Encapsulation Rate Research Articles

Study on preparation, characterization and application of mixed-colorants thermochromic microcapsules

In order to expand the color-change range and make the discoloration temperature suitable for the daily textiles, a new formulation of mixed-colorants thermochromic core material is designed, in which crystal violet lactone (CVL) is the basic color former, bisphenol A (BPA) is the developer, especially the solvent-based dye and dodecyl dedecanoate are used as the extended dye and the solvent, respectively. Scanning electron microscope (SEM), differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA) were applied to study the morphology, encapsulation rate, non-isothermal crystallization behavior and thermal stability of the mixed-colorant thermochromic microcapsules (MCTMs) prepared by in-situ polymerization. The results show that MCTMs have good sphericity, uniform particle size, good thermal stability and the encapsulation rate can reach 86.73%. Under the non-isothermal conditions, the encapsulation of formaldehyde-melamine resin wall material can slightly reduce the crystallization rate of the solvent, but does not affect the relative crystallinity, thermal properties and discoloration sensitivity of the core materials. With the variety of ambient temperatures in the range of 20–35 °C, the printed cotton fabrics with MCTMs could change color reversibly between different tones with good reliability and durability, and exhibit more gorgeous colors than the common thermochromic materials.

Comparison of milk protein concentrate, micellar casein, and whey protein isolate in loading astaxanthin after the treatment of ultrasound-assisted pH shifting

Milk proteins can be used as encapsulation walls to increase the bioavailability of active compounds because they can bind hydrophobic, hydrophilic, and charged compounds. The objective of this study was to investigate the effects of astaxanthin (ASTA) encapsulation and the functional properties of milk protein and ASTA nanocomposites by an ultrasound-assisted pH-shifting treatment of different milk proteins, including milk protein concentrate (MPC), micellar casein (MCC), and whey protein isolate (WPI). The ultrasound-assisted pH-shifting treatment of milk protein helped to improve the encapsulation rate of ASTA. Therein, MCC showed great improvement of encapsulating ASTA after co-treatment with the raised encapsulated rate of 5.11%, followed by WPI and MPC. Furthermore, the nanocomposites of ASTA with milk protein exhibit improved bioavailability, antioxidant capacity, and storage stability. By comparison, MCC-encapsulated ASTA has the best storage stability, followed by MPC, and WPI-encapsulated ASTA has the least stability over a 28-d storage period. The results of intrinsic fluorescence and surface hydrophobicity showed that milk protein underwent fluorescence quenching after binding to ASTA, which was due to the hydrophobic sites of the protein being occupied by ASTA. In general, the nanocomposites of milk protein and ASTA fabricated by using an ultrasound-assisted pH-shifting treatment have the potential to be better nano-delivery systems for ASTA in functional foods, especially MCC, which showed excellent performance in encapsulation after treatment technique.

Nanofibrous membranes with hydrophobic and thermoregulatory functions fabricated by coaxial electrospinning

AbstractIn the face of changing outdoor environments, it is necessary for us to develop advanced textiles with thermal regulation and hydrophobic properties. In order to create a fabric with both temperature control and waterproof properties, the study adjusted the ratio of polystyrene (PS) and polyvinylidene fluoride (PVDF) to produce nanofiber membranes with excellent morphology and dirt resistant properties. Furthermore, the hydrophobicity of the nanofibers was further improved by adding SiO2 to the spinning solution. Based on this, a core solution of octadecane (Oct) was used to give it thermal regulation functionality through coaxial electrospinning technique. The resulting composite nanofiber membrane exhibited excellent hydrophobicity and thermal regulation performance. The measurement results obtained from Differential Scanning Calorimetry (DSC) indicate that the maximum Oct encapsulation rate of the PS/PVDF/SiO2@Oct nanofiber membrane is 58.36%. The latent heat of the composite nanofiber membrane is 148.84 J/g, and the water contact angle (WCA) is 135°. The multifunctional composite nanofiber has great potential for applications in outdoor protective clothing and outdoor electronic device protection.

A curcumin oral delivery system based on sodium caseinate and carboxymethylpachymaran nanocomposites

The food industry has paid lots of attentions to curcumin because of its potential bioactive qualities. However, its use is severely constrained by its low bioavailability, stability and water solubility. Herein, we created sodium caseinate and carboxymethylpachymaran (CMP) nanoparticles (SMCNPs) that were loaded with curcumin. The composite nanoparticles were spherical, as characterized by SEM and TEM, the fluorescence spectroscopy, FTIR and XRD research revealed that hydrogen bonding, hydrophobic interaction and electrostatic interaction were the main drivers behind the creation of the nanoparticles. The SMCNPs exhibited lower particle size, greater dispersion and higher encapsulation rate when the mass ratio of sodium caseinate to CMP was 3:5 (particle size of 166.8 nm, PDI of 0.15, and encapsulation efficiency of 88.07 %). The composite nanoparticles had good antioxidant activity, physical stability and sustained release effect on intestinal tract during the in vitro simulation experiments, successfully preventing the early release of curcumin into gastric fluid. Finally, cytotoxicity studies told that the prepared composite nanoparticles have good biocompatibility and can inhibit the growth of tumor cells (HT-29). In conclusion, using CMP and sodium caseinate as carriers in this study may open up a fresh, environmentally friendly, and long-lasting way to construct a bioactive material delivery system.

Evaluation of Antioxidant Activity and Drug Delivery Potential of Cell-Derived Extracellular Vesicles from Citrus reticulata Blanco cv. 'Dahongpao'.

Plant extracellular vesicles (PEVs) have attracted increasing attention due to their rich composition, good antioxidant and anti-inflammatory activity, and ability to transport drugs. As a common fruit, citrus is an ideal material for extracting PEVs because of the diversity and abundance of bioactive substances in it. In our study, citrus-derived extracellular vesicles (CEVs) were extracted from red mandarin (Citrus reticulata Blanco cv. 'Dahongpao') and it was found that they contain high levels of lipids, proteins, and carbohydrates. The high levels of total phenols and total flavonoids suggest that CEVs have good chemical antioxidant properties. We also demonstrated through cell experiments that CEVs have significant antioxidant and anti-inflammatory effects. Furthermore, we found that CEVs have an encapsulation rate of 71.5 ± 0.19% and a high drug-carrying capacity of 4.96 ± 0.22% and can enhance antioxidant and anti-inflammatory activity when loaded with tangeretin. Our results show that CEVs contain abundant bioactive components, have low toxicity, exhibit good antioxidant and anti-inflammatory properties, and can serve as drug delivery agents. This study has important implications for utilizing citrus materials and developing natural anti-oxidative and anti-inflammatory biomaterials.

Investigations of the Photothermal Properties of a Series of Molecular Gold-bis(dithiolene) Complexes Absorbing in the NIR-III Region.

The photothermal properties of a series of neutral radical gold-bis(dithiolene) complexes absorbing in the near-infrared-III window (1550-1870 nm) have been investigated. This class of complexes was found to be good photothermal agents (PTAs) in toluene under 1600 nm laser irradiation with photothermal efficiencies around 40 and 60 % depending on the nature of the dithiolene ligand. To the best of our knowledge, these complexes are the first small molecular photothermal agents to absorb so far into the near infrared. To test their applicability in water, these hydrophobic complexes have been encapsulated into nanoparticles constituted by amphiphilic block-copolymers. Stable suspensions of polymeric nanoparticles (NPs) encapsulating the gold-bis(dithiolene) complexes have been prepared which show a diameter around 100 nm. The encapsulation rate was found to be strongly dependent on the nature of the dithiolene ligands. The photothermal properties of the aqueous suspensions containing gold-bis(dithiolene) complexes were then studied under 1600 nm laser irradiation. These studies demonstrate that water has strong photothermal activity in the NIR-III region that, cannot be overcome even with the addition of gold complexes displaying good photothermal properties.

Combinedly increased viability of Lactiplantibacillus plantarum grx16 by co‐encapsulation of cryoprotectants and porous starch within calcium alginate capsules

SummaryAlginate‐based encapsulation is an effective probiotics delivery system in the intestine. However, due to calcium ions and gastric juice damaging cell wall/membrane integrity during freeze‐drying and gastrointestinal ingestion, lots of cell lose their viability. This study, taking Lactiplantibacillus plantarum grx16 as an example, indicated that co‐encapsulation of cryoprotectants and porous starch within calcium alginate capsules (CAC) could combinedly improve the viability of probiotics encapsulated. Compared with calcium alginate‐protectant capsule (CAC‐Pro) (50.67%), the combination of porous starch increased the encapsulation rate of PS0.8‐CAC‐Pro to 82.68%. Meanwhile, the death rate constants of PS0.8‐CAC‐Pro decreased by 31.3% (−20 °C), 13.5% (4 °C) and 7.5% (25 °C), respectively. The survival rate of PS0.8‐CAC‐Pro was 81.94% after continuous simulated gastrointestinal digestion, which was significantly higher than that of CACs (69.46%) and CAC‐Pro (76.92%). This study provided an effective approach for modifying alginate capsule to reduce the loss of probiotics viability.

Preparation and characterization of oligomeric thermal phase change polyurethane foam

The generation of a large amount of heat during the formation process of polyurethane foam (PU) hinders the large-scale applications of the materials. Phase-change materials (PCM) can be introduced into PU to reduce the amount of heat accumulation inside PU. Silica-based urea-formaldehyde heteroshell phase-change microcapsules (S-MPCM) containing polydopamine were fabricated, followed by the fabrication of a novel composite polyurethane foam (PU/S-MPCM) doped with S-MPCM. The latter was fabricated using 4,4′-diphenylmethane diisocyanate and polyether polyol as the primary raw materials. The results revealed that the modifying effect of polydopamine resulted in the SiO2 layer deposited on the surface of the microcapsules improved the densification of S-MPCM, and the encapsulation rate of S-MPCM was 76.5 %, and the enthalpy of melting was 162.4 J/g. The compatibility of S-MPCM with the foam was also further improved, increasing the toughness of the composite foam and maximizing its retention of morphology after compression testing. The maximum internal temperature of the composite foam blended with 10 % S-MPCMs was reduced to 53.7 °C, showing excellent thermal regulation performance. The oligomeric thermal phase change polyurethane foam prepared in this study can be considered for applications such as building insulation and mine grouting.

Lutein-Based pH and Photo Dual-Responsive Novel Liposomes Coated with Ce6 and PTX for Tumor Therapy.

Liposomes are considered the best nanocarrier for delivering cancer drugs such as chlorin e6 (Ce6) and paclitaxel (PTX). However, the poor stability and non-selectivity release of liposomes may severely limit their further applications. In this study, based on the characteristics of lutein (L) photo-response and orthoester (OE) acid-response, stable and dual-responsive liposomes (Dr-lips) have been prepared. The Dr-lips exhibited a spherical shape with a uniform size of approximately 58.27 nm. Moreover, they displayed a zeta potential ranging from -45.45 to -28.25 mV and showed excellent storage stability, indicating stable colloidal properties. Additionally, they achieved high drug encapsulation rates, with 92.27% for PTX and 90.34% for Ce6, respectively. Meanwhile, under near-infrared (NIR) light at 660 nm, Ce6 plays a key role in accelerating the photodegradation rate of lutein and PEG-OE-L while also enhancing tissue penetration ability. Additionally, Dr-lips loaded with Ce6 and PTX not only displayed excellent pH and photo dual-responsiveness for targeted delivering and releasing but also showed remarkable reactive oxygen species (ROS) generation capacity and impressive anti-tumor activity in vitro. Therefore, it provides a novel strategy for optimizing stability and enhancing their targeted drug delivery of liposome.

Curcumin loaded Zein-alginate nanogels with “core-shell” structure: formation, characterization and simulated digestion

Zein nanoparticles tend to aggregate in water and are readily digested by enzymes in the gastrointestinal tract. In current study, the Zein-alginate nanogels loaded with curcumin (Cur@ZA) were fabricated with the “core-shell” structure. The Zein “core” was prepared via antisolvent precipitation method, and the alginate gel “shell” was formed by calcium-induced gelation method. The physicochemical properties, microstructure, encapsulation efficiency, stability and simulated digestion characteristics of nanogels were investigated. The results showed that Cur@ZA formed uniform gel spheres with small particle size (415.10 nm), while possessing a dense gel shell on the surface. The Zein “core” and alginate gel “shell” of Cur@ZA are tightly bound to each other by electrostatic adsorption, hydrophobic interaction and hydrogen bonding. Curcumin was able to be loaded in the Cur@ZA nanogels with a higher encapsulation rate (>92 %). Compared with the system which was not induced by calcium ion, the addition of calcium ions improved the photostability and thermal stability of curcumin, and facilitated slow and sustained release of curcumin in the simulated digestion. Therefore, this novel nanogel delivery system has the ideal physicochemical properties, stability and control-release ability, which has the potential to be used in the food industry.

Sodium alginate-sodium hyaluronate-hydrolyzed silk for microencapsulation and sustained release of kidney tea saponin: The regulation of human intestinal flora in vitro

Kidney tea saponin (KTS) exhibits considerable efficacy in lowering glucose levels; however, it does not have widespread applications owing to its low intestinal utilization. Therefore, in the present study, we prepared sodium alginate (SA)/sodium hyaluronate (HA)/hydrolyzed silk (SF) gel beads for the effective encapsulation and targeted intestinal release of KTS. The gel beads exhibited an encapsulation rate of 90.67 % ± 0.27 % and a loading capacity of 3.11 ± 0.21 mg/mL; furthermore, the release rate of KTS was 95.46 % ± 0.02 % after 8 h of simulated digestion. Fourier transform infrared spectroscopy revealed that the hydroxyl in SA/HA/SF–KTS was shifted toward the strong peak; this was related to KTS encapsulation. Furthermore, scanning electron microscopy revealed that the gel bead space network facilitates KTS encapsulation. In addition, the ability of KTS and the gel beads to inhibit α-amylase (IC50 = 0.93 and 1.37 mg/mL, respectively) and α-glucosidase enzymes (IC50 = 1.17 and 0.93 mg/mL, respectively) was investigated. In vitro colonic fermentation experiments revealed that KTS increased the abundance of Firmicutes/Bacteroidetes and butyric acid-producing bacteria. The study showed that the developed gel-loading system plays a vital role in delivering bioactive substances, achieving slow release, and increasing the abundance and diversity of intestinal flora.

Preparation of natural complex waxy structure for the evaluation of preservation performance of blueberry

As a perishable fruit, the quality of blueberries is rapidly decayed after harvesting due to their weight loss, softening of tissues, color changes and microbial proliferation. In order to mimic the waxy layer of the blueberry epidermis, the waxy layer of wax gourd epidermis were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and fourier transform infrared spectroscopy. Moreover, the magnolol-loaded shellac/zein nanoparticles were fabricated using coaxial electrospraying method. The average particle size of the optimal nanoparticles was 2.84 ± 0.03 nm, and the encapsulation rate of magnolol was 79.18% ± 0.61%. Finally, the optimized nanoparticles and wax gourd epidermis were dispersed in an arabic gum solution to obtain a coating and sprayed on the surface of postharvested blueberries. The shellac/zein/magnolol nanoparticles exhibited potential thermal stability, excellent DPPH radical scavenging, antifungal activities against four different types of molds including Penicillium, Botrytis cinerea, Alternaria alternaria and Pestalotiopsis. Overall, the shellac/zein/magnolol nanoparticles are suitable coating to retain the freshness and quality of blueberries during the storage.

Dendrobium officinale Kimura & Migo polysaccharide and its multilayer emulsion protect skin photoaging

Ethnopharmacological relevanceDendrobium officinale Kimura & Migo is traditionally used to treat skin diseases, gastrointestinal diseases, and other diseases. Dendrobium officinale polysaccharides (DOP) are the main component of Dendrobium officinale that accounts for its bioactivity, which shows a variety of effects such as moisturizing, antioxidant and anti-fatigue. However, there is no comprehensive study on the effect of DOP on skin photoaging combined with in vitro and in vivo models, and its specific mechanism is still unclear. Aim of the studyOur study aimed to explore the effect and underlying mechanism of DOP on skin photoaging, as well as to improve the stability and transdermal absorption of DOP. Materials and methodsDOP was extracted, purified and structurally characterized. In vitro HaCaT cell photoaging model was used to examine the photoprotection effect of DOP. Cell viability was detected by CCK-8; Intracellular reactive oxygen species were determined by DCFH-DA; DNA damage, cell apoptosis and cell cycle arrest were examined by flow cytocytometry. For autophagy flux detection, the adenovirus loaded with mRFP-GFP-LC3 was introduced into cells. Further, to enhance the stability and absorption of DOP, we designed and prepared the W/O/W type DOP multilayer emulsions (ME) by a two-step emulsification method. The emulsion stability, drug loading and encapsulation rate, DOP stability and DOP transdermal rate were detected. In vivo photoaging animal model was applied to compare the difference of photoaging protection effect between DOP solution and DOP ME. Specifically, skin appearance, histological change, antioxidant system, proinflammatory indicators, matrix metalloproteinases and autophagy level of skin tissues were examined and compared. ResultsThe results showed that DOP achieve photoaging protection by inhibiting oxidative stress, alleviating cell cycle arrest and apoptosis, and enhancing autophagy flux in photoaged HaCaT cells. The W/O/W type DOP multilayer emulsion (ME) with high encapsulation rate and strong stability was found to significantly improve the stability and transdermal absorption of DOP. In addition, our results showed that DOP (ME) remarkably improved skin condition of photoaged mice. Specifically, DOP (ME) enhanced the expression of antioxidant enzymes and autophagy and decreased the levels of pro-inflammatory factors and matrix metalloproteinases in the skin of photoaged mice as compared with DOP solution. ConclusionsIn conclusion, DOP was effective in improving skin photoaging, and the DOP multilayer emulsion we designed enhanced the stability and skin absorption of DOP, boosting DOP's protective effect against photoaging.

Microcapsules of a cinnamon, peppermint, and lemon essential oil mix by spray drying: Preparation, characterization and antibacterial functions

Plant essential oils (EO) are increasingly used as food preservatives due to their antibacterial and antioxidant activities. For such applications, EO are commonly microencapsulated to overcome their poor stability, low solubility and dominant aromas. But, typically, individual EO act against only a narrow range of bacterial species. Therefore, in this study, we aimed to develop a microencapsulated preservative using a combination of three EO and to determine its anti-bacterial action against three common food contaminants, viz. Escherichia coli, Salmonella and Staphylococcus aureus, and one, usually, beneficial species, viz. Lactoplantibacillus plantarum. The EO of cinnamon (Cinnamomum cassia), peppermint (Mentha haplocalyx) and lemon (Citrus limon) were combined in the proportions, 1.0 : 1.8: 2.4, respectively and were encapsulated in gelatin-chitosan by spray drying. The particle size, zeta potential, moisture content, and encapsulation rate of the essential oil microcapsules (EOM) were measured. With increasing EOM exposure time, the concentrations of E. coli, Salmonella, S. aureus and L. plantarum decreased by 3, 3, 4, and 5 orders of magnitude, respectively. Cell apoptosis accompanied loss of membrane integrity and permeability, inhibition of lactate dehydrogenase activity and disruption of organic acid metabolism. Gram-positive bacteria (S. aureus and L. plantarum) were more susceptible to those effects of EOM than Gram-negative bacteria (E. coli and Salmonella). It also demonstrates that in applications as preservatives for probiotic foods requiring live L. plantarum, EOM comprising cinnamon, peppermint or lemon EO should be avoided.

Investigating the anticancer and anti-angiogenic effects of graphene oxide nanoparticles containing 6-gingerol modified with chitosan and folate

Abstract Objective The use of nanocarriers to improve the targeting of treatment plays a key role in the treatment of many diseases, including cancer. This study was carried out to synthesize graphene oxide (GO) containing 6-gingerol (Ging) modified with chitosan (CS)-folic acid (FA) nanoparticles (Ging-GO-CS-FA) to improve the anti-cancer effects of Ging. Methods After the synthesis of nanoparticles, the average size, surface charge, and dispersion index (DPI) of nanoparticles were analyzed by the dynamic light scattering (DLS) method. Field emission scanning electron microscope (FESEM) and Fourier transform infrared spectroscopy (FTIR) were utilized to assess the morphology and functional groups of synthesized nanoparticles, respectively. The 2,5-diphenyl-2H-tetrazolium bromide (MTT) method was performed to assess the toxicity effect of nanoparticles on different types of cancer cells. The antioxidant power of nanoparticles was evaluated by ABTS and DPPH methods. In addition, the chorioallantoic membrane (CAM) test was conducted to investigate the anti-angiogenic effects of nanoparticles. Finally, the real-time quantitative PCR (qPCR) method was carried out to detect the changes in the expression of angiogenic and antioxidant genes in cancer cells. Results The nanoparticles have an average size of 73.21 nm, a DPI of 0.27, and a surface charge of 29.5. The encapsulation rate of Ging in nanoparticles was reported to be 81.7%. According to the MTT test, the most sensitive cell line to the Ging-GO-CS-FA nanoparticles was reported to be gastric cancer cells (IC50 ~ 27). The results of the antioxidant test showed the high antioxidant power of nanoparticles in the laboratory environment by inhibiting ABTS and DPPH free radicals. The pro-oxidant power of Ging-GO-CS-FA against cancer cells was confirmed by reducing the amount of the superoxide dismutase (SOD) gene in the treated cells. The decreasing effects of Ging-GO-CS-FA on angiogenesis were observed by reducing the average length, the number of blood vessels, average height, and weight of treated embryos. In addition, the decrease in the expression of VEGF and VEGF-R genes confirmed the anti-angiogenic of Ging-GO-CS-FA. Conclusions These results show the promising effect of Ging-GO-CS-FA on gastric cancer cells by inhibiting angiogenesis and increasing the level of oxidants.

Dual-template induced interfacial assembly of yolk-shell magnetic mesoporous polydopamine vesicles with tunable cavity for enhanced photothermal antibacterial

Yolk-shell magnetic polymer nanostructures with large cavity, movable magnetic core are attractive carriers for bulk storage, release and transport of guest molecules in various applications. However, it remains great challenge to achieve a controllable transport of guest species into and out from the hollow space in a controlled way due to the lack of tailor-made nanostructures. Herein, a dual-template-induced emulsion interfacial assembly and polymerization method (denoted as de-IAP) was developed to constructyolk-shell magnetic mesoporous polydopamine (YS-MMP) vesicles with magnetic core, large hollow space and uniform mesopores in the soft polymer shell. The obtained YS-MMP vesicles possess tunable cavity size (10–900 nm), flexible mesoporous PDA layer, large pores (21 nm), high surface area (217.4 m2·g−1) and high magnetization saturation (31.0 emu·g−1), thus exhibiting the merits of high loading capacity (29.1%) and encapsulation rates (41.0%) of Curcumin (Cur), and fast magnetic separation speed. Thanks to their superior photothermal effect and magnetic property, the obtained YS-MMP@Cur vesicles exhibit smart on-demand release of Cur and excellent recyclability. With 808 nm laser irradiation, YS-MMP@Cur vesicles show high-efficient photothermal bactericidal effect (>99%) against S. aureus and E. coli, opening up a new avenue for smart cargo delivery, lasting sterilization, and environmental remediation.

Preparation of nano-sized multi-vesicular vesicles (MVVs) and its application in co-delivery of doxorubicin and curcumin

Multi-vesicular vesicles (MVVs) offer structural advantages in terms of drug encapsulation and physiological stability. In this study, we address the challenge of preparing small-sized MVVs for drug delivery. The nano-sized MVVs (∼120 nm) loaded with doxorubicin (DOX) and curcumin (CUR) (DOX/CUR@MVVs) were successfully prepared using a glass bead combined with a thin film dispersion method. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis confirmed the independent non-homocentric vesicle structures of DOX/CUR@MVVs with homogeneous particle sizes. The experimental results showed high encapsulation rates of DOX and CUR in DOX/CUR@MVVs, reaching 82.5 ± 0.75 % and 85.9 ± 0.69 %, respectively. Moreover, the MVVs exhibited good biosafety and sustained release properties. Notably, the bioavailability of DOX and CUR in DOX/CUR@MVVs was enhanced compared to free DOX and CUR, with increases of 4.2 and 2.1 times, respectively. And the half-life of DOX and CUR was extended by 10 times in DOX/CUR@MVVs. In vivo antitumor experiments demonstrated that nano-sized DOX/CUR@MVVs significantly improved the antitumor activity while reducing the toxic side effects of DOX. Overall, the successful preparation of nano-sized DOX/CUR@MVVs and their potent and low-toxic antitumor effects provide a critical experimental reference for the combined antitumor therapy of MVVs and liposomes.

Preparation and characterization of lemon essential oil@β-cyclodextrin inclusion for blackberry postharvest preservation

Based on an investigation of the antifungal capacity of different citrus plant essential oils against Botrytis cinerea and Rhizopus stolonifer, lemon essential oil (LEO) was selected to prepare LEO@β-cyclodextrin inclusion complex (β-CD-IC) for blackberry preservation. The preparation parameter of LEO@β-CD with the highest encapsulation rate of LEO was chosen via Box-Behnken design (stirring time of 3h, LEO:β-CD = 1:4 and concentration of LEO ethanol solution 25%). Compared with β-CD and the physical mixture of β-CD and LEO, the microstructure of β-CD-IC was different in shape and size. Characterization of LEO@β-CD exhibited shift character peaks of chemical groups and new character peaks of the crystal due to the encapsulation of LEO in β-CD, interaction of hydrogen bonds and conformation of the new solid phase. Under different storage temperatures, LEO@β-CD effectively delayed the rapid decay and color deterioration of blackberries. Under storage of 4 °C and 25 °C, the decay rates of LEO@β-CD are 14.84% and 37.04%, respectively. The weight loss was inhibited by 4.80% and 10.08%, under 4 °C and 25 °C, respectively. The firmness and total soluble solid content was also maintained by the treatment of LEO@β-CD.

Toward function starch nanogels by self-assembly of polysaccharide and protein: From synthesis to potential for polyphenol delivery

Nanogels formed by self-assembly of natural proteins and polysaccharides have attracted great interest as potential carriers of bioactive molecules. Herein, we reported that carboxymethyl starch-lysozyme nanogels (CMS-Ly NGs) were prepared using carboxymethyl starch and lysozyme by green and facile electrostatic self-assembly, and the nanogels served as epigallocatechin gallate (EGCG) delivery systems. The dimensions and structure of the prepared starch-based nanogels (i.e., CMS-Ly NGs) were characterized by dynamic light scattering (DLS), ζ-potential, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermal gravimetric analyzer (TGA). FT-IR and 1H NMR spectra together confirmed the formation of CMS; FT-IR spectra confirmed the formation of CMS-Ly NGs; XRD spectra confirmed the disruption of the crystal structure of lysozyme after electrostatic self-assembly with CMS, and further confirmed the formation of nanogels. TGA demonstrated the thermal stability of nanogels. More importantly, the nanogels showed a high EGCG encapsulation rate of 80.0 ± 1.4 %. The CMS-Ly NGs encapsulated with EGCG exhibited regular spherical structure and stable particle size. Under the simulated gastrointestinal environmental conditions, CMS-Ly NGs encapsulated with EGCG showed the controlled release potential, which increased its utilization. Additionally, anthocyanins can also be encapsulated in CMS-Ly NGs and showed slow-release properties during gastrointestinal digestion in the same way. Cytotoxicity assay also demonstrated good biocompatibility between CMS-Ly NGs and CMS-Ly NGs encapsulated with EGCG. The findings of this research suggested the potential application of protein and polysaccharides-based nanogels in the delivery system of bioactive compounds.

PH-responsive PLGA/gelatin porous microspheres containing paclitaxel used for inhibition of cancer cell proliferation

Multi-functional drug-loaded microsphere system can overcome drug resistance and selectively transport drugs to tumor tissues, thus reducing the toxicity to normal tissues, and can achieve long-term effect through drug release, thus becoming a new way to treat tumor-related diseases. Poly (lactic-co-glycolic acid) PLGA/gelatin composite microspheres were prepared by an emulsion solvent evaporation technique. The microsphere shows that it has positive charge and pH response, which is more suitable for the weak acid environment of tumor and has certain targeting effect. At the same time, the scanning electron microscope showed that the surface was loose and rough, and the internal structure was porous, and the morphology was novel. In addition, UV spectrophotometer was used to test the drug loading rate and encapsulation efficiency of the microspheres. For smooth PLGA and PLGA/gelatin microspheres, the latter has better drug loading rate of 11.66% and encapsulation rate of 89.22%. The results showed that among pure paclitaxel, PLGA and PLGA/gelatin microspheres, the latter had the better than performance in the lethal rate of lung cancer cells and could achieve the goal of continuous lethal. Therefore, the preparation of porous drug-loaded microspheres in this study is pH responsive, and can achieve the goal of safe, targeted and efficient inhibition of cancer cell proliferation, and inspire the follow-up anti-cancer research.