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Tooth extractions can result in alveolar bone dimensional changes, necessitating additional bone grafting for implant placement. Alveolar ridge preservation (ARP) aims to counteract postextraction changes. This case series evaluates the bone regenerative properties of a freeze-dried bone allograft (FDBA) and the clinical outcomes of implants in grafted extraction sites. A total of 33 patients were enrolled, undergoing single/multiple tooth extractions followed by ARP. Biopsy samples were harvested during implant placement for histologic and histomorphometric analysis. Clinical outcomes included marginal bone loss and pink esthetic score (PES). Twenty-five patients completed the study. FDBA-augmented sockets exhibited new bone formation adjacent to graft particles. Implants (n = 25) showed 100% survival and success rates at 1 and 2 years. PES improved significantly over time (P < .001), while marginal bone loss did not significantly differ at 1 and 2 years (P = .096). Specimens showed trabecular bone, residual FDBA particles, and marrow spaces. High magnification revealed immature bone and woven bone bridges around graft particles. No inflammatory cells were observed. This case series provides valuable insights into ARP performed with FDBA (as implants were placed after 3 months of healing without any additional bone augmentation), the histologic outcomes were favorable, and implants were successful after a 2-year follow-up period. [ABSTRACT FROM AUTHOR]

By employing brute-force molecular dynamics, umbrella sampling, and seeding simulations, we investigate homogeneous nucleation during melting and freezing of hard spheres. We provide insights into these opposing phase transitions from the standpoint of classical nucleation theory. We observe that melting has both a lower driving force and a lower interfacial tension than freezing. The lower driving force arises from the vicinity of a spinodal instability in the solid and from a strain energy. The lower interfacial tension implies that the Tolman lengths associated with melting and freezing have opposite signs, a phenomenon that we interpret with Turnbull's rule. Despite these asymmetries, the nucleation rates for freezing and melting are found to be comparable. [ABSTRACT FROM AUTHOR]

Objective: The predictability and long-term success of periodontal regeneration begins with oral hygiene education, disease management, and an individually tailored periodontal maintenance protocol. The treatment outcomes could be enhanced when biologics and bone grafts are combined. The aim of this report was to describe the outcome of two complex infrabony defects in the same patient treated with recombinant human platelet-derived growth factor-BB (rhPDGF-BB) and freeze-dried bone allograft (FDBA) over 10 years. Case presentation: Two complex infrabony defects were treated following guided tissue regeneration principles and procedures. Fullthickness flaps were raised to allow visualization of the defects. The areas were debrided, and exposed root surfaces were planed. FDBA and rhPDGF-BB were combined to fill both defects. A collagen membrane was used over the bone graft in one case. The flaps were reapproximated to achieve primary closure. The patient was seen for regular periodontal maintenance visits and clinical and radiographic follow-ups over 10 years. Throughout the examination periods, the probing depths improved without bleeding on probing, and there was radiographic evidence of bone regeneration. Conclusion: The growth factorinfused bone graft was successfully utilized for periodontal regeneration in complex bony defects. [ABSTRACT FROM AUTHOR]

The storage of rAAV vectors for gene therapy applications is critical for ensuring a constant product quality and defined amount of medication at the time of administration. Therefore, we determined the influence of different storage conditions on the physicochemical and biological properties of rAAV8 and rAAV9 preparations. Particular attention was paid to short-term storage, which plays a crucial role in both the manufacturing process and in clinical applications. Additionally, we addressed the question, of viability of rAAV8 and rAAV9 when subjected to very low-temperature storage conditions (below −65 °C) or lyophilization. To determine the impact on rAAV vectors, various analyses were used, including the quantification of capsid and genome titers, as well as biopotency assessments, which are pivotal determinants in characterizing vector behavior and efficacy. Our data showed that freeze/thaw cycles hardly affected the functionality of rAAV9-aGAL vectors. In contrast, prolonged storage at room temperature for several days, resulted in a discernible decrease in biopotency despite consistent capsid and genome titers. When the storage temperature was further increased, the rAAV8-aGAL decay accelerated. For example, a short-term exposure of + 40 °C and more, led to a reduction in the physical viral titer and to an even faster decline in efficacy determined by biopotency. However, the addition of sucrose and sorbitol to the rAAV9-aGAL and rAAV9-GAA preparations reduced the temperature sensitivity of rAAV and improved its stability. Furthermore, exposure of rAAV9-aGAL to highly acidic conditions (pH 2.5) dramatically reduced its biopotency by 70% or more. Most interestingly, a long-term storage of rAAV9-aGAL and rAAV8-FVIII vectors over 12 and 36 months, respectively, demonstrated exceptional stability at storage temperatures below −65 °C. Also, lyophilization conserved functionality for at least 10 months. Our data showed how to maintain rAAV biopotency levels over the time without substantial loss. Storage at very low temperatures (below −65 °C) preserved its effectiveness over years. Overall, pH and temperature conditions during the manufacturing process, storage and clinical application are worth considering. Consistency in the rAAV capsid titer determination did not necessarily indicate the preservation of biopotency. In conclusion, our approach determined several options for maximizing rAAV stability. [ABSTRACT FROM AUTHOR]

Highly porous and lightweight aerogels of cellulose nanofibers (CNFs) have emerged as a promising class of material. This study delves into the impact of the composition (lignocellulose nanofibers–LCNFs and CNFs) and the drying methods (supercritical drying and freeze-drying) on the morphology and the properties of nanocellulose-based aerogels. The investigation evaluates the concentrations of nanofibers and the influence of lignin, a constituent of LCNFs recognized for enhancing the rigidity of plant cell walls, on the aerogel's properties. The shrinkage rates, density, pore structure, and mechanical properties of the obtained aerogels are comprehensively compared. Supercritical drying proves advantageous for aerogel formation, resulting in materials with lower density and higher surface area than their freeze-dried counterparts at each concentration level. The use of acetone for supercritical drying contributes to reduce the shrinkage rates compared to ethanol. This decrease is attributed to the formation of a more rigid hydrogel during solvent exchange. Freeze-drying exhibits the lowest shrinkage rates and relatively higher porosity. The presence of lignin in the nanofibers influences the microstructure, yielding smoother and thicker pore walls. This study contributes to the comprehensive understanding of the intricate factors shaping nanocellulose aerogel properties, paving the way for the development of innovative and environmentally-friendly materials. [ABSTRACT FROM AUTHOR]

Sugars, as cryoprotectants, can be added to NP formulations before lyophilization to ensure that NPs retain their size during long‐term storage. In this study, mannitol, glucose, and sucrose were used at different concentrations to extend the storage time of doxorubicin (DOX)‐loaded PLGA‐NPs prepared using two different copolymer ratios (75 : 25 and 50 : 50) at different storage temperatures (−20, +4, and +25 °C). After lyophilization, a glucose or sucrose concentration of only 5 % for DOX‐PLGA‐75 : 25‐NP and a glucose concentration of 10 % for DOX‐PLGA‐50 : 50‐NP were found to prevent agglomeration for up to 4 months at −20 °C. It is noteworthy that after storage at 4 °C for up to 4 months, agglomeration was prevented using 5 % sucrose and 10 % glucose in DOX‐PLGA‐50 : 50‐NP and 10 % sucrose content in both NP types. On the other hand, as expected, no sugar type or concentration could prevent agglomeration during long‐term storage of NPs at 25 °C. The sizes and encapsulation efficiencies (EE%) before lyophilization were 221.8±2.20 and 45.4 % for DOX‐PLGA‐50 : 50‐NP and 221.5±1.31 and 48.7 % for DOX‐PLGA‐75 : 25‐NP, respectively. Furthermore, the release profiles and encapsulation of DOX in both NPs were investigated by UV‐Vis analyses. DSC analysis revealed that DOX was present in the free form and amorphous in the NPs. Consequently, PLGA copolymer ratios were found to have an impact on the long‐term stability of DOX loaded PLGA lyophilizates, and DOX‐loaded NPs prepared with PLGA 75 : 25 or PLGA 50 : 50 can be stored at −20 and +4 °C for up to 4 months when combined with appropriate sugar contents and concentrations, demonstrating the versatility of these materials. [ABSTRACT FROM AUTHOR]

ABSTRACT In order to investigate the anti‐friction and anti‐wear performance of different crystal forms nano MoS2 in paraffin oil. Freeze‐drying method combined with hydrothermal was used to prepare different crystal forms nano MoS2 and their microstructures were characterised by X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The anti‐friction and anti‐wear performance of MoS2 nanoparticles as lubricat additives under different working conditions was investigated by the ball‐and‐disk friction and wear testing machine and the mechanism of friction and wear reduction was investigated. The results showed that the thickness of the floral sheet MoS2 flakes was about 10 nm and the particle size of the spherical MoS2 was about 90 nm. When the addition concentration was 3 wt%, the friction coefficient of the floral sheet MoS2 in paraffin oil was lower at 0.094, which was 29.3% lower than that of the pure paraffin oil, the width of the abrasion marks was 24.2% lower than that of the pure paraffin oil and the wear rate was 71.6% lower than that of the pure paraffin oil; The friction coefficient of the spherical MoS2 with 2.5 wt% addition was 0.082, which was 38.3% lower than the friction coefficient of pure paraffin oil, 24.1% lower than that of paraffin oil in terms of wear scar width and 81.9% lower than that of paraffin oil in terms of wear rate. [ABSTRACT FROM AUTHOR]

Whey protein concentrate (WPC) is consumed for its high protein content. The structure and biological functionality of whey proteins in WPC powders may be affected by the drying technique applied. However, the specific impact of spray drying and freeze drying on the overall protein profile of whey protein derived from sweet whey streams at scale is unknown. Herein, we examine the effects of commercial‐scale freeze drying and spray drying on WPC to determine which method better preserves bioactive whey proteins, with the goal of helping the dairy industry create high‐value products that meet the growing consumer demand for functional dairy products. WPCs were produced from pasteurized liquid whey using either a commercial spray dryer or freeze dryer. A variety of analytical techniques, including enzyme‐linked immunosorbent assay, polyacrylamide gel electrophoresis, and bottom‐up proteomics using liquid chromatography‐tandem mass spectroscopy were used to identify, quantify, and compare the retention of bioactive proteins in WPC before and after spray drying and freeze drying. In addition, the extent of denaturation was studied via solubility testing, differential scanning calorimetry, and hydrophobicity assessment. There was little to no difference in the retention or denaturation of key bioactive proteins between spray‐dried and freeze‐dried WPC powders. There was a higher percentage of select Maillard modifications in freeze‐dried and spray‐dried powders than in the control. The lack of significant differences between spray drying and freeze drying identified herein indicates that freeze drying does not meaningfully improve retention of bioactive proteins compared with spray drying when performed after multiple pasteurization steps. Practical Application: This study aimed to provide insight into the impacts of spray drying versus freeze drying on whey proteins. Overall, our results indicate that for commercial dairy processing that involves multiple rounds of pasteurization, freeze drying does not meaningfully improve the retention of bioactive proteins compared with spray drying. These findings may help the food and dairy industry make informed decisions regarding the processing of its whey protein products to optimize nutritional value. [ABSTRACT FROM AUTHOR]

Studies were conducted focusing on the drying of chili pepper fruits (Capsicum annuum L.), cultivar Cyklon, using convective (AD), convective-microwave (AMD), vacuum (VD), and freeze-drying (FD) methods. The influence of the drying method and temperature on the kinetics of the process and selected quality attributes of the dried product were evaluated. It was demonstrated that the Midilli model best described the drying kinetics for all methods across the entire measurement range. FD and VD produced dried products with the highest brightness and the greatest value of the a* color parameter. The lowest b* color parameter was observed for the product dried using FD at 40 °C, while the highest b* value was noted for samples dried using AMD (100 W) at 60 °C. The highest carotenoid retention was achieved with the FD method at 40 °C, while the lowest carotenoid content was found in the product obtained using the AMD method (100 W) at 60 °C. The smallest losses of capsaicinoids were observed after FD drying at 40 °C, while the largest were found for AMD (100 W) at 60 °C. The analysis of chili pepper fruit extracts revealed the quantitative composition of 12 main phenolic compounds using the UHPLC-UV method. The highest polyphenol content was obtained with FD, while the lowest total polyphenol content was recorded after AD. Regardless of temperature, the total flavonoid content was highest in extracts from FD products, and the lowest flavonoid content was found after AMD at 100 W. For all drying methods analyzed, the total flavonoid content in the pepper extracts decreased with increasing temperature. [ABSTRACT FROM AUTHOR]

Gamma-aminobutyric acid (GABA) from plants has several bioactivities, such as neurotransmission, anti-cancer cell proliferation, and blood pressure control. Its bioactivities vary when exposed to pH, heat, and ultraviolet. This study analyzed the protective effect of the GABA encapsulation technique using gum arabic (GA) and maltodextrin (MD) and the freeze-drying method. The impact of different ratios of the wall material GA and MD on morphology, GABA content, antioxidant activity, encapsulation efficiency, process yield, and physical properties were analyzed. Results showed that the structure of encapsulated GABA powder was similar to broken glass pieces of various sizes and irregular shapes. The highest GABA content and encapsulation efficiency were, respectively, 90.77 mg/g and 84.36% when using the wall material GA:MD ratio of 2:2. The encapsulated powder's antioxidant activity was 1.09–1.80 g of encapsulation powder for each formula, which showed no significant difference. GA and MD as the wall material in a 2:2 (w/w) ratio showed the lowest bulk density. The high amount of MD showed the highest Hausner ratio (HR), and Carr's index (CI) showed high encapsulation efficiency and process yield. The stability of encapsulated GABA powder can be kept in clear glass with a screw cap at 35 °C for 42 days compared to the non-encapsulated one, which can be preserved for only 18 days under the same condition. In conclusion, this study demonstrated that the freeze-drying process for GABA encapsulation preserved GABA component extracts from brown rice while increasing its potential beneficial properties. Using a wall material GA:MD ratio of 2:2 resulted in the maximum GABA content, solubility, and encapsulation efficiency while having the lowest bulk density. [ABSTRACT FROM AUTHOR]

Messenger RNA (mRNA) vaccines have revolutionized the fight against infectious diseases and are poised to transform other therapeutic areas. Lipid nanoparticles (LNP) represent the most successful delivery system for mRNA. While the mRNA-LNP products currently in clinics are stored as frozen suspensions, there is evidence that freeze-drying mRNA-LNP into dry powders can potentially enable their storage and handling at non-freezing temperatures. Previously, we successfully applied thin-film freeze-drying (TFFD) to transform a polyadenylic acid [poly(A)]-LNP formulation from a liquid suspension to dry powders. The poly(A)-LNP were structurally multilamellar spheres without blebs, but the mRNA vaccines in clinics are comprised of mRNA-LNP that are structurally spheres surrounded by a unilamellar lipid bilayer, with some containing blebs, and it was reported that the presence of blebs increases the sensitivity of mRNA-LNP to freeze-drying-induced stress. In the present study, using an influenza A virus hemagglutinin (HA) mRNA in LNP that were structurally similar to that in the COVID-19 mRNA vaccines currently in clinic, we studied the effect of TFFD on the physical properties, internal structure, as well as immunogenicity of the HA mRNA-LNP vaccine. We concluded that TFFD can be utilized to prepare dry powders of the HA mRNA-LNP, but a sufficient amount of excipients were needed to minimize changes in the physical properties, structure, and immunogenicity of the HA mRNA-LNP vaccine. [Display omitted] • The HA mRNA-LNP vaccine used in this study contained nanoparticles with unilamellar lipid bilayer, some with blebs. • TFFD was used to transform the HA mRNA-LNP vaccine from liquid to dry powders while maintaining its immunogenicity. • Sufficient excipients were needed to minimize the effect of the freeze-drying stress on the HA mRNA-LNP. [ABSTRACT FROM AUTHOR]

Bletilla striata is widely used as healthy food and herbal medicine for its hemostasis, anti-ulcer, promoting wound healing, antibacterial, anti-inflammatory, and immune regulatory functions. Drying methods affect the quality of herbal medicine, including appearance and more importantly the content of active components, which play a decisive role in the medical and tonic functions. In this study, hot air drying (HD), infrared drying (ID), microwave drying (MD), vacuum drying (VD), and freeze drying (FD) were used to evaluate the effect of drying methods on the quality of B. striata tubers. Significant effects of drying methods on the appearance, color, microstructure, water activity, water content, and active component content of B. striata tubers were observed. FD-treated samples retained the majority of the appearance, color, and microstructure, while samples processed with other methods exhibiting various deformation and discoloration. In addition, a significant decline in water content and water activity was detected in FD-treated samples, yet, the content of active components, such as B. striata polysaccharides, total polyphenols, and militarine, was relatively high. After comprehensive comparison, freeze-drying is proposed to be the most suitable method for B. striata drying, which is also recommendable for other tuber drying. [ABSTRACT FROM AUTHOR]

To precisely evaluate the concentration of iodine-129 (129I) in soil samples, changes in this concentration after thermal drying under several temperature conditions were investigated. The soil sample used in this study was collected from a site located near a nuclear fuel reprocessing plant, which atmospherically released 129I in a test operation in 2006–2008, resulting in the soil sample containing higher 129I concentrations than their natural levels. Thermal drying was conducted from 60°C to 110°C and compared with lyophilization result, showing that the 129I concentration in the soil sample was statistically comparable among all the drying treatments. [ABSTRACT FROM AUTHOR]

To enhance the pore structure of green coffee beans (GCB) and detect the sorption capacity and extraction characteristics of flavor compounds before roasting, this study employed several methods: hot air drying (HD), freeze-drying (FD), 3-levels short-time heating with puffing (SH1P, SH2P, and SH3P), and 3-levels microwave with puffing (MW45P, MW60P, and MW75P). These methods were applied to GCBs pre-soaked in water for different times. The effects of these treatments on color change, porosity, microstructure, citric acid sorption capacity, and caffeine and chlorogenic acid extraction yield were investigated. Results indicated that, except for GCBs treated with SH1P, SH2P, SH3P, and MW75P, all other modified GCBs showed minimal color change. GCBs treated with MW60P exhibited favorable pore structures. MW60P treatments significantly improved the extraction yield of caffeine and chlorogenic acid. Furthermore, the increased porosity and improved pore size distribution of GCB after MW60P resulted in a significant increase in the sorption of citric acid onto modified GCB. The rate of the sorption reaction followed the pseudo-first-order kinetics. In conclusion, MW60P are effective treatments for enhancing the microstructure of GCB, improving sorption capacity, and improving the extraction yield of flavor compounds. [ABSTRACT FROM AUTHOR]

Liposomes being a promising colloidal system facilitates delivery of drugs with limited pharmacokinetic properties to achieve desirable clinical applications. However, development of a stable liposomal system is always challenging due to multiple complexities involved. Aqueous instability of liposomes and impact of various process and formulation parameters can lead to serious alteration of its therapeutic performance. In the proposed work, the authors aim to develop stable Ibrutinib-loaded liposomes using lyophilization and Quality-by-Design and assess their long-term stability. Ibrutinib-loaded liposomes were developed and optimized using Quality-by-Design technique and were further PEGylated and characterized for the same. Effect of cryoprotectants during lyophilization and other parameters are evaluated to obtain a robust formulation. The stability studies were conducted upto 6 months at various storage conditions to evaluate the effect of lyophilization. The impact of formulation, processing and lyophilization parameters on physicochemical properties of developed liposomal systems were evaluated and are critically discussed. Liquid dispersion exhibited a %degradation of 16–36% at 25 °C/60% RH which was reduced for less than 1% in lyophilized formulation for 6 months. Critical analysis and assessment of various parameters lead to identification of optimum conditions to manufacture this drug product and also opens way forward for further evaluation and translational possibilities. [ABSTRACT FROM AUTHOR]

Microneedle patch (MNP) has become a hot research topic in the field of transdermal drug delivery due to its ability to overcome the stratum corneum barrier. Among the various types of microneedles, dissolving microneedles represent one of the most promising transdermal delivery methods. However, the most used method for preparing dissolving microneedles, namely microfabrication, suffers from issues such as long drying time, susceptibility to humidity, and large batch-to-batch variability, which limit the development of dissolving microneedles. In this study, we report for the first time a method for preparing dissolving microneedles using freeze-drying technology. We screened substrates suitable for freeze-dried microneedle patch (FD-MNP) and used coating technology to enhance the mechanical strength of FD-MNP, allowing them to meet the requirements for skin penetration. We successfully prepared FD-MNP using hyaluronic acid as the substrate and insulin as the model drug. Scanning electron microscopy revealed that the microneedles had a porous structure. After coating, the mechanical strength of the microneedles was 0.61 N/Needle, and skin penetration rate was 97%, with a penetration depth of 215 μm. The tips of the FD-MNP dissolved completely within approximately 60 s after skin penetration, which is much faster than conventional MNP (180 s). In vitro transdermal experiments showed that the FD-MNP shortened the lag time for transdermal delivery of rhodamine 123 and insulin compared to conventional MNP, indicating a faster transdermal delivery rate. Pharmacological experiments showed that the FD-MNP lowered mouse blood glucose levels more effectively than conventional MNP, with a relative pharmacological availability of 96.59 ± 2.84%, higher than that of conventional MNP (84.34 ± 3.87%), P = 0.0095. After storage under 40℃ for two months, the insulin content within the FD-MNP remained high at 95.27 ± 4.46%, which was much higher than that of conventional MNP (58.73 ± 3.71%), P < 0.0001. In conclusion, freeze-drying technology is a highly valuable method for preparing dissolving microneedles with potential applications in transdermal drug delivery. [ABSTRACT FROM AUTHOR]

Introduction: Limosilactobacillus reuteri effectively colonizing the gut, secretes antimicrobial compounds and strengthens immune system function. Considering these health benefits, increasing its stress assessments efficiency could improve its commercial viability. Methods: In this work, the resistance of L. reuteri FP41 to acid, bile salts, and freeze-drying was examined. Results: The findings showed that strain FP41 demonstrated a strong resistance to acid/bile salt stresses. The transcriptome revealed a significant up-regulation of various stress response genes, including those related to membrane integrity, glutamine metabolism, OsmC family protein, ABC transporters, and chaperonin. Subsequent research demonstrated that overexpression of three stress response-specific proteins, including glutamate decarboxylase GatD, osmotically induced bacterial protein OsmC, and membrane protein component CsbD, significantly increased the survival rate of L. reuteri Z204 under acid/bile salts stress. Notably, overexpression of the OsmC, CsbD, and GatD proteins also enhanced the survival of L. reuteri after freeze-drying. Discussion: The development of a unique cross-protection method is highlighted in this study, that might significantly increase cellular resistance to acid, bile salts, and cold stresses. This finding could significantly impact the way that L. reuteri is employed in industrial manufacturing processes. [ABSTRACT FROM AUTHOR]

In semiconducting aerogels, exciton–photon interactions occur in porous frameworks with solid–gas interfaces. Herein, by freezing and vacuum freeze-drying of cyclohexane dispersions of platelet-shaped nanocrystals of organic–inorganic metal halide perovskites, aerogels with macro-/meso-porosity, tunable luminescence in the visible light range, and photocurrent responses were fabricated. [ABSTRACT FROM AUTHOR]

AbstractAtmospheric freeze-drying (AFD) is a relatively new freeze-drying technology without the need for a vacuum, making it easy to operate and cost-effective. Although there have been studies using AFD to dehydrate solid foods, there is currently no research on using AFD to dehydrate frozen liquids in pharmaceutical vials. In this study, several approaches were evaluated to enhance the atmospheric sublimation of water in pharmaceutical vials. Using −4 °C impinging jet airflow to dry frozen water samples in the vial, it was found that convective action significantly affected the sublimation rate. On this basis, a 3D-printed air-guide model was designed to improve airflow circulation in the vial, and it was found that the drying rate was highest when airflow energy loss was minimized, and airflow velocity at the sample surface was maximized. Additionally, the geometric characteristics of the vial also influenced the sublimation rate; vials with a larger bottom area and shorter height showed the highest sublimation rate. Increasing the vial’s bottom radius from 11 mm to 13 mm, under atmospheric pressure and using cold air at approximately −5 °C, reduced the drying time of 1 g of frozen water from 8.5 h to 6 h; each 5 mm height increase added 0.5 h to the drying time. Using cold air at −10 °C to dry 1 g of frozen water in a 5 mL vial, the combination of ultrasonic-induced energy (at a frequency of 39.46 kHz) and the air-guide model effectively reduced the sublimation time from 7 h to 5 h, compared to using only the air-guide model. However, this technique may be vulnerable to melting at the vial-transducer contact point, should the transducer be directly attached to the vials. [ABSTRACT FROM AUTHOR]

RNA and protein‐based therapeutics constitute almost half of recent drug approvals and receive considerable attention within biotechnology industries. Ensuring their stability and longevity in the context of heat, freezing, and lyophilization processes are paramount to a successful deployment. However, the advancement of formulations designed to achieve this goal is still in its nascent phase. To address these challenges, a new class of semi‐dendritic hydrophilic polymer with extended linear units is reported, which showcase very high hydration. These novel polymers demonstrated exceptional efficacy in preserving messenger RNA‐ (mRNA‐) and self‐amplifying RNA‐ (saRNA‐) lipid nanoparticles during freezing and lyophilization. Additionally, they have been found to protect therapeutic proteins against external stressors such as freezing, heat, and lyophilization. These polymers are non‐toxic, which enables their utilization at high concentrations and eliminates the requirement for removal prior to administration. It is found that their unique topology contributes to the high hydration. These excipients are anticipated to create new prospects in biotechnology, food science, and cryopreservation. [ABSTRACT FROM AUTHOR]

[Display omitted] The construction of supramolecular aerogels still faces great challenges. Herein, we present a novel bio-based supramolecular aerogel derived from G-Quadruplex self-assembly of guanosine (G), boric acid (B) and sodium alginate (SA) and the obtained GBS aerogels exhibit superior flame-retardant and thermal insulating properties. The entire process involves environmentally friendly aqueous solvents and freeze-drying. Benefiting from the supramolecular self-assembly and interpenetrating dual network structures, GBS aerogels exhibit unique structures and sufficient self-supporting capabilities. The resulting GBS aerogels exhibit overall low densities (36.5–52.4 mg/cm3), and high porosities (>95 %). Moreover, GBS aerogels also illustrate excellent flame retardant and thermal insulating properties. With an oxygen index of 47.0–51.1 %, it can easily achieve a V-0 rating and low heat, smoke release during combustion. This work demonstrates the preparation of intrinsic flame-retardant aerogels derived from supramolecular self-assembly and dual cross-linking strategies, and is expected to provide an idea for the realization and application of novel supramolecular aerogel materials. [ABSTRACT FROM AUTHOR]

Highlights This study introduces an innovative technique for the fabrication of copper‐based polytetrafluoroethylene (PTFE)/graphite self‐lubricating composites. By harnessing the exceptional capabilities of selective laser sintering (SLS), we efficiently create three‐dimensional, continuous, and porous graphite preforms. Following this, the composite is formed through a combination of electroplating and vacuum extrusion methods. Subsequently, PTFE was vacuum impregnated into the microporous structure of the graphite preforms, and the composites were obtained through freeze‐drying, plasticizing, and machining processes. The resulting copper‐based PTFE/graphite self‐lubricating composites exhibit an exceptional blend of properties. Notably, there is a significant reduction in the average coefficient of friction, dropping from 0.14 to 0.02, and a marked decrease in the wear rate, from 1.358 × 10−5 to 1.109 × 10−5 mm3/N·m, as compared to graphite as a standalone lubricant. This represents a substantial improvement in performance, underscoring the effectiveness of the proposed fabrication method. The porous graphite with controllable shape distribution was prepared. Surface copper plating improves surface bonding. Controllable copper matrix composites with double lubricant were prepared. The average friction coefficient is as low as 0.02. [ABSTRACT FROM AUTHOR]

Yersinia pestis, the causative agent of plague, is a highly virulent bacterium that poses a significant threat to human health. Preserving this bacterium in a viable state is crucial for research and diagnostic purposes. This paper presents and evaluates a simple lyophilization protocol for the long-term storage of Y. pestis strains from Fiocruz-CYP, aiming to explore its impact on viability and long-term stability, while replacing the currently used methodologies. The lyophilization tests were conducted using the non-virulent Y. pestis strain EV76, subjected to the lyophilization process under vacuum conditions. Viability assessment was performed to evaluate the effects of lyophilization and storage conditions on Y. pestis under multiple temperature conditions (− 80 °C, − 20 °C, 4–8 °C and room temperature). The lyophilization protocol employed in this study consistently demonstrated its efficacy in maintaining high viability rates for Y. pestis samples in a up to one year follow-up. The storage temperature that consistently exhibited the highest recovery rates was − 80 °C, followed by − 20 °C and 4–8 °C. Microscopic analysis of the post-lyophilized cultures revealed preserved morphological features, consistent with viable bacteria. The high viability rates observed in the preserved samples indicate the successful preservation of Y. pestis using this protocol. Overall, the presented lyophilization protocol provides a valuable tool for the long-term storage of Y. pestis, offering stability, viability, and functionality. By refining the currently used methods of lyophilization, this protocol can improve long-term preservation for Y. pestis strains collections, facilitating research efforts, diagnostic procedures, and the development of preventive and therapeutic strategies against plague. [ABSTRACT FROM AUTHOR]

AbstractStarch-based foods have a large consumer base worldwide. It is known that the quality of freeze-dried starch-based products is subject to deterioration during the production process. The present study was unprecedented carried out to examine the effects of freeze-drying on the cross-linking between components of gelatinized starch-based system. The results showed that the retrogradation of starch in the process of dehydration, the weakening of the binding capacity between the substrate and water of the freeze-dried product and the weakening of the interaction strength between the components of the product were the key mechanisms leading to the quality deterioration of the wheat starch-based conditioned food during the freeze-drying. The addition of lipid and protein can inhibit starch retrogradation during freeze-drying, and the inhibition effect of oil is better. However, the intervention of oil and fat will cause dehydrated starch to re-adsorb the melted oil/water mixture during the freeze-drying process, resulting in the deterioration of product quality. The intervention of protein will improve the binding ability of freeze-dried wheat starch-based product matrix to water. In the ternary system, the intervention of protein will weaken the inhibition effect of lipid on retrogradation of starch in the freeze-drying process. In addition, the lower drying temperature will lead to the decrease of the interaction strength between the components of ternary mixed system. Avoiding the melting of frozen materials during drying is the key control point to improve the quality of freeze-dried wheat starch-based products. [ABSTRACT FROM AUTHOR]

Kratom (Mitragyna speciosa) is a psychotropic tropical plant that is used as a traditional remedy in Southeast Asia. It has many medicinal properties and has great potential for clinical applications. Mitragynine and 7-hydroxymitragynine (7-OH) are the important pharmacologically active compounds found in kratom with mitragynine as the major alkaloid found in the leaf. We report the development and validation of a high-performance liquid chromatography-photodiode array method for the determination and quantification of mitragynine from M. speciosa fresh leaf extract. Fresh leaf samples were cryogenically ground and freeze-dried before methanol extraction. Gradient elution was conducted using acetonitrile and ammonium bicarbonate buffer (pH 9.5) at a flow rate of 1 mL min-1. Chromatogram separation was achieved using Kinetex EVO C18 column in a duration of 25 min with MG eluted at 15.75 min. The calibration curves were in a linear relationship with determination coefficients (R2) = 0.99. Mitragynine quantification was calculated based on the calibration curve equation. The precision value (RSD) was less than 2% and accuracy range from 93%-100%. The values for limit of detection (LOD) and limit of quantification (LOQ) were 0.67 µg mL-1 and 1.51 µg mL-1, respectively. This method has been validated and found suitable for the quantification of mitragynine in fresh leaf. We found that freeze-drying during sample preparation from fresh leaf yielded more reliable mitragynine quantification, compared with that of conventional oven-drying method. [ABSTRACT FROM AUTHOR]

Glass vials with silicone stoppers are commonly used for pharmaceutical freeze-drying. Vials are partially stoppered before lyophilization to prevent contamination but introduce resistance to vapor flow through a small aperture. A Computational Fluid Dynamics (CFD) analysis using Comsol Multiphysics assessed mass transport resistance with different stopper geometries. Three case studies, representing conventional batch freeze-drying, continuous freeze-drying, and low-fill-volume drug products, were simulated, comparing stopper effects on process variables. While stoppers minimally influenced conventional freeze-drying, they significantly affected low-fill volume formulations. The study emphasizes the impact of stopper positioning on batch heterogeneity, especially when monitoring vials with thermocouples to infer product resistance. Heightened attention is essential in this regard. [ABSTRACT FROM AUTHOR]

The flesh oil content (OC) is a crucial commercial indicator of avocado maturity and directly correlates with its nutritional quality. To meet export standards and optimize edible characteristics, avocados must be harvested at the appropriate stage of physiological maturity. The significant variability in OC during maturation, without any external morphological indicators, poses a longstanding challenge. Currently, harvesting maturity is optimized through time-consuming, destructive laboratory methods like freeze-drying and chemical extraction, which use representative samples to estimate the maturity of entire orchards. In this study, for the first time, we employed fluorescence imaging of avocado skin using 365-nm UV polarized light excitation to estimate the OC in the 'Bacon' avocado cultivar. We developed a surface fluorescence index that strongly correlates with OC, achieving correlation coefficients up to − 0.91. Our non-destructive and rapid approach achieved a cross-validation accuracy with an R2 value of 0.81, enabling the classification of avocados with low and high OC. This pioneering method shows considerable potential for further improvement and refinement. This study lays the groundwork for developing a portable, cost-effective, and real-time method for non-destructive in situ monitoring of avocado OC in the field and its integration into large-scale post-harvest grading systems. [ABSTRACT FROM AUTHOR]

Introduction: Butterfly pea (Clitoria ternatea) flowers are rich in nutrients and anthocyanin, which contributes to their antioxidant properties. The utilisation of the natural blue colour of butterfly pea flowers as a substitute for synthetic colouring agents could add functional value to food products. Accordingly, this study was conducted to develop an instant blue drink from butterfly pea flowers and analyse its physicochemical properties and storage stability on the antioxidant activity. Materials and methods: The obtained extract was formulated with 12.3% xylitol and 0.03% citric acid and freeze-dried. The physicochemical including bulk density, colour, pH, nutritional analysis, mineral content and antioxidant properties of the instant blue drink were analysed. The antioxidant activity of the instant blue drink was evaluated after 30 days at four storage conditions as below: condition A = stored at 4°C with presence of light, condition B = stored at 4°C with absence of light, condition C = stored at 23°C with presence of light and condition D = stored at 23°C with absence of light. Results: The colour of the instant blue drink was mainly affected by the dilution of the extract and the addition of citric acid, which also subsequently changed the pH of the drink. Compared with fresh butterfly pea flowers, the instant blue drink showed value more than 50% in L*, showing the sample lighter in color. The instant blue drink had positive a* value and negative b* corresponds with blue. The moisture, ash, fat, protein and crude fibre percentage compositions of the instant blue drink were 1.46%, 0.13%, 1.94%, 0.89% and 0.43%, respectively and has the least amount of minerals. The antioxidant activity of the instant blue drink was significantly reduced (p< 0.05) by high temperature and present of light during storage. Conclusion: The optimal storage condition of instant blue drink is at 4 °C with the absence of light. Hence, instant blue drink from butterfly pea flowers (Clitoria ternatea) were successfully developed by using freeze-drying method. [ABSTRACT FROM AUTHOR]

Background: Proteins are commonly used in the healthcare industry to treat various health conditions, and most proteins are sensitive to physical and chemical changes. Lyophilization, also known as freeze-drying, involves sublimating water in the form of ice from a substance at low pressure, forming a freeze-dried powder that increases its shelf life. Extreme pressure and varying temperatures in the freeze-drying process may damage the protein's structural integrity. Lyoprotectants are commonly used to protect protein conformations. It is important to choose a suitable lyoprotectant to ensure optimal effectiveness. Method: Twenty articles screened from Scopus, Web of Science, and PubMed were included in this review that discussed potential lyoprotectants and their effectiveness with different protein models. Results: Lyoprotectants were categorized into sugars, polyols, surfactants, and amino acids. Lyoprotectants can exhibit significant protective effects towards proteins, either singularly or in combination with another lyoprotectant. They exert various interactions with the protein to stabilize it, such as hydrogen bonding, hydrophobic interactions, electrostatic interactions, and osmoprotection. Conclusions: This review concludes that disaccharides are the most effective lyoprotectants, while other groups of lyoprotectants are best used in combination with other lyoprotectants. [ABSTRACT FROM AUTHOR]

Background: It is well known that periodontitis affects the gums and surrounding connective tissue. The chronic inflammatory response induced by bacteria in the gingival tissue leads to the loss of the collagen connection between the tooth and the bone and ultimately to bone loss. Methods: In this context, the aim of this research was the obtaining and characterization of a drug release supports in the form of sponges based on collagen, hyaluronic acid as a support and metronidazole as an antibiotic for the treatment of periodontitis. The sponges were characterized by FT-IR spectroscopy, water uptake, contact angle, SEM microscopy, in vitro metronidazole release analysis from sponges and data modeling. Results: The results showed that all the sponges had a porous structure with interconnected pores, the pore sizes being influenced by hyaluronic acid and metronidazole; the spongious structure became much more dense for samples with metronidazole content. All metronidazole-loaded sponges showed good surface wettability and an adequate swelling capacity for a suitable antimicrobial release at the periodontal pocket. The porous structures allow a controlled release, fast in the first hour, essential to control the initial microbial load at the periodontal level, which continues slowly in the following hours to ensure an effective treatment of periodontitis. Conclusions: Correlating all physical–chemical and bio-pharmaceutical results obtained, a promising solution for periodontitis treatment could be a met-ronidazole–collagen–hyaluronic system consisting of 1% collagen, 1.5% metronidazole and 0.8% hyaluronic acid, and in vitro and in vivo tests are recommended to continue studies. [ABSTRACT FROM AUTHOR]

Background/Objectives: This study investigates the development of 3D chitosan-x-cobalt ferrite scaffolds (x = 5, 7.5, and 10 wt%) with interconnected porosity for potential biomedical applications. The objective was to evaluate the effects of magnetic particle incorporation on the scaffolds' structural, mechanical, magnetic, and biological properties, specifically focusing on their biocompatibility and antimicrobial performance. Methods: Scaffolds were synthesized using freeze-drying, while cobalt ferrite nanoparticles were produced via a pilot-scale combustion reaction. The scaffolds were characterized for their physical and chemical properties, including porosity, swelling, and mechanical strength. Hydrophilicity was assessed through contact angle measurements. Antimicrobial efficacy was evaluated using time kill kinetics and agar diffusion assays, and biocompatibility was confirmed through cytotoxicity tests. Results: The incorporation of cobalt ferrite increased magnetic responsiveness, altered porosity profiles, and influenced swelling, biodegradation, and compressive strength, with a maximum value of 87 kPa at 7.5 wt% ferrite content. The scaffolds maintained non-toxicity and demonstrated bactericidal activity. The optimal concentration for achieving a balance between structural integrity and biological performance was found at 7.5 wt% cobalt ferrite. Conclusions: These findings suggest that magnetic chitosan-cobalt ferrite scaffolds possess significant potential for use in biomedical applications, including tissue regeneration and advanced healing therapies. The incorporation of magnetic properties enhances both the structural and biological functionalities, presenting promising opportunities for innovative therapeutic approaches in reconstructive procedures. [ABSTRACT FROM AUTHOR]

The success of mRNA vaccines against SARS-CoV-2 has prompted interest in mRNA-based pharmaceuticals due to their rapid production, adaptability, and safety. Despite these advantages, the inherent instability of mRNA and its rapid degradation in vivo underscores the need for an encapsulation system for the administration and delivery of RNA-based therapeutics. Lipid nanoparticles (LNPs) have proven the most robust and safest option for in vivo applications. However, the mid- to long-term storage of mRNA-LNPs still requires sub-zero temperatures along the entire chain of supply, highlighting the need to develop alternatives to improve mRNA vaccine stability under non-freezing conditions to facilitate logistics and distribution. Lyophilization presents itself as an effective alternative to prolong the shelf life of mRNA vaccines under refrigeration conditions, although a complex optimization of the process parameters is needed to maintain the integrity of the mRNA-LNPs. Recent studies have demonstrated the feasibility of freeze-drying LNPs, showing that lyophilized mRNA-LNPs retain activity and stability. However, long-term functional data remain limited. Herein, we focus on obtaining an optimized lyophilizable mRNA-LNP formulation through the careful selection of an optimal buffer and cryoprotectant and by tuning freeze-drying parameters. The results demonstrate that our optimized lyophilization process maintains LNP characteristics and functionality for over a year at refrigerated temperatures, offering a viable solution to the logistical hurdles of mRNA vaccine distribution. [ABSTRACT FROM AUTHOR]

Controlled delivery of proteins and other biologics is a growing medium of therapy for diseases previously untreatable. Here we report a self-assembling, tunable vesicle for the controlled delivery of growth factors and cytokines. Coacervate made of heparin and a biocompatible polycation, PEAD, forms the core of the vesicle; lipids form the membrane of the vesicle. We call this vesicle lipocoacervate (LipCo), which has a high affinity for growth factors and cytokines due to heparin. LipCo is a tunable protein delivery vehicle. The vesicle size is controlled through polymer and salt concentrations. Membrane functionalization enables potential for targeting capabilities with long-term storage through lyophilization. Importantly, the controlled delivery of therapeutics also avoids high toxicity to treated cells in vitro. Here we report on these key principles of LipCo assembly and design. [ABSTRACT FROM AUTHOR]

This paper aimed to evaluate the effects of different preparation parameters, including agitation speed, agitation time, and chilling temperature, on the structural and mechanical properties of a novel gelatin/elastin/sodium hyaluronate tissue engineering scaffold, recently developed by our research group. Fabricated using a combination of foaming and freeze-drying techniques, the scaffolds were assessed to understand how these parameters influence their morphology, internal microstructure, porosity, mechanical properties, and degradation behavior. The fabrication process used in this study involved preparing a homogeneous aqueous solution containing 8% gelatin, 2% elastin, and 0.5% sodium hyaluronate (w/v), which was then subjected to mechanical agitation at speeds of 500, 1000, and 1500 rpm for durations of 5, 15, and 25 min. This mixture was subsequently frozen at −20 °C and −80 °C, followed by freeze-drying and cross-linking. Morphological analyses using laser microscopy and scanning electron microscopy (SEM) demonstrated that the scaffolds had pore sizes ranging from 100 to 300 µm, which are conducive to effective cell interaction and tissue regeneration. This confirmed the efficacy of the combined foaming and freeze-drying method in creating highly interconnected porous structures. Our findings indicated that chilling temperature slightly influenced pore size. In contrast, higher agitation speeds and longer duration times led to increased porosity and degradation rate but decreased modulus. Mathematical estimators were developed for the porosity and compressive modulus of the scaffolds by statistical analysis of the preparation parameters. The estimators were validated experimentally, with the error between estimated and experimental values being less than 6% for porosity and less than 21% for compressive modulus. [ABSTRACT FROM AUTHOR]

Gels, specifically hydrogels and aerogels, have emerged as versatile materials with profound implications in pharmaceutical sciences. This comprehensive review looks into detail at hydrogels and aerogels, providing a general introduction to gels as a foundation. The paper is then divided into distinct sections for hydrogels and aerogels, each delving into their unique formulations, advantages, disadvantages, and applications. In the realm of hydrogels, we scrutinize the intricacies of formulation, highlighting the versatile advantages they offer. Conversely, potential limitations are explored, paving the way for a detailed discussion on their applications, with a specific focus on their role in antimicrobial applications. Shifting focus to aerogels, a thorough overview is presented, followed by a detailed explanation of the complex formulation process involving sol–gel chemistry; aging; solvent exchange; and drying techniques, including freeze drying, supercritical drying, and ambient-pressure drying (APD). The intricacies of drug loading and release from aerogels are addressed, providing insights into their pharmaceutical potential. The advantages and disadvantages of aerogels are examined, accompanied by an exploration of their applications, with a specific emphasis on antimicrobial uses. The review culminates in a comparative analysis, juxtaposing the advantages and disadvantages of hydrogels and aerogels. Furthermore, the current research and development trends in the applications of these gels in pharmaceutical sciences are discussed, providing a holistic view of their potential and impact. This review serves as a comprehensive guide for researchers, practitioners, and enthusiasts, seeking a deeper understanding of the distinctive attributes and applications of hydrogels and aerogels in the ever-evolving research concerning pharmaceutical sciences. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Condiment is the property of China Condiment and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: This study was conceived with the aim of translating the experience and knowledge of the research group into the design and creation of multi-active phytocomplex cocktails from lyophilised winery by-products (Grape Pomace—GP) and weeds (Sambucus ebulus L., Dwarf Elder—DE). Methods: Quantification of bioactive molecules was performed by high-performance liquid chromatography (HPLC) method. Results: In the extract obtained from lyophilised GP, the most dominant component that was quantified was petunidin-3-glucoside. Prominent compounds that were quantified in DE extract were cyanidin derivatives. The total number of microorganisms in lyophilisates is low, but some of them still survive lyophilisation. Antibacterial activity was determined by microdilution, the minimum inhibitory concentration (MIC) of the tested bacteria ranged from 0.78 mg/mL to 25.00 mg/mL. Antibacterial susceptibility testing (AST) revealed that Klebsiella spp. and Acinetobacter baumannii complex are extensively drug-resistant (XDR). Conclusions: The GP + DE cocktail showed very strong AB power against both tested XDR bacteria. The total phenolic content and antioxidative effect (determined spectrophotometrically) indicate their linear correlation. [ABSTRACT FROM AUTHOR]

Fenbendazole is an antiparasitic drug widely used in veterinary medicine to treat parasitic infections caused in animals like cattle, horses, sheep, and dogs. Recently, it has been repositioned as a potential alternative for cancer treatment. However, it is a highly hydrophobic molecule (0.9 ug/mL), which can compromise its dissolution rate and absorption. Thus, this work aimed to apply a nanotechnological approach to improve drug solubility and dissolution performance. Fenbendazole nanoparticles stabilized by different poloxamers were obtained by lyophilization without cryoprotectants. The behavior of the drug in the solid state was analyzed by X-ray diffractometry, differential scanning calorimetry, and infrared spectroscopy. The nanosystems were also evaluated for solubility and dissolution rate. A long-term stability evaluation was performed for three years at room temperature. The yields of the lyophilization ranged between 75 and 81% for each lot. The nanoparticles showed a submicron size (< 340 nm) and a low polydispersity depending on the stabilizer. The physicochemical properties of the prepared systems indicated a remarkable amorphization of the drug, which influenced its solubility and dissolution performance. The drug dissolution from both the fresh and aged nanosystems was significantly higher than that of the raw drug. In particular, nanoparticles prepared with poloxamer 407 showed no significant modifications in their particle size in three years of storage. Physical stability studies indicated that the obtained systems prepared with P188, P237, and P407 suffered certain recrystallization during long storage at 25 °C. These findings confirm that selected poloxamers exhibited an important effect in formulating fenbendazole nanosystems with improved dissolution. [ABSTRACT FROM AUTHOR]

Wasted produce is a pertinent issue in agriculture, with billions of tons of produce going to waste even before it hits markets. Specifically, in Sub-Saharan Africa (SSA), nearly half of all produce is lost before market. To combat this, the Agricycle® passive solar drier was designed to provide a cost-effective method of drying fruit for preservation. Using a psychrometric chamber to simulate the SSA environment, vitamin C, total phenolic contents, and iron tests were conducted, along with microbial content determination, water content determination, dissolved solids testing, and color and microstructure analyses to validate passive solar drying, comparing the results to freeze-dried samples. Nutritional contents were comparable between fresh, freeze-dried, and solar-dried samples, with a loss in vitamin C (statistically significant), total phenolic contents, and dissolved solids during solar drying. The microbial analysis for solar-dried samples was below standard limits, and the water content in the solar-dried samples was ~10% w.b. (<20% w.b.) compared to ~3% w.b. of the freeze-dried samples. Although having comparable vitamin C, total phenolic contents, and iron values, freeze-dried and solar dried samples showed very different colors and microstructures based on colorimetry and SEM imaging. In conclusion, the Agricycle® passive solar drier is a promising alternative approach for food preservation. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AbstractThis study presents a pore network (PN) model with transient heat transfer and quasi-steady transitional vapor transport that is for the first time applied to irregular porous structures that are obtained by reconstruction of X-ray tomography image data. In contrast to previous studies, the irregular pores are not approximated by spheres but implemented in their original shape. Secondly, instead of assuming cylindrical throats as pore connections, the actual distance between pore centers as well as the pore cross sections are used for the computation of the vapor transport coefficient. The control volume elements of the computational model are matched with the cells obtained by Voronoi tessellation. The improvements have clear advantages over former approaches where the reconstructed void space is usually strongly simplified by balls and sticks confined in a regular lattice structure. A freeze-dried sample of maltodextrin DE12 with 20% (w/w) solid content is used for benchmarking the new methodology. Its morphological and thermal properties are determined by the novel PN model. The simulation results of primary freeze-drying (FD) are compared to reference cases in two ways. First, the differences in heat and mass transfer kinetics as compared to regular PNs are emphasized. Secondly, the PN simulation results are confronted with a simple literature model that neglects pore size distribution (PSD) and transient heat transfer. It is shown that already in small domains with relatively narrow PSD, the variation of the mass transfer coefficient affects the computed sublimation fluxes and yields a significant deviation from the simpler literature model. Moreover, it is revealed in this study that the structure has a significant impact on the sublimation front temperature. This is demonstrated by the comparison of FD in the irregular PN to a regular PN with almost identical PSD but different porosity. The development, verification, and benchmarking of the new PN model can be seen as an important step for studies of the structure dependence of FD. [ABSTRACT FROM AUTHOR]

As space exploration advances, the demand for lightweight, multifunctional materials has substantially grown. Hybrid two‐dimensional (2D) material foams of different boron nitride nanoplatelets (BNNP)‐to‐graphene nanoplatelets (GNP) ratios are developed, which exhibit dual functionality: neutron radiation shields and strain sensors. The relationship between the composition, processing, microstructure, and their resultant neutron shielding and strain‐sensing properties are investigated. The hybrid foam properties can be finely tuned by adjusting BNNP:GNP compositions (1:0, 3:1, 1:1, 1:3, and 0:1). In terms of neutron radiation shielding, the mass absorption coefficient of hybrid foams increased with added BNNP, peaking at 14.9 cm2 g−1 for a pure BNNP foam. This mass absorption coefficient is 1.6 times that of pure GNP foams and almost 75 times that of aluminum. The radiation shielding properties are simulated using Geant4, a Monte Carlo‐based platform, and the simulations displayed a similar trend to the experimental results. The strain‐sensing properties of hybrid foams, measured by their gauge factor, exhibited exponential growth with rising GNP concentrations. Starting from the electrically insulating BNNP foam, the gauge factor increased to 53.4 with 25% GNP concentration and reached 201.8 for pure GNP foams. These findings highlight the versatility of the hybrid 2D material foams for space exploration. [ABSTRACT FROM AUTHOR]

Application of tissue-engineered bones (TEBs) is hindered by challenges associated with incorporated viable cells. Previously, we employed freeze-drying techniques on TEBs to devitalize mesenchymal stem cells (MSCs) while preserving functional proteins, yielding functional proteins-based TEBs (FP-TEBs). Here, we aimed to elucidate their in vivo angiogenic and osteogenic capabilities and the mechanisms. qPCR arrays were employed to evaluate chemokines and receptors governing EC migration. Identified C-X-C chemokine receptors (CXCRs) were substantiated using shRNAs, and the pivotal role of CXCR2 was validated via conditional knockout mice. Finally, signaling molecules downstream of CXCR2 were identified. Additionally, Src, MAP4K4, and p38 MAPK were identified indispensable for CXCR2 function. Further investigations revealed that regulation of p38 MAPK by Src was mediated by MAP4K4. In conclusion, FP-TEBs promoted EC migration, angiogenesis, and osteogenesis via the CXCR2-Src-Map4k4-p38 MAPK axis. [ABSTRACT FROM AUTHOR]

Atmospheric freeze drying (AFD) has removed the vacuum-creating equipment to reduce energy consumption while maintaining the product quality, compared with traditional vacuum freeze drying. However, the increasing pressure can lead to a significant increase in the drying time. Water vapor diffusion can then be obstructed to limit the practical implementation. Therefore, it is essential to understand the controlling variables in the heat and mass transfer of the AFD process. The purpose of this study was to quantitatively investigate the effects of drying conditions on the drying time, drying rate, and heat/mass transfer resistances. Among them, the thermal/mass transfer resistances were analyzed to explore the drying mechanism during atmospheric freeze drying. The mathematical model of the lamellar product during AFD was proposed to consider the external flow. The Navier–Stokes equations were introduced for the external pressure field into the adsorption-sublimation model. The model was solved and validated using COMSOL Multiphysics 6.1. The accuracy was verified by the ±10% relative deviation of drying time between the model and experimental data. Drying kinetics were calculated under different conditions (product thickness 3-11 mm, equivalent pore diameter 2.0-6.0 μm, dry air temperature 263.15-273.15 K, dry air velocity 1.0-3.0 m/s). The results showed that the drying rate and time decreased with the decrease in product thickness and the increase in air temperature. But there was no outstanding influence of equivalent pore diameter and air velocity on the drying rate and time. Unlike the three stages of standard drying, only the initial accelerating and falling rate stages were observed in the AFD procedure. The absence of the constant rate stage was attributed to the assumption of material homogeneity and low moisture of the top surface. At the same time, the post-processing was carried out to calculate the external heat and mass transfer resistances between the external flow and the product, together with the internal heat and mass transfer resistances between the top surface of the product and the sublimation interface. The external heat/mass transfer resistances decreased, while the internal heat/mass transfer resistances increased linearly from zero, with the decreasing moisture content. The internal heat/mass transfer resistances exceeded the external heat/mass transfer resistances at a critical moisture content, indicating the transition from external heat/mass transfer control to internal heat/mass transfer control during AFD. There was some effect of condition parameters on the transfer resistances. The equivalent pore diameter shared no significant effect on either internal or external resistances. While the temperature increased to bring about a slight decrease in the internal heat-transfer resistance. By contrast, there was a decrease in the external and internal heat transfer resistance, due to the increasing air velocity. Especially, the reduction of product thickness was a significant contribution to the decrease of both internal and external transfer resistance. Therefore, small thickness product was more suitable for the AFD process, according to the drying kinetics and heat/mass transfer. It was expected to simultaneously realize both the reduction in the drying time and energy consumption. The findings can provide guidance to optimize the process parameters during atmospheric freeze-drying. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Facilitating the healing process of injured anterior cruciate ligament (ACL) tissue is crucial for patients to safely return to sports. Stem cell derived exosomes have shown positive effects on enhancing the regeneration of injured tendons/ligaments. However, clinical application of exosomes in terms of storage and pre-assembly is challenging. We hypothesized that lyophilized exosomes derived from human umbilical cord stem cells (hUSC-EX) could enhance the cell activity of chronically injured ACL cells. Materials and methods: We harvested the 8 weeks injured ACL cells from rabbit under IACUC (No. 110232) approval. The studied exosomes were purified from the culture medium of human umbilical cord stem cells (IRB approval No. A202205014), lyophilized to store, and hydrated for use. We compared exosome treated cells with non-exosome treated cells (control group) from the same rabbits. We examined the cell viability, proliferation, migration capability and gene expression of type I and III collagen, TGFβ, VEGF, and tenogenesis in the 8 weeks injured ACL cells after hUSC-EX treatment. Results: After hydration, the average size of hUSC-EX was 84.5 ± 70.6 nm, and the cells tested positive for the Alix, TSG101, CD9, CD63, and CD81 proteins but negative for the α-Tubulin protein. After 24 h of treatment, hUSC-EX significantly improved the cell viability, proliferation and migration capability of 8 weeks injured ACL cells compared to that of no exosome treatment group. In addition, the expression of collagen synthesis, TGFβ, VEGF, and tenogenesis gene were all significantly increased in the 8 weeks injured ACL cells after 24 h hUSC-EX delivery. Discussion: Lyophilized exosomes are easily stored and readily usable after hydration, thereby preserving their characteristic properties. Treatment with lyophilized hUSC-EX improved the activity and gene expression of 8 weeks injured ACL cells. Conclusion: Lyophilized hUSC-EX preserve the characteristics of exosomes and can improve chronically injured (8 weeks) ACL cells. Lyophilized hUSC-EX could serve as effective and safe biomaterials that are ready to use at room temperature to enhance cell activity in patients with partial ACL tears and after remnant preservation ACL reconstruction. [ABSTRACT FROM AUTHOR]

Microfluidic flow reactors functionalized with immobilized human liver microsomes (HLM chips) represent a powerful tool for drug discovery and development by enabling mechanism-based enzyme inhibition studies under flow-through conditions. Additionally, HLM chips may be exploited in streamlined production of human drug metabolites for subsequent microfluidic in vitro organ models or as metabolite standards for drug safety assessment. However, the limited shelf life of the biofunctionalized microreactors generally poses a major barrier to their commercial adaptation in terms of both storage and shipping. The shelf life of the HLM chips in the wetted state is ca. 2–3 weeks only and requires cold storage at 4 °C. In this study, we developed a freeze-drying method for lyophilization of HLMs that are readily immobilized inside microfluidic pillar arrays made from off-stoichiometric thiol–ene polymer. The success of lyophilization was evaluated by monitoring the cytochrome P450 and UDP-glucuronosyltransferase enzyme activities of rehydrated HLMs for several months post-freeze-drying. By adapting the freeze-drying protocol, the HLM chips could be stored at room temperature (protected from light and moisture) for at least 9 months (n = 2 independent batches) and up to 16 months at best, with recovered enzyme activities within 60–120% of the non-freeze-dried control chips. This is a major improvement over the cold-storage requirement and the limited shelf life of the non-freeze-dried HLM chips, which can significantly ease the design of experiments, decrease energy consumption during storage, and reduce the shipping costs with a view to commercial adaptation. [ABSTRACT FROM AUTHOR]