Cellulose microspheres with high specific surface area have considerable application prospects in drug delivery. The traditional methods for preparation of microspheres with diameter of less than 10 µm and controllable particle size are highly challenging. Herein, regenerated nanoporous cellulose microspheres (NCMs) with a high specific surface area up to 137 m2/g and a diameter sub-5 μm were prepared by membrane emulsification method. By optimizing the membrane pore size, cellulose concentration, and applied pressure, cellulose microspheres with control size and nanopores (10–50 nm) were prepared. Unlike conventional methods requiring chemical crosslinking, freeze-drying for physical solidification was applied to ensure biocompatibility and sustainability. The XRD results confirmed the transformation of cellulose crystalline structure from type I to type II, accompanied by reduced crystallinity. The NCMs demonstrated exceptional folic acid (FA) loading performance, achieving a maximum capacity of 35.21

Water sensitivity and brittleness have limited significantly the practical application of cellulose nanofibril (CNF) films. Herein, butane tetracarboxylic acid (BTCA) was integrated into CNF film to construct advanced material. Structurally, the multiple carboxylic acid groups in BTCA were able to form robust ionic bonding with quaternized CNF to improve the water stability. The optimal film, prepared by cross-linking with 0.1 mol L-1 of BTCA solution at pH 8.0, exhibited dramatically reduced water uptake, two orders of magnitude lower than that of the pristine film. After conditioned at 50% RH and 25 °C, the film showed a roughly doubled strain-at-break with only a negligible decline in tensile strength. Under wet conditions, this film demonstrated an ultrahigh strain-at-break of 26.5%, almost comparable to a stiff hard rubber (20%-50%), while the pristine film became too swollen and fragile to handle. Notably, the film retained its optical transparency, exhibiting optimal transmittance of 87.0% at 600 nm. Moreover, it displayed an exceptionally low oxygen permeability of 1.5 mL μm m-2 day-1 kPa-1 even at 90% RH, outperforming other recently reported nanocellulose-based films (3-60 mL μm m-2 day-1 kPa-1). The multifunctional CNF film is a promising alternative to petroleum-based materials for visible packaging, flexible electronics and biomedical materials.

Starch microspheres with uniform morphology and controllable particle size show significant application value. In this work, micrometer-sized natural starch microspheres (SMs) were prepared via membrane emulsification for the first time. Transmembrane pressure and the dispersed phase concentration significantly affect the morphology of SMs. The average particle size decreased with an increase in the transmembrane pressure, while a higher dispersed phase concentration yielded a more uniform particle size distribution. Under optimized membrane emulsification conditions (0.2 MPa and 10% dispersed phase concentration), debranched corn starch microspheres (CSM, 7.93 ± 0.12 μm) and debranched amaranth starch microspheres (ASM, 0.95 ± 0.01 μm) were successfully prepared. Gel permeation chromatography (GPC) analysis showed that the SMs had a lower molecular weight dispersity (D̅) than that of debranched starch (from 2.18 to 1.36 for CSM and from 2.04 to 1.59 for ASM), indicating a narrower molecular weight distribution and more densely arranged molecular chains. The crystallinity of conventional starch microspheres was generally lower than that of native starch because the ordered structure of starch molecules was destroyed during the microsphere formation process. Whereas, the SMs prepared in this work exhibited a significant increase in crystallinity compared with native starch (from 18.7 to 58.52% for CSM and from 25.8 to 69.67% for ASM), which was significantly higher than that of starch microspheres reported in previous papers. DSC proved that the gelatinization temperatures of SMs were higher than 90 °C, indicating that our SMs were difficult to gelatinize under conventional conditions. Because of the controllable particle sizes, the SMs prepared in this study had a narrow molecular weight distribution, extremely high crystallinity, and resistance to gelatinization, thus having broad application prospects in food, medicine, and other material fields.

The processing and modification of microcrystalline cellulose (MCC) are highly challenging due to its highly crystalline nature restricting its broader application. This study used NaOH/urea aqueous solution for the graded regeneration of MCC, which effectively disrupted its dense crystalline structure and exposed the additional free hydroxyl groups. A modified secondary regenerated cellulose derivative (MA-SRC) with a 0.182 degree of substitution (DS) was produced using esterification with maleic anhydride. The sequential regeneration and modification with maleic anhydride increased the specific surface area of MCC from 6.87 to 8.66 m2/g. Comprehensive characterisation revealed that MA-SRC had unchanged crystalline phases, with reduced crystallinity and significantly improved hydrophobic properties. However, the difficulty in testing the mechanical properties of MCC alone (requires matrix support for moulding) required the incorporation of polylactic acid (PLA) to investigate the characteristics of the composite material further. Compared to PLA/MCC and PLA/SRC, the tensile strength of PLA/MA-SRC increased by 10.89

Water contamination resulting from the presence of the various coexistent pollutants is an urgent environmental challenge, and effective treatment is demanded to remove the toxic substances. The removal of pollutants by adsorption, as an effective, efficient and economic strategy, has been widely used in water treatment. In this work, PEI@MCM-41 was prepared by infiltrating polyethyleneimine (PEI) into the pores of mesoporous MCM41, and applied for the removal of heavy metal ions. The adsorption kinetics of Cu2+, Ni2+ and Cd2+ by PEI@MCM-41 were supposed to be pseudo-second-ordered, and the adsorption capacities were as high as 39.30, 33.67 and 21.10 mg & sdot;g- 1, respectively. The influence of temperature, pH, coexistent salt and heavy metal ions concentration on the adsorption performance was studied. Owing to the nanoconfinement effect and hydrogen bond, PEI remained stable during the adsorption and desorption process, and the adsorption capacity for Cu2+ maintained 84.15 % even after four consecutive adsorption-desorption cycles. This work demonstrates that the potential practical applicability of PEI@MCM-41 as promising adsorbent in the removal of heavy metal ions.

This study aims to investigate biodegradable and biocompatible chitin as a natural carrier for loading the hydrophobic anti-cancer drug paclitaxel (PTX) for the first time, resulting in a new loading system of chitin nanoparticles–paclitaxel (ChNps–PTX). The well-dispersed chitin nanoparticles (ChNps) and ChNps–PTX were prepared via a water-dripping regeneration method. The functional groups, crystal form, and the high degree of acetylation (DA = 96.03%) of ChNps did not change during regeneration, suggesting that ChNps retained the complete molecular structure of chitin. The average particle size of ChNps–PTX was approximately 93.11 nm, which was larger than that of ChNps (84.06 nm) because of loading PTX (the drug loading was approximately 8.01%). TEM and CLSM were employed to confirm PTX existence in ChNps–PTX, and the nano-strip PTX (30.52 ± 6.78 nm in length and 16.02 ± 2.77 nm in width) was found for the first time. Loading of PTX resulted in ChNps–PTX presenting a new characteristic peak at 1734 cm−1 in FT-IR spectra, a new peak at 2θ = 5.3° in XRD pattern, and a new exothermic peak (252 °C) in DSC curve. While ChNps–PTX showed a lower crystallinity (19.86%) compared with that of ChNps (24.11%) and chitin (36.77%), utilizing the chitin carrier and mild regeneration method to load PTX were highly beneficial for pharmaceutical fields.

With the rapid development of fine chemical industries and electronics manufacturing industries, a large amount of wastewater containing endocrine disrupters, antibiotics, dyes and heavy metal ions have been discharged into the environment, threatening the safety of drinking water. In this work, polyethyleneimine-polyethersulfone (PEI-PES) copolymer was synthesized via the chain exchange reaction, then blended with polyethersulfone (PES) for the fabrication of polyethyleneimine functionalized polyethersulfone (PEI-PES/PES) membranes via phase separation process. The as-prepared membranes can efficiently remove multiple pollutants from water through the dual mechanism of filtration and surface adsorption of the PEI segments. The membranes are hydrophilic and positively charged, therefore they had well perm-selectivity. Especially, the PEI-PES/PES membrane with PEI loading of 30 wt% in polymers (namely M30) exhibited a good monovalent and divalent ion selectivity with a CaCl2 rejection of 78.0 % and NaCl rejection of 38.3 % at a water flux of 181 L & sdot;m- 2 & sdot;h- 1, owing to the sieving effect and the Donnan exclusion. In addition, the adsorption kinetics of the as-prepared membranes toward bisphenol A (BPA), tetracycline (Tc), sunset yellow (SY), and copper ion (Cu2+) followed a pseudosecond-order model. The corresponding equilibrium adsorption amount of M30 was 8.9, 7.1, 127.6 and 21.9 mg & sdot;g- 1, respectively. The adsorption performance was almost unaffected by salt and well recycled. The prepared PEI-PES/PES membranes demonstrated significant application potential in saline softening and security guarantee of drinking water.

Cellulose nanofibers (CNFs) are highly promising nanocarrier materials, boasting excellent drug adsorption and loading potential due to their tunable hydrophilic/lipophilic interfaces. This study is the first to report the successful synthesis of maleic anhydride-modified CNFs (MA-CNFs) via the esterification of CNFs using a solvent-free molten maleic anhydride (MA) system, and it systematically evaluates MACNFs’ dual adsorption performance for water-soluble and lipophilic drugs. A new characteristic peak at 1723 cm−1 in FT-IR confirms the formation of ester bonds, proving the successful grafting of MA onto CNFs. XRD analysis shows that the crystallinity slightly increases from 72.56% to 74.06%, indicating the reaction mainly occurs in the amorphous region. After modification, the material’s hydrophobicity is significantly enhanced (water contact angle: ~63.3° for CNFs vs. ~74.9° for MA-CNFs), and its BET specific surface area rises sharply from 5.03 to 26.29 m2/g. These structural advantages collectively enable MA-CNFs to have adsorption capacities for folic acid (FA, water-soluble) and vitamin E acetate (VEA, lipophilic) that are 1.15 and 2.04 times those of CNFs, respectively. The results demonstrate MA-CNFs are high-performance functional materials fabricated via a green method, with good biocompatibility.

Sodium carboxymethyl cellulose (CMC) is the most extensively utilized derivative of cellulose. In this study, an innovative approach was employed to disperse a CMC aqueous solution into olive oil in the form of liquid droplets, resulting in the direct formation of CMC microspheres after drying. The effects of CMC concentration and needle aperture size on microsphere formation were systematically investigated, showing that the particle size of the microspheres decreased with an increase in CMC concentration and a decrease in needle aperture. The CMC-based microspheres exhibited a consistently uniform spheroid morphology with particle sizes ranging from 1.5 to 2.5 mm, and a three-dimensional uniform polymeric network structure. Furthermore, the drug loading efficiency of the CMC-based olive oil microspheres reached 82.18%, which was markedly superior to that of other cellulose-based microspheres for fat-soluble substances. The CMC-based vitamin C (VC) microspheres exhibited an ultimate drug loading efficiency of approximately 24%, and their maximum encapsulation efficiency was 78.57% at a VC concentration of 30%, which was significantly higher than that of starch-based VC microspheres. Additionally, the CMC-based VC microspheres realized a sustained and stable release rate in ethanol at 30 °C.

Gelatin microparticles (GMPs) can load functional active substances, but they tend to redissolve in high-temperature aqueous solutions during food processing. In this study, a new loading system adapted to food processing and digestive environments was constructed through the crosslinking of tea polyphenols (TP) on GMPs. The effects of pH, temperature, and crosslinking time on the methylene blue (MB) retention rate in crosslinked gelatin microparticles (cGMPs) were investigated, resulting in optimized crosslinking conditions. Compared with GMPs, the surface of cGMPs was denser and smoother. ATR-FTIR results showed that the N–H groups were involved in the formation of hydrogen bonds during the crosslinking process. The crosslinking effect of TP significantly disrupted the triple-helical structure of gelatin. The melting temperature (Tm) of cGMPs is 147.79 °C, which is significantly higher than that of GMPs (87.11 °C), indicating a marked improvement in thermal stability. In high-temperature aqueous solutions, Folic acid-loaded cGMPs (FA-cGMPs) maintained morphological integrity for 2 h (at 40 °C) and 0.5 h (at 60 °C). In vitro digestion simulations revealed excellent sustained-release characteristics of FA-cGMPs, with a release rate of only 4.91% in simulated gastric fluid and 88.13% in simulated intestinal fluid. This study provides an ideal carrier with food processing stability and intestinal-targeted release capabilities for functional active substances.

As a pivotal biological and renewable resource, corn starch has extensive industrial applications. This study aims to investigate the debranched corn starch (DS) as a natural carrier for loading the high-melting-point hydrophobic anti-cancer drug paclitaxel (PTX) via efficient molecular interactions for the first time, resulting in a new loading system debranched corn starch-paclitaxel (DS-PTX). DS with a high degree of polymerisation was mainly involved in the loading process, resulting in a higher drug loading (DL, 34.9 % f 0.72 %). PTX loaded into DS-PTX was successfully isolated for the first time and characterised to exist as nanostrip crystals with an average length and an average diameter of 870 f 290 and 160 f 20 nm, respectively, differing from raw PTX. DS-PTX was verified to be a weak V-type crystalline structure comprising H-bonds, van der Waals forces and hydrophobic interactions between PTX and DS. In vitro digestion experiments confirmed that DS-PTX substantially decreased the release of PTX in artificial gastric juice (AGJ). After 24 h of digestion in artificial intestinal fluid (AIF), the cumulative release of PTX from DS-PTX (94.8 % f 0.91 %) reached its peak compared to other starch-based oral loading systems, indicating nearly complete digestion and a substantial increase in the solubility of nano-PTX. The cytotoxicity of DS-PTX to normal cells was lower than that of raw PTX. DS-PTX was believed as efficient molecular interactions, nearly complete digestion and high security. Utilising the DS carrier to load high-melting-point hydrophobic drugs could open new avenues for the application of corn starch.

Organic solvent nanofiltration (OSN) has emerged as a promising separation technology for product purification and solvent recycling in organic solution. Crosslinked polyimide (PI) membranes were widely used in the OSN system. However, the existence of some drawbacks, such as low utilization of crosslinkers and generation of profuse organic waste, hindered the development. Furthermore, when crosslinkers of large molecular weight were applied, the crosslinking degree of membranes was usually found to be insufficient, restricting their performance in harsh solvent systems. In this work, PEI with specific protonation degree, performing as a crosslinker, was directly introduced into PI solution for the preparation of OSN membranes. The partially activated PEI would graft onto PI chains, which could improve the retention of PEI chains during the membrane forming process, while preventing the gelation of PI solution. The as-prepared PEI/PI membrane showed enhanced hydrophilicity and highly positive charge with the isoelectric point as high as 9.1. The PEI/PI membranes were post-treated by K2CO3 solution, aiming to further improve the crosslinking degree. The PEI/PI membranes exhibited good organic solvent resistance even in N, N-dimethylformamide (DMF), with the tensile strength of 0.28 MPa and permeance of 2.38 L m- 2 h- 1 bar- 1. Meanwhile, the dye/salt separation performance of the membrane was carried out by using DMF/H2O (1:9 w/w) as the solvent, and the rejection for several dyes was above 97 %, with the rejection for salts below 8 %. After 80 h test, the membrane maintained high rejection for Congo Red and Methyl Blue and low rejection for salt, with the permeation retained at 20 L m- 2 h- 1 bar- 1, indicating excellent anti-fouling performance. The controlled activation method takes the advantage of high utilization and reaction efficiency, as well as simple procedure, rendering it valuable for fabrication of OSN membranes.

Benzophenone (BP) and N-vinylpyrrolidone (NVP) were used to modify the surface of polylactide (PLA) films by UV grafting method. The effects of light distance, temperature, reaction time, and modifier concentration on the structure and properties of PLA films were investigated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance spectroscopy, differential scanning calorimetry (DSC), and universal testing machine (UTM). With BP and NVP UV grafting, the hydrophilicity of PLA films is improved, but their thermal and mechanical properties are reduced under different surface modification condition. Base on the principle of good surface hydrophilicity, better mechanical and thermal properties, the hydrolytic degradation performance of modified PLA films in artificial seawater at 70 degrees C was studied by scanning electron microscopy, XPS and DSC. The research results show that the degradation of modified PLA films mainly occurs in the amorphous region, and the degradation process conforms to surface hydrolysis mechanism. The grafting modification of NVP is better than BP to accelerate the degradation process of PLA films in artificial seawater. The degradation of modified PLA undergoes water molecule erosion and autocatalytic degradation reaction. The degradation of BP-PLA obeys the first-order kinetics in part, while the degradation of NVP-PLA is more complex. Therefore, surface hydrophilicity modification is an effective technique for improving the degradability of PLA. Benzophenone (BP) and N-vinylpyrrolidone (NVP) were used to modify the surface of polylactide (PLA) films by UV grafting method. Hydrophilicity of modified PLA films is improved, but their thermal and mechanical properties are reduced. NVP-PLA is better than BP-PLA to accelerate the hydrolytic degradation process. The degradation of BP-PLA obeys the first-order kinetics in part, while the degradation of NVP-PLA is more complex. image

In this study, the structure and functional properties of prolamins extracted from sorghum, rye, oat, barley and amaranth was systematic compared with commercial zein, e.g. secondary structure, electrophoresis profiles, sulfhydryl and disulfide content, surface hydrophobicity, emulsifying property and thermal stability. Kafirin and amaranth prolamin (AP) possessed much more ordered secondary structure. The conformation of hordein was more unfolded than other prolamins. Commercial zein possessed more tryptophan residues, while stronger polarity was observed in secalin, AP and avenin. As for the functionality, better emulsion activity and stability was found in avanin. Kafirin had the lowest denaturation temperature but highest enthalpy, which may be due to its lowest amount of beta- turn and random coil. Stronger hydrophobicity was found with kafirin and AP, which was a positive correlation with oil holding capacity and emulsifying properties based on the principal component analysis. The findings provide some theoretical foundation in selecting desired prolamin to achieve more appropriate functional application.

Porous starch has been applied in numerous fields as a novel adsorbent because of its excellent adsorption capacity, safe properties, and abundant sources. In this study, high-amylose corn starch, as a particular native starch, is used to prepare porous starch. alpha-Amylase and glucoamylase are used for enzymolysis. The influence of five single factors on the adsorption capacity and loss ratio of porous high-amylose corn starch are analyzed. Differences in enzymolysis reactions due to high amylose content are found. Response surface methodology (RSM) is used to optimize the preparation conditions and establish a prediction model for adsorption ratio. The optimum preparation conditions are determined: Activity = 1550 U g-1, pH value = 5.0, proportion of glucoamylase = 44%. At the optimum preparation conditions, the water absorption ratio reaches 123.60%, and the oil absorption ratio reaches 120.82%. The optimized samples are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and apparent amylose content (AAC) and compared to existing porous corn starch. The results show that the optimized porous starch has better adsorption capacity, higher thermal stability, different crystal type, and complete particle structure than porous corn starch. These superior properties can be applied to many areas. A novel porous starch adsorption material is prepared by using high-amylose corn starch as raw material, and the preparation technology is optimized by the response surface method. An excellent thermoresistant adsorbent which can be widely used in medicine and food fields is obtained. image

Dye recovery and desalination are of great significance in the treatment of printing and dyeing wastewater. Nanofiltration (NF) has been proved an effective method for dye desalination. As organic solvents are usually coexisted, there is a great demand for organic solvent nanofiltration (OSN) membranes. Compared to thin film composite (TFC) membranes prepared by interfacial polymerized (IP), integrally skinned asymmetric (ISA) membranes with relatively thicker selective layer may present better separation stability in harsh solvent and cleaning reagent. In this work, polyethyleneimine-b-polyethersulfone (PEI-PES) is synthesized and added to PI solution directly, the crosslinking reaction proceeds along with phase conversion process. The PEI chains endow the membrane with good hydrophilicity and high positive charge. PEI-PES/PI membranes show stable permeability in organic solvents such as N, N-dimethylformamide (DMF), ethanol (EtOH) and toluene, etc. The rejections of dyes such as Congo Red (CR), Janus Green B, and Sunset Yellow are over 95 % in EtOH, while the rejections of salts like MgSO4 and Na2SO4 are around 20 %. After 200 h separation test, the rejection for CR remains around 92 % in DMF and 96 % in EtOH with a stable flux. The simple and cost-effective preparation process can accelerate the progress of the positively charged OSN membranes.

This study aimed to enhance the stability of Vitamin E by loading with regenerated cellulose. NaOH/Urea solution of MCC was used to prepare the RC complex with VE via a solution method. The properties and storage stability of the complex were characterized using XRD, FTIR, CLSM, XPS and SEM. Three experimental factors of reaction temperature, weight ratio of MCC to VE, and reaction time were studied to prepare the RC/VE complex. The results indicate that the complex formed along with the regeneration of cellulose. The complex exhibited a type II cellulose lattice. At experimental conditions of 0 °C, the weight ratio of MCC to VE is 4:6, and the time of 2.5 h, the loading rate of VE reached a maximum. The storage stability of the RC/VE complex was improved by a 44.58

Nano starch exhibits many advantages for application in diverse fields. Amaranth starch consisted of starch particle aggregates, isolated amaranth starch, and few natural nano starch (NNS), while NNS (0.92 ± 0.12 μm) was successfully isolated for the first time. Compared with the isolated amaranth starch, NNS showed smaller particle size but larger molecular weight, suggesting that the molecules arranged densely. NNS had a weak A-type crystal structure because of its more content of short starch chains, but higher amylose content resulted in the increase of its gelatinization temperature. The special NNS, owning several different physicochemical properties from amaranth starch, can open new ways for the production and application of nano biomass materials.

A novel composite edible film was synthesized by grafting gelatin chain onto hydroxypropyl methyl cellulose (HPMC) in the presence of glycerol (used as a plasticizer) using a solution polymerization technique. The reaction was carried out in homogeneous aqueous medium. Thermal properties, chemical structure, crystallinity, surface morphology, and mechanical and hydrophilic performance changes of HPMC caused by the addition of gelatin were investigated by differential scanning calorimetry, thermogravimetric, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, universal testing machine and water contact angle. The results shows that HPMC and gelatin are miscible and the hydrophobic property of the blending film can be enhanced with the introduction of the gelatin. Moreover, the HPMC/gelatin blend films are flexible, and exhibit excellent compatibility, good mechanical properties and also thermal stability, and could be promising candidates for food packaging materials.

Collagen (Col) hydrogels are an important biomaterial with many applications in the biomedical sector. However, deficiencies, including insufficient mechanical properties and a rapid rate of biodegradation, hamper their application. In this work, nanocomposite hydrogels were prepared by combining a cellulose nanocrystal (CNC) with Col without any chemical modification. The high-pressure, homogenized CNC matrix acts as nuclei in the collagen’s self-aggregation process. The obtained CNC/Col hydrogels were characterized in terms of their morphology, mechanical and thermal properties and structure by SEM, rotational rheometer, DSC and FTIR, respectively. Ultraviolet-visible spectroscopy was used to characterize the self-assembling phase behavior of the CNC/Col hydrogels. The results showed an accelerated assembling rate with the increasing loading of CNC. The triple-helix structure of the collagen was preserved with a dosage of CNC of up to 15 wt%. The CNC/Col hydrogels demonstrated an improvement in both the storage modulus and thermal stability which is attributed to the interaction between the CNC and collagen by the hydrogen bonds.