Pickering emulsions stabilized by whey protein isolate/nicotinamide mononucleotide complex and their application in pH-responsive drug delivery

The complexation of nicotinamide mononucleotide (NMN) with whey protein isolate (WPI) via hydrogen bonds is elucidated to significantly fortify fish oil Pickering emulsions, engendering a robust network matrix resilient to varied pH conditions. Our findings reveal that NMN/WPI complexes not only reduce the average droplet size but also increase the viscoelastic properties and oxidative stability of the emulsion, identifying an optimal NMN concentration of 0.7%. At this concentration, the emulsion demonstrates exemplary water retention (93.7%) and prolonged stability (up to 16 days). The adjustment of pH facilitates the controlled release of ibuprofen, with a 5% concentration in microspheres yielding a drug loading and encapsulation efficiency of 30.4% and 92.1%, respectively. Under acidic conditions (pH∼2), the emulsion facilitates a 75% release of ibuprofen within the initial two hours, extending a sustained delivery over 25 hours, culminating in a release efficacy of 97%. Exhibiting a pH-responsive nature, these emulsions stand as paragons for the precision in drug release methodologies.