 = 0.8770. Conclusion: The D-optimal design proved its effectiveness in the prediction and optimization of fibroin nanoparticle properties