Objective: The aim of this study is to optimize the formulation of insulin-loaded poly-caprolactone nanoparticles (INS-PCL-NP) for use in chronic wound healing using Box-Behnken experimental design. Material and Method: The response of independent variables (poly-caprolactone concentration, polyvinyl alcohol concentration and sonication time) on dependent variables (particle size, PDI and encapsulation efficiency) were evaluated. Nanoparticle formulations were produced by the double emulsion (w/o/w)-solvent evaporation method. The resulting formulations were characterized in terms of particle size, zeta potential, and encapsulation efficiency to determine the optimum formulation. Further analyses, including morphological analyses, Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and in vitro drug release studies were conducted on the optimized formulation. Result and Discussion: According to the results of the characterization studies, it was observed that the optimized nanoparticles had a particle size of 618.5±11.2 nm, a PDI of 0.194±0.021, a zeta potential of-8.21±1.1 mV and an encapsulation efficiency of 73.1±4.2%. In morphological analysis, it was observed that the nanoparticles had a spherical structure. The optimized nanoparticle formulation showed a rapid release of 49.1±2.1% within the first 24 hours, followed by a controlled release for 168 hours.