Characterization of insulin-loaded alginate nanoparticles produced by ionotropic pre-gelation through DSC and FTIR studies

• Autor(a) principal: Sarmento, Bruno
• Data de Publicação: 2006
• Outros Autores: Ferreira, Domingos, Veiga, Francisco, Ribeiro, António
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/5866; https://doi.org/10.1016/j.carbpol.2006.02.008
• topic: Alginate; Chitosan; Insulin; Nanoparticles

Insulin-loaded nanoparticles were prepared by ionotropic pre-gelation of alginate with calcium chloride followed by complexation between alginate and chitosan. The influence of the pH and stoichiometry relationship between polyelectrolytes providing individual particles with a nano-scale size was assessed by photon correlation spectroscopy (PCS) and scanning electron microscopy (SEM). Insulin-polyelectrolyte interactions at varying pH and polyelectrolytes stoichiometry were assessed by differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) studies. Individual and smaller sizing nanoparticles, around 800 nm, were obtained at pH 4.7 with an alginate:chitosan mass ratio of 6:1. Thermograms of insulin-loaded nanoparticles originated shifts on same unloaded nanoparticle peaks and suggested polyelectrolytes-protein interactions at pH around 4.5-5.0. FTIR spectra of insulin-loaded nanoparticles showed amide absorption bands characteristic of protein spectra and revealed the formation of new chemical entities.