New Biocompatible Nanoparticles Based on Fractionized Gelatin as Drug Delivery Systems for Nucleic Acids and Peptides

In 1978 Marty et al. described for the first time the preparation of gelatin nanoparticles using desalting or desolvating agents. The desolvation process using acetone or other non-solvents works only with very low concentrations of gelatin (0.1%) [1]. By increasing the gelatin concentration in the solution the formation of aggregations during desolvation and cosslinking also dramatically increases. In 1985 the molecular weight of gelatin was described to be between 60000-90000 Da [2]. With improved analytical equipment, the specification of the molecular weight of one of the largest gelatin producers worldwide (DGF Stoess AG, Eberbach, Germany) is today from below 20000 to over 400000 Da. This shows the heterogeneity of gelatin and makes it more understanding why there are many difficulties in the preparation of nanoparticles from this substance.