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1.
Rev. Ciênc. Méd. Biol. (Impr.) ; 21(1): 117-122, maio 05,2022. fig
Article in Portuguese | LILACS | ID: biblio-1370755

ABSTRACT

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.


Subject(s)
Humans , Cryopreservation/methods , Cryoprotective Agents , Free Tissue Flaps , Allografts , Glycerol , Freeze Drying/methods
2.
Arch. latinoam. nutr ; 72(1): 11-22, mar. 2022. tab, graf
Article in Spanish | LILACS, LIVECS | ID: biblio-1368344

ABSTRACT

El arándano (Vaccinium corymbosum L.) posee un alto contenido de compuestos fenólicos los cuales han sido estudiados principalmente por su actividad antioxidante, antiobesogénica, antiinflamatoria, entre otras. Objetivo. Evaluar el efecto de la digestión gastrointestinal in vitro sobre la bioaccesibilidad de compuestos fenólicos y actividad antioxidante de una formulación nutracéutica de arándano (cápsula), comparado con arándano fresco y polvo. Materiales y métodos. Se obtuvieron extractos metanólicos de muestras de arándano fresco y liofilizado y se determinó su contenido de fenoles, flavonoides y antocianinas totales, así como también actividad antioxidante. Se llevó a cabo un ensayo de simulación de digestión gastrointestinal para evaluar la bioaccesibilidad de los compuestos fenólicos presentes en las muestras. Resultados. Los resultados mostraron que la digestión gástrica de arándano en polvo y en cápsula promovió una mayor bioaccesibilidad de fenoles (42% y 40%), flavonoides (52% y 33%) y antocianinas (45% y 40%) comparado con digestos de arándano fresco. Posterior a la digestión intestinal, la bioaccesibilidad de fenoles (63%) y flavonoides (67%) fue mayor en la cápsula de arándano comparada con su contraparte arándano en polvo. Las condiciones de digestión intestinal afectaron negativamente la bioaccesibilidad de las antocianinas independientemente del tipo de muestra evaluada. Conclusión. Las condiciones de digestión gástrica promueven una mayor estabilidad de los compuestos fenólicos en arándano en polvo y en cápsula lo que pudiera ser relevante para el mantenimiento de un ambiente antioxidante a este nivel. Las condiciones de digestión intestinal afectaron de manera particular a los compuestos fenólicos de arándano fresco y polvo, pero no a la cápsula, lo que puede sugerir que el encapsulamiento protegió de las condiciones alcalinas a los fenoles presentes. Se sugieren estudios posteriores sobre absorción in vitro de los componentes remanentes en intestino y sus posibles efectos sobre biomarcadores de estrés oxidativo en modelos in vivo(AU)


Blueberry (Vaccinium corymbosum L.) has a high content of phenolic compounds which have been studied mainly for their antioxidant, antiobesogenic, anti-inflammatory activity, among others. Objetive. The objective of the present study was to evaluate the effect of in vitro gastrointestinal digestion on the bioaccessibility of phenolic compounds and antioxidant activity of a nutraceutical formulation of blueberry (capsule), compared to fresh and powder blueberry. Materials and methods. Methanolic extracts of fresh and lyophilized blueberry were obtained and determined its total phenols, flavonoids, anthocyanins content, as well as antioxidant activity. A gastrointestinal digestion simulation test also was carried out to assess the bioaccessibility of the phenolic compounds found in samples. Results. The results showed that gastric digestion of powder and capsule blueberry promoted greater bioaccessibility of phenols (42% and 40%), flavonoids (52% and 33%) and anthocyanins (45% and 40%), compared to fresh blueberry digests. After intestinal digestion, the bioaccessibility of phenols (63%) and flavonoids (67%) was higher in the blueberry capsule compared to its powdered blueberry counterpart. The intestinal digestion conditions negatively affected the bioaccessibility of anthocyanins regardless of the type of sample evaluated. Conclusion. Gastric digestion conditions promote greater stability of phenolic compounds in powdered and capsule blueberries, which could be relevant for the maintenance of an antioxidant environment at this level. The intestinal digestion conditions particularly affected the phenolic compounds of fresh and lyophilized blueberry, but not the capsule, which may suggest that encapsulation protected the phenols present from alkaline conditions. Further studies on in vitro absorption of the remaining components in the intestine and their possible effects on oxidative stress biomarkers in in vivo models are suggested(AU)


Subject(s)
Tannins , Flavonoids , Blueberry Plants , Phenolic Compounds , Gastrointestinal Absorption , In Vitro Techniques , Chronic Disease , Digestion , Freeze Drying
3.
Vitae (Medellín) ; 28(2): 1-14, 2021-05-18. Ilustraciones
Article in English | LILACS, COLNAL | ID: biblio-1363249

ABSTRACT

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


Subject(s)
Humans , Freeze Drying , Rheology , Yogurt , Nebulizers and Vaporizers , Food Preservation
4.
Article in Chinese | WPRIM | ID: wpr-921701

ABSTRACT

The freeze-drying technique, characterized by low-temperature processing, is especially suitable for sensitive volatile oils with thermal instability. However, there are few studies focusing on the retention of volatile oils in the processing of freeze-dried preparations. This study evaluated the effects of different addition methods(adsorption, emulsification, solid dispersion, and inclusion) on the retention rate of the main components in peppermint oil, aiming to explore the application feasibility of freeze-dried preparations of volatile oils. Firstly, the addition method was determined based on the retention rates of menthol in four freeze-dried preparations. Secondly, an orthogonal test was designed to optimize the preparation process based on the characteristics of the preferred addition method. The results showed that the most suitable preparation form of peppermint oil was inclusion with beta-cyclodextrin(β-CD), and the retention rate of menthol in freeze-drying was 86.36%. According to the two-step preparation process of inclusion and freeze-drying, we introduced the product of inclusion rate and retention rate, i.e., comprehensive retention rate, to determine the optimum processing parameters. The results showed that β-CD/oil ratio of 7∶1, inclusion temperature of 40 ℃, and inclusion time of 2 h were the optimum processing parameters. The product prepared with these parameter had the comprehensive retention rate of 68.41%, retention rate of 92.53%, and inclusion rate of 73.93%. The inclusion compound was white powder with significantly increased solubility. The pre-paration process based on cyclodextrin inclusion in this study is stable and reliable and provides a new idea for ensuring the efficacy and stability of volatile components in freeze-dried preparations.


Subject(s)
Cyclodextrins , Freeze Drying , Mentha piperita , Oils, Volatile , Plant Oils , Solubility , Technology
5.
Pesqui. vet. bras ; 41: e06999, 2021. tab, ilus
Article in English | LILACS, VETINDEX | ID: biblio-1351280

ABSTRACT

Platelet-rich plasma (PRP) has been considered a promising therapeutic alternative, since platelets are rich in growth factors that are used in the Regenerative Medicine field. However, fresh PRP cannot be stored for long periods. This study aimed to develop a protocol for obtaining lyophilized canine PRP capable of maintaining viability after its reconstitution. For that purpose, canine PRP extraction and lyophilization protocols were initially tested. Subsequently, assays were carried out to quantify the growth factors VEGF and TGF-β, before and after the lyophilization process, gelation test and the three-dimensional gel structure analysis of the reconstituted lyophilized PRP by electron microscopy, as well as in vitro cell proliferation test in lyophilized PRP gel. Additionally, the immunogenicity test was performed, using allogeneic samples of lyophilized PRP. The results showed that the lyophilized PRP had adequate therapeutic concentrations of growth factors VEGF and TGF-β (9.1pg/mL and 6161.6pg/mL, respectively). The reconstituted PRP gel after lyophilization showed an in vitro durability of 10 days. Its electron microscopy structure was similar to that of fresh PRP. In the cell proliferation test, an intense division process was verified in mesenchymal stem cells (MSCs) through the three-dimensional mesh structure of the lyophilized PRP gel. The immunogenicity test showed no evidence of an immune reaction. The findings were promising, suggesting the possibility of having a lyophilized canine PRP that can be marketed. New in vivo and in vitro studies must be carried out for therapeutic confirmation.(AU)


O plasma rico em plaquetas (PRP) é uma alternativa terapêutica promissora, pois as plaquetas são ricas em fatores de crescimento com ação na regeneração de tecidos. No entanto, o PRP fresco não pode ser armazenado por longos períodos. Esse trabalho teve como objetivo desenvolver um protocolo de obtenção de PRP liofilizado canino capaz de manter a viabilidade pós reconstituição. Portanto, foram testados diversos protocolos de extração e liofilização. Para validação do PRP canino liofilizado foi analisada a concentração dos fatores de crescimento VEGF e TGF-β antes e após o processo de liofilização, a estrutura tridimensional do PRP liofilizado reconstituído em forma de gel por microscopia eletrônica e seu efeito in vitro na proliferação de células-tronco mesenquimais. Os resultados demonstraram que o PRP liofilizado apresentou concentrações terapêuticas adequadas dos fatores de crescimento VEGF e TGF- β (9,1pg/ml e 6161,6pg/ml, respectivamente). O gel de PRP reconstituído após liofilização apresentou uma durabilidade in vitro de 10 dias, sua estrutura tridimensional mostrou-se semelhante ao PRP fresco e proporcionou intensa proliferação de células-tronco mesenquimais durante o cultivo. O teste de imunogenicidade não demonstrou evidências de reação imune. Os achados foram promissores, sugerindo a possibilidade de uso de PRP canino liofilizado para o mercado. Novos estudos in vivo e in vitro deverão ser conduzidos para comprovação terapêutica.(AU)


Subject(s)
Animals , Dogs , In Vitro Techniques , Platelet-Rich Plasma , Mesenchymal Stem Cells , Freeze Drying , Therapeutics , Dogs
6.
Electron. j. biotechnol ; 44: 1-5, Mar. 2020. graf, tab
Article in English | LILACS | ID: biblio-1087706

ABSTRACT

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


Subject(s)
Preservation, Biological/methods , Pseudoalteromonas/physiology , Freeze Drying/methods , Trehalose/chemistry , Cell Survival , Bacterial Physiological Phenomena , Disaccharides/chemistry , Microbial Viability , Salinity , Lactose/chemistry , Mannitol/chemistry
7.
Rev. peru. med. integr ; 5(2): 49-54, 2020. tab
Article in Spanish | LILACS, MTYCI | ID: biblio-1146105

ABSTRACT

Objetivos. Determinar la estabilidad de cremas fotoprotectoras a base de Myrcianthes rhopaloides «lanche colorado¼ de los páramos de Piura. Materiales y métodos. Se evaluaron tres extractos hidroetanólicos y dos acuosos que fueron purificados con Amberlite® XAD7HP. Se formularon cremas fotoprotectoras con los purificados para la realización de la prueba de shock térmico, la evaluación de los parámetros organolépticos y fisicoquímicos, antes y después del almacenamiento. Se escogieron las mejores formulaciones para la realización de la prueba de estabilidad acelerada. Resultados. No se evidenciaron cambios organolépticos y fisicoquímicos entre las formulaciones. Se optó por escoger la crema a base de purificado de 45%, a la cual se realizó la prueba de estabilidad acelerada; mostrando cambios organolépticos a los siete días, y cambios fisicoquímicos durante todo el tiempo de almacenamiento. Conclusiones. Se determinó que los parámetros físicos y químicos de la crema fotoprotectora a base de extracto purificado de 45% presenta moderada estabilidad.


Objectives. To determine the stability of photoprotective creams based on Myrcianthes rhopaloides "lanche colorado" from the paramos of Piura. Materials and methods. Three hydroethanolic and two aqueous extracts were evaluated that were purified with Amberlite® XAD7HP. Photoprotective creams were formulated with the purified ones for the thermal shock test, the evaluation of the organoleptic and physicochemical parameters, before and after storage. The best formulations were chosen to perform the accelerated stability test. Results. There were no organoleptic and physicochemical changes between the formulations. It was decided to choose the cream based on purification of 45%, to which the accelerated stability test was carried out; showing organoleptic changes at 7 days and physicochemical changes throughout the storage time. Conclusions. It was determined that the physical and chemical parameters of the photoprotective cream based on 45% purified extract presents moderate stability.


Subject(s)
Humans , Sunscreening Agents , Myrtaceae/chemistry , Peru , Plant Extracts , Freeze Drying
8.
Rev. peru. med. integr ; 5(1): 5-11, 2020. tab, ilus
Article in Spanish | LILACS, MTYCI | ID: biblio-1146111

ABSTRACT

La etnomedicina es una disciplina idónea para elegir especies vegetales con el fin de ser estudiadas farmacológicamente; las cuatro especies seleccionadas para el presente estudio se usan como hipoglucemiantes en la medicina tradicional de la Amazonía peruana. Objetivos. Estudiar la capacidad inhibitoria in vitro de los extractos de cuatro plantas de uso tradicional, sobre la actividad de la α-glucosidasa, una enzima importante involucrada en la regulación de la glicemia. Materiales y métodos. Mediante el ensayo de inhibición de la enzima α-glucosidasa se evaluaron diferentes concentraciones de cada extracto para determinar la concentración inhibitoria media (IC50) y compararlos con la droga control acarbosa. Resultados. El extracto acuoso liofilizado de Guazuma ulmifolia mostró significante efecto inhibitorio (IC50 :13,49±3,65 µg/mL), al compararlo con la droga control, acarbosa (IC50: 858,67±29,73 µg/mL) y los otros extractos. Conclusiones. Los resultados sugieren que la actividad antidiabética de la Guazuma ulmifolia estaría mediada por la inhibición de la α-glucosidasa, lo que implicaría su potencial en la reducción de la glucosa posprandial.


Ethnomedicine is an ideal discipline for choosing plant species to be studied pharmacologically; the four species selected for this study are used as hypoglycemics in the traditional medicine of the Peruvian Amazon. Objectives. To study the inhibitory capacity in vitro of the extracts of four plants of traditional use, on the activity of α-glucosidase, an important enzyme involved in the regulation of glycemia. Materials and methods. Using the inhibition test of the enzyme α-glucosidase, different concentrations of each extract were evaluated to determine the average inhibitory concentration (IC50) and to compare them with the control drug acarbose. Results. The freeze-dried aqueous extract of Guazuma ulmifolia showed a significant inhibitory effect (IC50:13,49±3,65 µg/mL) when compared with the control drug, acarbose (IC50: 858,67±29,73 µg/mL), and the other extracts. Conclusions. The results suggest that the antidiabetic activity of Guazuma ulmifolia would be mediated by the inhibition of α-glucosidase, which would imply its potential in the reduction of postprandial glucose.


Subject(s)
Humans , Tabebuia , Physalis , alpha-Glucosidases , In Vitro Techniques , Plant Extracts , Amazonian Ecosystem , Freeze Drying , Hypoglycemic Agents , Medicine, Traditional
9.
Bol. latinoam. Caribe plantas med. aromát ; 19(4): 344-356, 2020. tab, ilus
Article in English | LILACS | ID: biblio-1283652

ABSTRACT

Many chronic diseases require repetitive injections as maintenance treatment. It is therefore important to investigate a possible alternative. A simulated subcutaneous implant prototype was fabricated as a polymer matrix covered by cylinder-shape tubing having a porous membrane. Sucrose, bovine serum albumin, and gelatin were selected as matrix excipients. Eight APIs with different physiochemical properties were used to investigate the releasing mechanism. Drug release was tested through an in vitrodissolution apparatus. Drug release of eight APIs followed zero-order kinetics with a minimum 12-hour duration. Release rates also showed linear correlations with the APIs' solubilities under physiological pH. For releasing mechanism studies, different combinations of matrix and membrane were investigated in detail. A 144-hour continuous zero-order release of caffeine was achieved as the best controlled simulated prototype. The results showed that drug release of our simulated prototype was primarily achieved by drug diffusion rather than dissolution.


Muchas enfermedades crónicas requieren inyecciones repetitivas como tratamiento de mantenimiento. Por lo tanto, es importante investigar una posible alternativa. Se fabricó un prototipo de implante subcutáneo simulado a partir de una matriz de polímero cubierta por un tubo en forma de cilindro que tiene una membrana porosa. La sacarosa, la albúmina de suero bovino y la gelatina se seleccionaron como excipientes matriciales. Se utilizaron ocho APIs con diferentes propiedades fisicoquímicas para investigar el mecanismo de liberación. La liberación del fármaco se probó a través de un aparato de disolución in vitro. La liberación del fármaco de las ocho APIs siguió una cinética de orden cero con una duración mínima de 12 horas. Las tasas de liberación también mostraron correlaciones lineales con las solubilidades de las APIs a pH fisiológico. Para los estudios de mecanismos de liberación, se investigaron en detalle diferentes combinaciones de matriz y membrana. El prototipo simulado con mejor control logró una liberación continua de cafeína de orden cero durante 144 horas. Los resultados mostraron que la liberación del fármaco del prototipo simulado ocurrió principalmente mediante la difusión del fármaco en lugar de la disolución.


Subject(s)
Pharmaceutical Preparations/administration & dosage , Drug Implants/metabolism , In Vitro Techniques , Pilot Projects , Simulation Exercise , Chromatography, High Pressure Liquid , Subcutaneous Tissue , Delayed-Action Preparations , Drug Evaluation, Preclinical , Drug Liberation , Freeze Drying
10.
Rev. MVZ Córdoba ; 24(3): 7305-7313, sep.-dic. 2019. tab
Article in Spanish | LILACS | ID: biblio-1115255

ABSTRACT

RESUMEN Objetivo. Determinar la fermentación in vitro de consorcios bacterianos ruminales celulolíticos (CBC) conservados por liofilización usando carbón activado, maltosa y lactosa como preservadores. Materiales y métodos. Un CBC se aisló de fluido ruminal de una búfala de agua en medios selectivos celulolíticos. Los CBC se liofilizaron con carbón activado (CA), lactosa (LA) o maltosa (MA) como preservadores y sin preservador (SP). El diseño experimental fue completamente al azar para medir biogás a diferentes intervalos de tiempo; así como, un diseño completamente al azar con arreglo factorial 4x3, los factores fueron preservadores (SP, CA, LA y MA) y tiempo de fermentación (24, 48 y 72 h) para pH, nitrógeno amoniacal (N-NH3), degradación de materia seca (DMS) y de fibra detergente neutro (DFDN), actividad enzimática celulasas y la población de bacterias totales. Resultados. LA produjo mayor biogás acumulado a las 72 h y parcial a partir de las 12 h (p≤0.05). SP no mostró diferencias (p>0.05) en celulasas, conteo de bacterias total, DMS y DFDN en los tiempos de fermentación evaluados con el resto de los preservadores. Conclusiones. La producción de biogás parcial y acumulada, el aumento en la tasa de degradación de 8.3 y 91.1 % en la DMS y DFDN de las 24 a 72 h (p≤0.05) con el preservador LA, muestran que la lactosa puede usarse como preservador de bacterias celulolíticas ruminales.


ABSTRACT Objective. To determine in vitro fermentation of cellulolytic ruminal bacterial consortia (CBC) preserved by lyophilization using activated carbon, maltose and lactose as preservatives. Materials and methods. A CBC was isolated from the ruminal fluid of a female water buffalo in selective cellulolytic media. The CBC were lyophilized without preservative (SP), activated carbon (CA), lactose (LA) o maltose (MA) as preservatives. The experimental design was completely random to measure biogas at different time intervals; as well as completely random with 4x3 factorial arrangement, factors were preservative [SP, CA, LA and MA] and fermentation time (24, 48 and 72 h) for pH, ammoniacal nitrogen (NH3-N), dry matter degradation (DMD), neutral detergent fiber degradation (NDFD), enzymatic activity cellulases and total bacteria population. Results. LA produced higher accumulated biogas at 72 h and partial biogas after 12 h (p≤0.05). SP did not show differences (p>0.05) in cellulases, total bacteria population, DMD and NDFD in the fermentation times evaluated with the rest of the preservative. Conclusions. The production of partial and accumulated biogas, the increase in the degradation rate of 8.3 and 91.1% in the DMD and NDFD from 24 to 72 h (p≤0.05) in the LA preservative, show that lactose can be used as a preservative of ruminal cellulolytic bacteria.


Subject(s)
Animals , Charcoal , Disaccharides , Fermentation , Freeze Drying , Lactose , Maltose
11.
Rev. Asoc. Odontol. Argent ; 107(1): 10-18, ene.-mar. 2019. ilus, tab
Article in Spanish | LILACS | ID: biblio-998624

ABSTRACT

Objetivo: Evaluar ex vivo la confiabilidad de la medición electrónica de la longitud de trabajo obtenida por dos localizadores apicales en forámenes inmaduros simulados. Materiales y métodos: 20 incisivos centrales superiores humanos extraídos con conductos rectos se dividieron en dos grupos de 10 cada uno. En el grupo A, los conductos y los forámenes se prepararon paralelos hasta un calibre #100. En el grupo B, se procedió de manera similar al grupo A, pero los forámenes se prepararon divergentes. Las raíces se recubrieron con una membrana de intestino porcino simulando el ligamento periodontal y se insertaron individualmente en 20 orificios preparados en la tapa de una cuba de acrílico que contenía hueso bovino particulado humedecido. La tapa fue reposicionada en la cuba cuidando que las raíces quedaran sumergidas en el hueso. Mediante una lima K de tercera serie se determinó la longitud de trabajo con los localizadores apicales RootZx y Mini Apex. Luego, se retiró la tapa con los dientes y las membranas, se los preparó hasta un calibre #120 y se midieron nuevamente. Se repitió el procedimiento preparando los forámenes hasta un calibre #140. Se determinó la longitud de trabajo cuando la pantalla de los localizadores apicales marcaba 0,5. Resultados: Las diferencias entre localizadores apicales no fueron significativas, pero sí lo fueron entre ambos tipos de forámenes al prepararlos hasta un calibre #140. Conclusiones: La medición electrónica ex vivo en dientes con forámenes inmaduros simulados fue confiable excepto cuando se prepararon con calibre #140 (AU)


Aim: To evaluate ex vivo the reliability of two apical electronic localizers to determine the working length in teeth with simulated immature foramens. Materials and methods: Twenty extracted upper central human incisors with straight root canals were assigned to two groups of 10 teeth each. In group A, the canal walls and foramens were prepared parallel to a size #100. In group B, the canals were prepared similar but the foramens were divergent. Each root was surrounded with a porcine intestine membrane simulating the periodontal ligament and then placed through holes prepared on the cover of an acrylic box filled with humid particulate bovine bone. The cover holding the teeth was repositioned taking care that the roots were submerged into the particulate bone. A third series K-file along with Root Zx or Mini Apex apical electronic localizers was used to determine the electronic working length. The cover with the teeth and membranes was then removed, the canals were over-prepared to a #120 size file and the electronic working length was measured, then the foramens were widened to a #140 size and the measurements were repeated. The working length was determined when the apical electronic localizers showed 0.5 on the screen. Results: No significant differences were observed between the apical electronic localizers, while significant differences were detected between both types of foramens when prepared to a size #140 (AU)


Subject(s)
Humans , Tooth Apex , Freeze Drying , Odontometry , Tooth Root , Data Interpretation, Statistical , Electric Impedance , Acellular Dermis
12.
Article in Chinese | WPRIM | ID: wpr-774545

ABSTRACT

To study the effects of fresh-cut drying methods on the appearance and internal components of Panax notoginseng, and explore the feasibility of fresh-cut drying methods of P. notoginseng, so as to provide more effective processing methods for the production of P. notoginseng slices and Chinese patent medicines. In this study, we have compared the effects of 6 different drying methods on drying time, drying rate, density, appearance and internal components of P. notoginseng roots. It takes about 453 h to dry by whole-root drying in the sun, with a long constant speed period and a slow drying rate, the time of whole-root drying at 50 ℃ was shortened by 61.6% compared with whole-root drying in the sun, which resulted in the decrease of density and poor appearance of the medicinal material with hollow and crack appeared in the xylem, while the drying time of fresh-cut drying method was reduced by 61.82% to 91.58% and the drying rate increased greatly, due to the relatively slow drying process in the sun or in the shade after fresh-cut, salting-out and whitening appeared on the surface, and the internal components were all decreased to some extent. The drying time of fresh-cut drying at 50 ℃ was 91.58% and 68.83% shorter than that of whole-root drying in the sun and at 50 ℃, respectively. When drying at 50 ℃ after fresh-cut, the appearance and content of internal components of the medicinal materials were better, the appearance was yellowish green, the cut sections were clear with uniform pore distribution, and the content of saponin components was increased by 7.24% compared with that of the whole-root drying at 50 ℃, When drying at 40 ℃, the surface of slices has salting-out and whitening spots, and the loss of dencichine and total sugar was large, but at 60 ℃, this high temperature made the rate of dehydration of slices was extremely fast, which led to severe cracking and fragmentation, and the loss of total sugar and alcohol extract was large. By vacuum freeze drying after fresh-cut, the structure of medicinal materials slices was loose, the density was greatly reduced, and the appearance was different from those recorded in traditional books. The contents of total saponin components and dencichine were increased by 16.51% and 22.54%, respectively, compared with traditional whole-root drying. The fresh-cut process method is feasible in the production of P. notoginseng slices. In production, it is recommended that drying at 50 ℃ after fresh-cut can make the medicinal materials better in appearance and content of internal components, which is convenient for the subsequent processing and industrial feeding extraction. For the purpose of internal contents, it is better to adopt freeze-drying after fresh-cut processing method.


Subject(s)
Desiccation , Drugs, Chinese Herbal , Reference Standards , Freeze Drying , Panax notoginseng , Plant Roots , Quality Control , Saponins
13.
Article in Chinese | WPRIM | ID: wpr-774139

ABSTRACT

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.


Subject(s)
Calorimetry, Differential Scanning , Cryopreservation , Cryoprotective Agents , Chemistry , Freeze Drying , Freezing , Hep G2 Cells , Humans , Trehalose , Chemistry
14.
Article in Chinese | WPRIM | ID: wpr-773140

ABSTRACT

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.


Subject(s)
Chromatography, High Pressure Liquid , Cordyceps , Chemistry , Desiccation , Freeze Drying , Nucleosides
15.
Chinese Journal of Biotechnology ; (12): 319-326, 2019.
Article in Chinese | WPRIM | ID: wpr-771374

ABSTRACT

This study aimed to obtain a recombinant human-source collagen for industrialization. First, based on the Gly-X-Y sequence of human type I collagen, we optimized the hydrophilic Gly-X-Y collagen peptide, designed the human collagen amino acid sequence and the corresponding nucleotide sequence. Next, the expression vector pPIC9K-COL was constructed via endonuclease digestion technology. We obtained an engineering strain of human-source collagen by electrotransforming Pichia pastoris, and then it was fermented, purified and identified. As a result, the expression level reached 4.5 g/L and the purity was over 95%. After amino acid N-terminal sequencing, molecular weight analysis, amino acid analysis and collagenase degradation test, we confirmed that the obtained collagen was consistent with designed primary structure of human-source collagen. After freeze-drying, we analyzed the collagen by scanning electron microscope and cell cytotoxicity, confirming that the collagen has porous fiber reticular structure and superior cytocompatibility. This indicates that human-source collagen has potential to be applied as biomedical material. In conclusion, we successfully obtained the expected human-source collagen and laid a foundation to its further application.


Subject(s)
Amino Acid Sequence , Biocompatible Materials , Collagen , Freeze Drying , Humans , Pichia , Recombinant Proteins
16.
Article in English | WPRIM | ID: wpr-761906

ABSTRACT

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.


Subject(s)
Alkaline Phosphatase , Animals , Biopolymers , Bone and Bones , Bone Marrow , Collagen , Fourier Analysis , Freeze Drying , In Vitro Techniques , Ions , Mesenchymal Stem Cells , Nanocomposites , Nanoparticles , Porosity , Rats , Spectrum Analysis , Strontium , X-Ray Diffraction
17.
Article in English | WPRIM | ID: wpr-739226

ABSTRACT

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.


Subject(s)
Deoxycholic Acid , DNA , Freeze Drying , Glucose , Lactic Acid , Rabbits , Tissue Engineering , Trachea
18.
Rev. peru. med. integr ; 4(4): 121-126, 2019. graf, ilus
Article in Spanish | LILACS, MTYCI | ID: biblio-1145702

ABSTRACT

Objetivo. Evaluar la capacidad antioxidante in vitro del liofilizado de la pulpa y cáscara del rizoma de Zingiber officinale Roscoe (jengibre) mediante los ensayos DPPH, FRAP y TBARS. Materiales y métodos. Se separó la pulpa y la cáscara de los rizomas de Z. officinale, se preparó un macerado con solución hidroalcohólica (70:30 EtOH:H2O), y luego de rotaevaporar, se liofilizó. La capacidad antioxidante de los liofilizados se evaluó según porcentaje de inhibición del radical DPPH y el poder antioxidante de reducción férrica (FRAP), así como la capacidad de inhibir la peroxidación lipídica in vitro mediante el ensayo TBARS. Resultados. Los extractos liofilizados de la pulpa y cáscara evidenciaron moderada capacidad antioxidante, siendo similar según porcentaje de inhibición del radical DPPH (46,5 y 45,6% respectivamente). Sin embargo, mediante el ensayo FRAP la cáscara presentó una capacidad antioxidante de 31,09 µg/mL expresados como equivalentes de trolox (ET) en comparación a la pulpa (22,96 µg ET/mL). Además, solo el liofilizado de cáscara del rizoma de Z. officinale a bajas concentraciones (0,1, 0,2 y 0,3 mg/mL) es capaz de reducir significativamente (p < 0,01) la peroxidación lipídica in vitro. Conclusión. La cáscara del rizoma de Z. officinale posee mayor capacidad antioxidante en comparación con la pulpa según los ensayos FRAP y TBARS; sin embargo, la inhibición de radicales DPPH fue la misma tanto en la cáscara como en la pulpa.


Objective. To evaluate the in vitro antioxidant capacity of the freeze-dried pulp and peel of the rhizomes of Zingiber officinale Roscoe (ginger) using the DPPH, FRAP and TBARS assays. Materials and Methods. The pulp and peel were separated from the rhizomes of Z. officinale, then a macerate was prepared with a hydroalcoholic solution (70:30 EtOH: H2O), and after rotary evaporation, lyophilized. The antioxidant capacity of lyophilisates was evaluated according to the percentage of DPPH radical inhibition and the ferric reduction antioxidant power (FRAP), as well as the ability to inhibit lipid peroxidation in vitro using the TBARS assay. Results. Freeze-dried pulp and peel extracts showed moderate antioxidant capacity, being similar according to the percentage of DPPH radical inhibition (46.5% and 45.6% respectively). However, utilizing the FRAP assay, the peel presented an antioxidant capacity of 31.09 µg/mL expressed as Trolox Equivalents (ET) compared to the pulp (22.96 µg ET / mL). Also, only the freeze-dried peel of Z. officinale at low concentrations (0.1, 0.2 and 0.3 mg / mL) can significantly reduce p < 0.01 lipid peroxidation in vitro. Conclusion. The rhizome peel of Z. officinale has a higher antioxidant capacity compared to the pulp according to the FRAP and TBARS assays, however; DPPH radical inhibition was the same in both the peel and pulp.


Subject(s)
Thiobarbituric Acid Reactive Substances , Ginger , Antioxidants , Plants, Medicinal , In Vitro Techniques , Plant Extracts , Freeze Drying , Medicine, Traditional
19.
Braz. dent. j ; 29(4): 325-334, July-Aug. 2018. tab, graf
Article in English | LILACS | ID: biblio-974170

ABSTRACT

Abstract Several techniques have been proposed for vertical bone regeneration, and many of them use bone autogenous and allogeneic grafts. The purpose of this study was to compare demineralised freeze-dried bone allografts (DFDBA), fresh-frozen (FF) allografts, autogenous bone grafts to find differences between volumetric and histological quantity of bone formation and vertical bone growth dynamic. A vertical tissue regeneration bone model was performed in rabbit calvarias under general anaesthesia. Four hollow cylinders of pure titanium were screwed onto external cortical bone calvarias in eight rabbits. Each one of the cylinders was randomly filled with one intervention: DFDBA, FF, autogenous bone, or left to be filled with blood clot (BC) as control. Allogeneic grafts were obtained from a ninth animal following international standardised protocols for the harvesting, processing, and cryopreservation of allografts. Autogenous graft was obtained from the host femur scraping before adapting hollow cylinders. Animals were euthanized at 13 weeks. Vertical volume was calculated after probe device measurements of the new formed tissue inside the cylinders and after titanium cylinders were removed. Histomorphometry and fluorochrome staining were used to analyse quantity and dynamic of bone formation, respectively. Results showed that DFDBA and fresh-frozen bone improved the velocity and the quantity of bone deposition in distant portions of the basal plane of grafting. Remaining material in allograft groups was more intense than in autogenous group. Both allografts can be indicated as reliable alternatives for volume gain and vertical bone augmentation.


Resumo Várias técnicas foram propostas para regeneração óssea vertical, e muitas delas usam enxertos ósseos e alogênicos ósseos. O objetivo deste estudo foi comparar os aloenxertos ósseos congelados desmineralizados (DFDBA), os aloenxertos congelados frescos (FF) com os enxertos ósseos autógenos para encontrar diferenças entre o volume, a histologia da formação óssea e a dinâmica do crescimento ósseo vertical. Um modelo ósseo de regeneração tecidual vertical foi realizado em calvarias de coelho sob anestesia geral. Quatro cilindros ocos de titânio puro foram parafusados nas calvarias de osso cortical externo em oito coelhos. Cada um dos cilindros foi preenchido aleatoriamente com uma intervenção: DFDBA, FF, osso autógeno ou com coágulo sanguíneo (BC) como controle. Os enxertos alogênicos foram obtidos a partir de um nono animal seguindo protocolos internacionais padronizados para a coleta, processamento e criopreservação de aloenxertos. O enxerto autógeno foi obtido da raspagem do fêmur do hospedeiro antes de adaptar os cilindros ocos. Os animais foram eutanasiados após 13 semanas. O volume vertical foi calculado após a medição, por meio de sonda milimetrada, do novo tecido formado dentro dos cilindros e após a remoção dos cilindros de titânio. Histomorfometria e coloração com fluorocromios foram utilizados para analisar a quantidade e a dinâmica da formação óssea. Os resultados mostraram que DFDBA e osso fresco congelado melhoraram a velocidade e a quantidade de deposição óssea em porções distantes do plano basal de enxerto. O material remanescente nos grupos de aloenxerto foi mais intenso do que em grupo autógeno. Ambos os aloenxertos podem ser indicados como alternativas confiáveis para ganho de volume e aumento ósseo vertical.


Subject(s)
Animals , Male , Rabbits , Bone Regeneration , Bone Transplantation/methods , Models, Biological , Transplantation, Autologous , Transplantation, Homologous , Bone Screws , Fluorescent Dyes/chemistry , Freeze Drying , Microscopy, Fluorescence
20.
Rev. Asoc. Odontol. Argent ; 106(2): 63-69, abr.-jun. 2018. ilus
Article in Spanish | LILACS | ID: biblio-913178

ABSTRACT

Objetivo: Presentar un caso clínico en el que se utilizó un aloinjerto de hueso liofilizado como relleno en una técnica de preservación de reborde alveolar (TPRA), dejándolo expuesto al medio bucal. Caso clínico: Una paciente acudió a la consulta privada por dolor en la pieza 3.5, en la que se evidenciaba una fractura radicular. Con indicación de extracción y colocación de implante, se realizó una tomografía de haz cónico en la que se observó la ausencia parcial de la tabla vestibular. Se decidió realizar una TPRA y la colocación diferida del implante. Se efectuó la extracción atraumática y se colocó un aloinjerto de hueso liofilizado dentro del alvéolo hasta el nivel gingival. Se suturó con un punto colchonero cruzado, dejando el injerto expuesto. La cicatrización no mostró complicaciones. Tras 6 meses, se realizó una nueva tomografía, y luego de determinar el volumen óseo disponible, se colocó un implante. Conclusión: La TPRA empleada mostró ser favorable para la preservación del reborde ante la falta parcial de la tabla ósea vestibular, y permitió la colocación del implante de manera diferida en su ubicación tridimensional correcta (AU)


Aim: To report a case in which a freeze-dried bone allograft was used for an alveolar rigde preservation technique (TPRA), and was left uncovered. Case report: The patient arrived to consultation due to pain located in tooth 3.5, that presented a root fracture. Following extraction and implant placement indication, a cone beam tomography was performed and partial absence of buccal bone was found. The decision to perform a TPRA and the delayed placement of the implant was taken. An atraumatic extraction was performed and a freeze-dried bone allograft was placed inside the socket up to the gingival level. A crossed mattress point suture was used leaving the graft exposed. The healing did not show any complication. After 6 months a new tomography showed enough available bone volume, so an implant was placed. Conclusion: The TPRA that was used showed to be favorable for the preservation of the alveolar ridge when buccal bone deficiency is present. It made the delayed placement of the implant in its correct three-dimensional location possible (AU)


Subject(s)
Humans , Female , Middle Aged , Alveolar Bone Loss , Alveolar Process , Bone Transplantation , Dental Implants, Single-Tooth , Freeze Drying , Bone Resorption , Tooth Extraction , Wound Healing
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