Characterization of Cationic Modified Debranched Starch and Formation of Complex Nanoparticles with κ-Carrageenan and Low Methoxyl Pectin

Mechanism on microbial transglutaminase and Tremella fuciformis polysaccharide-mediated modification of lactoferrin: Development of functional food

Lactoferrin (LF) with various biological functions demonstrates great application potential. However, its application was restricted by its poor gelation and instability. The aim of this work was to explore the effect of microbial transglutaminase (MTGase) and Tremella fuciformis polysaccharide (TP) on the functional properties of LF. The formation of a self-supporting LF gel could be induced by MTGase through generating covalent crosslinks between the LF protein molecules. Meanwhile, TP was introduced into the gel system to improve the strength of LF-TP composite gels by enhancing non-covalent interactions such as hydrogen bond and electrostatic interactions during gel formation. Additionally, the LF-TP composite gel exhibited outstanding functional characteristics such as gastrointestinal digestive stability and antioxidant property. This work clarified the mechanism on MTGase and TP-mediated modification of lactoferrin, offered a novel strategy to increase the functional characteristics of LF, and enlarged the application range of LF and TP.

Lactoferrin-Chitosan Composite Hydrogels Induced by Microbial Transglutaminase: Potential Delivery Systems for Thermosensitive Bioactive Substances

In this work, lactoferrin (LF)-chitosan (CS) composite hydrogels with good loading capacity of thermosensitive bioactive substances were successfully obtained by microbial transglutaminase (MTG)-induced cross-linking. We evaluated the rheological, textural, and microstructural characteristics of the composite hydrogels under different conditions. The results demonstrated that the concentrations of LF and CS as well as the amount of MTG could regulate the textural properties, rheological properties, and water holding capability. The results of FTIR and fluorescence spectroscopy indicated that the main interactions within the composite gel were hydrogen and isopeptide bonds. Additionally, in vitro digestion simulation results verified that riboflavin kept stable in stomach due to the protection of LF-CS composite hydrogels and was released in small intestine. These results suggested that thermosensitive bioactive substance could be encapsulated and delivered by the LF-CS composite hydrogel, which could be applied in lots of potential applications in functional food as a new material.

Insights into formation and stability mechanism of V7-type short amylose-resveratrol complex using molecular dynamics simulation and molecular docking

Pre-formed V-type amylose as a kind of wall material has been reported to carry polyphenols, while the interaction mechanism between V-type amylose and polyphenol is still elusive. In this work, the formation and stability mechanism of a V7-type short amylose-resveratrol complex was investigated via isothermal titration calorimetry, molecular dynamics, and molecular docking. The results presented that two stoichiometric ratios of resveratrol to short amylose were calculated to 0.120 and 0.800, and the corresponding main driving force was hydrogen bonding and hydrophobic interaction, respectively. The folding and unfolding conformation of V7-type short amylose chains appeared alternately during the simulation. Resveratrol tended to be bound in the short amylose helix between 40 ns and 80 ns to form a more stable complex. Hydrogen bonds between resveratrol molecule and O6 at the 22nd glucose molecule/O2 at the 24th glucose molecules and hydrophobic interaction between resveratrol molecule and glucose molecules (19th, 20th, 21st and 23rd) could be found.

Cationic starch: A functionalized polysaccharide based polymer for advancement of drug delivery and health care system - A review

Research and development in health care industry is in persistence progression. To make it more patient-friendly or to get maximum benefits from it, special attention to different advanced drug delivery system (ADDS) is employed that delivers the drug at the target site and will be able to sustain/control release of drugs. ADDS should be non-toxic, biodegradable, biocompatible along with desirable showing physicochemical and functional properties. These drug delivery systems can be totally based on polymers, either with natural or synthetic polymers. The molecular weight of polymer can be tuned and different groups of polymers can be modified or substituted with other functional groups. Degree of substitution is also tailored. Cationic starch in recent years is exploited in drug delivery, tissue engineering and biomedicine. Due to their abundant availability, low cost, easy chemical modification, low toxicity, biodegradability and biocompatibility, extensive research is now being carried out. Our present discussion will shed light on the usage of cationic starch in health care system.

Efficient encapsulation of fat-soluble food-derived biofunctional substances (curcumin as an example) in dual-modified starch-based nanoparticles containing large conjugated systems

Acid-ethanol hydrolysis and subsequent cinnamic acid (CA) esterification were employed to prepare a series of dual-modified starches efficiently loaded with curcumin (Cur) utilizing large conjugation systems provided by CA. Structures of the dual-modified starches were confirmed by IR and NMR, and their physicochemical properties were characterized by SEM, XRD and TGA. The nanoparticles fabricated from the dual-modified starch have perfect spherical shape (250.7-448.5 nm, polydispersity index <0.3), excellent biosafety (no hematotoxicity, no cytotoxicity, no mutagenicity) and high loading of Cur (up to 26.7 % loading). By XPS analysis, this high loading is believed to be supported by the synergistic effect of hydrogen bonding (provided by hydroxyl groups) and π-π interactions (provided by large conjugation system). In addition, the encapsulation of dual-modified starch nanoparticles effectively enhanced the water solubility (18-fold) and physical stability (6-8-fold) of free Cur. In vitro gastrointestinal release showed that Cur-encapsulated dual-modified starch nanoparticles were released more preferably than free Cur and that the Korsmeyer-Peppas model was the most suitable release model. These studies suggest that dual-modified starches containing large conjugation systems would be a better alternative for encapsulating fat-soluble food-derived biofunctional substances in functional food and pharmaceutical applications.

Recent advances in exploiting carrageenans as a versatile functional material for promising biomedical applications

Carrageenans are a group of biopolymers widely found in red seaweeds. Commercial carrageenans have been traditionally used as emulsifiers, stabilizers, and thickening and gelling agents in food products. Carrageenans are regarded as bioactive polysaccharides with disease-modifying and microbiota-modulating activities. Novel biomedical applications of carrageenans as biocompatible functional materials for fabricating hydrogels and nanostructures, including carbon dots, nanoparticles, and nanofibers, have been increasingly exploited. In this review, we describe the unique structural characteristics of carrageenans and their functional relevance. We summarize salient physicochemical features, including thixotropic and shear-thinning properties, of carrageenans. Recent results from clinical trials in which carrageenans were applied as both antiviral and antitumor agents and functional materials are discussed. We also highlight the most recent advances in the development of carrageenan-based targeted drug delivery systems with various pharmaceutical formulations. Promising applications of carrageenans as a bioink material for 3D printing in tissue engineering and regenerative medicine are systematically evaluated. We envisage some key hurdles and challenges in the commercialization of carrageenans as a versatile material for clinical practice. This comprehensive review of the intimate relationships among the structural features, unique rheological properties, and biofunctionality of carrageenans will provide novel insights into their biomedicine application potential.

Hydrolytic Quinoa Protein and Cationic Lotus Root Starch-Based Micelles for Co-Delivery of Quercetin and Epigallo-catechin 3-Gallate in Ulcerative Colitis Treatment

The accumulation and sustained release of drugs in the colonic inflammatory region are the favorable strategy for treating ulcerative colitis (UC). In this study, we developed a synergistic anti-inflammatory drug (quercetin/EGCG)-loaded micelle using hydrolytic quinoa protein (HQP) and cationic lotus root starch (CLRS) by a layer-by-layer assembly method. The encapsulation efficiency of quercetin and EGCG in the Que-HQP-EGCG-CLRS micelles reached 91.5 and 89.4%, respectively. This composite micelle exhibited a core-shell structure, where Que-HQP-EGCG was the core and CLRS was the coating shell. Moreover, the in vitro experiments indicated that these micelles can make Que/EGCG pass through gastric environments stably and delay their release in the intestine. Animal experiments further confirmed that the Que-HQP-EGCG-CLRS micelles can efficiently accumulate in the colonic inflammatory region and enable sustained release of drugs (more than 24 h), thus notably alleviating the symptoms of UC. These results suggested that Que-HQP-EGCG-CLRS micelles have good gastric stability, colonic inflammatory-accumulated effect, and sustained drug release ability, which are a promising co-delivery system for UC treatment.

Elaboration of Cationic Soluble Soybean Polysaccharides-Epigallocatechin Gallate Nanoparticles with Sustained Antioxidant and Antimicrobial Activities

Epigallocatechin gallate (EGCG) is easily oxidized by environmental stress elements, including light, heat, and oxygen; thus, its biological activities can be reduced or even lost when exposed to a natural environment. Here, soluble soybean polysaccharide (SSPS) was successfully etherized by 3-chloro-2-hydroxypropyl trimethylammonium chloride (CHPTAC), positively charged to extract cationic SSPS (CSSPS). Nanoparticles based on CSSPS can improve the encapsulation efficiency (EE) and sustained bioactivity of EGCG. The EE of EGCG by CSSPS was improved significantly as compared with that of SSPS due to the electrostatic interactions. Furthermore, the protective and sustained-release effects of CSSPS on EGCG in the EGCG-CSSPS nanoparticles (EGCG-CSSPS-NPs) markedly improved the sustained antioxidant and antimicrobial activities of EGCG, which was confirmed by the results of a salmon-preservation experiment. In addition, cytotoxicity tests showed that EGCG-CSSPS-NPs could effectively inhibit the proliferation of tumor cells but had no obvious toxicity to normal cells.

Design and optimization of metformin hydrophobic ion pairs for efficient encapsulation in polymeric drug carriers

Loading small molecular weight hydrophilic drugs into polymeric carriers is a challenging task. Metformin hydrochloride (MET) is a highly soluble oral antidiabetic drug of small size and high cationic charge. Hydrophobic ion pairing (HIP) is an approach for reversible modulation of solubility and hydrophilicity of water-soluble drugs via complexation with oppositely charged molecules. Herein, we prepared MET ion pairs and carefully studied and characterized MET interaction with different ligands, with the aim of increasing MET lipophilicity and loading efficiency. HIP was successful using three hydrophilic anionic ligands; sodium dodecyl sulphate (SDS) Carbopol (CB) and tannic acid (TA). Electrostatic interaction and hydrogen bonding drove the complexation per spectroscopic and thermal studies. Complexation efficiency depended on ligand type and charge ratio. While complexes had varying interaction strengths, the excessive stability of TA/MET resulted in unfavorable poor MET dissociation. Notably, HIP imparted a 450 and tenfold lipophilicity increase for SDS/MET and CB/MET, respectively. The latter showed favorable controlled, yet complete release of MET at pH 6.8 and was loaded into alginate beads. Complex bulkiness and decreased lipophilicity resulted in a dramatic 88% increase of MET loading, demonstrating the success of HIP as a simple, efficient and applicable approach for modulating drug’s properties.

Encapsulation of Curcumin in a Ternary Nanocomplex Prepared with Carboxymethyl Short Linear Glucan-Sodium-Caseinate-Pectin Via Electrostatic Interactions

This work chemically modified short linear glucan (SLG) by introducing a surface carboxymethyl group to obtain carboxymethylated SLG (CMSLG), then prepared CMSLG-based ternary nanocomplex particles based on electrostatic interactions with sodium-caseinate (NaCas) and pectin. These nanocomplex particles are homogeneous, generally exhibiting sizes of <200 nm with spherical shape and negative surface charge. In addition, the results showed the increase in both the mass ratio of CMSLG and NaCas and the synthesis temperature can improve the colloidal stability of nanocomplex particles when they are exposed to simulated gastrointestinal fluids containing digestive enzymes. Moreover, nanocomplex particles have an exceptional capability to encapsulate curcumin, and this encapsulation efficiency increased as the mass ratios of CMSLG and NaCas were increased. The study also investigated the antioxidant activity and in vitro release properties of curcumin encapsulated by nanocomplex particles and found that CMSLG/NaCas/pectin had improved higher ABTS radical scavenging capacity and allowed for the controlled, sustained release of curcumin in simulated gastrointestinal fluid within 6 hours. Thus, this study provides new insights into the design of a CMSLG-based ternary nanocomplex and its use as a potential oral delivery system for lipophilic bioactive compounds. PRACTICAL APPLICATION: Curcumin, as a sort of natural polyphenolic compound, has many physiologic functions such as anti-oxidation, anticancer, and prevention of Alzheimer's disease. However, the application of the curcumin has been limited by its poor water solubility and unstable physicochemical property. To solve this problem, the nanotechnology has been used to prepare the nano-delivery carriers for curcumin. This work prepared a ternary nanoparticle based on the carboxymethyl short linear glucan, sodium-caseinate, and pectin. The ternary nanoparticle can achieve a higher encapsulation efficiency for curcumin. In addition, the ternary nanoparticle can enhance the ABTS radical scavenging capacity and provided control and sustained release of curcumin in the simulated gastrointestinal fluid.

Encapsulation of luteolin using oxidized lotus root starch nanoparticles prepared by anti-solvent precipitation

In this study, luteolin-oxidized lotus root starch (OLRS) nanoparticles (NPs) were developed to improve the stability and antioxidant activity of luteolin. Results showed that a stable luteolin-OLRS NPs was formed using luteolin and OLRS (oxidation degree, 15%) in the weight ratio of 3:1, as well as anti-solvent and solvent in the volume ratio of 10:1. Under this condition, the particle size, polydispersity index and zeta-potential of luteolin-OLRS NPs was 305 nm, 0.173 and -20.8 mV, respectively. The analysis of transmission electron microscopy, X-ray diffractometer and Fourier transform infrared spectroscopy demonstrated that the luteolin was successfully encapsulated in OLRS NPs, giving an encapsulation efficiency of 87.2%. The release characteristic and antioxidant activity of encapsulated luteolin were further investigated. Results exhibited that the OLRS NPs enabled luteolin to be stable in simulated gastric fluid and sustained release in simulated intestinal fluid, leading to the enhancement of antioxidant activity of luteolin.

Dual-modified starch nanospheres encapsulated with curcumin by self-assembly: Structure, physicochemical properties and anti-inflammatory activity

Pullulanase debranching and subsequent hydroxypropylation were applied to prepare a series of dual-modified starches (Hydroxypropylated debranched starch, HPDS) with different degrees of hydroxypropyl substitution. Their structural and physicochemical properties varied with the degree of hydroxypropyl substitution, and all HPDS exhibited the ability to self-assemble into well-shaped nanospheres (100-150 nm, PDI < 0.2). These HPDS nanospheres were attempted to encapsulate curcumin with the aim of improving the bioavailability, solubility and stability of curcumin. Their structural characteristics, thermal stability, iodine staining, morphology, safety, encapsulation efficiency, in vitro gastrointestinal release behavior, and anti-inflammatory activity were evaluated. The results showed that curcumin could be effectively encapsulated into the HPDS nanospheres, and the encapsulation efficiency, water solubility and physical stability were positively correlated with the degree of hydroxypropyl substitution. After encapsulation, the water solubility and physical stability of curcumin could be increased up to 226-fold and 6-fold, respectively. The HPDS nanospheres also exhibited good safety (including hemolysis and cytotoxicity) and sustainable release of curcumin. Evaluation of anti-inflammatory activity showed that the activity of curcumin-encapsulated HPDS was enhanced by 170% compared to unencapsulated curcumin. These suggest that HPDS nanospheres encapsulation may be a more suitable option for the development of functional foods containing bioactive compounds.

Characterization of Cationic Modified Short Linear Glucan and Fabrication of Complex Nanoparticles with Low and High Methoxy Pectin

In this study, we chemically modified the short linear glucan (SLG) using the 3-chloro-2-hydroxypropyl trimethylammonium chloride to introduce a positive surface charge via cationization (CSLG). We then prepared CSLG-based binary nanocomplex particles through electrostatic interactions with low and high methoxyl pectin. The two new types of binary nanocomplex were comprehensively characterized. It was found that the nanocomplex particles showed a spherical shape with the particle size of <700 nm, smooth surface, homogeneous distribution, and negative surface charge. Fourier transform infrared spectroscopy (FTIR) revealed that the driving forces to form nanocomplex were primarily electrostatic interactions and hydrogen bonding. In addition, increasing the CSLG concentration in the nanocomplex significantly enhanced both thermal stability and digestive stability. By comparing the two complex nanoparticles, the HMP-CSLG has a larger particle size and better stability under the GI condition due to the high content of the methoxy group. Additionally, the HMP-CSLG nanoparticle has a higher encapsulation efficiency and slower release rate under simulated gastrointestinal fluid for tangeretin compared with the LMP-CSLG. These results provide new insights into designing the CSLG-based nanocomplex as a potential oral delivery system for nutraceuticals or active ingredients.

Nanostarch: Preparation, Modification, and Application in Pickering Emulsions

Nanostarch, as a food-grade Pickering emulsion stabilizer, has attracted wide attention owing to its biodegradability, nontoxicity, small size, and large specific surface area. In this review, the preparation, modification, and application of Pickering emulsions incorporating nanostarch are described. At present, methods for nanostarch preparation mainly include acid hydrolysis, acid hydrolysis combined with other treatments, nanoprecipitation, ultrasonication, ball milling, and cross-linking. Nanostarch is a promising Pickering emulsion stabilizer, and its emulsifying ability of nanostarch is significantly improved by hydrophobic modification. The hydrophobicity, charge, size, and content of nanostarch affect the emulsion stability. Future developments in this area of research include the efficient and environmentally friendly preparation of nanostarch as well as the control of its hydrophobicity via modification. Future studies should focus on the digestibility and storage stability of Pickering emulsions stabilized by nanostarch under different conditions.

Carriers Based on Zein-Dextran Sulfate Sodium Binary Complex for the Sustained Delivery of Quercetin

Herein, a self-assembly formulation of Zein and dextran sulfate sodium (DSS) binary complex has been developed for the quercetin (Que) delivery. The prepared particles display a smooth sphere in the range of 180 ~ 250 nm. The addition of DSS shields the Trp residues of Zein that were located on the hydrophilic exterior and in-turn reduces the surface hydrophobicity of the nanoparticles. The presence of DSS, indeed, increases the encapsulation efficiency of Que from the initial 45.9 in the Zein to 72.6% in the Zein/DSS binary complex. A significant reduction of Que diffusion in the simulated intestinal conditions has been observed with the addition of DSS on the nanoparticles, which also improves Que bioavailability. The release mechanism of Que-loaded Zein/DSS composites is in accordance with the Higuchi model (Q = 0.0913t^0.5+0.1652, R² = 0.953). Overall, nanoparticles based on Zein-DSS complexes stand out as an attractive carrier system of quercetin and the outcome could be extended to several bioactive compounds.

Interactions of Surface-Functionalized Starch Nanoparticles with Pepsin and Trypsin in Simulated Gastrointestinal Fluids

Nanoparticles (NPs) can form a protein corona (PC) with proteins in biological fluids. We examined whether starch nanoparticles (SNPs) form a PC and interact with digestive enzymes in simulated gastric and intestinal fluids. We investigated the adsorption of pepsin and trypsin on unmodified, carboxyl-, and amino-modified SNPs (SNPs, COOH-SNPs, and NH₂-SNPs, respectively). Quartz crystal microbalance data showed that a tight and irreversible pepsin corona formed on the NH₂-SNPs, pepsin had little or no binding to the SNPs and COOH-SNPs, and trypsin had weak binding to all three kinds of NPs. Dynamic light scattering data showed that pepsin significantly increased the size of the NH₂-SNPs from 120 ± 2.6 to 203 ± 12.2 nm and decreased their surface potential from 23.2 ± 1.0 to 12.7 ± 0.2 mV. NH₂-SNPs could induce the fluorescence quenching of pepsin and change its secondary structures without affecting its activity.

Fabrication and characterization of hollow starch nanoparticles by heterogeneous crystallization of debranched starch in a nanoemulsion system

The development of hollow nanoparticles has attracted widespread interest due to their potential commercial applications. This work aimed to prepare a novel hollow starch nanoparticles (HSNPs) from debranched waxy corn starch (DBS) via an oil-in-water (O/W) emulsion templating method. The effects of different concentrations of DBS on the formation of HSNPs at 4 °C and 25 °C were investigated. The monodispersed HSNPs obtained with 0.5% concentrations of DBS at 25 °C had spherical shapes, ranging between 200 and 800 nm. HSNPs with relative crystallinities of 16.9%-29.7% exhibited V-type or B + V-type structures, which indicated that DBS at low concentrations (0.5%-2.0%) could recrystallize and concomitantly form starch-lipid complexes around emulsion droplets. This novel approach of preparing HSNPs is viable and simple. The developed HSNPs could have great potential for delivering drugs or active ingredients.

Cationic starches in paper-based applications-A review on analytical methods

This review focuses on cationic starches with a low degree of substitution (<0.06) which are mainly used for production of paper-based products. After a brief introduction on starch in general, cationization pathways and importance of cationic starches in paper production, this review emphasizes on the analytical challenges from different perspectives. These include the different length scales of starches when in solution: the macromolecular level, their assembly into nm aggregates and finally hydrocolloids with hundreds of nanometers of diameter. We give an overview on the current state of the art on the analysis of such challenging samples and aim at providing a guideline for obtaining and presenting reliable analytical data.