Steric stabilization of phycobiliprotein loaded liposome through polyethylene glycol adsorbed cellulose nanocrystals and their impact on the gastrointestinal tract

Abstract

The goal of the study was to encapsulate phycobiliprotein (PBP), a seaweed bioactive compound with the help of liposome and stabilized through polyethylene glycol adsorbed cellulose nanocrystals (CNC). The study investigated the stability of CNC coating and the release of PBP compounds using a simulated human gastrointestinal tract (GIT) model. Adsorption of polyethylene glycol (PEG) with molecular weights of 400–4000 gmol-1 on desulfated CNCs (DCs) did not show any significant stability of liposomes during in-vitro GIT experiments. The effect of GIT phase on the quality characteristics of the sample revealed that the simulated gastric juice phase of GIT helps on desorption of polyethylene glycol from desulfated CNCs surface followed by precipitation of DCs. This phenomena confirmed the effective agglomeration of liposomes in the gastric phase of the GIT. The liposomes stabilized through the higher molecular weight of PEG adsorbed with DCs (i.e., DPCs-4000, DPCs-1500, and DPCs-1000) displayed a higher degree of anti-agglomeration behavior as compared to the lower molecular weight of PEG with desulfated CNCs (DPCs-600 and DPCs-400). However, liposomes stabilized through pure DCs displayed insignificant (p > 0.05) effect on the stability of PBP loaded liposomes. We concluded that the adsorption of PEG onto DCs surface was enough to stabilize PBP loaded liposomes in a mouth and saliva environment. This finding is relevant to understand the stability of CNC as coating material and PBP as core bioactive compounds in the human digestive system for potential nutraceutical and food applications.