Turn down - turn up: a simple and low-cost protocol for preparing platelet-rich plasma

OBJECTIVE: To describe and analyze a new protocol for the extraction of platelet-rich plasma (PRP) for use in clinical practice and compare this technique with methods that have been previously described in the medical literature. METHODS: We extracted PRP from 20 volunteers using four different protocols (single spin at 1600 ×g, single spin at 600 ×g, double spin at 300 and 700 ×g, and double spin at 600 and 900 ×g). In another group of 12 individuals, we extracted PRP with our new technique (named 'turn down-turn up') consisting of a double spin (200 ×g and 1600 ×g) closed system using standard laboratory equipment (including an ordinary benchtop centrifuge), where the blood remained in the same tube during all processes, reducing the risk of contamination. Platelet counts adjusted to baseline values were compared using analysis of covariance (ANCOVA). RESULTS: Using the four previously described protocols (mentioned above), we obtained concentrations of platelets that were 1.15-, 2.07-, 2.18-, and 3.19-fold greater than the baseline concentration, respectively. With the turn down-turn up technique, we obtained a platelet count that was 4.17-fold (95% confidence interval (CI): 3.09 to 5.25) greater than the baseline platelet count (p=0.063 compared with the double spin at 600 and 900 ×g method). The total cost of the disposable materials used in the extraction process was less than US$10.00 per individual. CONCLUSION: In the present study, we described a simple and safe method for obtaining PRP using low-cost devices.

Separación de fosfolípidos mediante la aplicación de fuerzas centrífugas / Separation of phospholipids by the application of centrifuge strengths

Introducción: la separación centrífuga es muy utilizada para la obtención de productos farmacéuticos y biotecnológicos. Es la separación o concentración de fosfolípidos o ambas una de estas aplicaciones. Objetivo: seleccionar y evaluar el uso de diferentes separadores centrífugos así como el establecimiento de sus condiciones de operación, para la obtención de un concentrado de una mezcla fosfolipídica típica. Métodos: se realizó la caracterización física de la suspensión a tratar para seleccionar el tipo de centrífuga más adecuada y se determinaron las condiciones de operación de esta. Se evaluó además la composición de las mezclas fosfolípidicas obtenidas en cada caso. Resultados: se obtuvo que tanto una centrifuga de discos como una tubular son competentes para lograr la concentración de fosfolípidos, con una composición que puede ser utilizada para la formulación de liposomas, cosméticos y medicamentos. Conclusiones: Teniendo en cuenta la competencia de ambas centrífugas para rendir una mezcla fosfolipídica específica y los similares rendimientos en la separación, la mejor elección es una centrífuga tubular vertical por ser más económica y sencilla en su operación que la de discos.

Introduction: centrifuge separation is very useful for obtaining pharmaceutical and biotechnological products. One of these applications is the separation and/or concentration of phospholipids. Objective: to evaluate the use of different centrifuge separators, as well as the establishment of their operation conditions in order to obtain a typical phospholipidic mixture concentrate. Methods: a physical characterization of the suspension to be treated was made for selecting the most adequate kind of centrifuge and its operational conditions were determined. The composition of the phospholipidic mixtures in every case was also evaluated Results: both the disk and the tubular centrifuges turned to be fit for reaching the phospholipids concentration; hence the composition can be used for the formulation of liposomes, cosmetics and drugs. Conclusions: Given the adequacy of both centrifuges for reaching a specific phospholipidic mixture and their similar performances in the separation process, the best choice will be the vertical tubular centrifuge since it is less expensive and simpler in operation than the disk centrifuge.