Gelatin solution pH and incubation time influences the size of the nanoparticles engineered by desolvation

Gelatin nanoparticles (GNPs) have been extensively engineered by desolvation processes. However, engineering monodisperse GNPs of reproducible size remains a challenge. Therefore, the starting material processing steps such as gelatin solution pH adjustment and incubation time prior to desolvation were investigated to understand their implications on GNPs size and size distribution. The GNPs were engineered by one-step and two-step desolvation processes using ethanol as a desolvating agent. Irrespective of the desolvation steps, gelatin solution pH incubation times between 0 h and 24 h showed significant (p < 0.05) increase in GNPs size. This phenomenon was distinctly observed in GNPs engineered by one-step desolvation process. Additionally, two-step desolvation process resulted in relatively smaller monodisperse GNPs compared to one-step desolvation. Statistical rationales from traditional One-Factor-at-a-Time analysis corroborated the multivariate correlations derived from principal component analysis and standard partial least square-1 (PLS-1) regression. Significant predictive model equations to compute GNPs size and size distribution were modeled by PLS-1 regression and verified with experimental values. Our findings demonstrated the statistically significant (p < 0.05) decisive roles of gelatin solution pH and incubation time on size and size distribution of GNPs engineered by desolvation process. Furthermore, irrespective of incubation times, GNPs from two-step desolvation maintained relatively better physical stability for 238 days in terms of size and size distribution than one-step desolvation.