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Developing spray-freeze-dried particles containing a hyaluronic acid-coated liposome–protamine–DNA complex for pulmonary inhalation

Developing spray-freeze-dried particles containing a hyaluronic acid-coated liposome–protamine–DNA complex for pulmonary inhalation

Kaori Fukushige, Tatsuaki Tagami, Munekazu Naito, Eiichi Goto, Shuichi Hirai, Naoyuki Hatayama, Hiroki Yokota, Takao Yasui, Yoshinobu Baba, Tetsuya Ozeki

Abstract

The liposome–protamine–DNA complex (LPD) is an effective cationic carrier of various nucleic acid constructs such as plasmid DNA and small interfering RNA (siRNA). Hyaluronic acid coated on LPD (LPDH) reduces cytotoxicity and maintains the silencing effect of LPD-encapsulated siRNA. Herein, we aim to develop LPD- or LPDH-containing spray-freeze-dried particles (SFDPs) for therapeutic delivery of siRNA to the lungs. LPD- or LPDH-containing SFDPs (LPD- or LPDH-SFDPs) were synthesized and their structure and function as gene carriers were evaluated using physical and biological methods. The particle size of LPDH, but not of LPD, was constant after re-dispersal from the SFDPs and the amount of siRNA encapsulated in LPDH was larger than that in LPD after re-dispersal from the SFDPs. The in vitro pulmonary inhalation properties of LPDH-SFDPs and LPD-SFDPs were almost the same. The cytotoxicity of LPDH-SFDPs in human umbilical vein endothelial cells (HUVEC) was greatly decreased compared with that of LPD-SFDPs. In addition, Bcl-2 siRNA in LPDH-SFDPs had a significant gene silencing effect in human lung cancer cells (A549), whereas Bcl-2 siRNA in LPD-SFDPs had little effect. These results indicate that compared with LPD, LPDH is more useful for developing SFDPs for siRNA pulmonary inhalation.

Influences of drying methods on the structural, physicochemical and antioxidant properties of exopolysaccharide from Lactobacillus helveticus MB2-1

Influences of drying methods on the structural, physicochemical and antioxidant properties of exopolysaccharide from Lactobacillus helveticus MB2-1

Luyao Xiao, Yingying Li, Juanjuan Tian, Jianzhong Zhou, Qian Xu, Li Feng, Xin Rui, Xia Fan, Qiuqin Zhang, Xiaohong Chen, Mingsheng Dong, Wei Li

Abstract

In this study, in order to evaluate influences of different drying methods on the structural characteristics, physicochemical properties and antioxidant activities of exopolysaccharides (EPS) from Lactobacillus helveticus MB2-1, three drying methods, including spray-drying (SD), freeze-drying (FD) and spray freeze-drying (SFD), were applied to dry EPS. Results showed that different drying procedures had no significant influence on the primary structure and constituent monosaccharides of EPSs. However, the surface morphology of the three dried EPSs varied greatly in size and shape due to different drying processes. Among three dried EPSs, the particle size distribution of spray freeze-dried EPS (SF-EPS) was relatively narrower and uniform. Additionally, SF-EPS behaved better apparent viscosity and emulsifying property than spray-dried EPS (S-EPS) and freeze-dried EPS (F-EPS). SF-EPS exhibited stronger antioxidant activities when compared with S-EPS and F-EPS, according to the results of scavenging activities on different radicals and chelating activity on ferrous ion. Overall, SFD was the appropriate method for industrial production of EPS from Lactobacillus helveticus MB2-1 with better physicochemical properties and antioxidant activities.

Spray-freeze-drying of coffee

Spray-freeze-drying of coffee

S. Padma Ishwarya, C. Anandharamakrishnan

Abstract

The suitability of Spray-Freeze-Drying (SFD) technique for soluble coffee processing was evaluated. The resultant product characteristics were compared against its spray-dried (SD) and freeze-dried (FD) counterparts. SFD and FD coffee powders exhibited a comparable aroma profile as indicated by the electronic nose analysis. SFD resulted in higher volatile retention (93%) than FD (77%) and SD (57%), as inferred from GC–MS analysis. SFD coffee showed instantaneous solubility due to its highly porous nature as observed in morphology studies. SFD coffee depicted monomodal particle size distribution with mean diameter (91.1 μm) ranging between SD (50.41 μm) and FD (636.8 μm) particles. SFD resulted in higher free (ρB, 0.612 g/mL) and tapped (ρT, 0.679 g/mL) bulk densities of the product against SD (ρB: 0.328 g/mL; ρT: 0.388 g/mL) and FD (ρB: 0.345 g/mL; ρT: 0.361 g/mL). SFD coffee exhibited free flowing characteristics as indicated by its Hausner ratio (1.11) and Carr index (10%).

Keywords

Soluble coffee, Spray-Freeze-Drying, Volatile retention, Morphology, Bulk density, Tap density

Freeze Granulated Zeolites X and A for Biogas Upgrading

Freeze Granulated Zeolites X and A for Biogas Upgrading

Kritika Narang, Farid Akhtar

Abstract

Biogas is a potential renewable energy resource that can reduce the current energy dependency on fossil fuels. The major limitation of utilizing biogas fully in the various applications is the presence of a significant volume fraction of carbon dioxide in biogas. Here, we used adsorption-driven CO2 separation using the most prominent adsorbents, NaX (faujasite) and CaA (Linde Type A) zeolites. The NaX and CaA zeolites were structured into hierarchically porous granules using a low-cost freeze granulation technique to achieve better mass transfer kinetics. The freeze granulation processing parameters and the rheological properties of suspensions were optimized to obtain homogenous granules of NaX and CaA zeolites 2–3 mm in diameter with macroporosity of 77.9% and 68.6%, respectively. The NaX and CaA granules kept their individual morphologies, crystallinities with a CO2 uptake of 5.8 mmol/g and 4 mmol/g, respectively. The CO2 separation performance and the kinetic behavior were estimated by breakthrough experiments, where the NaX zeolite showed a 16% higher CO2 uptake rate than CaA granules with a high mass transfer coefficient, 1.3 m/s, compared to commercial granules, suggesting that freeze-granulated zeolites could be used to improve adsorption kinetics and reduce cycle time for biogas upgrading in the adsorption swing technology.

Keywords

freeze granulation, zeolite NaX, zeolite CaA, gas separation, carbon dioxide capture

Effect of encapsulation methods on the physicochemical properties and the stability of Lactobacillus plantarum (NCIM 2083) in synbiotic powders and in-vitro digestion conditions

Effect of encapsulation methods on the physicochemical properties and the stability of Lactobacillus plantarum (NCIM 2083) in synbiotic powders and in-vitro digestion conditions

K.S. Yoha, J.A. Moses, C. Anandharamakrishnan

Abstract

Encapsulation of probiotic bacteria requires precise control over a range of process parameters, all of which are technique-specific. The technology of encapsulation has received considerable attention in recent years, owing to the numerous ranges of benefits it offers, particularly in terms of quality retention, storage stability, and targeted delivery. In this research, spray-drying (SD) and spray-freeze-drying (SFD) techniques were used to encapsulate Lactobacillus plantarum (NCIM 2083). Fructo-oligosaccharide (FOS), whey protein (WP) and maltodextrin (MD) were used as encapsulating agents at different formulations. Changes in physicochemical properties were evaluated. FOS:WP:MD (2:0.5:0.5) gave higher encapsulation efficiencies of around 89.21% and 96.16% for SD and SFD, respectively. Probiotic stability was studied under simulated in-vitro digestion conditions and over the storage period of 60 days. SFD synbiotics showed better survivability during digestion; whereas, storage studies indicated around 0.95 fold increased retention of cell viability in SD synbiotics as compared to SFD.

Keywords

Synbiotics, Drying, Encapsulation, Microbial stability, Cell viability

Spray-freezing induced multidimensional morphology tuning of assembled spherical carbon for solar-driven steam generation

Spray-freezing induced multidimensional morphology tuning of assembled spherical carbon for solar-driven steam generation

Da Li, Ang Li, Yaxin Chen, Guanyu Chen, Xiaohong Chen, Dexu Zhang, Haitao Zhu, Imran Ahmed Samo, Huaihe Song

Abstract

Carbon materials have been extensively researched as solar absorbers in the field of solar steam generation (SSG) for their full spectrum absorption, non-biotoxicity, and excellent photothermal properties. In this work, we provide a general ice-templating method for obtaining multidimensional carbon materials controlled by regulating the surface tension during the phase separation of phenolic resin solution. Through spraying the atomized droplets into liquid nitrogen, freeze drying, and carbonization, a type of spherical carbon material assembled with carbon nanosheets with a thickness of about 3 nm can be obtained. With the enhancement of the surface tension by spray and the adjustment of the concentration of phenolic resin, a series of morphologies of carbon materials can be obtained from nanowires to nanosheets and further to spherical assemblies. In addition, an efficient SSG system was designed by combining the carbon material with polyurethane foam as matrix, notably showing good evaporation efficiency of 81.7% with a solar flux of 500 W/m2. This work provides a new idea for the morphology control of assembled carbon materials and has achieved excellent performance in the field of photothermal conversion.

Keywords

Hydroxypropyl beta cyclodextrin: a water-replacement agent or a surfactant upon spray freeze-drying of IgG with enhanced stability and aerosolization

Hydroxypropyl beta cyclodextrin: a water-replacement agent or a surfactant upon spray freeze-drying of IgG with enhanced stability and aerosolization

Shahriar Milani, Homa Faghihi, Abdolhosein Roulholamini Najafabadi, Mohsen Amini, Hamed Montazeri, Alireza Vatanara

Abstract

The great potential of hydroxypropyl beta-cyclodextrin (HPßCD), as a dried-protein stabilizer, has been attributed to various mechanisms namely water-replacement, vitrification and surfactant-like effects. Highlighting the best result in our previous study (weight ratio IgG: HPßCD of 1:0.4), herein we designed to evaluate the efficacy of upper (1:2) and lower (1:0.05) ratios of HPßCD in stabilization and aerosol properties of spray freeze-dried IgG. The protective effect of HPβCD, as measured by size exclusion chromatography (SEC-HPLC) was most pronounced at C3′ and C3″, IgG:trehalose:HPβCD ratios of 1:2:0.25 and 1:2:0.05 with aggregation rate constants of 0.46 ± 0.02 and 0.58 ± 0.01 (1/month), respectively. The secondary conformations were analyzed through Fourier transform infrared spectroscopy (FTIR) and all powders well-preserved with the lack of any visible fragments qualified through sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PPAGE). Scanning electron microscopy (SEM) and twin stage impinger (TSI) were employed to characterize the suitability of particles for further inhalation therapy of antibodies and the highest values of fine particle fraction (FPF) were achieved by C3′ and C3″, 56.43 and 48.12%. The powders produced at the current ratio 1:2:0.25 and 1:2:0.05 are superior to our previous examination with regards to manifesting lower aggregation and comparable FPF values.

Application of Spray Freeze Drying to Theophylline-Oxalic Acid Cocrystal Engineering for Inhaled Dry Powder Technology

Application of Spray Freeze Drying to Theophylline-Oxalic Acid Cocrystal Engineering for Inhaled Dry Powder Technology

Ryoma Tanaka, Yusuke Hattori, Makoto Otsuka, Kazuhide Ashizawa

Abstract

Spray freeze drying (SFD) produces suitable particles for the pharmaceutical formulation of dry powders used in dry powder inhalers (DPIs). However, SFD particles have large specific surface area and are partially made up of amorphous solids; this state is hygroscopic and would lead to changes in physicochemical properties by humidity when the particles are stored over the long-term or under high humidity conditions such as in the lungs. This study focused on the application of SFD with a cocrystal technique which can add humidity resistance to the active pharmaceutical ingredients (APIs), and the investigation of the physicochemical properties under high humidity conditions. Cocrystal samples containing theophylline anhydrate (THA) and oxalic acid (OXA) in a molar ratio of 2:1 were prepared by SFD. The crystalline structure, thermal behavior, solid-state, hygroscopicity, stability, and aerodynamic properties were evaluated. Simultaneous in situ measurement by near-infrared and Raman (NIR-Raman) spectroscopy was performed to analyze the humidification process. The SFD sample had a porous particle and an optimal aerodynamic particle size (3.03 μm) although the geometric particle diameter was 7.20 μm. In addition, the sample formed the THAOXA cocrystal with partial coamorphous. The hydration capacity and pseudopolymorphic transformation rate of the SFD sample were much lower than those of THA under conditions of 96.4% relative humidity and 40.0 °C temperature because of the cocrystal formation. The reasons were discussed based on the crystalline structure and energy. The SFD technology for cocrystallization would enable the pharmaceutical preparation of DPI products under environmentally friendly conditions.

Dense and homogeneous MOX fuel pellets manufactured using the freeze granulation route

Dense and homogeneous MOX fuel pellets manufactured using the freeze granulation route

F. La Lumia, L. Ramond, C. Pagnoux, P. Coste

Abstract

MOX fuels (UO2‐PuO2) are used in light water nuclear reactors of several countries and are also potential candidates for fast neutron reactors. Industrial MOX is currently manufactured by a dry‐route process, involving steps with fine powders. To reduce dusting, enhance MOX powder flow properties and decrease manufacturing scrap rate, a new wet‐route process is investigated: the freeze granulation of concentrated water‐based powder suspensions having optimized rheology and dispersion properties. Highly flowable, dustless and easy‐to‐press MOX granules have been elaborated. Sintering green compacts made of such granules gives highly dense and defect‐free pellets which have a very homogeneous U‐Pu spatial distribution, thus improving the fuel characteristics. Indeed, MOX fuels devoid of large Pu‐rich aggregates are thought to have a better behavior under irradiation in reactors by limiting/preventing the formation of the typical high burnup structure.

Rapid freezing using atomized liquid nitrogen spray followed by frozen storage below glass transition temperature for Cordyceps sinensis preservation: Quality attributes and storage stability

Rapid freezing using atomized liquid nitrogen spray followed by frozen storage below glass transition temperature for Cordyceps sinensis preservation: Quality attributes and storage stability

You Tian, Dongmei Li, Wenhuang Luo, Zhiwei Zhu, Wenjia Li, Zhengming Qian, Guangrong Li, Da-Wen Sun

Abstract

Fresh Cordyceps sinensis (CS) is rich in bioactive components but perishable with a short shelf-life and drying is the most common method for its preservation. For better retention of its quality and nutritional values, an innovative preservation technique using rapid freezing based on atomized liquid nitrogen (LN) spray followed by frozen storage below glass transition temperature (Tg) was developed in the current study. Atomized LN spray freezing of CS at −60 °C (LN-60), −80 °C (LN-80) and −100 °C (LN-100) was performed. Freezing rates and quality attributes of CS including electronic conductivity (EC), drip loss (DL), total sugar content (TSC), superoxide dismutase activity (ASOD), basic colour information (L*, a* and b* values) and total colour difference (ΔE) were investigated, and the stability of CS stored at −40 °C, which was below the Tg, for 16 weeks was evaluated. The Tg of CS was determined as −34.86 °C through differential scanning calorimeter (DSC) analysis. Multivariate data analyses including principal component analysis (PCA) and cluster analysis (CA) verified that LN-80 and LN-100 provided CS with better quality indicators, among which, ΔE, DL, and EC were the most predominant ones. The stability test suggested that LN-80 and LN-100 minimized the quality deterioration of CS during the frozen storage.

Keywords

Rapid freezing, Quality preservation, Multivariate data analysis, Principal component analysis, Cluster analysis