Zein nanocarriers for bioactive ingredients encapsulation and delivery

Lei, Yanlin

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https://hdl.handle.net/2142/122238 Copy

Description

Title

Zein nanocarriers for bioactive ingredients encapsulation and delivery

Author(s)

Lei, Yanlin

Issue Date

2023-11-29

Director of Research (if dissertation) or Advisor (if thesis)

Lee, Youngsoo

Doctoral Committee Chair(s)

Miller, Michael J

Committee Member(s)

• Cadwallader, Keith R
• Schmidt, Shelly J

Department of Study

Food Science & Human Nutrition

Discipline

Food Science & Human Nutrition

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Delivery system
• polymeric nanoparticles
• plant-based protein
• in vivo study
• probiotics.

Abstract

Bioactive ingredients, encompassing hydrophobic substances like phenolics, vitamins, minerals, essential fatty acids, essential oils, and probiotics, are essential for human health. However, their limited stability and poor bioavailability present significant challenges in the food and pharmaceutical industries. Nanoencapsulation techniques have emerged as indispensable tools for overcoming these challenges, offering protection, controlled release, and improved absorption efficiency. Smaller nanocarriers enhance adhesion to the intestinal mucus layer, increasing retention in the gastrointestinal tract, while larger surface areas of nanostructures facilitate ingredient dispersion, enhancing bioavailability. Zein, a generally recognized as safe (GRAS) protein derived from corn, exhibits exceptional properties as a nanocarrier material for bioactive components. Its amphiphilicity, self-assembly capabilities, stability, biocompatibility, and bioadhesive nature make it an ideal choice. Furthermore, zein's resistance to digestive enzymes enables controlled release of loaded active ingredients within its nanostructure, a crucial advantage. Despite the promise of zein-based nanocarriers, challenges persist in controlling particle size and distribution, potentially affecting product sensory attributes and sustained release properties. Our research addresses this issue by introducing a novel nozzle simulation chip designed to fabricate zein-based nanoparticles tailored for encapsulating and delivering bioactive ingredients. This comprehensive study encompasses curcumin, eugenol, and probiotics (Lactobacillus rhamnosus GG), offering valuable insights into nanoencapsulation using zein nanocarriers. Our findings hold the potential to expand applications in both the food and pharmaceutical sectors, ushering in a new era of improved bioavailability and controlled release for bioactive ingredients. In the initial phase, we utilized a nozzle chip for the scalable production of self-assembled curcumin-loaded zein nanoparticles, allowing precise control over their properties. A four-factor (zein concentration in dispersed phase, ethanol concentration in continuous phase, flow rate ratio, and total flow rate), three-level Box–Behnken design on the measured responses (particle size and polydispersity index [PDI]) was established. Under optimal conditions, we achieved curcumin-loaded zein nanoparticles with an encapsulation efficiency of 64.29% ± 0.29%, a loading capacity of 3.06% ± 0.01%, enhanced stability, and improved in vitro antioxidant properties. Furthermore, curcumin exhibited controlled release from zein nanoparticles within simulated intestinal conditions. To enhance the stability of zein nanoparticles, we introduced a surface coating technique, resulting in zein-tween-80-fucoidan (Z-T-FD) composite nanoparticles via the nozzle simulation chip. Eugenol served as the model bioactive ingredient for encapsulation. Our research explores a range of weight ratios of zein, tween-80, and fucoidan, culminating in the optimal Z-T-FD ratio of 5:1:15. Remarkably, this formulation exhibits exceptional colloidal stability across a spectrum of environmental conditions, including varying pH ranges, salt concentrations, heating, and extended storage periods. This stability is attributed to the synergy of hydrophobic interactions and hydrogen bonding, resulting in the formation of uniformly spherical eugenol-zein (EU-Z) nanoparticles. The EU-Z-T-FD nanoparticles, precisely configured at a ratio of 0.5:5:1:15, achieve an encapsulation efficiency of 49.29% ± 1.00%. Their particle size measures 205.01 ± 3.25 nm, with a PDI of 0.179 ± 0.006, indicative of homogenous particle distribution. Additionally, the zeta-potential is recorded at 37.12 ± 1.87 mV, underlining the electrostatic stability of the formulation. Beyond their physical characteristics, these EU-Z-T-FD nanoparticles exhibit superior in vitro antioxidant properties, in vitro bioaccessibility, notable thermal and storage stability, outperforming other formulations. Expanding our application scope to probiotics, we targeted LGG, a renowned probiotic with potent health benefits. Encapsulation via a layer-by-layer (LbL) technique, utilizing oppositely charged polymers chitosan (CHI) and zein/tween-80/fucoidan nanoparticles (ZTFD), aimed to enhance LGG's functional attributes and resilience in the GI tract. Our results demonstrated that the double layer coated LGG, designated as (CHI/ZTFD)2-LGG, exhibited superior survival rates even under extreme conditions such as freezing, heat, and storage treatments. In simulated gastrointestinal fluid, (CHI/ZTFD)2-LGG displayed a milder decrease (2.15 log CFU/mL) compared to plain LGG (3.92 log CFU/mL). In vivo studies in mice further validated the enhanced survivability of double-layer coated LGG, holding immense promise for advancing probiotic applications and delivering enhanced health benefits to consumers.

Graduation Semester

2023-12

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Yanlin Lei

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