Optimization of the preparation process of Soft-shelled turtle blood lyophilized powder using Box-Behnken response surface methodology / 中国药房

OBJECTIVE To optimize the preparation process of Soft-shelled turtle blood lyophilized powder （STBLP）， and to provide a reference for improving the availability and quality stability of soft-shelled turtle blood （STB）. METHODS STBLP was prepared with vacuum freeze-drying. Taking the solubility as the index， the preparation process parameters of STBLP were optimized by single factor experiment and Box-Behnken response surface method. RESULTS The optimal freeze-drying process for STBLP was obtained： pre-freezing time of 4 h， total drying time of 13 h （before at 0 ℃）， and resolution drying temperature of 25 ℃. The average solubility of 3 batches of STBLP prepared according to the optimal process was 95.72% （RSD＝0.68%， n＝3）， the relative error of which was －0.97% to the theoretical solubility （96.66%）. CONCLUSIONS Optimized lyophilization process in this study are stable and feasible， the solubility of the prepared sample is high.

Research progress on platelet-rich fibrin preparation and preservation technology / 国际外科学杂志

Platelet-rich fibrin(PRF), a second-generation of platelet concentrate with stereo fibrin structure, leukocyte and platelets, can release various cytokines and growth factors to promote wound healing. PRF has been widely used in the treatment of various acute and chronic wounds in traumatic surgery, plastic surgery and stomatology. Chronic wounds are common in traumatic surgery, but conventional treatment is often ineffective. Accumulating evidences have confirmed that PRF has excellent therapeutic effect on chronic wounds. According to various methods such as different specimen, centrifugation, centrifuge tube material, and freeze-drying, the researchers tried to improve the efficiency of PRF. The progress of platelet-rich fibrin preparation technology and preservation technology are reviewed in this paper.

Screening and safety evaluation of heat-resistant protective agents for live classic swine fever vaccine / 中国生物制品学杂志

@#Objective To screen the formulation of heat-resistant protective agent for live classic swine fever(CSF) vaccine in order to prolong the preservation time of vaccine under harsh conditions.Methods The heat-resistant protective agent prepared based on the formula containing gelatin,D-sorbitol,trehalose,D casein hydrolysate of different contents was mixed with the live virus antigen of CSF and then lyophilized.The finished products with qualified appearance were screened for routine detection and aging resistance test,and the over-dose(10 and 30 portions) of the products qualified in the aging resistance test were used to immunize piglets via subauricular neck,5 for each to evaluate the safety of the vaccines.Results Among the 6 batches of lyophilized live CSF vaccine,3 batches(20200301,20200302 and 20200303) met the requirements of the current Chinese Veterinary Pharmacopoeia.The lyophilized loss was within 0.04～0.33 titers,and the moisture contents were all less than 2%;20200301 and 20200302 batches of finished products passed the aging resistance test.No adverse clinical symptoms were observed in all piglets 30 min after vaccination;The body temperatures of piglets vaccinated with 10 and 30 doses of vaccine were normal for 14 d after vaccination.Conclusion The two formulations of heatresistant protective agent selected might be used for freeze-dried preparations of live CSF vaccine with good effect of aging resistance and safety to piglets.

Processamento e conservação de enxertos de pele: uma abordagem com foco nos métodos de criopreservação, liofilização e glicerolização / Skin grafts processing and conservation: an approach focusing on cryopreservation, freeze-drying and glycerol conservation methods

Introdução: o uso de substitutos cutâneos para o tratamento de diversas feridas graves é uma forma eficiente de prevenir infecções e favorecer o processo de reepitelização. No entanto, tecidos biológicos estão suscetíveis a degradação e contaminação. Por isso, devem ser submetidos a rigorosos protocolos de processamento e testes que comprovem suas contribuições benéficas e segurança de aplicação. Objetivo: trazer uma abordagem sobre as principais características dos métodos de criopreservação, glicerolização e liofilização e sua consequencia nos aspectos imunológicos, microbiológicos e de viabilidade tecidual de enxertos de pele humana. Metodologia: foi realizada uma busca online utilizando as palavras chaves "criopreservação", "liofilização", "glicerolização", "enxertos", "processamento tecidual" e "engenharia dos tecidos" em múltiplas combinações nos bancos de dados PubMed, LILACS e ScienceDirect. Resultados: 200 artigos científicos foram obtidos, 26 excluídos por duplicidade, 92 selecionados para leitura integral a partir da leitura de seus resumos e 27 utilizados na construção desta revisão. A liofilização e a glicerolização são métodos semelhantes considerando a viabilidade tecidual. O uso de glicerol traz como principal desvantagem sua citotoxicidade quando comparado aos outros métodos. A criopreservação mantém os tecidos viáveis. Contudo, pode ser mais cara e trazer riscos de transmissão de microorganismos patogênicos. De modo geral, não é bem estabelecido quais os melhores métodos de conservação para uma adequada conservação da viabilidade dos enxertos de pele. Considerações Finais: os 3 métodos, liofilização, glicerolização e criopreservação, possuem aplicabilidade na conservação de enxertos. A falta de padronização na aplicação de enxertos apesar de sua frequente aplicação e a escassez de estudos recentes sobre o tema justificam o presente estudo.

Introduction: the use of skin substitutes for treatment of several wounds is an efficient way to prevent infections and allow the re-epithelialization process. However, biological tissues are susceptible to degradation and contamination. Therefore, they must undergo rigorous processing and testing protocols that prove their beneficial contributions and application security. Objective:to bring an approach on the main characteristics of cryopreservation, freeze-drying and glycerol conservation methods and their implications on immunological, microbiological and tissue viability aspects when applied to human skin grafts. Methodology:a mostly online search was performed using the keywords "cryopreservation", "freeze-drying", "glycerol conservation", "grafts", "tissue processing" and "tissue engineering" in multiple combinations in PubMed, LILACS and ScienceDirect databases. Results: 200 scientific articles were rescued, 26 excluded by duplicity, 92 selected for full reading from the reading of their abstracts and 27 used in the construction of this review. Freeze-drying and glycerol conservation are similar methods, with glycerol conservation having greater economic advantage. The use of glycerol presents cytotoxicity when compared to the other methods. Cryopreservation keeps tissues viable, however, is more expensive and carry risks of transmission of pathogenic microorganisms. Overall, there is a lack of clarity about the importance of viability in the performance of skin grafts. Final considerations: the 3 methods have applicability in graft conservation. The lack of standardization in graft application despite its frequent application and the scarcity of recent studies on the subject justify the present study.

Effect of Different Drying Methods on Volatile Components in Pseudostellariae Radix Based on GC-IMS / 中国实验方剂学杂志

ObjectiveTo compare the effects of different drying methods on volatile components of Pseudostellariae Radix. MethodThe samples were dried by different methods， including air drying， sun drying， hot air drying （40， 60， 80 ℃） and vacuum freeze drying. Gas chromatography-ion mobility spectrometry （GC-IMS） was used to compare the changes of volatile components in the samples after different treatments. The samples were incubated at 80 ℃ and 500 r·min-1 for 15 min， the injection temperature was 85 ℃， the injection volume was 200 μL， the flow rate of carrier gas was from 2 mL to 150 mL during 20 min， and the temperature of IMS detector was 60 ℃. SE-54 capillary column （0.32 mm×30 m， 0.25 μm） was used， the column temperature was 60 ℃， and the analysis time was 35 min. The differential spectra of volatile components were constructed and analyzed by principal component analysis （PCA）. ResultA total of 37 volatile components were identified from dried Pseudostellariae Radix. The number of compounds in descending order was ketones， aldehydes and alcohols. There were some differences in the volatile components in samples dried by different methods. And the volatile components in samples with sun drying， air drying and hot air drying at 40 ℃ were similar， compared with other drying methods， vacuum freeze drying and hot air drying at 80 ℃ had great effects on the volatile components of Pseudostellariae Radix， and the compounds in the samples with vacuum freeze drying were the least. ConclusionIn this study， GC-IMS for the detection and analysis of volatile components in Pseudostellariae Radix is established， which has the characteristics of high efficiency， nondestructive inspection and simple sample processing. This method can be used for the distinction of Pseudostellariae Radix dried by different methods. And hot air drying at 40 ℃ can effectively retain the volatile components of Pseudostellariae Radix， and achieve similar flavor to samples with sun drying and air drying.

Effect of the drying method and texture improvers on reconstitution behavior of yogurt powder: physical and microbiological properties / Efecto del método de secado y mejoradores de textura sobre el comportamiento de reconstitución de un yogurt en polvo: propiedades físicas y microbiológicas

Background: One of the most used and effective preservation strategies in foods is drying. However, there are problems with the rheological properties, color, and viability of lactic acid bacteria in the yogurt once reconstituted when applying such conservation strategies. Objectives: Determine the concentration of the type of texture improver and drying that minimizes the negative effect on the rheological, color, and microbiological properties of a reconstituted yogurt powder. Methods: Intended to determine the texture improver which increases rheological properties of reconstituted yogurt powder, a mixture type experimental design was applied where three texture improvers were assessed; carboxymethylcellulose (CMC) (mass fraction 0 - 1), pectin (mass fraction 0 - 1), and xanthan gum (mass fraction 0 - 1). The rheological parameters; consistency index (K), flow behavior (n), viscosity at 100s-1 (η), the storage (G') and loss (G'') modules, and the phase shift angle (δ) of each of the reconstitutions were considered as design-dependent variables. Secondly, a central composite design (face-centered) was used for assessing the effectiveness of the drying (convection, spray-drying, and freeze-drying), the concentration of the texture improver (0.0 - 1.0 %), and the yogurt powder concentration (8.0 - 15.0 %). The above-mentioned rheological parameters, color, and viability of the lactic acid bacteria from each reconstituted yogurt powder were considered as the dependent variables. Optimization sought to match the parameters of reconstituted yogurt powder that approximated the conditions of fresh yogurt. Results: The independent variables in their lineal expression and some interactions between them had statistically significant differences (p < 0.05). At a concentration of 10.59 % with 0.03 % xanthan gum, the reconstitution of freeze-dried yogurt powder was the optimized condition (p < 0.05) and obtained the rheological, color, and microbiological parameters closest to fresh yogurt. Conclusions: The drying of the yogurt by freeze-drying mixed with xanthan gum as a texture improver allowed to obtain a reconstituted yogurt with properties close to the fresh product for direct consumption

Antecedentes: Una de las estrategias de conservación más utilizadas y efectivas en los alimentos es el secado. Sin embargo, existen problemas en las propiedades reológicas, el color y la viabilidad de bacterias ácido lácticas en el yogur una vez reconstituido al aplicar tales estrategias de conservación. Objetivos: Determinar la concentración del tipo de mejorador de textura y secado que minimiza el efecto negativo sobre las propiedades reológicas, de color y microbiológicas de un yogur en polvo reconstituido. Métodos: Para determinar el mejorador de textura que aumente las propiedades reológicas del yogur en polvo reconstituido, se aplicó un diseño experimental de tipo de mezcla donde se evaluaron tres mejoradores de textura; carboximetilcelulosa (CMC) (fracción de masa 0 -1), pectina (fracción de masa 0 -1) y goma xantan (fracción de masa 0 -1); los parámetros reológicos: índice de consistencia (K), comportamiento de flujo (n), viscosidad a 100s-1 (η), módulos de almacenamiento (G') y pérdida (G''), y ángulo de desfase (δ) de cada una de las reconstituciones fueron considerados como variables dependientes. En segundo lugar, se utilizó un diseño central compuesto (centrado a las caras) para evaluar el efecto del tipo de secado (convección, secado por aspersión y liofilización), la concentración del mejorador de textura (0.0 - 1.0 %) y concentración del yogur en polvo (8.0 - 15.0 %). Como variables dependientes se consideraron los parámetros reológicos mencionados anteriormente, el color y la viabilidad de las bacterias ácido lácticas de cada yogur en polvo reconstituido. La optimización buscó igualar los parámetros del yogur en polvo reconstituido que se aproximaran a las condiciones del yogur fresco. Resultados: Las variables independientes en su expresión lineal y algunas interacciones entre ellas tuvieron diferencias estadísticamente significativas (p < 0.05). La reconstitución de yogur liofilizado en polvo a una concentración de 10.59 % con 0.03 % de goma xantan, fueron las condiciones optimizadas (p < 0.05) que obtuvieron los parámetros reológicos, de color y microbiológicos más cercanos al yogur fresco. Conclusión: El secado del yogur por liofilización mezclado con goma xantan como mejorador de la textura, permitió obtener un yogur reconstituido con propiedades cercanas al producto fresco para consumo directo

Tert-butanol application and related research progress in biomedicine / 药学学报

italic>Tert-butanol is an organic solvent, widely used in the medical field and chemical industry. It could be characterized by high crystallization temperature and vapor pressure. It could be easily sublimed and removed during the freeze-drying process. This review mainly describes the use of tert-butanol in the lyophilized formulations of poorly soluble drugs, the lyophilization solvent of porous structure productions, and as an ice crystal growth guider. In addition, the application of tert-butanol in nano drugs and aerogels has also been reviewed, as well as the current research progress in its quality and safety.

Effects of Different Drying Methods on the Main Components of Forsythia suspensa Flowers / 中国药房

OBJECTIVE：To establish the method for the content det ermination of 4 components in Forsythia suspensa flowers by drying in shade ，vacuum freeze-drying ，oven（30，50，70 ℃）and sun ，so as to evaluate the effects of different drying methods on the main components of F. suspensa flowers and screen the optimal drying method. METHODS ：UPLC method was adopted. The determination was performed on Waters ACQUITY UPLC BEH C 18 column with mobile phase consisted of acetonitrile- 0.1％ phosphoric acid aqueous solution （gradient elution ）at the flow rate of 0.3 mL/min. The detection wavelength was set at 230 nm， and column was 35 ℃. The sample size was 1 μL. Euclidean closeness（C）i of different drying methods was calculated by TOPSIS comprehensive analysis method ，and the optimal drying method was defined. RESULTS ：The linear range of forsythiaside A ， rutin，forsythin，（+）-pinoresinol-4-O-β-D-glucopyranoside were 0.007 5-0.037 7，0.027 4-0.137 2，0.001 9-0.009 5，0.005 6-0.028 8 µg（all r＞0.999）. RSDs of precision ，stability（32 h）and reproducibility tests were all lower than 2％. The recoveries were 97.27％-102.53％，100.53％-104.11％，98.45％-104.02％，98.66％-104.82％，respectively；and all RSDs ＜3％（n＝3）. The contents were 1.645 8-4.987 9，11.730 2-20.978 0，0.875 5-2.005 0，2.366 0-5.535 7 mg/g. The content of forsythiaside A was the highest after drying at 30 ℃，rutin and （+）-pinoresinol-4- O-β-D-glucopyranoside were the highest after vacuum freeze-drying，forsythiaside was the highest after drying at 50 ℃ . Results of TOPSIS analysis showed that Ci of F. suspensa flowers by drying in shade ，vacuum freeze-drying ，oven（30，50，70 ℃）and sun were 0.079 9，0.553 5，0.495 4， 0.503 8，0.157 9，0.217 2，respectively；the order of Ci was vacuum freeze-drying ＞ 50 ℃ oven drying ＞ 30 ℃ oven drying＞sun drying ＞70 ℃ oven drying ＞ shade drying. CONCLUSIONS：Established method is simple ，reproducible and can be used for the content determination of 4 components in F. suspensa flowers. The samples are preferably dried by vacuum freeze-drying，followed by 50 ℃ oven drying ，30 ℃ oven drying ， and then dried in the sun and oven at 70 ℃ and finally in the shade.

Development of a new protocol for freeze-drying preservation of Pseudoalteromonas nigrifaciens and its protective effect on other marine bacteria

Background: Freeze-drying is known as one of the best methods to preserve bacterial strains. Protectant is the key factor affecting the survival rate of freeze-dried strains. In addition, salinity, bacterial suspension concentration, drying time, and other factors can also affect the survival rate of strains to varying degrees. At present, there are relatively few studies on freeze-drying preservation of marine bacteria. In the present study, we performed the freeze-drying protectant screening and optimized the preservation conditions for Pseudoalteromonas nigrifaciens, which is widely distributed in marine environment. The protective effects of the screened protectants were verified by 18 other marine bacterial strains. Results: The results indicated that the combination of 5.0% (w/v) lactose, 5.0% (w/v) mannitol, 5.0% (w/v) trehalose, 10.0% (w/v) skim milk powder, 0.5% (w/v) ascorbic acid and 0.5% (w/v) gelatin was the best choice for the preservation of P. nigrifaciens. The suggested salinity and concentration of initial cell suspension were 10 g/L NaCl and 1.0 × 109 CFU/mL, respectively. Furthermore, stationary-phase cells were the best choice for the freeze-drying process. The highest survival rate of P. nigrifaciens reached 52.8% when using 5­10% (w/v) skim milk as rehydration medium. Moreover, the other 18 marine strains belonging to Pseudoalteromonas, Vibrio, Photobacterium, Planomicrobium, Edwardsiella, Enterococcus, Bacillus, and Saccharomyces were freezedried under the abovementioned conditions. Their survival rates were 2.3­95.1%. Conclusion: Collectively, our results supported that the protectant mixture and parameters were beneficial for lyophilization of marine bacteria

Preparation of silymarin nanosuspension with glycyrrhizic acid as stabilizer and study of its stabilization mechanism / 中草药

Objective: To prepare silymarin nanosuspension (SM-NS) with glycyrrhizic acid as stabilizer, and investigate the in vitro release characteristics and charge stabilization mechanism. Methods: SM-NS was prepared by high-speed shear-high pressure homogenization method. SM-NS lyophilized powder were prepared by freeze-drying method and characterized by physical and chemical characterization and in vitro release. The stability mechanism of SM-NS was studied from the ionic strength and pH value. Results: The dosage of glycyrrhizic acid (GA) was 0.15%. The preparation process was shear rate of 19 000 r/min, shear time of 4 min, homogenization pressure of 100 MPa, homogenization times of 12 times, and lyoprotectant was mannitol 3%, the average particle size of SM-NS lyophilized powder was (516.4 ± 10.4) nm, PDI was (0.260 ± 0.046); The in vitro release results showed that the dissolution rate and solubility of SM-NS lyophilized powder were significantly higher than the physical mixture; The study of charge stability mechanism showed that licorice acid can provide good charge stabilization and strong resistance to environmental impact. Conclusion: SM-NS is a potential and new nano-drug with high safety, which is formed by the charge stability of GA to significantly improve the solubility and stability of silymarin.

Preparation and in vitro evaluation of puerarin nanoemulsion lyophilized powder with glycyrrhizic acid as stabilizer / 中草药

Objective: Puerarin nanoemulsion lyophilized powder (Pue-NE-LP) was prepared using natural surfactant glycyrrhizic acid as stabilizer and evaluated in vitro. Methods: Pue-NE was prepared by high-speed shear and high-pressure homogenization method, and further combined with freeze-drying method to prepare Pue-NE-LP. Taking the average particle size and polydispersity index (PDI) as the evaluation indexes, the optimal prescription and process parameters of this experiment were screened out through a single factor test. The prepared Pue-NE-LP was characterized by physicochemical properties and dissolution in vitro. Results: The average particle size and PDI of Pue-NE-LP prepared with 5% glyceryl caprylate as oil phase, 2.0 mg/mL glycyrrhizic acid as stabilizer, and 7% glucose as lyophilization protectant was (215.1 ± 0.7) nm and (0.133 ± 0.024), respectively. Scanning electron microscopy showed that Pue-NE-LP was irregularly small and uniform in size; X-ray diffraction showed that Pue-NE-LP existed in an amorphous state. In vitro release results showed that the dissolution rate of Pue-NE-LP was significantly higher than the physical mixture. Conclusion: Pue-NE-LP prepared with natural surfactant glycyrrhizic acid as a stabilizer is not only simple to prepare, but also can significantly improve the solubility and bioavailability of puerarin. It provides a reference for the multiple development of Pue-NE formulations.

Increasing Macrophages in Tooth Extraction Wound Healing after induction of Freeze-drying Gel Aloe vera 90% on Cavia cobaya

@#Introduction: Tooth extraction is a regular method in dentistry in which it will result a lesion on the socket. The healing process of the lesion might lead to complication for instance bleeding, swelling, socket drying, and spreading of the infection. However, the healing process could be helped by the use of herbal medicine for it can reducing the complication risk. 90% freeze-drying Aloe vera gel, can grow the number of macrophages cells in which they play a significant role in the healing process. The purpose of this study was to determine an increasing number of macrophage cells in the wound healing process after tooth extraction after applying 90% freeze-drying Aloe vera gel. Method: freeze-drying Aloe vera consisted in CMC Na. Cavia cobaya divided into control group, day 1 and day 3, consists of the two groups without Aloe vera treatment and Treatment group, day 1 and day 3, consists of the two group treated with Aloe vera. Results: There is significant dissimilarity in both control and treatment group. In the treatment group, the number of macrophages between days 1 and 3 has been grown. It is because of the anti-inflammatory properties of Aloe vera. The activities and number of macrophages in tissue would be disrupted, if it is inhibited. Conclusion: 90% freeze-drying Aloe vera gel extract could increase number of macrophages in the healing process after tooth extraction on Cavia cobaya in observation days 1 and 3.

How drying methods can influence the characteristics of mucilage obtained from chia seed and psyllium husk / Como os métodos de secagem podem influenciar as características da mucilagem obtida de sementes de chia e casca de psyllium

ABSTRACT: The influence of drying methods (oven drying at 50 °C, and freeze drying) on the centesimal composition, functional characteristics and rheological properties of mucilage obtained from chia seed and psyllium husk were investigated. Results showed that high temperature of oven drying reduced fiber content, solubility, emulsion activity and emulsion stability of mucilage. All samples showed pseudo plastic behavior, with the best result produced by Heschel-Bulkley and Power Law models of chia and psyllium mucilage, respectively. These results will be helpful in selecting suitable drying methods depending on the functional and rheological properties desired of the chia and psyllium mucilage in a food product.

RESUMO: Este estudo teve como objetivo avaliar a influência dos métodos de secagem (secagem em estufa a 50 °C e liofilização) sobre a composição centesimal, características funcionais e propriedades reológicas da mucilagem obtida a partir de sementes de chia e casca de psyllium. Os resultados mostraram que a alta temperatura de secagem em estufa reduziu o teor de fibras, a solubilidade, a atividade da emulsão e a estabilidade da emulsão das mucilagens. Todas as amostras apresentaram comportamento pseudoplástico, com o melhor ajuste produzido pelos modelos Heschel-Bulkley e Power Law das mucilagens de chia e psyllium, respectivamente. Estes resultados serão úteis na seleção do método de secagem adequado, dependendo das propriedades funcionais e reológicas desejadas das mucilagens de chia e psyllium.

Decellularization of Trachea With Combined Techniques for Tissue-Engineered Trachea Transplantation

OBJECTIVES: The purpose of this study is to shorten the decellularization time of trachea by using combination of physical, chemical, and enzymatic techniques. METHODS: Approximately 3.5-cm-long tracheal segments from 42 New Zealand rabbits (3.5±0.5 kg) were separated into seven groups according to decellularization protocols. After decellularization, cellular regions, matrix and strength and endurance of the scaffold were followed up. RESULTS: DNA content in all groups was measured under 50 ng/mg and there was no significant difference for the glycosaminoglycan content between group 3 (lyophilization+deoxycholic acid+de-oxyribonuclease method) and control group (P=0.46). None of the decellularized groups was different than the normal trachea in tensile stress values (P>0.05). Glucose consumption and lactic acid levels measured from supernatants of all decellularized groups were close to group with cells only (76 mg/dL and 53 mg/L). CONCLUSION: Using combination methods may reduce exposure to chemicals, prevent the excessive influence of the matrix, and shorten the decellularization time.

Preparation and Characterization of Nanocomposite Scaffolds (Collagen/β-TCP/SrO) for Bone Tissue Engineering

BACKGROUND: Nowadays, production of nanocomposite scaffolds based on natural biopolymer, bioceramic, and metal ions is a growing field of research due to the potential for bone tissue engineering applications. METHODS: In this study, a nanocomposite scaffold for bone tissue engineering was successfully prepared using collagen (COL), beta-tricalcium phosphate (β-TCP) and strontium oxide (SrO). A composition of β-TCP (4.9 g) was prepared by doping with SrO (0.05 g). Biocompatible porous nanocomposite scaffolds were prepared by freeze-drying in different formulations [COL, COL/β-TCP (1:2 w/w), and COL/β-TCP-Sr (1:2 w/w)] to be used as a provisional matrix or scaffold for bone tissue engineering. The nanoparticles were characterized by X-ray diffraction, Fourier transforms infrared spectroscopy and energy dispersive spectroscopy. Moreover, the prepared scaffolds were characterized by physicochemical properties, such as porosity, swelling ratio, biodegradation, mechanical properties, and biomineralization. RESULTS: All the scaffolds had a microporous structure with high porosity (~ 95–99%) and appropriate pore size (100–200 µm). COL/β-TCP-Sr scaffolds had the compressive modulus (213.44 ± 0.47 kPa) higher than that of COL/β-TCP (33.14 ± 1.77 kPa). In vitro cytocompatibility, cell attachment and alkaline phosphatase (ALP) activity studies performed using rat bone marrow mesenchymal stem cells. Addition of β-TCP-Sr to collagen scaffolds increased ALP activity by 1.33–1.79 and 2.92–4.57 folds after 7 and 14 days of culture, respectively. CONCLUSION: In summary, it was found that the incorporation of Sr into the collagen-β-TCP scaffolds has a great potential for bone tissue engineering applications.

Quality Relevance of Standard Decoction and Different Drying Methods Products for Gentianae Macrophyllae Radix Granules Based on HPLC Fingerprint / 中国实验方剂学杂志

Objective:To establish the fingerprints of standard decoction of Gentianae Macrophyllae Radix-dried products by different methods,and to evaluate the quality correlation. Method:HPLC,InertSustain C18 chromatographic column(4.6 mm×250 mm,5 μm),Gradient elution was performed for the mobile phase of acetonitrile-phospho,detection wavelength at 240 nm and flow rate of 0.8 mL·min-1,and column temperature was 40℃. The quality correlation analysis of different methods for different kinds of Gentianae Macrophyllae Radix standard decoction was carried out from the aspects of chemical composition consistency,common chemical composition consistency,main chemical composition content and transfer rate. Result:The control fingerprint of Gentianae Macrophyllae Radix standard decoction was established. According to the peak matching data,there were 10 common peaks in the fingerprint of 15 batches of Gentianae Macrophyllae Radix standard decoction.Among the 10 common peaks,5 chemical constituents of loganic acid,6'-O-β-D-glucosyl gentiopicroside,swertiamarin,gentiopicroside and swertia glycosides were identified. The results of quality correlation analysis showed that the three different drying methods were consistent with the chemical composition and quantity of Gentianae Macrophyllae Radix standard decoction. But in terms of the content consistency of common chemical components and the transfer rate of main chemical components,the quality correlation between the products obtained from vacuum drying and the standard decoction was lower than that obtained from spray drying and freeze-drying. Conclusion:The fingerprint of different method of Gentianae Macrophyllae Radix standard decoction was established. Through the analysis of the mass correlation of chemical composition consistency,common chemical composition content consistency,main chemical composition content and transfer rate,the mass correlation between them was comprehensively reflected. It is suggested that spray drying or freeze drying should be used for the key drying process of Gentianae Macrophyllae Radix granules. This study provides a reference for the preparation process and quality control of Gentianae Macrophyllae Radix granules.

Study on thermophysical properties and effect of lyoprotectants in freezing human hepatoma Hep-G cells / 生物医学工程学杂志

Cell freeze-drying can be divided into the freezing and drying processes. Mechanical damage caused by ice crystals and damage from solute during freezing shall not be ignored and lyoprotectants are commonly used to reduce those damages on cells. In order to study the mechanism of lyoprotectants to protect cells and determine an optimal lyoprotectant formula, the thermophysical properties and percentage of unfrozen water of different lyoprotectants in freezing were investigated with differential scanning calorimeter (DSC). The survival rate indicated by trypan blue exclusion test and cell-attachment rate after 24 h using different lyoprotectants to freeze hepatoma Hep-G cells were measured after cell cryopreservation. The results show that 40% (W/V) PVP + 10% (V/V) glycerol + 15% (V/V) fetal bovine serum + 20% (W/V) trehalose formula of lyoprotectant demonstrate the best effect in protecting cells during freezing, for cell-attachment rate after 24 h is 44.56% ± 2.73%. In conclusion, the formula of lyoprotectant mentioned above can effectively protect cells.

Microencapsulated β-carotene preparation using different drying treatments / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

β-Carotene is one of the most abundant natural pigments in foods; however, usage of β-carotene is limited because of its instability. Microencapsulation techniques are usually applied to protect microencapsulated β-carotene from oxidization. In this study, β-carotene was microencapsulated using different drying processes: spray-drying, spray freeze-drying, coating, and spray granulation. The properties of morphology, particle size, water content, thermal characteristic, and chemical stability have been explored and compared. Scanning electron microscopy measure¬ments showed that the coated powder had a dense surface surrounded by starch and suggested that the coating process gave a microencapsulated powder with the smallest bulk density and the best compressibility among the prepared powders. The chemical stabilities of microcapsules were evaluated during six months of storage at different temperatures. The coated powder had the highest mass fraction of β-carotene, which indicated that the coating pro¬cess was superior to the three other drying processes.

ESTABLISHING FREEZE DRYING PROCESS FOR CORTICAL AND CANCELLOUS BONE ALLOGRAFT CUBES

@#Freeze drying is a dehydration method to dry bone under freezing environment, enabling removal of water with no or minimial effects on bone strength and durability. Larger size bones obviously require longer freeze drying time to reduce water content to the required level for long term storage at room temperature. For small size bone cubes or chips, it is a normal practice to pool cortical and cancellous bones for freeze drying. The study was aimed at determining if different type of bones of the same size influence the drying time. Human bone cubes of 10 mm x 10 mm x 10 mm were prepared from cortical bone of tibiae and cancellous bone from femoral heads. The bone cubes were freeze dried to reduce water content to less than 6%. Moisture content was monitored using gravimetric method.Weight and density of cortical bone were significantly higher than cancellous bone despite of having similar small size (p<0.05). Cortical bones (density 2.05 ± 0.35 g/cm3) with initial water content of 10.93% required 5 hours to freeze dry, while cancellous bone cubes (density 0.72 ± 0.44 g/cm3) with initial water content of 78.95% required only 1.87 hours. This study confirmed that the structure hence density of human bone cubes determine the freeze drying time. Therefore in the standard operating procedure for freeze drying of bone allograft cubes, high density cortical bone cubes and low density cancellous bone cubes must be freeze dried separately despite being of similar small size

Comparative study for freeze-drying and sun-drying on multi-index ingredients of Cordyceps sinensis / 中国中药杂志

The aim of this paper was to compare the influence of freeze-drying and sun-drying on six main nucleosides and nucleobases of Cordyceps sinensis by HPLC. Hypoxanthine,xanthine,uridine,inosine,guanosine and adenosine were reference substances. HPLC analysis was performed on a GL Inertsustain AQ-C_(18) column( 4. 6 mm×250 mm,5 μm),with mobile phase consisting of water( A)-acetonitrile( B) at the flow rate of 1. 0 mL·min~(-1)( 0-10 min,0-1% B; 10-65 min,1%-3% B). The detection wavelength was 260 nm,the column temperature was controlled at 30 ℃,and the injection volume was 5 μL. The linear ranges of hypoxanthine,xanthine,uridine,inosine,guanosine and adenosine were 1. 025-20. 50( r = 0. 999 8),0. 545-10. 90( r = 0. 999 9),4. 051-81. 02( r = 0. 999 8),4. 044-80. 88( r= 0. 999 9),2. 075-41. 50( r= 0. 999 9),4. 032-80. 64( r = 0. 999 9) mg·L~(-1),respectively. The average recoveries of them( n = 6)were as follows: 102. 3%( RSD 2. 1%),101. 1%( RSD 2. 4%),97. 80%( RSD 1. 7%),101. 8%( RSD 1. 8%),98. 90%( RSD2. 0%) and 98. 10%( RSD 1. 4%),respectively. Each sample was processed by freeze-drying and sun-drying so as to compare the difference between the two drying methods. The contents of six index ingredients were significantly different between freeze-drying and sun-drying sample of C. sinensis. The total contents of six index ingredients in sun-drying sample were higher than that in the corresponding freeze-drying sample. This research results provide the scientific basis for the drying methods and quality evaluation of C. sinensis.