Lower Release Rate Research Articles

Peptide Hydrogel for Sustained Release of Recombinant Human Bone Morphogenetic Protein-2 In Vitro

This study aimed to investigate the impact of varying the formulation of a specific peptide hydrogel (PepGel) on the release kinetics of rhBMP-2 in vitro. Three PepGel formulations were assessed: (1) 50% v/v (peptides volume/total volume) PepGel, where synthetic peptides were mixed with crosslinking reagents and rhBMP-2 solution; (2) 67% v/v PepGel; (3) 80% v/v PepGel. Each sample was loaded with 12 µg of rhBMP-2 and incubated in PBS. Released rhBMP-2 was quantified by ELISA at 1 h, 6 h, and 1, 2, 4, 7, 10, 14, and 21 days. To explore how PepGel formulations influence rhBMP-2 release, the gel porosities, swelling ratios, and mechanical properties of the three PepGel formulations were quantitatively analyzed. The results showed that rhBMP-2 encapsulated with 50% v/v PepGel exhibited a sustained release over the 21-day experiment, while the 67% and 80% v/v PepGels demonstrated significantly lower rhBMP-2 release rates compared to the 50% formulation after day 7. Higher histological porosity of PepGel was significantly correlated with increased rhBMP-2 release rates. Conversely, the swelling ratio and elastic modulus of the 50% v/v PepGel were significantly lower than that of the 67% and 80% v/v formulations. In conclusion, this study indicates that varying the formulation of crosslinked PepGel can control rhBMP-2 release rates in vitro by modulating gel porosity, swelling ratio, and mechanical properties. Encapsulation with 50% v/v PepGel offers a sustained rhBMP-2 release pattern in vitro; if replicated in vivo, this could mitigate the adverse effects associated with burst release of rhBMP-2 in clinical applications.

Preparation of modified epoxy resin with high hydrophobicity, low dielectric constant, toughness, and flame retardant by epoxy-functionalized siloxanes

A series of α, ω-dimethylglycidoxypropyl-terminated PDMS oligomer (PDMS-GE) oligomers with different polymerization degrees were synthesized and used to modify the bisphenol-A diglycidyl ether E51 (DGEBA) / 4,4-diaminodiphenylmethane (DDM) epoxy resin, resulting in epoxy resins with high hydrophobicity, low dielectric constant, good impact toughness, low combustion heat release rate, and low total heat release. The combustion heat release rate and total heat release of the material decreased with the increase in the loadings of PDMS-GE. Relative to pure epoxy resin, the composite E51/D30–10, which using DGEBA as the matrix, PDMS-GE with a degree of polymerization of 30 as the modifier in an amount of 10 phr relative to the mass sum of DGEBA, PDMS-GE and DDM, exhibited the best comprehensive performance with a water contact angle of 102.42°, a dielectric strength of 6.49 kV/mm, a dielectric constant of 2.93 at 14.2 GHz, the peak rate of heat release (PRHR) and total heat release (THR) are of 378.3 kW/m2 and 134.4 MJ/m2, respectively. These comprehensive performances underscore the potential of PDMS-GE oligomers in significantly improving epoxy resin properties. When the loadings of PDMS-GE oligomers are less than 5 wt%, PDMS-GE with a lower degree of polymerization can improve the toughness of epoxy resins. The impact strength of the composite E51/D24–5, which uses DGEBA as the matrix, PDMS-GE with a degree of polymerization of 24 as the modifier in an amount of 5 phr relative to the mass sum of DGEBA, PDMS-GE, and DDM, reaches 98.1 kJ/m2, which is about 28.9 % higher than that of pure epoxy resin. The results also indicated that the degree of polymerization of PDMS-GE oligomers has less influence on the dielectric properties and mechanical properties of composite materials.

Honokiol-loaded PLGA-PEG nanoparticles with solubility in water for infusion treatment of solid cancer

This study aimed to investigate honokiol-loaded PLGA-PEG nanoparticles with good stability in water for infusion treatment. The characteristics of this nanoparticle-based delivery system were analyzed in a previous study. Additionally, fourier transform infrared spectroscopy confirmed the successful loading of honokiol into PLGA-PEG nanoparticles, revealing characteristic chemical shifts. In vitro drug release studies demonstrated sustained release over 72 h, with lower release rates compared to free honokiol. Cytotoxicity assays on A549 and 3LL lung cancer cells showed that the IC50 values for the nanoparticles were significantly lower than those for free honokiol, with values of 8.76 ± 1.51 μg/ml and 7.46 ± 0.53 μg/ml for the nanoparticles, compared to 12.03 ± 1.07 μg/ml and 10.51 ± 1.27 μg/ml for free honokiol, respectively. Apoptosis induction in cancer cells was demonstrated, emphasizing the potential therapeutic benefits. In vivo studies using a murine carcinoma model showed higher concentrations of honokiol in tumor tissues and major organs with the nanoparticle formulation. Tumor growth inhibition was significantly greater in the nanoparticle-treated group, achieving an inhibition ratio (IR) of 85.32 %, compared to 65.99 % for free honokiol. Hematological and biochemical analyses and histopathological examination indicated no significant adverse effects. The study suggests that honokiol-loaded PLGA-PEG nanoparticles covered by carboxyl (COOH) groups (Nano-HK), with good solubility in water, enhance the delivery and therapeutic efficacy of honokiol, providing a promising avenue for cancer treatment.

Encapsulation and controlled release of Streptomyces sp. herbicidal metabolites for pre-plant weed germination control

ABSTRACT Streptomyces sp. herbicidal metabolite encapsulation with controlled release properties is considered an innovative method for weed control without negatively affecting the environment. This research reports the preparation and application of new herbicidal metabolites-core/alginate-shell encapsulation systems with controlled release properties of Streptomyces sp. metabolites with pre-plant herbicidal activity for the control of weeds, Lolium perenne, Amaranthus retroflexus and Bidens pilosa showing good germination inhibition capacity. The production of Streptomyces sp. metabolites was performed by the liquid fermentation method. Three alginate polymer-coated Streptomyces sp. herbicidal metabolites-controlled release systems with an encapsulation efficiency of > 94%, were successfully prepared using the dripping extrusion method. Well-defined and compact release systems were obtained with a spherical shape and average diameters of 4.4-4.5 mm and an alginate shell thickness in the order of 400 µm with different pore sizes (26-5 µm). An increase in the alginate concentration of 0.75-2.0% (w/v) during the preparation resulted in a decrease in the shells' porosity size and a decrease in the release of the Streptomyces sp. herbicidal metabolites. The release activity of the herbicidal metabolites was evaluated by UV-Vis optical absorption spectroscopy. The statistical results showed that porous shell release systems with a lower release rate over time have a higher potential for the inhibition of germination in > 91% of weeds than the direct herbicidal metabolite application and the control group (P < 0.05). These results indicate that Streptomyces sp. herbicidal metabolites-controlled release systems represent a potentially sustainable alternative for pre-plant weed management.

Eurasian spruce bark beetle detects lanierone using a highly expressed specialist odorant receptor, present in several functional sensillum types

BackgroundInsects detect odours using odorant receptors (ORs) expressed in olfactory sensory neurons (OSNs) in the antennae. Ecologically important odours are often detected by selective and abundant OSNs; hence, ORs with high antennal expression. However, little is known about the function of highly expressed ORs in beetles, since few ORs have been functionally characterized. Here, we functionally characterized the most highly expressed OR (ItypOR36) in the bark beetle Ips typographus L. (Coleoptera, Curculionidae, Scolytinae), a major pest of spruce. We hypothesized that this OR would detect a compound important to beetle fitness, such as a pheromone component. We next investigated the antennal distribution of this OR using single sensillum recordings (SSR) and in situ hybridization, followed by field- and laboratory experiments to evaluate the behavioural effects of the discovered ligand.ResultsWe expressed ItypOR36 in HEK293 cells and challenged it with 64 ecologically relevant odours. The OR responded exclusively to the monoterpene-derived ketone lanierone with high sensitivity. Lanierone is used in chemical communication in North American Ips species, but it has never been shown to be produced by I. typographus, nor has it been studied in relation to this species’ sensory physiology. Single sensillum recordings revealed a novel and abundant lanierone-responsive OSN class with the same specific response as ItypOR36. Strikingly, these OSNs were co-localized in sensilla together with seven different previously described OSN classes. Field experiments revealed that low release rates of lanierone inhibited beetle attraction to traps baited with aggregation pheromone, with strongest effects on males. Female beetles were attracted to lanierone in laboratory walking bioassays.ConclusionsOur study highlights the importance of the so-called ‘reverse chemical ecology’ approach to identify novel semiochemicals for ecologically important insect species. Our discovery of the co-localization pattern involving the lanierone OSN class suggests organizational differences in the peripheral olfactory sense between insect orders. Our behavioural experiments show that lanierone elicits different responses in the two sexes, which also depend on whether beetles are walking in the laboratory or flying in the field. Unravelling the source of lanierone in the natural environment of I. typographus is required to understand these context-dependent behaviours.

Improving onchocerciasis elimination surveillance: trials of odour baited Esperanza Window Traps to collect black fly vectors and real-time qPCR detection of Onchocerca volvulus in black fly pools

BackgroundEntomological data for onchocerciasis surveillance relies on sampling black flies through human landing collectors in the field and laboratory testing of the flies for infection using pooled screening O-150 PCR-ELISA assay. Both techniques require improvements. This study aimed to optimize the Esperanza Window Trap (EWT) for black fly collection. We tested alternative carbon dioxide (CO2) mimics to attract black flies to the traps. Additionally, we evaluated new quantitative PCR (qPCR) methods that target mitochondrial DNA markers and have been proposed to enhance the sensitivity and specificity for detecting Onchocerca volvulus infections in blackflies.MethodsTraps baited with low, medium and high release rates of either 2-butanone or cyclopentanone as CO2 mimics were field tested against traps baited with organically generated CO2 in four ecological zones in Nigeria: Guinea savannah, derived savannah, rainforest and montane forest. The performance of EWTs baited with CO2 or in combination with 2-butanone (low release) were subsequently evaluated against the human landing collection (HLC). Trap scaling was also pilot tested by comparing two EWTs to a single HLC team. Collected black flies were used to test detection of O. volvulus in black flies using Ov ND5 real-time PCR (qPCR) compared to the conventional pool screening O-150 PCR.ResultsEWTs baited with 2-butanone caught similar numbers of black flies (Simulium damnosum s.l.) to those baited with CO2, while cyclopentanone collected significantly fewer flies in all locations. The low release of 2-butanone was the most effective overall, although HLCs collected higher numbers of black flies than EWT baited with CO2 either singly or in combination with low-release 2-butanone. The combination of two EWTs baited with CO2 and deployed 100 m apart from each other collected similar numbers of flies as one HLC. More black fly pools were positive for O. volvulus by Ov ND5 qPCR compared with O-150 PCR in derived savannah (31.15 vs. 15.57%), montane forest (11.54 vs. 0%) and rainforest (23.08 vs. 2.56%), with only one positive pool in Guinea savannah detected by both methods.ConclusionsThe 2-butanone has potential to be used in xenomonitoring as a standardized replacement for organically generated CO2. Ov ND5 qPCR detected more positive pools than O-150 PCR. The positive pools found in foci hitherto considered to have interrupted/eliminated onchocerciasis highlight the need for more sensitive and specific methods that support programmatic assessments to identify and combat recrudescence.Graphical

Comprehensive evaluation of the antibacterial and antibiofilm activities of NiTi orthodontic wires coated with silver nanoparticles and nanocomposites: an in vitro study.

Fixed orthodontic appliances act as a niche for microbial growth and colonization. Coating orthodontic wires with antimicrobial silver nanoparticles (AgNPs) and nanocomposite was adopted in this study to augment the biological activity of these wires by increasing their antibacterial and antibiofilm properties and inhibiting bacterial infections that cause white spot lesions and lead to periodontal disease. Three concentrations of biologically synthesized AgNPs were used for coating NiTi wires. The shape, size, and charge of the AgNPs were determined. Six groups of 0.016 × 0.022-inch NiTi orthodontic wires, each with six wires, were used; and coated with AgNPs and nanocomposites. The antimicrobial and antibiofilm activities of these coated wires were tested against normal flora and multidrug-resistant bacteria (Gram-positive and Gram-negative bacterial isolates). The surface topography, roughness, elemental percentile, and ion release were characterized. AgNPs and nanocomposite coated NiTi wires showed significant antimicrobial and antibiofilm activities. The chitosan-silver nanocomposite (CS-Ag) coated wires had the greatest bacterial growth inhibition against both Gram-positive and Gram-negative bacteria. The surface roughness of the coated wires was significantly reduced, impacting the surface topography and with recorded low Ni and Ag ion release rates. NiTi orthodontic wires coated with AgNPs, and nanocomposites have shown increased antimicrobial and antibiofilm activities, with decreased surface roughness, friction resistance and limited- metal ion release.

Dual-Mode Reactive Oxygen Species-Stimulated Carbon Monoxide Release for Synergistic Photodynamic and Gas Tumor Therapy.

Controllable carbon monoxide (CO) release simulated by light-generated reactive oxygen species (ROS) represents a promising approach for cancer therapy but is hampered by low CO release rate and low ROS generation of conventional photosensitizers in hypoxia tumor microenvironments. In this study, we developed a highly efficient nanoplatform (TPyNO2-FeCO NPs) through co-encapsulating organic AIE photosensitizers (PSs) and CO prodrug (Fe3(CO)12), which are capable of light-triggered robust ROS generation and CO release for synergistic photodynamic therapy (PDT) and CO gas therapy. The success of this nanoplatform leverages the design of a PS, TPyNO2, with exceptional type I and type II ROS generation capabilities, achieved through the introduction of the α-photoinduced electron transfer (α-PET) process. With the incorporation of a 4-nitrobenzyl unit as a typical PET donor, the intramolecular α-PET process not only suppresses the radiative decay to redirect the excited-state energy to intersystem crossing for more triplet-state formation but also promotes electron separation and transfer processes for radical-type ROS generation. The resultant TPyNO2 demonstrates superior singlet oxygen, superoxide anion, and hydroxyl radial generation capabilities in the aggregate state. Upon light irradiation, TPyNO2-FeCO NPs release CO via the type I and type II dual-mode ROS-mediated processes in a controlled and targeted manner, overcoming the limitations of conventional CO release systems. TPyNO2-FeCO NPs also demonstrate a self-accelerating ROS-CO-ROS loop as the released CO induces intracellular oxidative stress, depolarizes mitochondria membrane potentials, and inhibits ATP production, leading to further intracellular ROS generation. Both in vitro and in vivo experiments validated the excellent antitumor performance of the combined PDT and CO gas therapy. This study provides valuable insights into the development of advanced PSs and establishes TPyNO2-FeCO NPs as promising nanoplatforms for safe and effective antitumor applications.

Tracking Microplastics Contamination in Drinking Water Supply Chain in Haikou, China: From Source to Household Taps.

The presence of microplastics (MPs) in aquatic environments has become a significant global concern due to their potential adverse effects on human health. This study aimed to investigate the contamination of MPs throughout the drinking water supply chain in Haikou City, China, and to conduct risk assessments regarding the relationship between MPs contamination and human health. The results revealed that the abundance of MPs in raw, treated, and tap water was 0.6 ± 0.6, 5.2 ± 2.7, and 1.2 ± 1.1 particles·L-1, respectively. Fragments were identified as the most prevalent shape across all samples, with the size category of 20-50 μm showing the highest abundance of MPs. Among the 11 types of polymers identified, polyethylene and polypropylene accounted for 50% and 29%, respectively. The potential risk index values were significantly higher for treated water (370.26) and tap water (303.85) compared to raw water (13.46), suggesting that plastic pipes may be a key contributor to MPs contamination in drinking water. Therefore, efforts should be directed toward developing pipes with low release rates of MPs, as well as improving detection methods for smaller particles and accurately assessing associated risks.

Enhancement of corrosion, biocompatibility and drug delivery properties of nitinol implants surface by Al-Zn-LDH nanohybrids

This study investigates the enhancement of drug delivery and corrosion resistance by incorporating dexamethasone sodium phosphate into aluminum-zinc layered double hydroxide (LDH) coated nickel-titanium alloys. The nickel-titanium samples were fabricated from titanium and nickel powders using spark plasma sintering (SPS) and cold press sintering (CPS), followed by electrophoretic deposition of LDH nanoparticles. This composite construction aims to utilize the biocompatibility and mechanical properties of nickel-titanium, combined with the controlled drug release and corrosion resistance properties of LDH coatings. Structural and microstructural characterizations were performed using X-ray diffraction and scanning electron microscopy. The results indicated that SPS samples exhibited superior microstructural homogeneity and corrosion resistance compared to CPS samples. Dexamethasone sodium phosphate was successfully intercalated into the LDH layers, as evidenced by an increase in layer spacing from 7.14 Å to 20.130 Å. The LDH-coated nickel-titanium with intercalated dexamethasone sodium phosphate demonstrated a 5 % lower drug release rate and significantly improved corrosion resistance compared to uncoated samples. Cell adhesion studies confirmed good biocompatibility between cells and the coated surface. This composite material shows promise for enhanced performance in biomedical applications, particularly in drug delivery and corrosion resistance.

Using zero nano-valent iron/thin film composite (ZNVI/TFC) membrane for brackish water desalination and purification

This study looked at the use of synthetic Zero Nano-valent Iron (ZNVI) particles in a unique interfacial polymerization technique on a polyamide thin film PA(TF) composite membrane for the treatment and desalination of brackish wastewater. Zero nano-valent iron (ZNVI) particles were created utilizing chemical reduction technique. ZNVI/PA(TF) NCs membrane is the outcome of advancing the PA(TF) membrane by combining with different concentration of ZNVI particles into the organic phase 1,3,5-benzenetricarbonyl trichloride (TMC). ZNVI/PA(TF) NCs membranes and ZNVI particles' surface properties were examined by the use of mechanical activity, contact angle, BET, FTIR, SEM, XRD, zeta potential, TEM analysis, and EDX studies. Using a variety of salt solutions, such as NaCl, Na2SO4, MgSO4, NaHCO3, CaSO4, CaCl2, and MgCl2, the ZNVI/PA(TF) NCs membrane performance towards salt rejection, flux (at varying pressure), anti-fouling activity, and ZNVI particles stability was assessed. This work investigated the removal efficiency of four dyes: methylene blue (MB), methyl orange (MO), Congo red (CR), and malachite green oxalate (MG). The water flux of the pristine PA(TF) membrane improved from 22 to 35 L/m2.h at 15 bar, indicating a 63% flux enhancement and the NaCl rejection was improved from 88.5 to 98.6%, indicating an 11.4% rejection improvement by incorporation of 0.3 wt.% of ZNVI particles into PA(TF) matrix. The ZNVI/PA(TF) NCs membrane's separation performances were evaluated using 5000 mg/L feed solutions of various salts at 15 bar. It was discovered that the water flux and salt rejection are, respectively, 33.4, 33, 32.7, 32, 31, 30 and 29 L/m2.h for CaSO4, MgSO4, Na2SO4, NaCl, CaCl2, MgCl2, and NaHCO3, and 97.4, 97, 96.5, 96, 94, 93.2, and 92.8%. It demonstrates that the flux recovery ratio (FRR) of the ZNVI/PA(TF) NCs membrane is greater than that of pristine PA(TF) (78%), coming in at 87%. High stability and fixing of the ZNVI particles on the modified membrane surface is indicated by the low overall ZNVI particles release rate over the course of the 10-day experiment.

One-pot biocatalysis of potato rhamnogalacturonan and the role of its deacetylation in efficient inhibition of colon cancer cells and hydrogel mediated colon-targeted drug delivery

Deacetylation of potato rhamnogalacturonan (PRG) by rhamnogalacturonan acetyl esterase (CtPae12B) was explored for enhanced hydrolysis of PRG by rhamnogalacturonan lyase (CtRGLf) and the effects of deacetylated PRG were studied in enhancing inhibition of colon-cancer cells and formation of colon-targeting drug delivery material. Pre-treatment of PRG with CtPae12B resulted in increased relative activity of CtRGLf. CtPae12B removed acetyl groups from both O-2 and O-3 positions of D-galactopyranosyluronic acid residues of PRG, resulting in 98 % deacetylation. PRG displayed 21.9 % degree of acetylation and 7.7 % degree of methylation. TLC and ESI-MS analysis of CtRGLf hydrolysed PRG showed unsaturated RG di-saccharide as the smallest product, with m/z 322. Deacetylated PRG-oligosaccharides displayed higher, 50 % inhibition of colon-cancer HCT-116 cells (with shrunken and globular morphology) than 35 % inhibition by acetylated PRG-oligosaccharides. FESEM and BET analysis of CtPae12B-treated PRG showed porous structure and significantly higher total surface area and pore volume than non-enzyme treated PRG. Higher drug entrapment efficiency and lower drug release rate of CtPae12B-treated PRG hydrogel (0.0033 min−1 at pH 1.2 and 0.009 min−1 at pH 7.4), than non-enzyme treated PRG hydrogel, (0.0057 min−1 at pH 1.2 and 0.02 min−1 at pH 7.4), showed it to be a potential biomaterial for sustainable colon-targeted drug delivery.

Preparation and release pattern study of long-term controlled release Blonanserin microspheres

To prepare a PLGA microsphere loaded with the antipsychotic Blonanserin without release leg period and released in a near-zero model for long time, in this study, 15 kDa and 75 kDa PLGA were chosen to be mixed with different ratios, and Blonanserin microspheres (Bn-MS) without significant differences in the particle size, drug loading capacity, and encapsulation rate were prepared by microfluidics. The release kinetic model was fitted to the release behavior by monitoring the changes in particle size and morphology during the Bn-MS release to investigate microspheres’ in vitro release pattern. The results showed that the addition of appropriate ratios of mixed molecular weights to Bn-MS could eliminate the release hysteresis period. When the ratio of 15 kDa and 75 kDa was 1:9 (F3), the Bn-MS had a low burst release rate, moderate release rate, no release hysteresis period, a long release period of up to 35 days, and a stable release pattern close to the zero level. The results of the release mechanism study indicated that the hybrid PLGA improved the release behavior of the microspheres by adjusting the dissolution degradation rate of Bn-MS, which in turn affected the release mechanism of the microspheres.

Enhanced chitosan and Carboxymethylcellulose scaffolds with natural fiber reinforcement for hernia repair meshes

AbstractChitosan (Chi) and carboxymethylcellulose (CMC) scaffolds, with and without reinforcement by Luffa cylindrica (Lc) or Asclepias curassavica (Ac), were synthesized to evaluate their potential application as hernia repair meshes. These meshes are crucial as they provide structural support to weakened tissues, reducing the risk of hernia recurrence and promoting faster recovery. They improve patient outcomes by enhancing the durability and effectiveness of hernia repairs. Chi scaffolds exhibited lower porosity compared to CMC scaffolds, with fiber inclusion enhancing porosity. The CMC4‐Ac scaffold demonstrated the highest porosity at 67.2%, which is crucial for supporting cell growth and tissue regeneration. All scaffolds exhibited exceptional hydration levels, which is vital for cell growth. Scanning electron microscope (SEM) images revealed open pores in the CMC4 scaffolds, which enhances tissue formation. Tensile strength tests indicated that all scaffolds surpassed the minimum requirements, with CMC4‐Ac standing out for its exceptional properties. CMC scaffolds showed greater degradation, which was mitigated by fiber reinforcement. Chi scaffolds absorbed more Croton draco extract (Cdext) but exhibited lower release rates compared to CMC scaffolds. No hemolytic and non‐cytotoxicity effects were observed. CMC4‐Ac emerged as the most promising scaffold due to its superior properties, making it suitable for hernia repair meshes.

Microencapsulation of flaxseed oil by complex coacervation of with apricot tree (Prunus armeniaca L.) gum and low molecular chitosan: Formation and structural characterization

Chitosan and Prunus armeniaca gum exudate complex coacervation was developed to encapsulate the flaxseed oil (FSO), which is high in polyunsaturated fatty acids (PUFAs). Flaxseed oil microcapsules were produced by complex coacervation method using chitosan (CH; low molecular weight); 1 % w/v), apricot tree's (Prunus armeniaca L.) gum (PAGE; 0.05, 0.1 and 0.2 % w/v), tween 40 and potassium hydroxide, as a cross-linking agent, the various ratios of CH/PAGE (1:1, 2:1 and 3:1) and different ratios of wall: core ratios (20:1, 30:1 and 40:1) was considered. Also, the characteristics of microcapsules were investigated using SEM, DLS, DSC, FTIR, SGF, as well as encapsulation efficiency (EE %), antioxidant and chemical properties, release behavior, morphological of microcapsules and unencapsulated oil. The optimum microsphere termed M4 was selected which was composed of CH: PAGE ratio of 3:1 with PAGE concentration of 0.05 % and the FSO to biopolymer ratio of 1:20, based on its higher EE %, antioxidant activity, oxidative stability, and lower release rate. Morphological properties by SEM indicated that using excessive concentrations of PAGE (0.1 and 0.5 %) led to non-uniform coacervates which led to reduction of EE % and increase in surface oil. DSC and FTIR analysis indicated that FSO was physically entrapped within the complex polyelectrolytes structure. Complex coacervation is a promising method to preserve the highly sensitive FSO to oxidation and the produced microspheres can be used to promote functional food products.

Pomegranate peel extract incorporated soy protein isolate/Artemisia sphaerocephala Krasch. gum composite films for fresh-cut apples preservation

The objective of this study was to prepare an active packaging film using phosphorylated soy protein isolate (PPS) and Artemisia sphaerocephala Krasch. gum (ASKG) as film matrices, with the incorporation of pomegranate peel extract (PPE) to preserve fresh-cut apples. The results showed that PA-PPE (PPS/ASKG-PPE) films significantly increased thickness by 24.47 %, tensile strength by 58.76 %, and elongation at break by 30.48 %. Additionally, water vapor permeability and oxygen permeability decreased significantly to 6.17 × 10−13 and 0.62 × 10−13 Kg•m•m−2•s−1•Pa−1, respectively. FTIR, XRD, and SEM analyses confirmed the formation of intermolecular hydrogen bonds between PPS, ASKG, and polyphenols extracted from pomegranate peel, indicating excellent compatibility. Furthermore, radical scavenging activity experiments demonstrated that these films exhibited a remarkable ability to scavenge DPPH and ABTS+ radicals up to 70.44 % and 74.28 %, respectively, when the PPE content was at 3 wt%. Moreover, PPS could achieve a sustained release effect on polyphenols with a relatively low release rate (63.83 %) even after seven days' time elapsed. Finally, the PA-PPE film displayed superior performance in reducing the weight loss and browning index of fresh-cut apples within 24 h of storage. The development of PA-PPE film could promote sustainable resource protection and demonstrate promising prospects in the field of fresh-cut fruit packaging.

Preparation and characterization of mesoporous HA coating with paclitaxel loaded lignin nanospheres on titanium surface

BackgroundPrimary malignant bone tumor is a disease that can lead to death. The usually applied clinical treatment strategy is surgical resection of the primary tumor. However, tumor cells are difficult to clean up, easy to make the tumor recurrence, and the bone defect caused by surgical resection also hindered the postoperative recovery. Materials and methodsHerein, in this work, mesoporous hydroxyapatite (HA) coating with petal-structure was prepared on titanium (Ti) implant surfaces by micro-arc oxidation (MAO) to accelerate the bone growth, and then paclitaxel (PTX) loaded lignin nanospheres were deposited into the HA coatings to get a sustained release for killing residual tumor cells. ResultsThe results showed that many gaps and holes of micro-scale were formed in the petal-structured HA coatings, they worked as traps for the PTX loaded nanospheres to enhance the deposited amount and immobilization stability, playing good role of drug loading platform. The encapsulation of PTX by lignin ensured a lower release rate and a higher sustaining release time when compared with the PTX without encapsulation. In addition, the HA coating with PTX loaded lignin nanospheres showed higher killing effect to tumor cells than to osteoblast. ConclusionThe mesoporous HA coating with paclitaxel loaded lignin nanospheres endowed the titanium surface with good biological property and tumor cell-killing effect, so the obtained Ti-based material had a highly hopeful application as the localized implant for therapy of primary malignant bone tumor.

Ferrocene-functionalized magnetic core-shell nanoparticles based on hydrosilylation reaction for pH-responsive doxorubicin delivery system

This study describes the development of an innovative pH-sensitive drug delivery system (DDS) utilizing ferrocene (Fc) and magnetic nanoparticles (MNPs) for cancer therapy. One potential method for generating a diverse range of functional NPs involves attaching functional substances to MNPs. In this investigation, we display the successful modification of Fe3O4 NPs by an Fc derivative (4-Ferrocenylbutyl)dimethylsilane through a hydrosilylation reaction toward the synthesis of the Fe3O4@SiO2@VTES@Fc nanocarrier (NC). The doxorubicin (DOX) drug was loaded onto Fe3O4@SiO2@VTES@Fc NC with a drug loading capacity of about 80 % via π-π stacking interactions. Also, the prepared materials were thoroughly characterized using FT-IR, XRD, FE-SEM, EDX-MAP, VSM, DAPI, MTT, antioxidants, and CV techniques. In vitro studies on the release of DOX from Fe3O4@SiO2@VTES@Fc NC indicated a pH-responsive behavior with a lower release rate (< 10 %) at pH 7.4 compared to pH 5 (approximately 70 %) over a period of 96 h. Moreover, cytotoxicity assessments demonstrated notable cytotoxic effects of DOX-loaded Fe3O4@SiO2@VTES@Fc on MCF-7 cells (IC50 value: ∼8 µg/mL). The study findings suggest that the fabricated magnetic core-shell NC (Fe3O4@SiO2@VTES@Fc/DOX) exhibits stimulus-responsive behavior and holds promise as a sophisticated approach to specifically transport therapeutic agents into tumor sites while minimizing exposure to healthy tissues.

Experimental research on the flow field and flame geometry of free buoyant diffusion flames with low dimensionless heat release rates

The flame geometry of turbulent diffusion flames is dominated by the turbulent mixing between the gaseous fuel and the entrained air. The significant variations of the power law for the mean flame height regarding the dimensionless heat release rate (Q˙*) in different Q˙* ranges implied that the turbulent mixing characteristics would change greatly among these Q˙* regimes. This paper presents a combined experimental and analytical study to reveal the turbulent transport properties and flame shape of free turbulent buoyant diffusion flames of relatively low Q˙* prevalent in large-scale fires. The instantaneous velocity fields of free buoyant methane diffusion flames (burner diameter: d = 0.30 m, Q˙*= 0.22–0.40) were measured by the stereo particle image velocimetry (SPIV) technique. The results indicate that the radial profiles of the time-averaged axial velocity, axial normal stress, radial normal stress, shear stress, and turbulent kinetic energy exhibited self-similarity at different heights under all the heat release rates. The turbulent flow in the buoyant flame was found to be anisotropic. Based on the gradient transport approximation, the mean turbulent viscosity within the mean flame height (νt=) was scaled by g1/2d3/2, where g is the gravitational acceleration. The semi-physical correlations for the mean flame height and width were derived based on the concepts of turbulent mixing and equal axial convection and radial diffusion times, respectively. The two correlations agreed reasonably with the experimental data of this work.

A manganese doping deficient cerium base metal organic framework as radical scavenger for highly-durable proton exchange membrane water electrolysis

Eliminating hydrogen peroxide and free radicals from electrochemical reactions is crucial for mitigating chemical degradation and improving the durability of proton exchange membranes (PEMs). Herein, we prepare a metal–organic framework containing manganese and cerium ions that possesses oxygen vacancy defects and amino functional groups. The prepared Ce4MnBDC-NH2 acts as a catalyst for H2O2 decomposition and as a free radical scavenger, and it is incorporated into a perfluorosulfonic acid (PFSA) ionomer matrix. Featuring large pore volume, high porosity, and abundant amino groups, the Ce4MnBDC-NH2 is locked in a PEM. The obtained Ce4Mn-NH2BDC@PFSA composite membrane exhibits high dimensional stability, excellent proton conductivity and low high-frequency impedance, yielding a proton conductivity of up to 137 mS cm–1 and superior water electrolysis performance of up to 1.83 V at 3.0 A cm–2. Moreover, the obtained Ce4Mn-NH2BDC@PFSA membrane experiences lower weight loss during the Fenton reaction, a low fluoride-ion release rate, and excellent stability in high current density durability testing: its decay rate is only 5.2 μV h–1, which is lower than that of CeO2@PFSA and Nafion 117 membranes. This work provides a promising method to prepare efficient free radical scavengers for steady-state PEM water electrolysis.