Encapsulation of iron within whey protein-pectin nanocomplexes: Fabrication, characterization, and optimization

Iron is an important micronutrient that cannot be added directly into food products due to potential reactions with the food matrix, impact on color, and taste. Complexed biopolymeric nanocarriers can overcome these challenges particularly for oral delivery of iron, but selecting appropriate biopolymers, their ratio and pH of complexation is very important. In this study, whey protein concentrate (WPC)-pectin nanocomplexes were prepared at different concentrations (WPC 4, 6 and 8%; pectin 0.5, 0.75 and 1%), and pH (3, 6 and 9) to encapsulate iron. The smallest carriers were observed at pH 3; higher pH led to higher zeta potential (zero to -32.5 mV). Encapsulation efficiency of iron in nanocarriers formulated at pH = 3, 6 and 9 were 87.83, 75.92 and 20%, respectively. Scanning electron microscopy revealed the spherical particles at pH 3. To conclude, a WPC to pectin ratio of 4: 1 at pH 3 was the best conditions for loading iron.

Unveiling the critical pH values triggering the unfolding of soy 7S and 11S globulins and enhancing their encapsulation efficiency

The pH-shifting process is an effective encapsulation method, and it is typically performed at extreme alkaline pH, which severely limits the application. In this study, we found that there were critical pH for the unfolding proteins during pH-shifting from 7 to 12, and upon the critical pH, physiochemical characteristics of protein greatly changed, leading to a sharp increase of encapsulation of hydrophobic actives. Firstly, the critical pH for β-conglycinin (7S) or Glycinin (11S) unfolding was determined by multispectral technology. The critical pH for 7S and 11S were 10.5 and 10.3, respectively. The encapsulation efficiency (EE) obtained by β-conglycinin-curcumin nanocomposite (7S-Cur) (88.80 %) and Glycinin-curcumin nanocomposite (11S-Cur) (88.38 %) at critical pH was significantly higher than that obtained by pH 7 (7S-Cur = 16.66 % and 11S-Cur = 15.78 %), and both values were close to EE obtained by at 12 (7S-Cur = 95.16 % and 11S-Cur = 94.63 %). The large-scale application of hydrophobic functional compounds will be enhanced by the experimental results.

The improvement of tyrosol bioavailability by encapsulation into liposomes using pH-driven method

To improve the poor water solubility and oral bioavailability of tyrosol, novel tyrosol liposomes (Tyr-LPs) were prepared by pH-driven method. Fourier transform infrared (FTIR) absorption spectra and X-ray diffraction (XRD) analysis indicated that Tyr-LPs were successfully encapsulated and tyrosol was in an amorphous state in liposomes. When tyrosol content in Tyr-LP was 1.33 mg/ml and the Tyr:LP (mass ratio) = 1:2, favorable dispersibility of Tyr-LP was exhibited, with an instability index of 0.049 ± 0.004, PDI of 0.274 ± 0.003, and the EE of 94.8 ± 2.5 %. In vivo pharmacokinetic studies showed that after oral administration of tyrosol or Tyr-LP (Tyr:LP = 1:2), concentration-versus-time curve (AUC0-720mins) and maximum concentration (Cmax) values of Tyr-LP was respectively 1.5-fold (P < 0.01) and 2.25-fold (P < 0.01) higher than tyrosol, which indicated that the oral bioavailability of tyrosol was effectively improved in Tyr-LPs. Our study thereby provides theoretical support for the application of Tyr-LP for optimal delivery of tryosol.

Encapsulation and characterization of ω-3 medium- and long-chain triacylglycerols microencapsulated with different proteins as wall materials

In this study, ω-3 medium- and long-chain triacylglycerols (MLCTs) microcapsules with excellent performance were obtained using soy protein as the wall component to address the oxidation-related problems of MLCTs. Additionally, the effect of soy, whey, or pea proteins on microcapsules in terms of the changes in their structure and physicochemical properties was investigated. The results showed that the small particle size, low PDI (polydispersity index) and zeta potential, fast adsorption rate, and low interfacial tension of these protein-based samples fabricated through the O/W template method were conducive to maintaining the integrity of microcapsules during spray-drying. The microcapsules, characterized by a spherical shape, exhibited superior encapsulation efficiency of 94.56%, surpassing the findings of previous investigations. Overall, these microcapsules exhibited long-term storage stability and low controllable release rates, which could be utilized as carriers for liposoluble actives.

Effect of cinnamaldehyde-nanoemulsion and nanostructured lipid carriers on physicochemical attributes of reduced-nitrite sausages

This study aimed to produce cinnamaldehyde (CA)-loaded nanostructured lipid carriers (NLC) and nanoemulsion (NE) to replace nitrite in sausage. The NLC and NE droplet sizes were 132 and 116 nm with encapsulation efficiency of 98 and 96 %, respectively. In in vitro antimicrobial assessment, the free CA and NE showed higher microbial activity against S. aureus and E. coli than NLC. Meanwhile, NE showed a faster release profile for CA than NLC. Among the samples, NE and NE + nitrite indicated the lowest peroxide value (3.7 ± 0.1), TVBN amount (8.6 ± 0.2), acidity (0.3 ± 0.02), microbial quality (against E. coli, C. perfringens, lactic acid bacteria, psychrophilic bacteria, total mold and yeast, and total viable counts), and sensory attribute, while the NE + nitrite sample exhibited better color properties and higher oxymyoglobin content (5-10 % higher). Therefore, NE + nitrite can be the best choice due to supporting the different quality parameters of sausage.

Encapsulation and characterization of soy protein-based ω-3 medium- and long- chain triacylglycerols microencapsulated with diverse homogenization techniques for improving oxidation stability

Recently, MLCTs have attracted considerable attention as a potential alternative to traditional oils due to their suppressive effect on fat accumulation and insulin sensitivity. In this study, the microcapsules of MLCTs with superior performance were fabricated through different homogenization processes to overcome the limitations of ω-3 medium- and long- chain triacylglycerols (MLCTs), including poor stability and prone oxidation. Additionally, the impact of various homogenization techniques, namely, high-pressure, ultrasound, and cavitation jet, on the particle structure, encapsulation efficiency, and oxidation stability of microcapsules (MLCTs) was investigated. The MLCTs microcapsules fabricated through high-pressure homogenization had a smaller particle size of 295.12 nm, lower PDI of 0.24, and a higher zeta-potential absolute value of 32.65, which significantly improved their dispersion and encapsulation efficiency, reaching 94.56 % after the spray-drying process. Furthermore, the low moisture content and superior storage stability of MLCTs microcapsules have the potential to serve as carriers of liposoluble actives.

Improved physicochemical properties and in vitro digestion of walnut oil microcapsules with soy protein isolate and highly oxidized konjac glucomannan as wall materials

This study investigated the effect of the oxidation degrees of oxidized konjac glucomannan (OKGM) on the encapsulation efficiency (EE), physicochemical and in vitro digestive properties of soy protein isolate (SPI)-based microcapsules walnut oil using experimental and computational approaches. Microcapsules had the highest EE when the ratio of OKGM and SPI to oil was 2.5:1. With increasing the oxidation degree of OKGM, the EE of microcapsules was increased and the hygroscopicity was decreased. Molecular dynamics simulation results showed that SPI/oil/highly OKGM had relatively low binding energy (-4.03 × 106 kJ/mol) and strong electrostatic interactions, which may contribute to a higher EE and lower hygroscopicity of microcapsules, respectively. The oxidative stability of the oil was markedly improved by SPI and OKGM, and microcapsules prepared with SPI and highly OKGM had the highest in vitro digestion. This study provided theoretical support for broadening the application of microcapsules prepared with SPI and OKGM.

Chitosan for improved encapsulation of thyme aqueous extract in alginate-based microparticles

Ionotropic gelation is a low-cost, easy and green microencapsulation technique. However, the encapsulation of highly soluble compounds is challenging because of the wide loss of material into the external water phase by passive diffusion and the consequent low encapsulation efficiency. In this work an important increase of encapsulation efficiency for Thymus vulgaris L. aqueous extract in alginate-based microparticles has been obtained. A formulation with the proper thyme extract/alginate ratio (30:70) was used as reference and then optimized by adding different co-carrier excipients. Microparticles obtained by dropping a solution containing thyme extract and alginate into a chitosan/calcium-chloride/acid acetic solution lead to a high encapsulation efficiency (70.43 ± 5.28 %). After drying, microparticles had a particle size of 1096 ± 72 μm, 20.087 ± 1.487 % of extract content, 6.2 % of residual water, and showed a complete release of thyme extract within one hour. Combining alginate and chitosan as polymeric co-carrier was a valuable option for efficiently encapsulating an aqueous extract by ionotropic gelation.

Pharmacokinetics study of ginsenoside Rg1 liposome by pulmonary administration

Ginsenoside Rg1 (Rg1), a monomer saponin component, is one of the components with the highest content in total saponins of Panaxnotoginseng. It had various pharmacological effects. The bioavailability of oral tablets is only 1-20 %, and it is eliminated quickly in the blood. The development of new dosage forms and new routes of administration of ginsenoside Rg1 with sustained release and high bioavailability has become a significant problem to be solved. The Rg1 liposomes study used a thin film dispersion ultrasound method for its preparation. This study focused the pharmacokinetic parameters of ginsenoside Rg1 liposomes in rats through the lung perfusion method. Ginsenoside Rg1 liposomes were round and uniform in shape, the particle size was 2-3 μm, and the encapsulation efficiency of ginsenoside Rg1 liposome was 51.2 %. Results showed that, after pulmonary administration of ginsenoside Rg1, the time of ginsenoside Rg1 detected by Rg1 liposomes was longer than that of Rg1 solution, the relative bioavailability of ginsenoside Rg1 liposome lung administration AUC liposome/AUC solution = 122.67 %. These results provided the scientific theoretical and experimental basis for further development of new dosage forms and new routes of administration of ginsenoside Rg1.

Fish oil-loaded multicore submillimeter-sized capsules prepared with monoaxial electrospraying, chitosan-tripolyphosphate ionotropic gelation, and Tween blending

In order to load fish oil for potential encapsulation of fat-soluble functional active substances, fish oil-loaded multicore submillimeter-sized capsules were prepared with a combination method of three strategies (monoaxial electrospraying, chitosan-tripolyphosphate ionotropic gelation, and Tween blending). The chitosan-tripolyphosphate/Tween (20, 40, 60, and 80) capsules had smaller and evener fish oil cores than the chitosan-tripolyphosphate capsules, which resulted from that Tween addition induced smaller and evener fish oil droplets in the emulsions. Tween addition decreased the water contents from 56.6 % to 35.0 %-43.4 %, increased the loading capacities from 10.4 % to 12.7 %-17.2 %, and increased encapsulation efficiencies from 97.4 % to 97.8 %-99.1 %. In addition, Tween addition also decreased the highest peroxide values from 417 meq/kg oil to 173-262 meq/kg oil. These properties' changes might result from the structural differences between the chitosan-tripolyphosphate and chitosan-tripolyphosphate/Tween capsules. All the results suggested that the obtained chitosan-tripolyphosphate/Tween capsules are promising carriers for fish oil encapsulation. This work also provided useful knowledge to understand the preparation, structural, and physicochemical properties of the chitosan-tripolyphosphate capsules.

Composite alginate-based hydrogel delivery of antioxidant pumpkin protein hydrolysate in simulated gastrointestinal condition

Pumpkin seeds are rich in protein (24-36.5%). Some of them are consumed as nuts, while others are regarded as waste and used for feeding animals. Protein hydrolysates from pumpkin seeds possess some bioactive properties, such as anti-oxidant activity. In this work, various composite alginate hydrogels contain Aloe vera, CMC, and tragacanth have been employed to protect PSPH against degradation in simulated gastrointestinal digestion (SGI) and regulate its release rate. The encapsulation efficiency of PSPH in plain alginate and beads with Aloe vera, CMC, and tragacanth combinations was 71.63, 75.63, 85.07, and 80.4%, respectively. The release rate of the plain alginate beads was %30.23 in the SGF and %52.26 in the SIF, and decreased in the composite-based beads. The highest decreasing rate in the antioxidant activity during SGI was observed in free PSPH, and the decreasing rate slowed down in the alginate-based composites. The swelling rate in plain alginate was %-23.43 and %25.43 in the SGF and SIF, respectively, and increased in the composite-based beads. The FTIR spectra of hydrogels before and after loading with PSPH showed identical absorption patterns and were similar to each other. Based on the data for SEM, it was revealed that substituting other polymers in polymer combinations with alginates resulted in a porosity reduction of the beads and smoother and more uniform surfaces. Based on the results, the combination of polysacchared with alginate could protect and increase the applicability of PSPH as a functional component in the food industry.

Preparation, characterisation and in vitro anti-inflammatory activity of Baicalin microsponges

Baicalin, a flavonoid extracted from traditional Chinese medicine, Scutellaria baicalensis has significant anti-inflammatory effects. Microsponges are drug delivery systems that improve drug stability and slow the release rate. The combination of baicalin and the microsponges produced a new and stable system for its delivery, resulting in a novel formulation of baicalin. Baicalin microsponges (BM) were prepared using the quasi-emulsion solvent diffusion method. Effects of the mass ratio of the polymer (ethylcellulose) to baicalin, the concentration of the emulsifier polyvinyl alcohol (PVA), the stirring speed on the encapsulation efficiency (EE), and yield of the microsponges were investigated by combining the one-factor test and Box-Behnken design (BBD). The preparation process was standardised using 2.61:1 mass ratio of ethyl cellulose to baicalin, 2.17% concentration of PVA, with stirring at 794 rpm. Optimised BM formulations were evaluated for the parameters of EE (54.06 ± 3.02)% and yield of (70.37 ± 2.41)%, transmission electron microscopy (TEM), and in vitro cell evaluation. Results of the in vitro anti-inflammatory assay showed that baicalin microsponges-pretreated-lipopolysaccharide (LPS)-induced RAW264.7, mouse macrophages showed reduced inflammatory response, similar to that seen in baicalin-treated macrophages.

Fabrication and characterization of pectin-zein nanoparticles containing tanshinone using anti-solvent precipitation method

Tanshinone compounds are secondary metabolites which their application in food and pharmaceutical industry is limited due to the low solubility in water and sensitivity to heat. This study aimed to develop a novel biopolymer nanocarriers system based on pectin/zein for the encapsulation of tanshinone compounds using the anti-solvent precipitation method. The concentration of pectin and mass ratio of tanshinone/zein in the final formulation of nanoparticles were optimized. According to the results, a pectin concentration of 1 g/L and a tanshinone/zein ratio of 0.1:1 g/g were considered the optimal nanoparticle formulation. The resulting nanoparticles exhibited a spherical core-shell structure, with approximate values for size, zeta potential, TSI, and encapsulation efficiency of 132 ± 0.002 nm, -38.6 ± 0.019 mV, 0.600 ± 0.084, and 79.41 ± 0.62 %, respectively. The FTIR test confirmed the presence of hydrophobic, hydrogen, and electrostatic interactions among the constituents within the nanoparticles. Additionally, XRD and DSC tests verified the amorphous nature of the nanoparticles. Morphological examination conducted through TEM, and SEM revealed the characteristics of the resulting nanoparticles. Furthermore, this carrier system significantly enhanced the solubility of tanshinone compounds in water.

Enhancing the physicochemical stability and antioxidant activity of cape gooseberry calyx extract through nanoencapsulation in soy lecithin liposomes

The focus of this study was on the development, physicochemical characterisation and evaluation of the antioxidant activity of cape gooseberry calyx extract loaded into nanoliposomal systems. Various nanoliposomes were prepared and optimised using the ethanol injection method and characterised based on particle size, polydispersity and zeta potential measurements. Subsequently, the encapsulation efficiency and in vitro release profile of the natural antioxidant extract (NAE) were evaluated, and its antioxidant activity was assessed using the oxygen radical absorbance capacity assay. The results revealed that NAE-loaded nanoliposomes described desired quality features (e.g., particle size of < 200 nm, polydispersity index of < 0.3, zeta potential of > -40 mV and encapsulation efficiency of ∼70%). Furthermore, it was found that NAE release is controlled by various stages, and its antioxidant activity improves by around 30% when loaded into the nanoliposomes, suggesting that it could be a promising antioxidant functional raw material.

Fabrication of double nano-emulsions loaded with hyssop (Hyssopus officinalis L.) extract stabilized with soy protein isolate alone and combined with chia seed gum in controlling the oxidative stability of canola oil

The aim of this study was to encapsulate hyssop (Hyssopus officinalis L.) extract obtained through ultrasound-assisted cold plasma pretreatment extraction within a double emulsion stabilized by soy protein isolate alone (SPI) and combined with chia seed gum (CSG) in the external aqueous phase on the stabilization of canola oil. FTIR analysis verified that there were electrostatic interactions between CSG and SPI. The SPI/CSG-stabilized emulsion demonstrated lower viscosity, smaller droplets, higher ζ-potential, and encapsulation efficiency compared to the SPI-stabilized emulsion. Non-Newtonian, pseudoplastic behaviors were shown by emulsions. Also, according to the dynamic rheological parameters (G' and G''), the SPI/CSG-stabilized emulsion had elastic behavior with weak gel properties. The antioxidant activity of the encapsulated extract at 1500 ppm during the storage in canola oil was investigated and compared to unencapsulated extract and TBHQ. The results showed that oil containing encapsulated extract had lower oxidative alterations than the unencapsulated form.

A non-thermal modification method to promote the interaction of zein-alginate oligosaccharides composites for better encapsulation and stability-Cold plasma

This current research explored the application of cold plasma (CP) treatment to modify zein-alginate oligosaccharide (zein-AOS) composites in an ethanol-water solution. Anti-solvent method was used to prepare zein-AOS nanoparticles (NPs), and the objective was to investigate the mechanism by which CP promotes interaction between protein and saccharides. Characterization results indicated that CP treatment improved hydrogen bonding and electrostatic interaction between zein and AOS. The CP zein-AOS NPs underwent dispersion and rearrangement, resulting in smaller aggregates with better dispersibility. Among the various induction conditions tested, the zein-AOS85 NPs (induced at 85 W for 2 min) exhibited superior performance as delivery wall materials, with smaller particle size (234.67 nm), larger specific surface area (9.443 m2/g), and higher surface charge (-35.43 mV). In addition, zein-AOS85 showed high stability when used as delivery wall material, providing more binding sites and self-assembly dynamics for nutrients. Curcumin was used as the nutrient model in this study, and CP was found to enhance hydrogen bonding, electrostatic interaction, and hydrophobic interaction between zein, AOS, and nutrients, resulting in increased encapsulation efficiency (EE) from 63.80 % to 85.17 %. The delivery system also exhibited good pH, ionic strength, storage, and dispersion stability.

Lipid carriers for mRNA delivery

Messenger RNA (mRNA) is the template for protein biosynthesis and is emerging as an essential active molecule to combat various diseases, including viral infection and cancer. Especially, mRNA-based vaccines, as a new type of vaccine, have played a leading role in fighting against the current global pandemic of COVID-19. However, the inherent drawbacks, including large size, negative charge, and instability, hinder its use as a therapeutic agent. Lipid carriers are distinguishable and promising vehicles for mRNA delivery, owning the capacity to encapsulate and deliver negatively charged drugs to the targeted tissues and release cargoes at the desired time. Here, we first summarized the structure and properties of different lipid carriers, such as liposomes, liposome-like nanoparticles, solid lipid nanoparticles, lipid-polymer hybrid nanoparticles, nanoemulsions, exosomes and lipoprotein particles, and their applications in delivering mRNA. Then, the development of lipid-based formulations as vaccine delivery systems was discussed and highlighted. Recent advancements in the mRNA vaccine of COVID-19 were emphasized. Finally, we described our future vision and perspectives in this field.

Combining orthogonal measurements to unveil diclofenac encapsulation into polymeric and lipid nanocarriers

The quantification of the drug associated to nanoparticle carriers, often expressed in terms of encapsulation efficiency, is a regulatory requirement. The establishment of independent methods to evaluate this parameter provides a means for measurement validation, which is critical in providing confidence in the methods and enabling the robust characterization of nanomedicines. Chromatography is traditionally used to measure drug encapsulation into nanoparticles. Here, we describe an additional independent strategy based on analytical centrifugation. The encapsulation of diclofenac into nanocarriers was quantified based on the mass difference between placebo (i.e. unloaded) and loaded nanoparticles. This difference was estimated using particle densities measured by differential centrifugal sedimentation (DCS) and size and concentration values measured by particle tracking analysis (PTA). The proposed strategy was applied to two types of formulations, namely poly(lactic-co-glycolic acid) (PLGA) nanoparticles and nanostructured lipid carriers, which were analysed by DCS operated in sedimentation and flotation modes, respectively. The results were compared to those from high performance liquid chromatography (HPLC) measurements. Additionally, X-ray photoelectron spectroscopy analysis was used to elucidate the surface chemical composition of the placebo and loaded nanoparticles. The proposed approach enables the monitoring of batch-to-batch consistency and the quantification of diclofenac association to PLGA nanoparticles from 0.7 ng to 5 ng of drug per 1 μg of PLGA, with good linear correlation between DCS and HPLC results (R² = 0.975). Using the same approach, similar quantification in lipid nanocarriers was possible for a loading of diclofenac ≥1.1 ng per 1 μg of lipids, with results in agreement with the HPLC method (R² = 0.971). Hence, the strategy proposed here expands the analytical tools available for evaluating nanoparticles encapsulation efficiency, being thus significant for increasing the robustness of drug-delivery nanocarriers characterization.

Interaction between ultrasound-modified pectin and icaritin

Pectin can improve the bioaccessibility of icaritin as a nanocarrier, and ultrasound can modify the pectin structure. However, the interaction between ultrasound-modified pectin (UMP) and icaritin remains unclearly. In this work, the effects of UMP on the physiochemical properties of icaritin/pectin micelles (IPMs) were investigated. The IPMs prepared with UMP (UMP-IPMs) showed lower encapsulation efficiencies and loading capacities, comparing with native IPMs. UMP-IPMs had smaller particle sizes (325-399 nm) than native IPMs (551 nm). The Mw, viscosity, G' and G" of pectin were determined. NMR spectra indicated that the repeating unit in pectins remained consistently before and after ultrasound treatment, and 7-OH of icaritin was involved in hydrogen bond formation with pectin. The larger chemical shift movement of 6-H and 7-OH for U3-IPMs than P0-IPMs suggested that stronger hydrogen bond interaction between icaritin and pectin. UMP-IPMs exhibited stronger anti-proliferation activities against HepG2 cells than native IPMs.

Microencapsulation of marjoram essential oil as a food additive using sodium alginate and whey protein isolate

Encapsulation techniques are generally used to preserve the volatile compounds of essential oils. This study aimed to evaluate the influence of process variables on the microencapsulation of marjoram essential oil (MEO) (Origanum majorana L.) by ionic gelation. The effect of sodium alginate concentration (0.5-2 g/100 mL), emulsifier concentration (0.5-2 g/100 mL whey protein isolate (WPI)), and cationic bath concentration (0.05-0.3 mol/L CaCl₂) on the emulsions and beads properties were investigated, according to a rotatable central composite design. MEO chemical composition and antimicrobial activity were assessed. Emulsions were characterized for droplet size and viscosity, while the particles were analyzed for encapsulation efficiency, size and circularity, and morphology. High concentrations of alginate and WPI intensified the porous structure of the beads, reducing droplet mean diameter and encapsulation efficiency. High alginate concentrations also increased emulsion viscosity, affecting positively beads' circularity. The intermediate concentration of sodium alginate (1.25 g/100 mL), WPI (1.25 g/100 mL), and CaCl₂ (0.175 mol/L) were selected as the most appropriate conditions to produce beads with satisfactory circularity and high encapsulation efficiency.

Preparation of DRV Liposomes

Dried reconstituted vesicle (DRV) liposomes are formulated under mild conditions. The method has the capability to entrap substantially higher amounts of hydrophilic solutes, compared to other passive-loading liposome preparation methods. These characteristics make this liposome type ideal for entrapment of labile substances, such as peptides, proteins, or DNA's (or other nucleotides or oligonucleotides), or in general biopharmaceuticals and sensitive drugs. In this chapter, all possible types of DRV liposomes (in respect to the encapsulated molecule characteristics and/or their applications in therapeutics) are introduced, and preparation methodologies (for each type) are described in detail.

Garden cress gum and maltodextrin as microencapsulation coats for entrapment of garden cress phenolic-rich extract: improved thermal stability, storage stability, antioxidant and antibacterial activities

The obtained garden cress 6-day sprouts phenolic-rich extract (GCSP) contained efficient health-promoting antioxidant-phenolic compounds. To improve the stability, bioavailability, and functional properties of these valuable phenolic compounds, GCSP was encapsulated by freeze-drying technique using different ratios of garden cress gum (GG) and maltodextrin (M) in the absence and presence of sonication (S). The prepared S/GG-microcapsule retained the highest phenolic content (95%), antioxidant activity (141.6%), and encapsulation efficiency (98.2%). It displayed the highest bio-accessibility of GCSP-phenolic compounds in simulated intestine fluid (87%) and demonstrated the greatest storage-stability at 40 °C for 60 days. S/GG-microcapsule possessed better physical properties including moisture, solubility, swelling, and morphological structures using SEM. The main spectral features, crosslinking, and improved thermal stability were demonstrated for S/GG-microcapsule using FTIR and thermogravimetric analyses. S/GG-microcapsule demonstrated much greater antibacterial activity than GCSP against pathogenic bacteria. S/GG-microcapsule can be added to different food products to improve their antioxidant and antibacterial properties.

Efficient encapsulation of curcumin into spent brewer's yeast using a pH-driven method

Curcumin (CUR) was encapsulated into yeast cells (YCs) through a pH-driven method with a 5.04-fold increase in loading capacity and a 43.63-fold reduction in incubation time compared to the conventional diffusion method. Optimal encapsulation was obtained when the mass ratio of CUR to YCs was 0.1, and the loading capacity and encapsulation efficiency were 8.07% and 80.66%, respectively. Encapsulation of CUR into YCs was confirmed by fluorescence microscopy, differential scanning calorimetry, and thermogravimetric analysis. Fourier transform infrared spectroscopy and X-ray diffraction further demonstrated that the encapsulated CUR was interacted with mannoprotein and β-glucan of the cell wall network through hydrophobic interaction and hydrogen bond in amorphous state. The in vitro bioaccessibility of YCs-loaded CUR was significantly increased by 6.05-fold. The enhanced encapsulation efficiency and rapid encapsulation process proposed in this study could facilitate YCs-based microcarriers to encapsulate bioactive substances with higher bioaccessibility.

Hybrid liposome/metal-organic framework as a promising dual-responsive nanocarriers for anticancer drug delivery

In this work, liposome-coated iron (III) benzene-1,3,5-tricarboxylate (Fe-BTC) metal-organic framework is examined as a promising pH/Ultrasound dual-responsive nanocarriers for doxorubicin (DOX) delivery. The successful coating of the MOF particles (Lip-Fe-BTC) with the phospholipid bilayer (PBL) was established by direct fusion into the synthesized liposomes. The liposome coating was verified using several techniques, including dynamic light scattering (DLS) and transmission electron microscopy (TEM). The DLS measurements showed an increase in the average particle diameter of liposomes from 150 nm to 163.1 nm for Lip-Fe-BTC particles. The Fe-BTC particles had the highest average particle diameter (287.3 nm). These results demonstrated that the PBL reduced the aggregation of the particles and improved their dispersity in the release medium. The TGA results demonstrated the MOF's excellent thermal stability. Furthermore, the nanocarrier's loading efficiency and capacity were determined to be ~90% and ~13.5 wt%, respectively. The in-vitro DOX release experiments demonstrated that the DOX-loaded Fe-BTC and liposome-coated Fe-BTC particles showed good pH and US dual-responsive capability, making them promising nanocarriers for drug delivery. The application of US enhanced DOX release from both Fe-BTC and liposome-coated Fe-BTC. In the case of Fe-BTC-DOX particles, the application of US enhanced the DOX release to around 38% and 67%, at pH levels of 7.4 and 5.3, respectively. Similarly, DOX release from the Lip-Fe-BTC-DOX particles reached ~35% and ~53%, at pH levels of 7.4 and 5.3, respectively. The MTT assay showed the biocompatibility and low cytotoxicity of these nanocarriers below 100 µg/ml.

Physicochemical and release behaviour of phytochemical compounds based on black jamun pulp extracts-filled alginate hydrogel beads through vibration dripping extrusion

The phytochemical-rich extract obtained from black jamun pulp were encapsulated using vibrating dripping extrusion technique. The utilisation of alginate (AL) with four variations of core-shell material comprising gum Arabic (AL-GA), guar gum (AL-GG), pectin (AL-P) and xanthan gum (AL-X) was engaged to form calcium-alginate based lyophilised jamun extract encapsulated beads. It resulted that among four variations, lyophilised alginate with AL-GG based encapsulated jamun extract filled beads have better physicochemical characteristics and 95% encapsulation efficiency. The results revealed the morphological comparison of each variation. The release behaviour of AL-GG based beads has a higher release of total phenolics (TPC) and total anthocyanin content (TAC). The release kinetics model involving Ritger-Peppas and Higuchi model were applied for release TPC and TAC of all variations of beads. The Ritger-Peppas model was found best suitable in terms of average R² (0.965) and lowest χ² (0.0039). The release kinetics study showed that AL-GA based beads followed by AL-GG could also be the best suitable in release behaviour using simulated gastrointestinal fluids at 140-160 min. Overall, results shown the encapsulated Jamun beads have the best agro-industrial efficacy in form of phytochemical compounds based microparticles, holding decent antioxidant potential.

Fast and versatile analysis of liposome encapsulation efficiency by nanoParticle exclusion chromatography

Liposomes are an attractive drug delivery platform for a wide variety of pharmaceutical molecules. Encapsulation efficiency, which refers to the amount of drug contained inside liposomes compared with the total amount of drug, is a critical quality attribute of liposome products, as the free drug in a liposomal formulation may cause toxicity or undesired biodistribution. The determination of encapsulation efficiency requires the measurement of at least two of the three drug populations: total drug, encapsulated drug and free drug. However, direct measurement of the encapsulated drug and free drug remains a challenging analytical task. Nanoparticle exclusion chromatography (nPEC), an emerging high-performance liquid chromatography (HPLC) technique, has shown great potential in separating and quantifying the free drug in liposomal formulations. In this study, nPEC was systematically evaluated for two representative liposomal formulations containing either hydrophilic or hydrophobic small molecule drugs. It is reported for the first time that the insoluble free drug suspended in the aqueous formulation can be directly measured by nPEC. This free drug in the suspension sample was quantified with excellent accuracy and precision. On the other hand, the total drug measurement from dissociated liposomes was confirmed by the benchmark methodology of reversed phase liquid chromatography (RPLC). The facile quantitation of free and total drug in the liposome formulation enables the fast and accurate determination of the encapsulation efficiency, which can be used to guide the formulation development and characterize the product quality.

Exploring the physical and quality attributes of muffins incorporated with microencapsulated squalene as a functional food additive

Squalene, a triterpenoid compound is proven to possess immense bioactivities by virtue of its high antioxidant activity. The present study was designed to investigate the quality attributes of muffins as influenced by addition of encapsulated squalene. Nutritional analysis showed that calorific value of prepared muffins has ranged from 480.78 ± 0.10 to 501.61 ± 0.38 kcal. Baking loss was lowest in case of muffins prepared with encapsulated squalene with its crumb region recorded higher moisture content. Color kinetics study indicated that browning index (BI) was higher in crust portion of encapsulated squalene enriched muffins. Scanning electron micrographs showing that muffins with encapsulated squalene had stronger structural organization. This was further supported by the textural studies showed that the muffins with encapsulated squalene was cohesive, springier and chewy with less gumminess and stiffness indicating their efficacy in improving the textural quality. Oxidative stability and microbiological quality were also high in squalene enriched foods suggesting that squalene might have some antimicrobial effects. Outcome of the study indicated that encapsulated squalene can be very well utilised as a functional food ingredient in ready -to-eat functional foods.

Supplementary information

The online version contains supplementary material available at (10.1007/s13197-020-04955-9).

Preparation and characterization of bupivacaine multivesicular liposome: A QbD study about the effects of formulation and process on critical quality attributes

This study extends QbD principles to liposomal products containing a hydrophilic active pharmaceutical ingredient (API). The feasibility and advantages of the QbD concept for multivesicular liposome-based systems were demonstrated. We selected the local anesthetic drug bupivacaine as a model compound. Desired properties for three critical attributes of multivesicular liposome drug products, namely, the particle size, morphology, and drug encapsulation efficiency, were defined and evaluated. The liposome preparation process significantly affected both the liposome particle size and drug encapsulation efficiency. In this study, the effects of material attributes and processing parameters during the preparation of liposomes were studied in detail using a microscope and particle size analyzer. We used risk assessment to monitor several factors that substantially affect the encapsulation rate and particle size.

Preparation and characterization of octenyl succinylated starch microgels via a water-in-oil (W/O) inverse microemulsion process for loading and releasing epigallocatechin gallate

Corn starch (CS), octenyl succinic anhydride modified corn starch (OSCS) and shells (OSC_s) microgels have been prepared using water-in-oil (W/O) inverse microemulsions for loading and releasing of epigallocatechin gallate (EGCG). The structural and morphological properties of CS, OSCS, and OSC_s microgels were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Thermogravimetric analysis (TGA). The strong hydrogen bonds between starch molecules in the W/O system and interplay between hydroxyl groups of EGCG and oxygen atoms of starch microgels were formed. OSC_s microgel showed low average particle size and weak thermal stability with an irregular shape and a typical V-type crystalline structure. Encapsulation efficiency (EE) and clearance rate of 2,2-diphenyl-1-picrylhydrazyl (DPPH) for EGCG were ranged between 41.78 and 63.89% and 75.53-85.37%, respectively, when absorbed into OSCS and OSC_s microgels, the values which were higher than that of CS microgel. Further, OS starch microgels (particularly OSC_s) modulated the slow release of EGCG into simulated gastrointestinal tract conditions and therefore could be proposed as an encapsulating agent for loading polyphenols.

Functionalization of whey protein isolate fortified with blackcurrant concentrate by spray-drying and freeze-drying strategies

A solution of whey protein isolate was combined with blackcurrant concentrate via spray-drying and freeze-drying techniques separately to develop novel protein ingredients, (SWB and FWB). Chemical compositions, colour profiles, total anthocyanin content and encapsulation efficacy of the protein ingredients were evaluated. An in vitro digestion process was employed to observe the changes in total phenolic content, antioxidant activity, and predictive in vitro glycaemic response of the protein ingredients. The half maximal inhibitory concentration (IC₅₀) towards α-Amylase, and a molecular docking study on the interactions of α-Amylase with anthocyanins, were both performed to investigate the potential mechanisms of hypoglycaemic properties of these protein ingredients. The protein contents of SWB and FWB were 67.94 ± 0.47% and 68.16 ± 0.77%, respectively. Blackcurrant concentrate significantly (p < 0.001) changed the colour profiles of whey protein isolate. SWB obtained a higher total phenol content (3711.28 ± 4.36 μg/g), total anthocyanin content (85390.80 ± 162.81 μg/100 g), and greater encapsulation efficacy (99.64 ± 0.16%) than those of FWB (3413.03 ± 20.60 μg/g, 64230.24 ± 441.08 μg/100 g, and 95.43 ± 0.14%, respectively). Total phenolic content and antioxidant activities of SWB and FWB decreased after the in vitro digestion. The reducing sugar released during the in vitro digestion from SWB and FWB decreased compared with their corresponding controls (SWC and FWC). FWB (IC₅₀ = 73.46 μg/mL) exhibited stronger α-Amylase inhibitory activity than SWB (IC₅₀ = 81.46 μg/mL). Different anthocyanins differed from binding affinities to bind with the active sites of α-Amylase via formation of hydrogen bonds. This study suggested whey protein encapsulated-blackcurrant concentrate might be an innovative food product with improved nutritional profiles. Both spray- and freeze-drying are potential options to this encapsulation.

Encapsulation of bacterial cells in cytoprotective ZIF-90 crystals as living composites

Exploiting metal-organic frameworks (MOFs) as selectively permeable shelters for encapsulating engineered cells to form hybrid living materials has attracted increasing attention in recent years. Optimizing the synthesis process to improve encapsulation efficiency (EE) is critical for further technological development and applications. Here, using ZIF-90 and genetically engineered Escherichia coli (E. coli) as a demo, we fabricated E. coli@ZIF-90 living composites in which E. coli cells were encapsulated in ZIF-90 crystals. We illustrated that ZIF-90 could serve as a protective porous cage for cells to shield against toxic bactericides including benzaldehyde, cinnamaldehyde, and kanamycin. Notably, the E. coli cells remained alive and could self-reproduce after removing the ZIF-90 crystal cages in ethylenediaminetetraacetic acid, suggesting a feasible route for protecting and prolonging the lifespan of bacterial cells. Moreover, an aqueous multiple-step deposition approach was developed to improve EE of the E. coli@ZIF-90 composites: the EE increased to 61.9 ± 5.2%, in contrast with the efficiency of the traditional method (21.3 ± 4.4%) prepared with PBS buffer. In short, we develop a simple yet viable strategy to manufacture MOF-based living hybrid materials that promise new applications across diverse fields.

Bovine alpha-lactalbumin assemblies with capsaicin: Formation, interactions, loading and physiochemical characterization

Numerous human conditions can benefit from diets rich in proteins and bioactives, such as capsaicin (CAP), yet their effective delivery is a sensorial, scientific and technological challenge. This study hypothesized that CAP can form various complexes with native bovine alpha-lactalbumin (holo-ALA) and decalcified-ALA (apo-ALA). Calorimetric and spectroscopic techniques reveals ALA-CAP molecular complexation is spontaneous, exothermic and accompanied by various conformational changes. ITC shows the interaction stoichiometry (n) and binding constant (K_b) for holo-ALA to be 0.87 ± 0.03, 1.54 ± 0.23 × 10⁵ M^-1 and for apo-ALA to be 0.64 ± 0.09, 9.41 ± 2.16 × 10⁴ M^-1. Molecular docking further elucidates that hydrogen bonds govern CAP binding to holo-ALA while hydrophobic interactions dominate binding to apo-ALA in a structural cleft. Finally, this work shows these interactions along with controlled aggregation can be utilized to form CAP-loaded colloids with encapsulation efficiency of 47.1 ± 1.0%. Thus, this study shows great promise in the prospective use of ALA as an edible delivery vehicle for CAP.

Three way ANOVA for emulsion of carotenoids extracted in flaxseed oil from carrot bio-waste

The juice expelled from carrot, a globally produced root vegetable, leavesbehind carrot pomace (a bio- and horticultural waste) which is potentially rich source of micro-nutrients and carotenoids.However, it is discarded as waste or used as animal feed. It holds potential to be channelized to food chain by a couple of technological interventions. In this regard, present work was aimed at preparing stable emulsion based delivery system for 'green' carotenoids extracted from carrot-pomace in flaxseed oil (a green solvent), and at maximizing the amount of core material so that the resultant emulsion can potentially be used as a source of both carotenoids and omega-3 fatty acid of flaxseed oil origin. The study used natural emulsifier. Preparation of oil-in-water emulsion was optimized using 3³ factorial experiment by varying levels of extract containing carotenoid (30-40%), whey protein concentrates (WPC-80) and lactose. The optimized emulsion (CREm) was selected on the basis of particle size, zeta potential, color values (L*, a*, b*) and viscosity statistically analyzed via three-way ANOVA using Proc GLM of SAS 9.3 (described in detail in this paper); the respective values of these parameters being 120.03 ± 8.20 nm, -16.57 ± 0.49 mV, 75.11 ± 0.04, 9.66 ± 0.32, 50.29 ± 0.62, and 0.124 ± 0.0115 Pa.s for CREm. CREm contained 35% flaxseed oil, 10% WPC-80 and 5% lactose and showed good centrifugal and gravitational stability (15 days). It was analyzed for total carotenoid content, antioxidant activities (ABTS (2,2-azinobis-(3-ethylbenzthiazoline-6sulfonic acid), DPPH (2,2-Diphenyl-1-picrylhydrazyl) and FRAP (Ferric reducing antioxidant power assay)) and microstructure.

Yeast encapsulation in nanofiber via electrospinning: Shape transformation, cell activity and immobilized efficiency

To realize encapsulation of living microbial cells and easily evaluation of cell viability after immobilization, the yeast cells were encapsulated in water soluble PAAm nanofiber by a facile and effective electrospinning technology. Firstly, the conductivity, shear viscosity and surface tension of PAAm/yeast electrospinning solution as a function of mass ratios of yeast/PAAm were investigated to determine the optimum solution condition for electrospinning immobilization. After electrospinning, it is interesting to note that the original ellipsoidal structure of yeast cells turns to oblate spheroid structure. To distinguish immobilization structure from the bead appearing during general electrospinning process, immobilization structure and bead structure were compared and analyzed by FESEM and EDX. Free cell activity, the immediate cell activity after electrospinning and cell activity for seven days storage after immobilization were evaluated by dying methods of CTC and methylene blue, respectively. The results show that encapsulation efficiency maintained at about 40%, and immobilized yeast cells remain active even after seven days storage, which provides a promising application prospect for electrospinning immobilization.

Preparation of rutin-loaded microparticles by debranched lentil starch-based wall materials: Structure, morphology and in vitro release behavior

Different treatments of autoclaving, pullulanase debranching and/or ultrasound were applied to prepare debranched lentil starch (DBLS). Their fine structures can affect the retrogradation patterns of DBLSs, which consequently could affect their potential use as delivery carrier of sensitive bioactive compounds. An attempt was made to use these DBLSs as wall materials to encapsulate rutin, aiming to improve the bioaccessibility, meanwhile to enhance the aqueous solubility and stability of rutin molecules. Their encapsulation efficiency, structural characteristics, thermal stability, morphological features, antioxidant activity and in vitro release behavior under simulated upper gastrointestinal tract environment were evaluated. The results suggested that rutin was dispersed in the DBLS polymer matrix, showing the amorphous nature that further authenticates the encapsulation and entrapment of rutin. The structural analyses of microparticles revealed that rutin could interacted with DBLS biopolymer chains by hydrogen bonds, making the starch molecular chains less susceptible to interact with themselves for reordering. The encapsulation efficiency was found to be in an opposite trend with those values obtained for relative crystallinity, melting enthalpy, degree of order/double helices of DBLS wall materials before encapsulation. The release rate results indicated that DBLS carrier with lower M_w, DP_n and higher molecular order was beneficial for the slower release of rutin encapsulated in the microparticles.

Fluorescence-based method for sensitive and rapid estimation of chlorin e6 in stealth liposomes for photodynamic therapy against cancer

Chlorin e6 is a chlorine-based porphyrin containing photosensitizer mainly used for the therapy in cancers like neck and head, early-stage lung cancer, and topical skin cancers. The present study provides a comprehensive account of a highly sensitive, precise, and validated method for the quantification of chlorin e6 in its liposomal formulation. This method is based on the systemic study of the fluorescence action of chlorin e6 in acetonitrile solvent. This experiment follows the analytical method validation parameters as per the International Conference on Harmonization (ICH). Chlorin e6 molecule exhibits strong fluorescence at a wavelength of emission 665 nm, upon excitation at a wavelength of excitation 400 nm in acetonitrile. The linearity of the fluorescence concentration plot was observed over a concentration range of 50 to 1000 ng/mL. The developed and validated method was successfully applied for the estimation of encapsulation efficiency in in-house developed stealth liposomes. Also, stock solution stability and photodegradation study of chlorin e6 were further conducted.

Complex coacervation assisted by a two-fluid nozzle for microencapsulation of ginger oil: Effect of atomization parameters

This study investigates the influence of the atomization parameters on complex coacervation by atomization, and is following a preceding study that presented the technique and investigated the effects of formulation. Complex coacervated capsules were produced by atomization, using emulsions with 1 and 6%(w/w) of gelatin and ginger oil atomized over a 1%(w/w) solution of gum Arabic, at constant polymer ratio of 1:2 (gelatin:gum Arabic) at pH 3.5. The air velocity at the nozzle varied from 72 to 168 m/s and the emulsion velocity at the nozzle varied from 0.4 to 0.6 m/s, maintaining the air to liquid velocity ratio at 170, 220 and 270. The mean diameter of the microcapsules produced varied from 52 to 75 μm and no crosslinking agents were used. The influence of atomization numbers Weber (We) and Ohnesorge (Oh), shear rate and shear stress on the encapsulation performance was carried out and a proposed model was able to predict the final size of the microcapsules produced at We ≥ 180 and Oh = 0.063. Encapsulation efficiency varied from 9 to 95%, and encapsulation yield varied from 50 to 99%. Finally, optimum conditions based on size prediction and microencapsulation parameters were proposed.

Addition of a mushroom by-product in oil-in-water emulsions for the microencapsulation of sunflower oil by spray drying

The by-product generated after ergosterol extraction from mushrooms (A. bisporus) is rich in polysaccharides (β-glucans) and proteins. The usefulness of this mushroom's by-product (MC) in oil microencapsulation by spray drying was evaluated partially replacing maltodextrin (13.5% w/w dry matter) and totally substituting Tween®20 with MC. Ergosterol was investigated as antioxidant. Non-Newtonian stable emulsions with mono-modal droplet size distributions were obtained with MC. Oil encapsulation efficiency was high (≥89%) and oil within microcapsules containing MC exhibited higher (p < 0.05) oxidative stability during spray drying. Powders containing MC exhibited larger particles (d₅₀27% larger), 12% lower solubility in water and perceptible color changes. During storage (35 °C 50% RH), conjugated dienes increased more slowly in microcapsules containing MC. Reductions up to 28% in linoleic acid were observed after 150 days. Ergosterol was 95% degraded after 150 days in powders with MC and totally degraded after 2 days in powders without MC.

Continuous in-line homogenization process for scale-up production of naltrexone-loaded PLGA microparticles

Injectable, long-acting drug delivery systems provide effective drug concentrations in the blood for up to 6 months. Naltrexone-loaded poly(lactide-co-glycolide) (PLGA) microparticles were prepared using an in-line homogenization method. It allows the transition from a laboratory scale to scale-up production. This research was designed to understand how the processing parameters affect the properties of the microparticles, such as microparticle size distributions, surface and internal morphologies, drug loadings, and drug release kinetics, and thus, to control them. The in-line homogenization system was used at high flow rates for the oil- and water-phases, e.g., 100 mL/min and 400 mL/min, respectively, to continuously generate microparticles. A high molecular weight (148 kDa) PLGA at various concentrations was used to generate oil-phases with a range of viscosities and also to compare with a 64 and 79 kDa at a single, high concentration. The uniformity of the microparticles was found to be related to the viscosity of the oil-phase. As the viscosity of the oil-phase increased from 52.6 mPa∙s to 4046 mPa∙s, the span value (a measure of uniformity) increased from 1.24 to 3.1 for the microparticles generated at the homogenization speed of 2000 RPM. Increasing the PLGA concentration from 5.58% to 16.85% showed a corresponding rise in the encapsulation efficiency from 74.0% to 85.8% and drug loading (DL) from 27.4% to 31.7% for the microparticles made with the homogenization speed of 2000 RPM. These increases may be due to a faster shell formulation, enabling PLGA microparticles to entrap more naltrexone into the structure. A higher DL, however, shortened the drug release duration from 56 to 42 days. The changes in morphology of the microparticles during different phases of the in vitro release study were also studied for three types of microparticles made with different PLGA concentrations and molecular weights. As PLGA microparticles went through structural changes, the surface showed raisin-like wrinkled morphologies within the first 10 days. Then, the microparticles swelled to form smooth surfaces. The in-line approach produced PLGA microparticles with a highly reproducible size distribution, DL, and naltrexone release rate.

Evaluation of optimum conditions for decoquinate nanoliposomes and their anticoccidial efficacy against diclazuril-resistant Eimeria tenella infections in broilers

Decoquinate (DQ) is used for prophylaxis against coccidian infections within the digestive tract of chickens, but DQ is extremely insoluble in water. Hence, improving the water solubility of DQ is extremely important. First, decoquinate nanoliposomes (DQNLs) were prepared by the thin-film dispersion-ultrasonic method. The preparation conditions of DQNLs were optimized using the orthogonal test. The optimal preparation conditions of DQNLs were: a ratio of egg-yolk lecithin:drug (w/w) of 10:1, ratio of egg-yolk lecithin:cholesterol (w/w) of 5:1, rotary-evaporation temperature of 50 ℃, and ultrasound duration of 15 min. The encapsulation efficiency of DQNLs prepared under these conditions reached 99.24 % and drug loading was 5.67 %. The characterization of optimized DQNLs was also done. Transmission electron microscopy of DQNLs showed that they had the characteristic structure of liposomes. The mean particle size was 115.6 nm. The polydispersity index was 0.175. The zeta potential was -39.1 mV. The stability of DQNLs was high upon storage at 4 ℃. In vivo studies demonstrated that the lower dose (5 mg/L) of DQNLs in drinking water obtained the similar anticoccidial efficacy to that of 40 mg/kg DQ in feed against diclazuril-resistance Eimeria tenella isolate. The in vitro inhibitory effect of DQNLs on the sporulation of Eimeria tenella oocysts was dose-dependent. Therefore, the anticoccidial efficacy of DQ was enhanced significantly after being encapsulated into nanoliposomes.

Vesicles as antibiotic carrier: State of art

Antimicrobial resistance (AMR) has become a global health problem. Bacteria are able to adapt to different environments, with the presence or absence of a host, forming colonies and biofilms. In fact, biofilm formation confers chemical protection to the microbial cells, thus making most of the conventional antibiotics ineffective. Prevention and destruction of biofilms is a challenging task that should be addressed by a multidisciplinary approach from different research fields. One of the medical strategies used against biofilms is the therapy with drug delivery systems. Lipidic nanovesicles are a good choice for encapsulating drugs, increasing their pharmacodynamics and reducing side effects. These soft nanovesicles show significant advantages for their high biocompatibility, physical and chemistry properties, good affinity with drugs, and easy route of administration. This review summarizes the current knowledge on different types of vesicles which may be used as antibiotic carriers. The main preparation and purification methods for the synthesis of these vesicles are also presented. The advantages of drug encapsulation are critically reviewed. In addition, recent works on endolysin formulations as novel, "greener" and efficient antibiofilm solution are included. This paper can provide useful background for the design of novel efficient formulations and synergistic nanomaterials and could be also useful at the pharmaceutical industry to develop wastewater treatments and reduce the antibiotics in the environmental waters.

Fabrication and assessment of milk phospholipid-complexed antioxidant phytosomes with vitamin C and E: A comparison with liposomes

Evidences have shown that phytosome assemblies are novel drug delivery system. However, studies of phytosomes in food applications are scarce. The characteristics of milk phospholipid assemblies and their functionality in terms of in vitro digestibility and bioavailability of encapsulated nutrients (ascorbic acid and α-tocopherol) were studied. The phytosomes were fabricated using ethanolic evaporation technique. Spectral analysis revealed that polar parts of phospholipids formed hydrogen bonds with ascorbic acid hydroxyl groups, further, incorporating ascorbic acid or α-tocopherol into the phospholipid assembly changed the chemical conformation of the complexes. Phospholipid-ascorbic acid phytosomes yielded an optimal complexing index of 98.52 ± 0.03% at a molar ratio of 1:1. Phytosomes exhibited good biocompatibility on intestinal epithelial cells. The cellular uptake of ascorbic acid was 29.06 ± 1.18% for phytosomes. It was higher than that for liposomes (24.14 ± 0.60%) and for ascorbic acid aqueous solution (1.17 ± 0.70%).

Effects of carrier agents on powder properties, stability of carotenoids, and encapsulation efficiency of goldenberry (Physalis peruviana L.) powder produced by co-current spray drying

Maltodextrin, modified starch, inulin, alginate, gum arabic, and combinations thereof were used as carrier agents for spray drying of carotenoid-rich goldenberry (Physalis peruviana L.) juice and compared to cellobiose as an alternative carrier. Powders were analyzed with respect to particle size and morphology, yield, moisture content, cold water solubility, suspension stability, hygroscopicity, carotenoid encapsulation efficiency, and carotenoid retention during storage. A high initial carotenoid concentration after spray drying, a high encapsulation efficiency of 77.2%, and a slow carotenoid degradation kinetics favored the high carotenoid content of the cellobiose powder at the end of the storage. Cellobiose might protect the carotenoids from degradation processes by light exposure, high temperature, and oxygen due to a tighter particle crust and larger particle sizes. Therefore, cellobiose may be considered a potential carrier agent for the encapsulation of carotenoid-rich fruit juices.

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Goldenberry juice was spray dried with different carrier agents.

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Cellobiose was used as carrier agent in the present study for the first time.

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The cellobiose powder provided the best retention of carotenoids.

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Spray drying promoted isomerization reactions of all-trans-β-carotene.

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Cellobiose proved to be effective for spray drying of carotenoid-rich juices.

Ginger essential oil-based microencapsulation as an efficient delivery system for the improvement of Jujube (Ziziphus jujuba Mill.) fruit quality

Microencapsulation of Zingiber officinale essential oil (EO) in polysaccharide, chitosan (CH) and sodium carboxymethyl cellulose (CMC) based on the electrostatic interaction between charged polysaccharides at pH 3.0 in dual delivery system. Ratio variations of CH and CMC in microencapsulation were studied at 1:2, 2:1 and 1:1. This study aimed to evaluate the influence of the encapsulating materials combination on freeze-dried EO powders and to present the mechanisms for loading and releasing EO involved in the preparation of CH/CMC microcapsules. The spectroscopy analysis, physical properties, microstructural, encapsulation efficiency and EO release behavior in obtained EO microparticles were evaluated by using the analysis of fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and gas chromatography mass spectrometry (GC-MS), respectively. Afterwards, the above prepared microcapsules were applied on winter jujube fruit (Ziziphus jujuba Mill.) preservation. Results demonstrated that both the microstructure and stability of microencapsulation were improved in delivery system loading with CH and CMC (1:1) with the encapsulation efficiency of 88.50%, compared to other ratios of CH and CMC (1:2 and 2:1). Furthermore, the microencapsulation had a capacity to control and reduce the EO release, therefore the morphological and sensory quality of jujube fruits in EO delivery system during storage was enhanced significantly (P < 0.05), in comparison to control. Results revealed that the microparticles produced with CH and CMC (1:1) was considered to present better characteristics of microstructure, encapsulation efficiency, as well as to maintain higher nutritional quality for jujube fruit. Thus, EO microencapsulation loaded in CH/CMC-based dual delivery system has potential application and developmental value prospects in food industries.

Encapsulation of grape seed extract phenolics using whey protein concentrate, maltodextrin and gum arabica blends

Grape seed extract (GSE) contain phenolic compounds that decrease the proclivity to various chronic diseases such as several types of cancer and cardiovascular diseases. The objective of the present study was to investigate the encapsulation of GSE polyphenols and their characterization. For this study, whey protein concentrate (WPC), maltodextrin (MD) and gum arabic (GA) were evaluated as encapsulating materials. For the preparation of stable microcapsules different WPC:MD/GA (5:0, 4:1, 3:2 and 0:5) ratios were assessed using ultrasonication for different time periods (20-40 min) followed by freeze drying. Encapsulation efficiency, antioxidant activity, particle size, surface morphology and release mechanism were determined. The GSE microcapsules coated with WPC:MD/GA ratio of 4:1 and 3:2 with core to coat ratio of 1:5 and prepared by sonication for 30 min were found to have highest encapsulation efficiency (87.90-91.13%) and the smallest particle size with maximum retention of antioxidant activity. Under optimized conditions, the low level release (43-49%) of phenolic compounds resulted under simulated gastric condition and significantly (p < 0.05) increased (88-92%) under simulated intestinal condition. Thus the results indicated blending of MD or GA with WPC improved the microencapsulation of GSE.

Nanoemulsions and acidified milk gels as a strategy for improving stability and antioxidant activity of yarrow phenolic compounds after gastrointestinal digestion

The aim of this study was to improve the stability and antioxidant activity of yarrow phenolic compounds upon an in vitro simulated gastrointestinal digestion. Therefore, two types of caseins-based delivery systems, sodium caseinate stabilized nanoemulsions (NEs) and glucono delta-lactone acidified milk gels (MGs), were formulated containing an ultrasound-assisted yarrow extract (YE) at two concentrations (1 and 2.5 mg/mL). Formulations with 1 mg/mL of YE were chosen based on their higher encapsulation efficiency to perform the in vitro digestion experiments. After digestion, YE-loaded NEs only partially protected phenolic compounds from degradation; meanwhile the phenolic composition of YE including in MGs after digestion was quite similar to undigested YE. Moreover, the antioxidant activity of MGs after digestion was higher than NEs digested samples, which confirms the higher protection of YE phenolic compound by the milk gels systems. This research demonstrated the potential use of acidified MGs as carriers to improve the stability and antioxidant activity of yarrow phenolic compounds. Therefore, these matrices could be employed to develop new dairy products enriched with phenolic compounds.

Effect of drug molecular weight on niosomes size and encapsulation efficiency

Encapsulation into nanocarriers, such as niosomes, is a promising way to protect them from degradation, and allow controll and target delivery of bioactive compounds. For biotechnological applications, a tight control of particle size with acceptable encapsulation efficiencies (EE) is a technological challenge, especially for hydrophilic compounds due to its capability to diffuse across biological barriers. Niosomes formulated with mixture of surfactants represent promising nanocarriers due to the advantages of non-ionic surfactants, such as low cost, versatility and enhanced physico-chemical properties. In this work, the effect of both, composition of the hydrating solution and molecular weight of the loaded compound, on the particle size and EE of niosomes prepared by using the thin film hydration method was studied. Particularly, mili-Q water, glycerol solution and PEG-400 solution were tested for niosomes formulated with Span®80-Tween®80 with/without dodecanol as membrane stabilizer. It was found that particle size highly depends on hydration media composition and an interaction with compound MW could exist. Larger vesicles results in an increase in EE, which could be purely related with physical aspects such as vesicle loading volume capacity. The effect of hydration solution composition could be related with their ability to change the bilayer packing and physical properties, as observed by differential scanning calorimetry. Finally, it was possible to compare the suitability of dialysis and gel filtration as purification methods, demonstrating that gel filtration is not an adequate purification method when viscous solutions are used, since they could affect the particle vesicles retention and hence EE measurements would be misrepresentative.

Insights about stabilization of sulforaphane through microencapsulation

The health–promoting properties of sulforaphane (SFN) are well known, however its instability is still a hurdle for its incorporation into food matrices. SFN can be stabilized by microencapsulation, technique sparingly explored for isothiocyanates so far. This review summarizes the advances in microencapsulation of SFN and other isothiocyanates. Encapsulation efficiency and degradation rate of sulforaphane in different systems are compared and discussed. Ionic gelation and complex coacervation seem more adequate for SFN, both underexplored until now. Drying conditions after chemical encapsulation are determinant, most likely related to thermal degradation of SFN. The current information is insufficient to identify the most adequate encapsulation system and the optimal process conditions to stabilize SFN aiming at its incorporation into food matrices. Accordingly, encapsulation conditions should be investigated, which arises as a new research line. Stability studies are encouraged since this information will help in designing SFN microencapsulation strategies that extend the industrial application of this promising health-promoting compound.

Preparation and Pharmacokinetic Study of Daidzein Long-Circulating Liposomes

In this study, daidzein long-circulating liposomes (DLCL) were prepared using the ultrasonication and lipid film-hydration method. The optimized preparation conditions by the orthogonal design was as follows: 55 to 40 for the molar ratio of soybean phosphatidylcholine (SPC) to cholesterol, 1 to 10 for the mass ratio of daidzein to total lipid (SPC and cholesterol) (w:w), the indicated concentration of 5% DSPE-mPEG2000 (w:w), 50 °C for the hydration temperature, and 24 min for the ultrasonic time. Under these conditions, the encapsulation efficiency and drug loading of DLCL were 85.3 ± 3.6% and 8.2 ± 1.4%, respectively. The complete release times of DLCL in the medium of pH 1.2 and pH 6.9 increased by four- and twofold of that of free drugs, respectively. After rats were orally administered, a single dose of daidzein (30 mg/kg) and DLCL (containing equal dose of daidzein), respectively, and the MRT_0-t (mean residence time, which is the time required for the elimination of 63.2% of drug in the body), t_1/2 (the elimination half-life, which is the time required to halve the plasma drug concentration of the terminal phase), and AUC_0-t (the area under the plasma drug concentration-time curve, which represents the total absorption after a single dose and reflects the drug absorption degree) of daidzein in DLCL group, increased by 1.6-, 1.8- and 2.5-fold as compared with those in the free group daidzein. Our results indicated that DLCL could not only reduce the first-pass effect of daidzein to promote its oral absorption, but also prolong its mean resident time to achieve the slow-release effect.

Fabrication of nano-structured lipid carrier for encapsulation of vitamin D3 for fortification of 'Lassi'; A milk based beverage

A phase inversion based cold water dilution method was developed to encapsulate Vitamin D₃ (Vit D) in nano-structured lipid carrier (NLC) by blending caprylic-/capric triglyceride, Leciva S70 and Kolliphor HS®15, Vit D and sodium chloride. To optimize the process; a total of forty one formulations prepared by varying in their composition were tested for presence of NLC. Out of forty one formulations, only thirteen formulations resulted in NLC formation which were further evaluated for their physico-chemical attributes (particle size, zeta potential, transmittance, encapsulation efficiency and Vit D release). During principal component analysis using XLstats it was found that NLC-19, fabricated with 20% (v/v) Kolliphor, 20% (v/v) CCTG and 60% (v/v) water, 2.5% (w/v) Leciva, 2% (w/v) Vit D and 5% (w/v) sodium chloride was the most suitable for purpose of encapsulating Vitamin D. Hence, NLC-19 formulation was further taken up for stability studies under the following environmental stress conditions: (a) Temperature and humidity: accelerated condition: 45 ± 2 °C and RH 75 ± 5%, ambient condition: 25 ± 3 °C and RH 65 ± 5% and refrigerated condition: 6 ± 2 °C and RH 55 ± 5%, (b) pH: 3, 4, 5, 6, and 7, and (c) Ionic strength (NaCl concentration): 0 mM, 250 mM, 500 mM and 750 mM. The sensory evaluation of 'Lassi' (fortified with NLC-19) and its acceptability further confirmed the suitability of NLC-19 for the purpose of fortification of Vitamin D₃ in 'Lassi' (A milk based beverage).