Yangchao Luo

• Ph.D.
• Professor (Assistant) at University of Connecticut

The toxicity associated with concentrated synthetic surfactants and the poor stability at gastrointestinal condition are two major constraints for practical applications of solid lipid nanoparticles (SLN) as oral delivery vehicles. In this study, a synthetic surfactant-free and cross-linker-free method was developed to fabricate effective, safe, an...

Solid lipid nanoparticles (SLNs) are regarded as promising carriers to improve the safety and effectiveness of delivery for drugs and nutrients, however, the clinic applications for oral administration are limited by their poor stability in gastrointestinal conditions. In this study, surface modification was explored to confer new physicochemical p...

Zein is the major storage protein from corn with strong hydrophobicity and unique solubility and has been considered as a versatile food biopolymer. Due to the special tertiary structures, zein can self-assemble to form micro- and nano-particles through liquid–liquid dispersion or solvent evaporation approaches. Zein-based delivery systems have bee...

Chitin nanofibers (ChNFs) were successfully prepared from lobster shells using deep eutectic solvents (DESs) and ammonium persulfate oxidation (APS), offering a sustainable approach for marine waste utilization. DES-treated chitin (DES-Chitin) with a yield of 26.22% and 94.78% purity retained a high degree of acetylation (96%), while APS oxidation...

Bioactive peptides have garnered significant attention for their health benefits and therapeutic potential across food and biomedical industries. However, their application is often limited by poor stability, low bioavailability, and susceptibility to degradation. This review provides a comprehensive overview of conventional and stimuli-responsive...

Fresh produce waste, particularly strawberries, poses significant economic and environmental challenges across the entire supply chain. Bio-sourced polymers offer a sustainable alternative to systematic packaging materials, with edible active films gaining attention for their potential to improve food preservation and quality. This study focuses on...

Biofilms pose significant challenges in various fields, including food, healthcare, and environmental industries, where they compromise safety, quality, and operational efficiency. Understanding their behavior, evaluating antimicrobial efficacy, developing control strategies, and implementing monitoring systems are crucial steps in mitigating biofi...

Microalgae are well-known for their role as sustainable bio-factories, offering a promising solution to the global food and nutrition crisis. To clarify the potential of Chlorella sorokiniana UTEX 1230 for food applications, particularly as an alternative protein source, the study employed a mixotrophic cultivation mode with sodium acetate (NaAc) a...

Maintaining freshness and quality is crucial in the meat industry, as lipid oxidation can lead to undesirable odors, flavors, and potential health risks. Traditional methods for assessing meat freshness often involve time‐consuming and destructive techniques, highlighting the need for rapid, noninvasive approaches. Recent advancements in spectrosco...

Listeria monocytogenes is a major foodborne pathogen in the United States that is capable of forming sanitizer-tolerant biofilms on diverse food contact surfaces and under varying temperature conditions. A plethora of research in the last decade has explored the potential of phytochemicals as antibiofilm agents. However, the low solubility of phyto...

Mucoadhesion has been demonstrated to be a tangible strategy for designing oral delivery systems with advantages over other existing systems such as increased local retention and sustained release. The polymeric nanoparticles have emerged as promising platforms to enable mucoadhesive properties for efficient oral delivery of bioactive compounds. Th...

The poor interfacial stability protein-stabilized high internal phase Pickering emulsions (HIPEs) is a major hurdle to realize their practical applications in food processing. In this study, four plant-based oils (palm oil, soybean oil, olive oil and perilla oil) were studied to understand their respective effects on the interfacial stability of HI...

Listeria monocytogenes, Salmonella Enteritidis, and Escherichia coli O157:H7 are the major foodborne pathogens that have been implicated in outbreaks related to consumption of contaminated cantaloupes. Current chlorine-based decontamination strategies are not completely effective for inactivating the aforementioned pathogens on cantaloupes, especia...

Among the animal derived food products, contamination of poultry eggs, and egg shell surface is one of the major causes for foodborne salmonellosis in the United States. As a means of reducing the pathogen transfer to the internal egg contents, polysaccharide-based coatings containing antimicrobial phytochemicals could potentially serve as a biocon...

The present work aimed to explore the feasibility of using egg yolk low density lipoproteins (LDL) as naturally occurring nanoparticles to prepare high internal phase Pickering emulsions (HIPEs), and to understand the role of pectin (PE) as a natural food thickener in improving the emulsifying stability to prepare HIPEs. Colloidal complexes were fo...

Developing sustainable technology to grow nutritious produce under controlled environment is an important strategy to practice urban agriculture. Being rich in nutrients and having short growth cycle, sprouts and microgreens are regarded as microscale vegetables that become ideal candidates for indoor farming. But as immature plants, sprouts and mi...

There has been growing interest in water-processable conjugated polymers for biocompatible devices. However, some broadly used conjugated polymers like poly(3-hexylthiophene) (P3HT) are hydrophobic and they cannot be processed in water. We herein report a facile yet highly efficient assembly method to prepare water-dispersible pyridine-containing P...

In this study, thymol-loaded hydrophobically modified phytoglycogen/zein nanocomplexes with a particle size around 100 nm were developed for improving microbial safety of fresh produce. The antimicrobial activities, including the determination of minimum inhibitory and bactericidal concentration, growth kinetic curves, and inhibition zone of the na...

Zinc oxide (ZnO) is one of the promising food additives, which adds nutrients and provides antimicrobial properties when incorporated into various food matrices. In this study, carboxymethyl cellulose capped ZnO (ZnO-CMC) were developed via a low-energy and cost-effective technique without calcination or grinding. The fabrication involved two steps...

High internal phase Pickering emulsions (HIPEs) were prepared by using egg yolk low density lipoprotein (LDL) and its role as a stabilizer was comprehensively studied in this work. LDL exists as homogenous nanoparticles with an average size of 49 nm and amphiphilic nature having a contact angle close to 90°. HIPEs were studied by varying compositio...

While egg yolk high-density lipoprotein (HDL) is a potential stabilizer for preparing high internal phase Pickering emulsions (HIPPEs), its poor solubility and stability are the critical challenges to overcome. In this work, soluble HDL was obtained from dissolving egg yolk granules and removing phosvitin. HIPPEs were prepared by HDL as a sole stab...

Proteins are essential on human nutrition and health, and it is crucial for the development of the human body. While animal protein is considered to be the primary dietary protein source for decades, there is a paradigm shift in recent years on the dietary consumption patterns among the general population towards plant-based food proteins. As a res...

Biopolymer-based nanoparticles, prepared from stearic acid-chitosan derivative, sodium caseinate (NaCas) and oxidized dextran (Odex), have been shown to have high biocompatibility and exceptional gastrointestinal (GI) stability. However, the mucoadhesive properties of such nanoparticles have yet to be analyzed. Therefore, interactions between the n...

While protein-stabilized high internal phase Pickering emulsions (HIPEs) have demonstrated promising potential for various applications in food, their poor interfacial stability remains as the major challenge to overcome. In this work, tannic acid (TA) was used to increase the stability of ovalbumin (OVA)-stabilized HIPEs. The binding clusters betw...

Phytoglycogen (PG), a water-soluble glycogen-like α-d-glucan, exists as natural dendritic nanoparticles which are known as a promising solubility enhancer and delivery vehicle for lipophilic compounds. However, the practical applications of PG in food and pharmaceutical fields are limited by their high hydrophilicity and relatively low encapsulatio...

In this study, the innovative and multi-functional chitosan-based hydrogel beads were immobilized with silver nanoparticles (AgNPs) via polydopamine coating to simultaneously enhance antimicrobial and adsorption activity. The morphological observation under scanning electron microscopy along with elemental mapping by energy disperse X-ray spectrome...

The carriers for hydrophobic bioactives have been extensively studied, while those for hydrophilic bioactives are still challenging. The partition of bioactives in the particles depends greatly on their solubility, interaction with carrier materials, as well as structure of carriers. In this study, chitosan-coated hollow zein particles using calciu...

In this study, a novel self-assembled protein-nanoclay system was developed for curcumin delivery. Experimentally, curcumin was dissolved and deprotonated in sodium caseinate-laponite® (NaCas-LAP) dispersion at pH 12.0 for 30 min followed by neutralization to pH=7. Due to the pH-mediated dissociation and re-association process, curcumin was success...

Chitosan, obtained by deacetylation of chitin, is widely available, biocompatible and biodegradable polysaccharide. In the same way, nanoclays have been reported to be abundant, low-toxic, and low-cost, which could be obtained either naturally or synthetically. Due to excellent film forming property, chitosan has been extensively employed in preser...

Phytoglycogen (PG) is a food-derived and glycogen-like nanoscale dendrimer. While its unique dendritic nanostructures offer promising structural features to harbor bioactive compounds, the strong hydrophilicity limits its applications for encapsulating lipophilic molecules. Here, we report a proof-of-concept study to modify PG with valeric acid (VA...

Both epidemiological and clinical studies have indicated that antioxidants found within fruits, vegetables, cereals, and teas can decrease oxidative stress and its associated diseases. Various types of nanoparticles have gained attention for their use as nanocarriers to increase the bioavailability of natural antioxidants by providing protection ag...

To overcome the poor aqueous solubility and bioavailability of curcumin, emphasize its functional features, and broaden its applications in the food and pharmaceutical industries, many nanoscale systems have been widely applied for its encapsulation and delivery. Over many decades, chitosan as a natural biopolymer has been extensively studied due t...

As a natural polysaccharide, dextran and its derivatives have gained great attention in the development of delivery systems for pharmaceutical and medical applications. In recent years, numerous dextran-based delivery systems with tailor properties and geometries have been fabricated, including self-assembled micelles and nanoparticles, nanoemulsio...

Astaxanthin (ASTX) has been reported as a potential therapeutic agent for hepatic fibrosis treatment. However, its therapeutic effect is limited due to low bioavailability and poor aqueous solubility. In this study, biopolymer-based nanoparticles were fabricated using stearic acid-chitosan conjugate (SA-CS) and sodium caseinate (NaCas) via ionic ge...

Phytoglycogen (PG)is a plant-based carbohydrate nanoparticle comprising of highly branched glucose monomers. In this study, we have compared three commonly used methods varying in the removal process of proteins and lipids, and developed a novel extraction/purification approach to obtain highly purified PG nanoparticles via a simple, easy, cost-eff...

Poor stability in gastrointestinal (GI) tract is a major challenge for applications of natural biopolymer-based nanoparticles as oral delivery vehicles. In this study, chitosan was modified by grafting stearic acid on its backbone to improve its amphiphilicity. The polymeric nanoparticles were prepared using stearic acid-conjugated chitosan and sod...

In this study, the innovative and multifunctional nanoparticles–hydrogel nanocomposites made with chitosan hydrogel beads and solid lipid–polymer hybrid nanoparticles (SLPN) were prepared through conjugation between SLPN and chitosan beads. The SLPNs were first fabricated via coating the bovine serum albumin (BSA)-emulsified solid lipid nanoparticl...

Alginate hydrogel beads have been extensively investigated as drug delivery systems due to promising gastric environment stability. In the present study, alginate-based hydrogel beads were prepared with Ca2+ or Fe3+ to serve as the loading vehicles for egg yolk low density lipoprotein (LDL)/pectin nanogels. Scanning electron microscope was carried...

Encapsulation of lipophilic bioactives into solid lipid nanoparticles (SLNs) has been a promising approach to incorporate them into functional foods with attempt to improve bioavailability. Nevertheless, how these bioactives should be loaded into the lipid core have never been systematically studied before. Thus, in the present study, biopolymer-em...

Three food polymers, zein, sodium caseinate (NaCas) and pectin were exploited as the matrix to formulate colloidal complex nanoparticles for encapsulation of eugenol. A heat- and pH-induced complexation process was optimized via polymer concentrations, loading percentage of eugenol, as well as pH conditions, to obtain small, homogeneous, and stable...

In this study, pectin was applied as a carbohydrate-based coating to improve physicochemical stability of sodium caseinate/zein (CZ) complex protein nanoparticles. Pectin coating was achieved via a pH- and heating-induced facile electrostatic adsorption process. The effect of pectin coating was tested on two different nanoparticle structures, i.e....

In this work, egg yolk high density lipoprotein (HDL) was first extracted and solubilized with a salt-free method. The freshly purified egg yolk HDL was characterized for its physicochemical properties and its delivery potentials for hydrophobic bioactives were also investigated. Native chitosan (NACS) and its amphiphilic derivative (stearic acid c...

Egg yolk low density lipoprotein (LDL)/polysaccharide nanogels are newly explored as oral delivery systems with promising encapsulation potentials. Nonetheless, the stability of nanogels against aggregation in gastrointestinal tract remains a challenge. Therefore, chemical crosslinking by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysucc...

Exploitation of lipid nanoparticles for oral delivery of nutrients and drugs is limited by their poor stability under gastrointestinal tract and low loading capacity, unless a high concentration of synthetic surfactants is formulated. The main objective of present study is to design a series of new formulations for solid lipid nanoparticles (SLN) a...

The formation of protein-polysaccharide complex nanoparticles was investigated using caseinate (NaCas), zein, and three polysaccharides, i.e. pectin, carboxymethyl cellulose (CMC) and gum arabic. Their complexation behavior was examined by dynamic light scattering, Fourier transform infrared and fluorescence spectroscopy. Chemical cross-linkers, 1-...

In this study, pectin was used as coating material to form zein/caseinate/pectin complex nanoparticles through pH adjustment and heating treatment for potential oral delivery applications. The preparation conditions were studied by applying heating treatment at different pHs, either the isoelectric point of zein (pH 6.2) or caseinate (pH 4.6), or c...

Although drug delivery technologies in biomedicine and pharmacy have received extensive attention for decades, the delivery of nutrients in the food industry is an emerging research area that has begun to attract increasing interests in recent years. Nanotechnology-based strategies for nutrient delivery are of particular interest for both food scie...

Background: It is not clear how oil-in-water nanoemulsions of lutein may affect bioavailability and consequently alter lipoprotein metabolism, oxidative stress, and inflammation. Objective: The bioavailability as well as effects of a powdered lutein (PL) and an oil-in-water lutein nanoemulsion (NANO; particle size: 254.2 nm; polydispersity index...

The major objective of this work was to develop a green and facile process to prepare gallic acid-chitosan conjugate and comprehensively evaluate the physicochemical properties and biological activities of as-prepared water soluble chitosan derivative. A free radical induced grafting approach using ascorbic acid/hydrogen peroxide redox pair was ado...

Sodium carbonate was proposed as a sacrifice template and tannic acid was used as a natural cross-linker to prepare hollow zein nanoparticles (HZN/T). The formulation of nanoparticles, including the amount of water, zein and sodium carbonate, were optimized by surface response methodology (Box-Behnken design). The optimized HZN/T exhibited a small...

Solid lipid nanoparticles (SLNs) have gained tremendous attraction as carriers for controlled drug delivery. Despite numerous advances in the field, one long-standing historical challenge for their practical applications remains unmet: redispersibility after drying. In this work, a novel design of SLNs using a layer-by-layer (LbL) technique was dev...

Polyelectrolyte complex (PEC) nanoparticles between chitosan (CS) and biomacromolecules offer better physicochemical properties as delivery vehicles for nutrients than other CS-based nanoparticles. Our major objective was to fabricate PEC nanoparticles between water soluble gallic acid-chitosan conjugate (GA-CS) and gum arabic. The optimal fabricat...

Five polysaccharides, pectin, carboxymethyl cellulose (CMC), gum arabic, carrageenan and alginate, were studied to form complex nanogels with egg yolk low density lipoprotein (LDL). All nanogels were smaller than 85 nm with highly negative zeta potential, while LDL/carrageenan and LDL/alginate nanogels exhibited more heterogeneous size distribution...

Bovine serum albumin (BSA) microspheres were prepared through a facile and low-cost route including a high-speed dispersion of BSA in cross-linking solution followed by spray drying. Interestingly the as-prepared BSA microspheres possess unique blue-green, green, green-yellow, and red fluorescence when excited by specific wavelengths of laser or LE...

We developed a nano‐emulsion of lutein disolved in medium chain triglyceride (MCT) oil with d‐alpha tocopheryl polyethylene glycol 1000 succinate (TPGS) as the surfactant. The average particle size was 223.6 nm, with a polidispersity index (PDI) of 0.5 and a zeta (ζ) potential of −17 mV. Then the efficacy of this nano emulsion was compared to regul...

Zein is the major storage protein from corn with strong hydrophobicity and unique solubility and has been studied as an excellent natural biomaterial for encapsulation and delivery of nutraceuticals. Although zein nanoparticles can be easily prepared by anti‐solvent liquid‐liquid dispersion method, the nanoparticles usually have a dimension greater...

We investigated the effects of two different breakfasts on HDL antioxidant and size properties. This was a randomized crossover design in which 48 subjects (24 women and 26 men) aged 18 to 30 y had for breakfast either 2 eggs/d or 1 packet of oatmeal/d. Participants were randomly assigned to consume the egg or oatmeal breakfast for 4 weeks and afte...

Development of delivery systems from natural protein/polysaccharide complexes is of particularly interests for applications in food, pharmaceutics and biomedicine. In this study, novel nanogels smaller than 60 nm were prepared from egg yolk low density lipoprotein (LDL) and pectin complexation via a pH- and heat-induced facile process. The nanostru...

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn’s disease, is a chronic and relapsing inflammation of gastrointestinal (GI) tract, especially at the site of large intestine (colon). The incidence of IBD has been increasing by doubling every decade since the 1950s. The slowly progressing but lethal effects of IBD are becomin...

The poor water solubility and bioactivity of lipophilic phytochemicals can be potentially improved by delivery systems. In this study, a low-cost, low-energy, and organic solvent-free encapsulation technology was studied by utilizing the pH-dependent solubility properties of curcumin and self-assembly properties of sodium caseinate (NaCas). Curcumi...

Low-cost emulsification technologies using food ingredients are critical to various applications. In the present study, a novel self-emulsification technique was studied to prepare clove bud oil (CBO) emulsions, without specialized equipment or organic solvents. CBO was first dissolved in hot alkaline solutions, added at 1% v/v into neutral solutio...

Aquatic toxicity testing generally focuses on the water absorption/dermal route of exposure to potential toxic chemicals, while much less work has been done on the oral route of exposure. This is due in part to the difficulties of applying traditional oral toxicity testing to aquatic environments, including the tendency for test chemicals to dissol...

Cellular evaluation of zein nanoparticles has not been studied systematically due to their poor redispersibility. Caseinate (CAS) stabilized zein nanoparticles have been recently developed with better redispersibility in salt solutions. In this study, zein-CAS nanoparticles were prepared with different zein/CAS mass ratios. The prepared nanoparticl...