Synthesis of controlled size starch nanoparticles (SNPs)

Formation mechanism of anisotropic zein-modified starch nanoparticles

The aim of this study was to develop shape-controlled hydrophobic modified starch nanoparticles (SNPs). Here, we investigated the formation mechanisms of zein-modified starch nanoparticles (Z-SNPs) with irregular, worm-like, and spherical shapes with the three-phase contact angle of 91.6 ± 1.3°, 86.9 ± 1.5°, and 84.8 ± 0.9°, respectively. 1H NMR, Fourier transform-infrared spectroscopy, and X-ray diffractometry confirmed that the zein was effectively bound to the starch molecules through hydrogen bonding and hydrophobic interaction in V-crystalline structure. In addition, the formation mechanism of three-shaped nanoparticles were related to the stirring temperature and concentration of zein. This study presents significant implications for the fabrication of Z-SNPs with various shapes using entirely novel and highly efficient methods, which can be applied as an effective nanocarrier by delivering active compounds for nutraceutical and pharmaceutical industries.

Preparation and characterization of liposoluble tea polyphenol based functional emulsion films and the regulation of its releasing property

Functional films based on hydroxypropyl methylcellulose (HPMC)/ sodium citrate (SC) porous film and liposoluble tea polyphenol (LTP)/water Pickering emulsions stabilized by different contents of starch nanoparticles (NPs) were prepared. Addition of Pickering emulsion endowed the film surface pores, decreased oxygen permeability, water vapor permeability (WVP), hydrophilicity and good anti-oxidant effect. With increasing NPs, more smaller emulsion droplets appeared in the emulsion and filled into the porous structures of the film, the light transmittance and contact angle of the film increased. Functional film with 2 % NPs showed the lowest WVP and Tg, and highest stable LTP release ratio (4-12 week). That more surficial holes appeared and more emulsion droplets protrusions accumulated near the cross-sectional pores during the releasing process might facilitate the higher release of film-2 % NPs. The functional films have great potential to be used as light-shielding coatings, antioxidant capsule shells and sustained fresh-keeping "cards" for different oil systems.

Morphological modulation of starch chains from nanorod to nanospindle via temperature-controlling rearrangement

Polymorphic nanoparticles, including starch nanoparticles (SNPs), have increasingly attracted attention, particularly rod-shaped variants, which are used for constructing anisotropic systems. Compared to symmetrically spherical particles, they show superior properties such as gastrointestinal retention for functional nutrients/drugs delivery and mechanical enhancement of filled materials, but their controlled fabrication remains a challenge. In this study, we yielded polymorphic SNPs with nearly axisymmetric geometries through a combined alkaline hydrolysis and nanoprecipitation method, followed by temperature-controlling rearrangement. The change from starch nanorod (SNR) to starch nanoellipsoid (SNE) and starch nanospindle (SNSP) was obtained when heat-induced rearrangement of starch chains occurred from temperature 90 °C to 20 °C. Interestingly, the sodium ions introduced by NaOH solution could be separated from the samples to varying extents. Both raw materials of normal and high-amylose starches have the above rules of nano-morphological alternation and salting out phenomenon, whereas their microstructures are not totally the same. Compared to SNR/SNE/SNSP fabricated from normal starch, those from high-amylose starch have a higher proportion of long chains (DP > 24) while less short chains (DP 6-12), with higher degrees of order and crystallinity.

Design strategies of polysaccharide, protein and lipid-based nano-delivery systems in improving the bioavailability of polyphenols and regulating gut homeostasis

Polyphenols are plant secondary metabolites that have attracted much attention due to their anti-inflammatory, antioxidant, and gut homeostasis promoting effects. However, food matrix interaction, poor solubility, and strong digestion and metabolism of polyphenols cause barriers to their absorption in the gastrointestinal tract, which further reduces bioavailability and limits polyphenols' application in the food industry. Nano-delivery systems composed of biocompatible macromolecules (polysaccharides, proteins and lipids) are an effective way to improve the bioavailability of polyphenols. Therefore, this review introduces the construction of biopolymer-based nano-delivery systems and their application in polyphenols, with emphasis on improving the solubility, stability, sustained release and intestinal targeting of polyphenols. In addition, there are possible positive effects of polyphenol-loaded nano-delivery systems on modulating gut microbiota and gut homeostasis, with particular emphasis on modulating intestinal inflammation, metabolic syndrome, and gut-brain axis. It is worth noting that the safety of bio-based nano-delivery systems still need to be further studied. In summary, the application of the bio-based nano-delivery system to deliver polyphenols provides insights for improving the bioavailability of polyphenols and for the treatment of potential diseases in the future.

Folic acid functionalized Ag@MOF(Ag) decorated carboxymethyl starch nanoparticles as a new doxorubicin delivery system with inherent antibacterial activity

Considering the benefits of controlled drug delivery in cancer treatment, as well as the importance of biological macromolecules in this area, herein, the pre-synthesized carboxymethyl starch (CMS) was converted to CMS nanoparticles (CMS NPs) in one easy nanoprecipitation way. Thereafter, the Ag@MOF(Ag) was in situ synthesized in the presence of pre-prepared CMS NPs (CMS NPs/Ag@MOF(Ag)). Eventually, the functionalization with folic acid (FA) obtained the CMS NPs/Ag@MOF(Ag)-FA. The success of the accomplished process was approved by doing several techniques, including FT-IR, XRD, EDX, AFM, etc. The SEM analysis showed a combination of rod-like and spherical-like morphology for the fabricated bio-nanocomposite. The generated CMS NPs/Ag@MOF(Ag)-FA with a surface area of 10.595 m2/g displayed a pore size of 13.666 nm and 82.99 % of doxorubicin (DOX) loading efficiency (DOX@CMS NPs/Ag@MOF(Ag)-FA). The 38.46 % and 58.19 % of loaded DOX were released respectively within 240 h at pH 7.4 and pH 5.0, referring to the pH-responsivity of the constructed system. 27.25 % of inhibitory effects on HeLa cells were obtained for the drug-loaded bio-nanocomposite. The CMS NPs/Ag@MOF(Ag)-FA also displayed an inherent antibacterial activity towards two common gram-negative and gram-positive bacteria. All of these results can contribute to developing polysaccharide-based porous systems in controlled cancer therapy.

Preparation of starch/PVA nanoparticles and evaluation of their ability to stabilize Pickering emulsions

Biodegradable and biocompatible polymer-based nanoparticles (NPs) hold great promise for various industries. We report the first development of composite NPs consisting of starch (St) and polyvinyl alcohol (PVA) using the nanoprecipitation technique with ethanol as an antisolvent. We varied the St:PVA ratios in the precursor solutions to evaluate their impact on the structure and properties of the composite NPs. The ratios used were 4:1, 1:1, and 1:4. Characterization by X-ray diffraction, differential scanning calorimetry, and thermogravimetric analysis revealed distinct XRD and TGA patterns for the composite St/PVANPs compared to their corresponding physical blends. This indicated the presence of mixed St/PVA crystallites within their structures. Additionally, the crystallinity of St/PVANPs increased with rising St content. Dynamic light scattering and scanning electron microscopy showed that nanoparticle sizes increased with higher PVA proportions. The St/PVANPs showed superior performance as stabilizers in Pickering emulsions, forming denser continuous networks in the gel-like structure of the emulsions. Additionally, increasing the PVA content in the composition of St/PVANPs strengthened the structure of Pickering emulsions. The emulsion stabilized by St20/PVA80NPs showed exceptional stability for one month. These findings highlight the potential of St/PVANPs as innovative materials for various applications, including emulsion stabilization.

Metal and Metal Oxides Nanoparticles as Nanofillers for Biodegradable Polymers

Polymeric materials, despite their many undeniable advantages, nowadays are a major environmental challenge. Thus, in recent years biodegradable polymer matrices have been widely used in various sectors, including the medicinal, chemical, and packaging industry. Their widespread use is due to the properties of biodegradable polymer matrices, among which are their adjustable physicochemical and mechanical properties, as well as lower environmental impact. The properties of biodegradable polymers can be modified with various types of nanofillers, among which clays, organic and inorganic nanoparticles, and carbon nanostructures are most commonly used. The performance of the final product depends on the size and uniformity of the used nanofillers, as well as on their distribution and dispersion in the polymer matrix. This literature review aims to highlight new research results on advances and improvements in the synthesis, physicochemical properties and applications of biodegradable polymer matrices modified with metal nanoparticles and metal oxides.

Nanostarch-Stimulated Cell Adhesion in 3D Bioprinted Hydrogel Scaffolds for Cell Cultured Meat

Three-dimensional (3D) bioprinting has great potential in the applications of tissue engineering, including cell culturing meat, because of its versatility and bioimitability. However, existing bio-inks used as edible scaffold materials lack high biocompatibility and mechanical strength to enable cell growth inside. Here, we added starch nanoparticles (SNPs) in a gelatin/sodium alginate (Gel/SA) hydrogel to enhance printing and supporting properties and created a microenvironment for adherent proliferation of piscine satellite cells (PSCs). We demonstrated the biocompatibility of SNPs for cells, with increasing 20.8% cell viability and 36.1% adhesion rate after 5 days of incubation. Transcriptomics analysis showed the mechanisms underlying the effects of SNPs on the adherent behavior of myoblasts. The 1% SNP group had a low gel point and viscosity for shaping with PSCs infusion and had a high cell number and myotube fusion index after cultivation. Furthermore, the formation of 3D muscle tissue with thicker myofibers was shown in the SNP-Gel/SA hydrogel by immunological staining.

Preparation and characterization of fine and stable short amylose nanocarriers for curcumin using a highly efficient and convenient method

To prepare fine and stable nanocarriers for curcumin using a highly efficient and convenient method, nanoprecipitation combined with ultrasonication and a high-speed dispersion (US+HSS) method were used to prepare short amylose nanoparticles with pre-formed helical structures. Their morphology, structural characteristics, and embedding effects for curcumin were investigated. The results showed that the optimal ratio of ethanol to short amylose solution and ultrasonic time was 4:1 and 4 min, respectively. The nanoparticles showed a small size (82.43 nm), relatively high loading capacity (11.57 %), and a peak gelatinization temperature of 97.74 °C. Compared to the nanoprecipitation method, the short amylose nanoparticles prepared using the US+HSS method possessed a higher V-type crystalline structure ratio. In addition, the US+HSS method was easier to use to prepare nanoparticles with high stability against NaCl, and the stable nanoparticles showed the best in vitro sustained release effect for curcumin. The Peppas-Sahlin model was the optimal model that matched curcumin release from nanoparticles during digestion.

Bioactive delivery systems based on starch and its derivatives: Assembly and application at different structural levels

Starch and modified starch, spanning various structural levels, are comprehensively reviewed, with a special emphasis on the advancement of starch and its derivative-based delivery systems for bioactive substances. The pivotal aspect highlighted is the controlled release of active ingredients by starch-based delivery systems with distinct hierarchical structures. At the molecular level, diverse categories of starch degradation products, such as dextrin and highly branched starch, serve as versatile amphiphilic carriers for encapsulating active ingredients. At the level of helical structure, the distinctive configuration of the starch-guest complex partly determines the mechanism of controlled release for diverse active components. At the crystal and particle structural level, starch assumes the role of a carrier, effectively modulating the release of active substances, and enhances the innate physiological activity of different active components. As a natural polymer molecule, starch can also generate hydrogel materials in polymer form, expanding its utility in the fields of food, materials, and even medicine.

Polymorphic nanostarch-mediated assembly of bioactives

Starch as an edible, biosafe, and functional biopolymer, has been tailored at nanoscale to deliver bioactive guests. Nanostarches fabricated in various morphologies including nanosphere, nanorod, nanoworm, nanovesicle, nanopolyhedron, nanoflake, nanonetwork etc., enable them to assemble different kinds of bioactives due to structural particularity and green modification. Previous studies have reviewed nanostarch for its preparation and application in food, however, no such work has been done for the potential of delivery system via polymorphic nanostarches. In this review, we focus on the merits of nanostarch empowered by multi-morphology for delivery system, and also conclude the assembly strategies and corresponding properties of nanostarch-based carrier. Additionally, the advantages, limitations, and future perspectives of polymorphic nanostarch are summarized to better understand the micro/nanostarch architectures and their regulation for the compatibility of bioactive molecules. According to the morphology of carrier, nanostarch effectively captures bioactives on the surface and/or inside core to form tight complexes, which maintains their stability in the human microenvironment. It improves the bioavailability of bioactive guests by different assembly approaches of carrier/guest surface combination, guest@carrier embedment, and nanostarch-mediated encapsulation. Targeted release of delivery systems is stimulated by the microenvironment conditions based on the complex structure of nanostarch loaded with bioactives.

Starch physical treatment, emulsion formation, stability, and their applications

Pickering emulsions are increasingly preferred over typical surfactant-based emulsions due to several advantages, such as lower emulsifier usage, simplicity, biocompatibility, and safety. These types of emulsions are stabilized using solid particles, which produce a thick layer at the oil-water interface preventing droplets from aggregating. Starch nano-particles (SNPs) have received considerable attention as natural alternatives to synthetic stabilizers due to their unique properties. Physical formulation processes are currently preferred for SNP production since they are environmentally friendly procedures that do not require the use of chemical reagents. This review provides a thorough overview in a critical perspective of the physical processes to produce starch nano-particles used as Pickering emulsion stabilizers, fabricated by a 2-step process. Specifically, the reviewed physical approaches for nano-starch preparation include high hydrostatic pressure, high pressure homogenization, ultrasonication, milling and antisolvent precipitation. All the essential parameters used to evaluate the effectiveness of particles in stabilizing these systems are also presented in detail, including the hydrophobicity, size, and content of starch particles. Finally, this review provides the basis for future research focusing on physical nano-starch production, to ensure the widespread use of these natural stabilizers in the ever-evolving field of food technology.

Effect of fatty acid chain length on physicochemical properties of starch nanocomposites obtained via nanoprecipitation

To evaluate the effect of elaborate difference in the hydrophobicity of core material on encapsulation process and physicochemical properties of the composites, composites of starch and FA with various chain lengths (C:12-22) were prepared via nanoprecipitation. X-ray diffraction analyses revealed that all composites had a V_h-amylose crystalline unit cell, but the chain length of FA did not induce a clear change in crystallinity or the hydrodynamic mean diameter of the composites. As the chain length of FA increased from 12 to 22, FA content in the composites increased from 1.69 to 14.85 mg/g composite. The absorption analyses of Rose Bengal on the composite surfaces revealed that their hydrophobicity increased with increasing chain length of FA. The incorporation of FA enhanced the emulsification activity of the composites, and this result revealed that the composites could be applied as an emulsification agent. For longer FA, composite storage stability increased, but the release of FA by in vitro digestion was delayed.

Synthesis of controlled-size starch nanoparticles and superparamagnetic starch nanocomposites by microemulsion method

In this study, a synthesis process based on the microemulsion method (ME) was developed with the aim to produce controlled-size starch nanoparticles (SNPs). Several formulations were tested for the preparation of the W/O microemulsions varying the organic/aqueous phase ratios and co-stabilizers concentrations. SNPs were characterized in terms of size, morphology, monodispersity and crystallinity. Spherical shape particles with mean sizes 30-40 nm were prepared. The method was then used to simultaneously synthesize SNPs and iron oxide nanoparticles with superparamagnetic properties. Starch-based nanocomposites with superparamagnetic properties and controlled size were obtained. Therefore, the microemulsion method developed could be considered an innovative technology for the design and development of novel functional nanomaterials. The starch-based nanocomposites were evaluated in terms of morphology and magnetic properties, and they are being considered as promising sustainable nanomaterials for different biomedical applications.

Gefitinib-loaded starch nanoparticles for battling lung cancer: Optimization by full factorial design and in vitro cytotoxicity evaluation

Lung cancer is the number one killer among all cancer types. For decades, clinicians have been using conventional chemotherapeutics, but they can't rely on them alone anymore, because they poison bad cells and good cells as well. Researchers exploited nanotechnology as a potential tool to develop a platform for drug delivery to improve therapeutic efficiency. A quality by design synthesis of gefitinib-loaded starch nanoparticles (Gef-StNPs) has emerged as an essential tool to study and optimize the factors included in their synthesis. Therefore, we applied design of experiment (DOE) tools to attain the essential knowledge for the synthesis of high-quality Gef-StNPs that can deliver and concentrate the gefitinib (Gef) at A549 cells, thereby improving therapeutic efficacy and minimizing adverse effects. The in vitro cytotoxicity after exposing the A549 human lung cancer cells to the optimized Gef-StNPs was found to be much higher than that of the pure Gef (IC50 = 6.037 ± 0.24 and 21.65 ± 0.32 μg/mL, respectively). The optimized Gef-StNPs formula showed superiority over the pure Gef regarding the cellular uptake in A549 human cell line (3.976 ± 0.14 and 1.777 ± 0.1 μg/mL) and apoptotic population (77.14 ± 1.43 and 29.38 ± 1.11 %), respectively. The results elucidate why researchers have a voracious appetite for using natural biopolymers to combat lung cancer and paint an optimistic picture of their potential to be a promising tool in battling lung cancer.

Preparation, characterization and evaluation of capsaicin-loaded indica rice starch nanoparticles

Capsaicin (CAP) is an alkaloid with multiple physiological effects, but its application is difficult. In this research, indica rice starch nanoparticles (IRSNPs) based nanocarrier was used to load CAP to obtain capsaicin-loaded indica rice starch nanoparticles (CAP-IRSNPs). The microstructure, characteristics and in vitro release behaviors of CAP-IRSNPs were analyzed. CAP-IRSNPs presented average particle sizes of 617.84 ± 6.38 nm, encapsulation efficiency of 70.05 ± 1.78% and loading capacity of 13.41 ± 0.18%. Fourier-transform infrared spectroscopy confirmed that CAP-IRSNPs might be formed by hydrogen-bonding action. Differential scanning calorimetry and X-ray diffraction showed that IRSNPs influenced the crystallization and melting temperatures of CAP. In in vitro release study, CAP-IRSNPs exhibited a sustained release. The CAP concentration, CAP diffusion from matrix and matrix erosion might be the potentially possible mechanisms for capsaicin release from CAP-IRSNPs. These new results concluded that IRSNPs may be a promising nanocarrier for CAP or other hydrophobic bioactive ingredients.

Biopolymeric Nanoparticles-Multifunctional Materials of the Future

Nanotechnology plays an important role in biological research, especially in the development of delivery systems with lower toxicity and greater efficiency. These include not only metallic nanoparticles, but also biopolymeric nanoparticles. Biopolymeric nanoparticles (BPNs) are mainly developed for their provision of several advantages, such as biocompatibility, biodegradability, and minimal toxicity, in addition to the general advantages of nanoparticles. Therefore, given that biopolymers are biodegradable, natural, and environmentally friendly, they have attracted great attention due to their multiple applications in biomedicine, such as drug delivery, antibacterial activity, etc. This review on biopolymeric nanoparticles highlights their various synthesis methods, such as the ionic gelation method, nanoprecipitation method, and microemulsion method. In addition, the review also covers the applications of biodegradable polymeric nanoparticles in different areas-especially in the pharmaceutical, biomedical, and agricultural domains. In conclusion, the present review highlights recent advances in the synthesis and applications of biopolymeric nanoparticles and presents both fundamental and applied aspects that can be used for further development in the field of biopolymeric nanoparticles.

Synthesis of starch nanoparticles with controlled morphology and various adsorption rate for urea

Starch nanoparticles (SNPs) with different morphology and particle size can be prepared by modulating the reaction conditions over SNPs preparation. This study was to synthesize various SNPs by using ultrasound assisted nanoprecipitation method, and characterized by particle size analysis, SEM and XRD performing. SNPs were successfully produced via nanoprecipitation and the particle size were controlled in the range of 95 to 150 nm. Moreover, variously different morphologies were obtained when using corn, potato or Trichosanthes kirilowii pulp (TKP) starch to produce nanoparticles, including fiber, flake and film. Results shown film TKP SNPs demonstrated an improved urea adsorption rate to 135.60 mg/g with the highest q_m at 1.00 mg/mL. SNPs can be developed using ultrasound assisted nanoprecipitation method and the particle size together with surface morphology can be varied according to the source of starch and preparation method, while surface morphology is the key factor in altering adsorption performance.

Mechanical force-induced dispersion of starch nanoparticles and nanoemulsion: Size control, dispersion behaviour, and emulsified stability

High amylose starch nanoparticles (HS-SNPs) were rapidly synthesised by high-speed circumferential force of homogenisation (3000 and 15,000 rpm) during nanoprecipitation. Morphology and dynamic light scattering analyses showed that HS-SNPs fabricated by stronger circumferential shearing were excellent stabilisers in smaller sizes (20-50 nm). Their aggregates were liable to separate in the aqueous phase with the nano effect under either homogenisation over 6 min or ultrasonication in 2 min. SNP-based nanoemulsion (<200 nm) of high-water fraction was achieved, though the high hydrophilicity of the SNPs were identified by the contact angle. For homogenisation (with 100-2000 nm emulsion size), only time prolongation led to a better dispersion of SNP aggregates. Ultrasonication with periodic cavitation could disintegrate SNP aggregates into micro-aggregates for a stable emulsion system in a short period. In contrast, long-term ultrasound caused simultaneous re-agglomeration and solubilisation of the SNPs, leading to weakened interface barriers and decreased storage stability.

Jin Shofu Starch Nanoparticles for the Consolidation of Modern Paintings

Matte, porous, and weakly bound paint layers, typically found in modern/contemporary art, represent an unsolved conservation challenge. Current conservation practice relies on synthetic or natural adhesives that can alter dramatically the optical properties of paints. Alternatively, we propose a novel nanostructured consolidant based on starch, a renewable natural polymer. We synthesized starch nanoparticles (SNPs) to boost their penetration into the porous painted layers; upon solvent evaporation, the particles were expected to adhere to the pigments thanks to their large surface area and abundant -OH groups. The SNPs were formulated through a bottom-up approach, where gluten-removed Jin Shofu wheat starch was gelatinized and then precipitated in a nonsolvent. The low gelatinization temperature of wheat starch is likely key to favor disassembly in alkali and reassembly in the nonsolvent. The synthesis conditions can be tuned to obtain amorphous SNPs of ca. 50 nm with acceptable polydispersity. The particles swell in water to form nanosized gel-like fractal domains (as observed with cryogenic electron microscopy), formed by the organization of smaller units in polymer-rich and -deficient regions. Aqueous and hydroalcoholic particles' dispersions were assessed on aged ultramarine blue mock-ups that mimic degraded modern/contemporary paints. The consolidation effectiveness was evaluated with a specifically designed in-house protocol: the SNPs distribute across the paint section and strongly increase pigments' cohesion while preserving the original optical properties of the painted layer, as opposed to dispersions of bulk starch that simply accumulate on the paint surface, forming superficial glossy films. The Jin Shofu SNPS proved to be a new promising tool for the consolidation of weakened paintings, opening perspectives in the formulation and application of consolidants for modern and contemporary art.

Starch Nanoparticles for Enhancement of Oral Bioavailability of a Newly Synthesized Thienopyrimidine Derivative with Anti-Proliferative Activity Against Pancreatic Cancer

Purpose

This research aimed to improve water solubility and oral bioavailability of a newly synthesized thienopyrimidine derivative (TPD) with anti-pancreatic cancer activity by loading on starch nanoparticles (SNPs).

Methods

TPD was synthesized, purified and its ADME behavior was predicted using Swiss ADME software. A UV spectroscopy method was developed and validated to measure TPD concentration at various dosage forms. SNPs loaded with TPD (SNPs-TPD) were prepared, characterized for particle size, polydispersity index, zeta potential, transmission electron microscopy, Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), entrapment efficiency, in-vitro release, and in-vivo animal study.

Results

The Swiss ADME results showed that TPD can be administered orally; however, it has low oral bioavailability (0.55) and poor water solubility. The significant regression coefficient of the calibration curve (r² = 0.9995), the precision (%RSD < 0.5%) and the accuracy (99.46−101.72%) confirmed the efficacy of the developed UV method. SNPs-TPD had a spherical monodispersed (PDI= 0.12) shape, nanoparticle size (22.98 ± 4.23) and good stability (−21 ± 4.72 mV). Moreover, FT-IR and DSC revealed changes in the physicochemical structure of starch resulting in SNPs formation. The entrapment efficiency was 97% ± 0.45%, and the in-vitro release showed that the SNPs enhanced the solubility of the TPD. The in-vivo animal study and histopathology showed that SNPs enhanced the oral bioavailability of TPD against solid Ehrlich carcinoma.

Conclusion

SNPs-TPD were superior in drug solubility and oral bioavailability than those obtained from TPD suspension.

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.

Synthesis of Starch Nanoparticles and Their Applications for Bioactive Compound Encapsulation

In recent years, starch nanoparticles (SNPs) have attracted growing attention due to their unique properties as a sustainable alternative to common nanomaterials since they are natural, renewable and biodegradable. SNPs can be obtained by the breakdown of starch granules through different techniques which include both physical and chemical methods. The final properties of the SNPs are strongly influenced by the synthesis method used as well as the operational conditions, where a controlled and monodispersed size is crucial for certain bioapplications. SNPs are considered to be a good vehicle to improve the controlled release of many bioactive compounds in different research fields due to their high biocompatibility, potential functionalization, and high surface/volume ratio. Their applications are frequently found in medicine, cosmetics, biotechnology, or the food industry, among others. Both the encapsulation properties as well as the releasing processes of the bioactive compounds are highly influenced by the size of the SNPs. In this review, a general description of the different types of SNPs (whole and hollow) synthesis methods is provided as well as on different techniques for encapsulating bioactive compounds, including direct and indirect methods, with application in several fields. Starches from different botanical sources and different bioactive compounds are compared with respect to the efficacy in vitro and in vivo. Applications and future research trends on SNPs synthesis have been included and discussed.