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In the realm of natural polysaccharides, hydrogen bonding is a prevalent feature, yet its role in enhancing photocatalytic antimicrobial properties has been underexplored. In this paper, heterojunctions formed by graphene oxide (GO) and ZIF-8 were locked in sodium alginate/ carboxylated cellulose nanocrystals via hydrogen bonding networks, designated as SCGZ. The SCGZ films exhibit superior photocatalytic performance compared to either ZIF-8 or heterojunctions. This enhancement is primarily due to two key factors: firstly, the hydrogen bonding network significantly enhances the transfer of protons and holes, thereby improving the separation efficiency of photo-generated carriers; secondly, the hydrogen bonding between the layers facilitates a more efficient charge transfer, which expedites the movement of electrons from ZIF-8 to GO upon illumination. In vitro studies demonstrated that the SCGZ films possess remarkable antibacterial capabilities, achieving 99.75 % and 99.61 % inhibition rates against S. aureus and E. coli, respectively. In vivo animal experiments have shown that SCGZ films can significantly accelerate the healing process of damaged tissues, with a healing efficiency of up to 90.5 %. This research provides additional insights into the development of natural polysaccharide-based multi‑hydrogen bonded macromolecules with enhanced photocatalytic properties., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Nanodrug delivery systems (NDSs), such as mesoporous silica, have been widely studied because of their high specific surface area, high loading rate, and easy modification; however, they are not easily metabolized and excreted by the human body and may be potentially harmful. Hence, we aimed to examine the synergistic anti-tumor effects of ex vivo chemo-photothermal therapy to develop a rational and highly biocompatible treatment protocol for tumors. We constructed a biodegradable NDS using organic mesoporous silica with a tetrasulfide bond structure, copper sulfide core, and folic acid-modified surface (CuS@DMONs-FA-DOX-PEG) to target a tumor site, dissociate, and release the drug. The degradation ability, photothermal conversion ability, hemocompatibility, and in vitro and in vivo anti-tumor effects of the CuS@DMONs-FA-DOX-PEG nanoparticles were evaluated. Our findings revealed that the nanoparticles encapsulated in copper sulfide exhibited significant photothermal activity and optimal photothermal conversion rate. Further, the drug was accurately delivered and released into the target tumor cells, annihilating them. This study demonstrated the successful preparation, safety, and synergistic anti-tumor effects of chemo-photothermal therapeutic nanomaterials., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

The high expression of reduced glutathione (GSH) and low pH in tumor sites have encouraged new ideas for targeted drug release. The tumor microenvironment is a crucial target for studying the anti-tumor efficiency of photothermal therapy because the microenvironment plays a key role in cancer progression, local resistance, immune escaping, and metastasis. Herein, active mesoporous polydopamine nanoparticles loaded with doxorubicin and functionalized with N,N'-bis(acryloyl)cystamine (BAC) and cross-linked carboxymethyl chitosan (CMC) were used to induce simultaneous redox- and pH-sensitive activity to achieve photothermal enhanced synergistic chemotherapy. The inherent disulfide bonds of BAC were able to deplete glutathione, thus increasing the oxidative stress in tumor cells and enhancing the release of doxorubicin. Additionally, the imine bonds between CMC and BAC were stimulated and decomposed in the acidic tumor microenvironment, improving the efficiency of light conversion through exposure to polydopamine. Moreover, in vitro and in vivo investigations demonstrated that this nanocomposite exhibited improved selective doxorubicin release in conditions mimicking the tumor microenvironment and low toxicity towards non-cancerous tissues, suggesting there is high potential for the clinical translation of this synergistic chemo-photothermal therapeutic agent., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Chemotherapy is a common method for tumor treatment. However, the non-specific distribution of chemotherapeutic drugs causes the death of normal cells. Nanocarriers, particularly mesoporous carriers, can be modified to achieve targeted and controlled drug release. In this study, mesoporous polydopamine (MPDA) was used as a carrier for the antitumor drug doxorubicin (DOX). To enhance the release efficiency of DOX in the tumor microenvironment, which contains high concentrations of glutathione (GSH), we used N,N-bis(acryloyl)cysteamine as a cross-linking agent to encapsulate the surface of MPDA with fucoidan (FU), producing MPDA-DOX@FU-SS. MPDA-DOX@FU-SS was characterized via transmission electron microscopy, thermogravimetric analysis, and X-ray photoelectron spectroscopy (XPS), and its antitumor efficacy in vitro was investigated. The optimal conditions for the preparation of MPDA were identified as pH 12 and 20 °C, and the optimal MPDA-to-FU ratio was 2:1. The DOX release rate reached 47.77% in an in vitro solution containing 10 mM GSH at pH 5.2. When combined with photothermal therapy, MPDA-DOX@FU-SS significantly inhibited the growth of HCT-116 cells. In conclusion, MPDA-DOX@FU-SS may serve as a novel, highly effective tumor suppressor that can achieve targeted drug release in the tumor microenvironment.

Porous microsphere hemostatic materials, which possess rapid hemostatic, antibacterial, and wound healing-promotion properties, have key advantages over hemostatic dressings with a single hemostatic function. Using rod-shaped cellulose nanocrystals as the supporting framework, sodium alginate/cellulose nanocrystal porous microspheres (SA/CNC) were prepared using an inverse emulsion method. After SA/CNC self-assembly with the antibacterial polymer ε-polylysine, the hemostatic porous microspheres (PSLMs) showed high porosity, high liquid absorption capacity, and excellent coagulation properties. The in vitro and in vivo coagulation properties of PSLMs were evaluated and compared with those of the commercially available chitosan hemostatic powder. PSLMs had marked hemostatic effects in the following mouse hemorrhage models: caudal (81.20 s), liver (48.44 s), and femoral artery (71.66 s). After the introduction of ε-polylysine with excellent antibacterial properties to PSLMs, PSLMs effectively inhibited the activities of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Mesoporous silica nanoparticles (MSN) are effective drug delivery carriers because of their adjustable large pore size and high porosity. In this study, complex nanoparticles containing disulfide bonds (SS) were designed and prepared as curcumin (Cur) carriers by using fucoidan (FUC) and MSN as the polymer matrix. The product was characterized using scanning electron microscopy, transmission electron microscopy, dynamic light scattering, Fourier-transform infrared spectroscopy, and an N 2 adsorption and desorption test. When the mass ratio of MSN to FUC was 2:1, the nanospheres particle size was the smallest (295.6 ± 0.98 nm, -35.2 ± 0.8 mV). Furthermore, the curcumin encapsulation rate by MSN-Cur-SS-FUC was over 90%, and the cumulative release rate in 24 h was over 80% due to the combined effect of weak acidity and high glutathione concentration in the tumor site microenvironment. When the Cur concentration was 50 μg/mL, the cell viability of free Cur was 63.8%, the cell viability of MSN-Cur-SS-FUC was 14.5%, and the cell viability of MSN-SS-FUC at the same concentration remained above 74.6%. MSN-SS-FUC composite nanoparticles showed a good delivery of Cur, a lipid-soluble active compound, and provides a new delivery route for other lipid-soluble and poorly bioavailable active compounds., (Copyright © 2022 Elsevier B.V. All rights reserved.)

We develop a route to prepare two types of cellulose nanocrystals (CNCs, CNC1 and CNC2) from a unique biomass resource, the fruit shell of Camellia oleifera Abel (SCOA), by integrating sulfuric acid hydrolysis and high-pressure homogenization and examine the effects of hydrolysis time on characteristics of the CNCs during the process. The CNCs exhibit different evolutions in size, morphology, surface charge, and crystallinity with increasing hydrolysis time. While both the CNCs have high crystallinity, CNC1 is of rod-like character with a relatively low aspect ratio, and CNC2 exhibits a hairy appearance with a high aspect ratio. We highlight that controlled acid hydrolysis contributes to the formation of weak spots with an increased susceptibility for homogenizing cellulosic solid residues into hairy CNCs. This is a good step toward tailoring CNC properties in a conventional and scalable approach to maximize their potential applications.

In this study, zein and fucoidan-based composite nanoparticles were prepared by the antisolvent precipitation method. The effects of different calcium ion (Ca 2+ , 0-3.0 mM) concentrations on the stability of the composite nanosystems loaded with quercetin were studied under different conditions (pH, temperature, salt concentration, and ultraviolet light irradiation), and the composite nanoparticles were characterized. Electrostatic interactions, hydrogen bonding, and hydrophobic interactions are the main forces underlying the formation of composite nanoparticles. The addition of Ca 2+ led to improved release of the active substances from the composite nanoparticles in simulated digestive solutions (especially when the Ca 2+ concentration was 1.5 mM). The composite nanosystems based on alcohol-soluble proteins and anionic polysaccharides with added Ca 2+ can be potentially applied for the delivery of active substances., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This study aimed to use xanthan gum as a stabilizer to improve the stability of zein nanoparticles. Zein-xanthan gum composite nanoparticles were prepared via anti-solvent precipitation at pH 4.0. The particle size, zeta potential, and stability of the system were related to the amount of xanthan gum added. When 20 mg of xanthan gum was added, spherical nanoparticles with a small particle size (179 ± 2.1 nm) and sufficient negative zeta potential (-42 ± 1.6 mV) were obtained. The zeta potential and Fourier transform infrared spectroscopy results indicated that electrostatic attraction was the main driving force, followed by hydrogen bonding and hydrophobic interactions. Composite nanoparticles were coated by xanthan gum and remained stable over a wide pH range and at high temperatures and salt concentrations; they did not precipitate or aggregate after 30 days of storage. Moreover, the addition of xanthan gum considerably improved the encapsulation efficiency and loading capacity of nanoparticles containing high curcumin amounts, which facilitated slow and sustained release of curcumin in simulated intestinal fluid. Therefore, zein-xanthan gum nanoparticles can be used for the delivery of biologically active compounds in food and pharmaceutical preparations., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In this study, we developed novel complex nanoparticles as carriers for curcumin (Cur) delivery by using soy protein isolate (SPI) and cellulose nanocrystals (CNC) as polymer matrices. We found that the SPI-to-CNC mass ratio influenced the stability and physical properties of the SPI-CNC complex nanoparticles. Moreover, SPI-CNC complex nanoparticles had a relatively small size (197.7 ± 0.2 nm) and low polydispersity index (0.14) at a 6:1 mass ratio. The nanosystem was relatively stable at different pH values (3-9), temperatures (30-90 °C), and salt concentrations (0-40 mmol/L). Furthermore, the complex nanoparticles exhibited a high encapsulation efficiency (88.3%) and sustained release during simulated gastrointestinal digestion. Therefore, SPI-CNC complex nanoparticles are a promising delivery system for hydrophobic bioactive compounds., (Copyright © 2020 Elsevier B.V. All rights reserved.)

We aimed to develop a stable nanosystem with k-carrageenan (Kc), an anionic polysaccharide, combined with tween 80 to stabilize zein nanoparticles. The experimental results showed that the particle size, zeta-potential, and stability of the system depend on the Kc amount when the zein amount was unchanged. We found that the nanosystem with 5.0 and 10.0 mg Kc had a smaller particle size (250.1 ± 0.9 and 287.6 ± 1.4 nm, respectively), low polydispersity index (PDI, ≤ 0.20), and high stability when the external conditions changed. No obvious flocculation or deposition was observed at pH of 3-9, salt ion concentrations of 0-500 mmol/L, temperature of 30 °C and 50 °C-90 °C, and storage at 4 °C for 30 days. When the Kc-ZNP system was loaded with curcumin (Cur), there was a good encapsulation effect (5.0 mg Kc with 1.00 mg Cur (EE (%) = 34.69% ± 2.02%, size = 380.23 ± 5.80 nm, PDI = 0.252 ± 0.018) and 10.0 mg Kc with 2.00 mg Cur (EE (%) = 20.13% ± 1.05%, size = 431.27 ± 0.78 nm, PDI = 0.269 ± 0.020), ensuring that the particle size was not too large. Therefore, Kc-ZNPs could be a potential delivery system for fat-soluble drugs., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Residual diclofenac sodium (DS) in the environment is harmful to human health. A promising method for DS removal is the use of adsorbents functionalized with amino groups that can form an ionic bond with the carboxyl group of DS at a suitable pH. In this work, a novel composite adsorbent composed of cellulose nanocrystals (CNC) and chitosan (CS) has been synthesized and functionalized by ethylenediamine (ED) in both layers. Characterization methods, including scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectrometry, and X-ray photoelectron spectroscopy, were used to confirm the morphology and synthetic mechanism of the double- amino-functionalized adsorbent. Based on the optimization of adsorption conditions and modeling of the adsorption mechanism, the DS adsorption process on CNC-ED@CS-ED involves chemical adsorption, and the maximum adsorption capacity obtained from the Langmuir model is 444.44 mg/g. CNC-ED@CS-ED exhibits good adsorption capacity and high sustainability; thus, it is a promising composite material for the removal of DS from wastewater., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Carboxylated cellulose nanocrystal-sodium alginate (CCN-Alg) hydrogel beads were easily prepared through a cross-linking method. The structure and properties of the composite beads were characterized by TEM, FTIR, SEM, XPS, thermogravimetric analysis (TGA), and zeta potential measurement. A high ratio of 76% of the Pb(II) ion was adsorbed within the first 2h, and the adsorption equilibrium was nearly reached after 3h. The experimental isotherm could be fitted by the Langmuir model, yielding an extreme adsorption capacity of 338.98mgg -1 . The adsorption process followed a pseudo-second-order kinetic model, and thermodynamic analyses confirmed that the adsorption is a spontaneous and endothermic process. Regeneration tests with acid treatment indicated that the CCN-Alg beads performed well in repeated Pb(II) adsorptions, as they could maintain an adsorption capacity of 223.2mgg -1 after five repeated cycles. These results indicate that these CCN-Alg beads are a potentially effective and sustainable adsorbent for application in wastewater treatment., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A novel adsorbent with high selectivity for fluoroquinolone (FQ) compounds was developed, based on the surface functionalization of magnetic carboxylated cellulose nanocrystals (M-CCNs) with molecularly imprinted polymer (MIP) comprising amine moieties. The imprinting was achieved by a radical polymerization technique, which uses glycidyl methacrylate, tetraethylenepentamine, ofloxacin, ethylene glycol dimethacrylate, and azobisisobutyronitrile as the functional monomer, active groups provider, template molecule, crosslinking agent, and initiator, respectively. The developed material (M-CCNs@MIP) was comprehensively characterized and shown to exhibit high adsorption capacity and selectivity with rapid equilibration time. Moreover, the adsorption isotherms could be well-fitted with the Freundlich model, and the adsorption kinetics followed the pseudo-second-order model. The maximum adsorption capacities for M-CCNs@MIP after 2 and 20min were 34.09 and 40.65mgg -1 , respectively, compared to 9.98 and 15.28mgg -1 observed for the unimprinted polymer (M-CCNs@NIP). By coupling the M-CCNs@MIP adsorbent with high-performance liquid chromatography, an approach was established to enhance the selective adsorption of seven structurally similar FQ compounds in river water samples. The recoveries of the seven FQs ranged from 81.2 to 93.7%, and the limits of detection were between 5.4 and 12.0ngmL -1 . The M-CCNs@MIP adsorbent also retained good performance after seven consecutive cycles of reuse., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In the present study, a new adsorbent based on carboxylated cellulose nanocrystal (CCN) was developed for the adsorption of Pb(II) from fish sauce. The prepared adsorbent material was characterized by zeta potential, FT-IR, XRD, and XPS tools. The changes in the morphological structure of the developed CCN surface were evidenced by SEM and TEM. The favorable adsorption conditions were selected by studying the contact time, initial concentration, temperature, and concentration of the used glutamic acid and NaCl. The results indicated that the Langmuir isotherm model agrees very well with experimental adsorption data (R 2 =0.9962) with a maximum adsorption capacity 232.56mg/g of Pb(II) at 293.2K. Additionally, data of the adsorption kinetics follow the pseudo-second-order kinetics (R 2 >0.9990). On the other hand, the thermodynamics studies show that the adsorption process is spontaneous and endothermic. Furthermore, the developed CCN could be regenerated using acid treatment with a good reusability for Pb(II) adsorption. The results clearly indicated that the synthesized CCN could be effectively applied as a new material for Pb(II) adsorption from fish sauce solutions., (Copyright © 2017 Elsevier B.V. All rights reserved.)

We herein describe a novel adsorbent based on molecularly imprinted polymers (MIPs) on the surface of magnetic carboxylated cellulose nanocrystals (Fe 3 O 4 @CCNs@MIPs) for the separation and purification of six fluoroquinolones (FQs) from egg samples. The obtained Fe 3 O 4 @CCNs@MIPs not only exhibited a large surface area and specific recognition toward FQs, but also were easily gathered and separated from the egg samples using an external magnetic field. The morphologies and surface groups of the Fe 3 O 4 @CCNs@MIPs were assessed by X-ray photoelectron spectroscopy, transmission electron microscopy, vibrating sample magnetometry, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller surface area analysis. The Fe 3 O 4 @CCNs@MIPs exhibited high selectivity toward six structurally similar FQs. An enrichment approach was established for the measurement of six FQs from egg samples using Fe 3 O 4 @CCNs@MIPs coupled to high-performance liquid chromatography. The recovery of spiked FQs ranged from 75.2-104.9% and limit of detection was in the range of 3.6-18.4 ng g -1 for the six FQs. Therefore, the proposed method is a promising technique for the enrichment, separation, and determination of FQs from biomatrices.

The flow properties of two kinds of cellulose nanocrystal (CNC) rods with different aspect ratios and similar zeta potentials in aqueous suspensions have been investigated. The aqueous CNC suspensions undergo a direct transition from dilute solution to colloidal glass instead of phase separation with the increasing CNC concentration. The viscosity profile shows a single shear-thinning behavior over the whole range of shear rates investigated. The shear-thinning behavior becomes stronger with the increasing CNC concentration. The viscosity is much higher for the unsonicated suspension when compared with the sonicated suspensions. The CNC rods appear arrested without alignment with an increasing shear rate from the small-angle light scattering patterns. The arrested glass state results from electric double layers surrounding the CNC rods, which give rise to long-ranged repulsive interactions. For the first time, we demonstrate that, within a narrow range of CNC concentrations, a shear-induced breakup process of the CNC aggregates exists when the shear rate is over a critical value and that the process is reversible in the sense that the aggregates can be reformed. We discuss the competition between the shear-induced breakup and the concentration-driven aggregation based on the experimental observations. The generated aggregate structure during the breakup process is characterized by a fractal dimension of 2.41. Furthermore, we determine two important variables-the breakup rate and the characteristic aggregate size-and derive analytical expressions for their evolution during the breakup process. The model predictions are in quantitative agreement with the experimental results.

This study was carried out to investigate the protective effects of chitosan nanoparticles (CNP) against hydrogen peroxide (H₂O₂)-induced oxidative damage in murine macrophages RAW264.7 cells. After 24 h pre-incubation with CNP (25-200 μg/mL) and chitosan (CS) (50-200 μg/mL, as controls), the viability loss in RAW264.7 cells induced by H2O2 (500 μM) for 12 h was markedly restored in a concentration-dependent manner as measured by MTT assay (P < 0.05) and decreased in cellular LDH release (P < 0.05). Moreover, CNP also exerted preventive effects on suppressing the production of lipid peroxidation such as malondialdehyde (MDA) (P < 0.05), restoring activities of endogenous antioxidant including superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) (P < 0.05), along with increasing total antioxidant capacity (T-AOC) (P < 0.05). In addition, pre-incubation of CNP with RAW264.7 cells for 24 h resulted in the increase of the gene expression level of endogenous antioxidant enzymes, such as MnSOD and GSH-Px (P < 0.05). At the same concentration, CNP significantly decreased LDH release and MDA (P < 0.05) as well as increased MnSOD, GSH-Px, and T-AOC activities (P < 0.05) as compared to CS. Taken together, our findings suggest that CNP can more effectively protect RAW264.7 cells against oxidative stress by H₂O₂ as compared to CS, which might be used as a potential natural compound-based antioxidant in the functional food and pharmaceutical industries.

Curcumin (Cur) has anticancer activities but has poor stability, which can be improved using carrier materials. In this study, chitosan was aminated to increase the number of amino groups on its surface, modified with folic acid (FA), and then made into nanoparticles by ionic crosslinking. Owing to ion interaction, the negatively charged, non-toxic tripolyphosphate (TPP) interacted with the positively charged amino group on the aminated chitosan (AmCS) surface, producing FA-AmCS-TPP nanoparticles, which were then characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectrophotometry (FT-IR), and thermogravimetric analysis (TGA). Their small particle size (175.2 ± 0.99 nm) and good surface positive potential (+42.4 mV) are beneficial for carrying antitumor drugs. We subsequently investigated whether coating of Cur by AmCS allows slow drug release by FA-AmCS-TPP nanoparticles in different pH environments, and estimated the Cur loading efficiency (EE-Cur). Our results showed that the cumulative release rate of Cur at 48 h was 56.2%, and that the EE-Cur reached 94.26 ± 0.91% with nanoparticles composed of 0.10 g AmCS, 10.0 mg FA, 10.0 mg TPP, and 15.0 mg Cur. Additionally, cytotoxicity experiments showed that the Cur/FA-AmCS-TPP nanoparticles had good targeting ability for tumor cells. Therefore, the non-toxic targeted composite nanoparticles had potential as a new antitumor agent that can overcome the limitations of Cur. [ABSTRACT FROM AUTHOR]

Curcumin (Cur) is a natural polyphenol with beneficial biological and pharmacological activities; however, it has limited applications owing to its low solubility and light sensitivity. The protein-polysaccharide complex can effectively embed lipid-soluble drugs to increase their stability and dispensability in aqueous solutions. Soybean protein isolate (Spi) and fucoidan (Fuc) were used as a polymer matrix, and core-shell nanoparticles were prepared to encapsulate Cur via electrostatic interaction under acidic and neutral conditions. The structure of the Spi-Fuc nanoparticles was studied via Fourier-transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy. Concurrently, we evaluated the efficacy of the nanoparticles based on stability, drug loading rate, and simulated release. Our results showed that the Spi-Fuc nanoparticles (size, approximately 236.56 nm) had a spherical, core-shell structure and that they could effectively load Cur with an embedding efficiency of >95%; moreover, the system had long-term dispersion stability. Thus, we provide a simple method for Cur delivery, which can also be potentially used for delivering lipid-soluble active ingredients. • Spi-Fuc nanoparticles effectively loaded curcumin with >95% embedding efficiency. • The system had long-term dispersion stability and heat and salt resistance. • Spi and Fucoidan had a good synergistic effect in curcumin nanoparticle preparation. • Spi-Fuc nano system is a potential drug delivery system for lipid-soluble active ingredients. [ABSTRACT FROM AUTHOR]

• Nanoparticles conjugated with DOX and COS via DF-PEG-DF. • Nanoparticles showed significant pH sensitivity on in vitro release assays. • Introduction of COS increases the biocompatibility and solubility of DOX. • Nanoparticles have a good potential as lipid-soluble drug carriers. In this study, we developed pH-sensitive chito-oligosaccharide nano-drug-loaded particles with good biocompatibility, biodegradation, and controlled drug delivery. Chitosan oligosaccharides (COS), Doxorubicin (DOX) amino groups, and aromatic aldehydes of benzaldehyde-terminated polyethylene glycol were used to spontaneously form pH-sensitive aniline bonds. We aimed to achieve site targeting under weak acidic tumor conditions, improve the efficacy, and reduce the toxic side effects of the drug. Particle size, drug encapsulation efficiency, loading efficiency, and zeta potential of nanoparticles were optimized by altering the ratios of aldehyde, amino groups, and sodium tripolyphosphate. The drug encapsulation efficiency and loading efficiency of COS-DOX1 were 5.55 ± 0.13% and 88.81 ± 2.00%, respectively, and the in vitro drug release process displayed a specific pH responsiveness. Co-culture of COS-DOX with HCT-116 human colon cancer cells showed that the nanoparticles exhibited dose-dependent cytotoxicity. At a low dose, COS-DOX1 can promote DOX uptake of tumor cells and exhibit higher cytotoxicity than DOX alone. [ABSTRACT FROM AUTHOR]

• Alginate oligosaccharide (AOS) was used to stabilize zein nanoparticles. • Zein-AOS nanoparticles were relatively stable under different pH and temperatures. • The encapsulation efficiency of zein-AOS nanoparticles was fairly good. In this study, zein was stabilized using alginate oligosaccharides (AOS) for the delivery of curcumin (Cur) through antisolvent precipitation. Zein-AOS 2:1 nanoparticles were uniform and stable (size 116.5 nm, polydispersity index (PDI) 0.16, charge −30 mV). The complex nanoparticle system was relatively stable under different conditions, including pH 4–9 and temperature 30–90 °C. In addition, the encapsulation efficiency of the Cur/zein-AOS 2:1 complex nanoparticles was 89.7%. Zein was protected during gastrointestinal digestion. Only 32.9% Cur was released in the stomach after 90 min and 83.8% was released in the intestinal tract after 240 min proving that zein-AOS complex nanoparticles showed a good sustained-release effect. Thus, the zein-AOS complex nanoparticle system is suitable for delivering encapsulated lipophilic bioactive compounds. [ABSTRACT FROM AUTHOR]

In this study, we used fucoidan (FD), a sulfated polysaccharide, to stabilize zein and obtain a composite nanosystem with better performance that can be used to encapsulate and deliver hydrophobic active substances. The composite nanoparticles of zein and FD with different mass ratios were prepared by the antisolvent precipitation method. The solution (zein/FD = 1:2) could maintain its stable solution state without precipitation under different environmental conditions (pH 2–8, heating at 80 °C for 120 min, salt concentration < 25 mmol/L and storage at 4 °C for 28 days). Subsequently, curcumin (Cur) was used as the model of hydrophobic active substances. When 2 mg Cur was added, the composite nanosystem had a high encapsulation efficiency (81.07%) and could reduce the release of Cur in simulated gastrointestinal digestion. Our results demonstrated that the composite nanosystem prepared by FD and zein, which are both natural biopolymers, has great potential in the encapsulation and delivery of hydrophobic active substances. [Display omitted] • FD, a sulfated polysaccharide, was used to stabilize zein. • Zein/FD composite nanoparticles have good stability in different conditions. • Main forces of zein/FD were electrostatic attraction and hydrogen bonding. • Addition of FD can reduce the release of Cur in simulated gastroenteric fluid. [ABSTRACT FROM AUTHOR]