Low viscosity silicone with less shrinkage for brain slices.

Plastination consists of replacing lipid and water with a curable polymer. This technique has numerous advantages, of which the production of non-toxic, inert, highly durable, dry, and easy maintenance and storage specimens stand out. Like all anatomical techniques, plastination also has disadvantages, and one of them is tissue shrinkage. The feasibility of using low viscosity domestic silicone (0,1Pa.s at 20°C) to plastinate brain slices was examined. Twenty humans, 10 millimeters (mm) brain slices were impregnated, ten slices each with two polymers [10 with domestic low viscosity polymer - P1 and 10 slices with Biodur® (0,45-0,6Pa.s at 20°C) S10]. Shrinkage was accessed by volume and area measurements. Volume shrinkage was significantly less in the slices impregnated with low viscosity domestic polymer, demonstrating the feasibility to plastinate brain slices with domestic low viscosity silicone polymer.

Through the fingers: Use of plastinated anatomical specimens for visually impaired students.

The plastination technique produces non-toxic human tissues, ensuring their safe handling in educational settings. This investigation aimed to understand if visually impaired students profit from the use of plastinated anatomical specimens in learning the anatomy of the nervous system. For this purpose, their learning performance was compared to sighted and blindfolded students recruited from three primary schools in Fortaleza city, in the state of Ceará. Initially, a questionnaire was applied before carrying out the pedagogical practice, followed by an anatomy lecture with practical components with the use of plastinated anatomical specimens and synthetic anatomical models of the nervous system. After these steps, the students answered the questionnaire previously applied. Our results showed that the tactile perception of the visually impaired participants was significantly more developed compared to sighted (p < 0.001) and the blindfolded (p < 0.0001) students. The average of correct answers in the reapplied questionnaire was higher in the groups that used plastinated specimens (p < 0.05). In conclusion, the use of plastinated specimens has proven to be an effective tool in promoting a better understanding of anatomical structures, mainly for students with or without visual impairments, making it a valuable asset in anatomy teaching.

Is domestic polyester suitable for plastination of thin brain slices?

Plastination is a technique used to preserve biological tissues while retaining most of their original appearance. In the technique, developed by Dr. Gunther von Hagens in 1977, specimens were impregnated with a polymer, such as silicone, epoxy, or polyester. Considered the most suitable material for brain plastination, polyester has a wide application in teaching and research compared with imaging techniques. The materials for plastination are usually imported from Germany and more expensive than domestic products. If domestic polymers were to enter the market it would favor the expansion of plastination in Brazil. Hence, this study evaluated the feasibility of using domestic polyesters to replace the usual Biodur® (P40) in plastination of brain slices. For this evaluation, 2-mm-thick sections of bovine brains were prepared and plastinated with domestic polyester. Slices were compared before impregnation and after curing using standardized photographs taken after dehydration and after curing. Plastination followed the standard protocol: fixation, dehydration, forced impregnation, and curing. Fifteen brain slices were plastinated with each polyester (P40, P18, and C1-3). There was no significant difference in the percent shrinkage between groups after plastination of P18 and P40, but the curing time of Cristalan© polymer was too short for impregnation. Therefore, no initiator was used for C polymers impregnation. Thus, domestic polyester P18 was a viable option for the process.

An improved plastination method for strengthening bamboo culms, without compromising biodegradability.

Biomaterials are increasingly being designed and adapted to a wide range of structural applications, owing to their superior mechanical property-to-weight ratios, low cost, biodegradability, and CO2 capture. Bamboo, specifically, has an interesting anatomy with long tube-like vessels present in its microstructure, which can be exploited to improve its mechanical properties for structural applications. By filling these vessels with a resin, e.g. an applied external loading would be better distributed in the structure. One recent method of impregnating the bamboo is plastination, which was originally developed for preserving human remains. However, the original plastination process was found to be slow for bamboo impregnation application, while being also rather complicated/methodical for industrial adaptation. Accordingly, in this study, an improved plastination method was developed that is 40% faster and simpler than the original method. It also resulted in a 400% increase in open-vessel impregnation, as revealed by Micro-X-ray Computed Tomography imaging. The improved method involves three steps: acetone dehydration at room temperature, forced polymer impregnation with a single pressure drop to - 23 inHg, and polymer curing at 130 °C for 20 min. Bamboo plastinated using the new method was 60% stronger flexurally, while maintaining the same modulus of elasticity, as compared to the virgin bamboo. Most critically, it also maintained its biodegradability from cellulolytic enzymes after plastination, as measured by a respirometric technique. Fourier transform infrared-attenuated total reflection, and thermogravimetric analyses were conducted and showed that the plastinated bamboo's functional groups were not altered significantly during the process, possibly explaining the biodegradability. Finally, using cone calorimetry, plastinated bamboo showed a faster ignition time, due to the addition of silicone, but a lower carbon monoxide yield. These results are deemed as a promising step forward for further improvement and application of this highly abundant natural fiber in engineering structures.

Detailed anatomy of the corpora-glans ligament via the P45 plastination method / Anatomía detallada de los ligamentos cuerpo cavernoso-glande mediante el método de plastinación P45

SUMMARY: The corporo-glans ligament is the ligament connecting the corpus cavernosum and the glans of the penis. The anatomical description of the corporo-glans ligaments shape is still uncertain, this knowledge affects penile reconstructive procedures. The anatomy of the corporo-glans ligament was analyzed and recorded via observing sagittal sections of 10 different penile P45 plastination sections. According to the P45 plastination sections, the corporo-glans junction displayed a fibrous tissue band connecting the distal ends of the two corpus cavernous (CC) with the glans penis (GP). The fibrous band was a round-obtuse shape and ran deep into the glans of the penis and occupied about 2/3 of the whole GP. The original end was laid in a socket embedded in the GP. The density of the fibers of the ligament at the original end close to the tunica albuginea was less than that of the other parts. The fibers originating from the tunica albuginea, directly extended to the blind end of the two CC, covering the distal end of the two CC.

El ligamento cuerpo cavernoso-glande es el ligamento que conecta el cuerpo cavernoso y el glande del pene. La descripción anatómica de la forma de los ligamentos cuerpo cavernoso -glande aún es incierta; este conocimiento afecta los procedimientos reconstructivos del pene. La anatomía del ligamento cuerpo cavernoso-glande se analizó y registró mediante la observación de 10 secciones sagitales diferentes del pene a través de plastinación P45. Según las secciones de plastinación, la unión cuerpo-glande mostraba una banda de tejido fibroso que conectaba los extremos distales de los dos cuerpos cavernosos con el glande del pene. La banda fibrosa tenía una forma redonda y obtusa y se adentraba profundamente en el glande del pene ocupando alrededor de 2/3 de él. En su origen se coloca en un espacio profundo en el glande del pene. La densidad de las fibras del ligamento cuerpo cavernoso-glande en su origen cercano a la túnica albugínea era menor que el de las otras partes. Las fibras que se originan en la túnica albugínea, se extienden directamente hasta el extremo ciego de los dos cuerpos cavernosos, cubriendo el extremo distal de estos.

Influence of Plastination on Ultrasound Transmission Through the Human Skull.

Development, optimization and validation of transcranial ultrasound methods require the use of fresh human or animal skulls. However, to avoid fresh skull degradation over time, fixation methods are required for conservation, such as formaldehyde buffer solution. This method allows for conservation of the skull properties over a relatively long period, but requires specific conditioning (de-gassing) and storage conditions, such that its practical use is limited. Plastination appears to be a unique solution for the preservation and transportation of body parts without constraints. However, the influence of this conservation process has yet to be characterized with respect to ultrasound transmission to verify that the acoustic and mechanical properties of the skulls are not altered by the plastination process. The objective of the study described here was to quantify the effect of plastination on ultrasound transmission through the temporal and parietal areas of the human skull between 200 kHz and 2 MHz. To achieve this, transmission measurements were performed on three different skulls and four areas before and after plastination. It was found that the plastination process results in a transmission loss of 5 dB. Moreover, results indicate that the plastination process does not induce any phase shift in the transmitted signal, validating the proper use of plastinated skulls for in vitro measurements and development of new transcranial ultrasound methods.

Bony structures at the attachment areas of the cruciate ligaments in human knee joints and their clinical significance-studied using the P45 plastination technique / Estructuras óseas en las áreas de inserción de los ligamentos cruzados en las articulaciones de la rodilla humana y su importancia clínica, estudiadas mediante la técnica de plastinación P45

SUMMARY: For treating cruciate ligament injuries, especially for characterizing the mechanics of the tunnel in cruciate ligament reconstruction, correctly understanding the bony information of the attachment area of the cruciate ligaments is significant. We studied 31 knee joints of middle-aged Chinese adults using the P45 sheet plastination technique, focusing on the attachment areas of the cruciate ligaments, especially the bony structures. The trabeculae at the attachment area were distributed radially and extended deep into the medial wall of the lateral condyle of the femur. However, in the anterior part of the intercondylar eminence, the trabeculae of the anterior group were parallelly arranged along the tendinous fibers of the anterior cruciate ligament, while the trabeculae of the posterior group were parallelly arranged along the perpendicular direction of the anterior cruciate ligament fibers. Similarly, at the attachment area of the lateral wall of the medial condyle of the posterior cruciate ligament, the trabeculae extended radially toward the deep medial condyle. Deep in the posterior part of the intercondylar eminence, the trabeculae were arranged longitudinally. In the anterior part of the intercondylar eminence, the trabeculae were parallelly arranged along the perpendicular directions of ligament fibers. The distribution patterns of the trabecular at the attachment areas of the cruciate ligaments at the ends of the femur and tibia were different. This difference should be considered when orthopedic surgeons reconstruct anterior cruciate ligaments.

Para el tratamiento de lesiones de los ligamentos cruzados, especialmente para caracterizar la mecánica del túnel en su reconstrucción, es importante comprender correctamente la información ósea del área de inserción de estos ligamentos. Estudiamos 31 articulaciones de rodilla de individuos chinos, adultos, de mediana edad, utilizando la técnica de plastinación de láminas P45, centrándonos en las áreas de unión de los ligamentos cruzados, especialmente en las estructuras óseas. Las trabéculas en el área de inserción se distribuyeron radialmente y se extendieron profundamente en la pared medial del cóndilo lateral del fémur. Sin embargo, en la parte anterior de la eminencia intercondílea, las trabéculas del grupo anterior estaban dispuestas paralelamente a lo largo de las fibras tendinosas del ligamento cruzado anterior, mientras que las trabéculas del grupo posterior estaban dispuestas paralelamente a lo largo de la dirección perpendicular de las fibras del ligamento cruzado anterior. De manera similar, en el área de inserción en la cara lateral del cóndilo medial del ligamento cruzado posterior, las trabéculas se extendían radialmente y profundas hacia el cóndilo medial. Profundamente en la parte posterior de la eminencia intercondílea, las trabéculas estaban dispuestas longitudinalmente. En la parte anterior de la eminencia intercondílea, las trabéculas estaban dispuestas paralelamente a lo largo de las direcciones perpendiculares de las fibras del ligamento. Los patrones de distribución del tejido óseo trabecular en las áreas de unión de los ligamentos cruzados en los extremos del fémur y la tibia eran diferentes. Estas diferencias deben tenerse en consideración cuando los cirujanos ortopédicos reconstruyen los ligamentos cruzados anteriores.

Plastination with low viscosity silicone: strategy for less tissue shrinkage.

Plastination is an anatomical technique for preserving biological tissues based on the principle of replacing body fluids with a curable polymer. An inconvenient aspect of this technique is the tissue shrinkage it causes; several studies seek ways to reduce or avoid this shrinkage. Additionally, there are no studies in the literature that quantitatively evaluate the use of low viscosity silicones in plastination having shrinkage of tissue as a parameter. Therefore, this study aimed to evaluate the use of Silicones S10 (Biodur) and P1 (Polisil) in the plastination of different types of biological tissues of a sliced human body, having as a parameter the tissue shrinkage caused in the forced impregnation stage. Human cardiac, pulmonary, splenic, renal, hepatic, muscular, and bone tissues were analyzed. For such purpose, a male human body was used, sliced in 13-15-mm-thick pieces, having as a parameter the before and the after plastination with the different silicones. The standard protocol of the plastination of the slices was followed: dehydration, forced impregnation, and curation. Half of the pieces obtained were plastinated with silicone P1 (group P1) and the other half with S10 (group S10). All tissues and anatomical segments analyzed in this study showed less or equal shrinkage when plastination of the control group (S10) was compared with that of the P1 group. Therefore, we concluded that the lower viscosity silicone promoted less tissue shrinkage, making it a viable alternative to the reference.

Colorimetric evaluation of cross-sectional silicone plastination of the Total head region of sheep and Deplastination of the histological sections of brain tissue.

The aim of the study is to protect and preserve the cross-sectional diagnostic characteristics of the anatomy samples by using silicone plastination method, to examine them both macroscopically and microscopically, and to use them as an educational material. After the dissection procedures of 10 total sheep heads obtained from the slaughterhouse were completed, they were freshly frozen and sliced to prepare cross-sectional samples. Then, statistical analysis was performed after the colorimetric measurements. For microscopic examination, 30 brain samples were divided into three groups (Fresh-F, plastination-P, plastination/deplastination-P/D). Of the total brain samples, 20 were subject to routine plastination protocol. After the plastination/deplastination procedure, the changes occurring in cerebral histology were compared. In terms of tissue preservation, the effect of plastination and deplastination was examined using a light microscope. Plastinates subject to silicone plastination under room temperature were very similar to their natural appearance, and it was observed that they preserved their morphological features. Colour changes in the tissues were statistically evaluated. Volumetric shrinkages were observed as qualitative, especially in the brain. As a result of the evaluation done, it was seen that deplastination with toluene is not possible for the brain tissues. In addition, it was not possible to take cross sections of the plastinated tissues that were not deplastinated. On the contrary, findings regarding that deplastination with 5% sodium methoxide dissolved in methanol can allow microscopic examination in long-term preserved plastinated brain tissues were obtained.

Congenital atlanto-occipital fusion and its effect on the myodural bridge: a case report utilizing the P45 plastination technique / Fusión atlanto-occipital congénita y su efecto sobre el puente miodural: reporte de un caso utilizando la técnica de plastinación P45

SUMMARY: The atlanto-occipital joint is composed of the superior fossa of the lateral masses of the atlas (C1) and the occipital condyles. Congenital Atlanto-occipital fusion (AOF) involves the osseous union of the base of the occiput (C0) and the atlas (C1). AOF or atlas occipitalization/assimilation represents a craniovertebral junction malformation (CVJM) which can be accompanied by other cranial or spinal malformations. AOF may be asymptomatic or patients may experience symptoms from neural compression as well as limited neck movement. The myodural bridge (MDB) complex is a dense fibrous structure that connects the suboccipital muscular and its related facia to the cervical spinal dura mater, passing through both the posterior atlanto-occipital and atlanto-axial interspaces. It is not known if atlas occipitilization can induce structural changes in the MDB complex and its associated suboccipital musculature. The suboccipital region of a cadaveric head and neck specimen from an 87-year-old Chinese male having a congenital AOF malformation with resultant changes to the MDB complex was observed. After being treated with the P45 plastination method, multiple slices obtained from the cadaveric head and neck specimen were examined with special attention paid to the suboccipital region and the CVJM. Congenital atlanto-occipital fusion malformations are defined as partial or complete fusion of the base of the occiput (C0) with the atlas (C1). In the present case of CVJM, unilateral fusion of the left occipital condyle with the left lateral mass of C1 was observed, as well as posterior central fusion of the posterior margin of the foramen magnum with the posterior arch of C1. Also noted was a unilateral variation of the course of the vertebral artery due to the narrowed posterior atlanto-occipital interspace. Surprisingly, complete agenesis of the rectus capitis posterior minor (RCPmi) and the obliques capitis superior (OCS) muscles was also observed in the plastinated slices. Interestingly, the MDB, which normally originates in part from the RCPmi muscle, was observed to originate from a superior bifurcation within an aspect of the nuchal ligament. Therefore, the observed changes involving the MDB complex appear to be an effective compensation to the suboccipital malformations.

RESUMEN: La articulación atlanto-occipital está compuesta por las caras articulares superiores de las masas laterales del atlas (C1) y los cóndilos occipitales. La fusión atlanto-occipital congénita (FAO) implica la unión ósea de la base del occipucio (C0) y el atlas (C1). La FAO u occipitalización/asimilación del atlas representa una malformación de la unión craneovertebral (MUCV) que puede presentar otras malformaciones craneales o espinales. La FAO puede ser asintomática o los pacientes pueden experimentar síntomas de compresión neural así como movimiento limitado del cuello. El complejo del puente miodural (PMD) es una estructura fibrosa densa que conecta el músculo suboccipital y su fascia relacionada con la duramadre espinal cervical, pasando a través de los espacios intermedios atlanto-occipital posterior y atlanto-axial. No se sabe si la occipitilización del atlas puede inducir cambios estructurales en el complejo PMD y en la musculatura suboccipital. Se observó en la región suboccipital de un espécimen cadavérico, cabeza y cuello de un varón chino de 87 años con una malformación congénita de FAO con los cambios resultantes en el complejo PMD. Se examinaron múltiples cortes obtenidos de la muestra de cabeza y cuello después de ser tratados con el método de plastinación P45, con especial atención a la región suboccipital y la MUCV. Las malformaciones congénitas por fusión atlanto-occipital se definen como la fusión parcial o completa de la base del occipucio (C0) con el atlas (C1). En el presente caso de MUCV se observó la fusión unilateral del cóndilo occipital izquierdo con la masa lateral izquierda de C1, así como fusión posterior central del margen posterior del foramen magnum con el arco posterior de C1. También se observó una variación unilateral del curso de la arteria vertebral por el estrechamiento del espacio interatlanto-occipital posterior. Se observó además agenesia completa de los músculos Rectus capitis posterior minor (RCPmi) y oblicuos capitis superior (OCS) en los cortes plastinados. Curiosamente, se observó que el MDB, que normalmente se origina en parte del músculo RCPmi, se origina en una bifurcación superior dentro de un aspecto del ligamento nucal. Por lo tanto, los cambios observados en el complejo PMD parecen ser una compensación de las malformaciones suboccipitales.

Silicone plastination of nasus and lingua in large ruminants with and without use of formaldehyde / Plastinación de silicona de nasus y lengua en rumiantes mayores con y sin el uso de formaldehido

SUMMARY: Plastination is an anatomical preparate preparation technique characterized by the replacement of tissue fluids with a reactive polymer. Although more challenging and economically costly than many anatomical methods, this method is desirable because of the fact that specimens created in this method are highly similar to the natural appearance of the intended objects, and they are durable and harmless end products for human health. Our main goal was to completely leave out formaldehyde and similar carcinogenic chemicals used in a method like plastination and to allow production of formaldehyde-free plastinates to be used in anatomy training and examinations in our country. To that end, we compared nose and tongue of 10 large ruminants by subjecting them to plastination, 5 of them with formaldehyde and 5 of them without formaldehyde, and aimed to leave formaldehyde out by taking into account the difference between them. Silicone plastination is the most commonly-used and best-known technique among the plastination techniques because specimens created using this technique look aesthetically impressive. Silicone plastination consists mainly of 5 phases. First of all, we obtained the anatomical situs we wanted and made specimens ready by dissecting some of them after fixation and some of them without fixation. Then, after the implementation of a dehydration phase in acetone baths at -25 °C, a forced impregnation phase was implemented by using a mixture of S10-S3 chemical under negative pressure. In the final phase, the curing and hardening phase, the plastination process was completed by giving the specimens their final shape with the use of the S6 solution. As a result, no significant difference was observed between silicone plastination with and without formaldehyde.

RESUMEN: La plastinación es una técnica de preparados anatómicos caracterizada por la sustitución de fluidos tisulares por un polímero reactivo. A pesar de ser económicamente más costoso que muchas métodos anatómicos, este técnica es deseable debido a que las muestras creadas son muy similares a la apariencia natural de los objetos previstos y son productos finales duraderos e inofensivos para la salud humana. Nuestro objetivo principal fue dejar completamente de lado el formaldehído y las sustancias químicas cancerígenas similares utilizadas en un método como la plastinación y permitir la producción de plastinados libres de formaldehído para su uso en la formación y los exámenes de anatomía en nuestro país. Con ese fin, comparamos la nariz y la lengua de 10 rumiantes mayores sometiéndolos a plastinación, 5 de ellos con formaldehído y 5 de ellos sin formaldehído, y buscamos eliminar el formaldehído considerando la diferencia entre ellos. La plastinación con silicona es la técnica más utilizada y más conocida entre las técnicas de plastinación porque los especímenes creados con ella se ven estéticamente impresionantes. La plastinación con silicona consta principalmente de 5 fases. En primer lugar, obtuvimos el situs anatómico que queríamos y preparamos los especímenes diseccionando algunos de ellos después de la fijación y otros sin fijación. Luego, de la implementación de una fase de deshidratación en baños de acetona a -25 °C, se implementó una fase de impregnación forzada utilizando una mezcla del químico S10-S3 a presión negativa. En la fase final, la fase de curado y endurecimiento, se completó el proceso de plastinación dando a los especímenes su forma definitiva con el uso de la solución S6. Como resultado, no se observaron diferencias significativas entre la plastinación con silicona con y sin formaldehído.

Protocolo unificado de plastinación con silicona en frío y a temperatura ambiente / Unified plastination protocol with silicone at cold and room temperature

RESUMEN: En la actualidad, la técnica de plastinación es considerada una de las más novedosas formas de conservación cuerpos completos, secciones y órganos, tanto humanos como animales, para su uso en docencia de pre y postgrado, como así también investigación morfológica. En este sentido, para desarrollar las diversas técnicas de plastinación se requiere de equipamiento específico y formación especializada de académicos, que tengan la capacidad de llevar adelante la diversidad de protocolos que existen, según el material anatómico que se desee preservar. En el año 2015, desde el Laboratorio de Plastinación y Técnicas Anatómicas de la Universidad de La Frontera, se propuso por primera una nueva técnica de plastinación a temperatura ambiente, que permitió obtener preparaciones plastinadas de igual calidad que las técnicas clásicas de plastinación. En la actualidad, desde nuestro laboratorio, se propone un nuevo protocolo de plastinación con silicona que unifica las técnicas que se desarrollan en frío como así también a temperatura ambiente para la conservación de cuerpos humanos y animales completos, secciones anatómicas, regiones corporales, y órganos aislados.

SUMMARY: At present, plastination technique is considered one of the newest forms of conservation of whole bodies, sections and organs, both human and animal, for use in undergraduate and graduate teaching, as well as morphological research. In this sense, to develop the various plastination techniques requires specific equipment and specialized training of academics, who have the ability to carry out the diversity of protocols that exist, according to the anatomical material that is to be preserved. In 2015, from the Laboratory of Plastination and Anatomical Techniques of Universidad de La Frotera, a new plastination technique was proposed for the first time at room temperature, which allowed obtaining plastinated preparations of the same quality as the classic plastination techniques. At present, from our laboratory, a new protocol for plastination with silicone is proposed that unifies the techniques that are developed in cold as well as at room temperature for the conservation of complete human and animal bodies, such as as well as anatomical sections, body regions, and isolated organs.

Micro-plastination: technique for obtaining slices below 250 µm for the visualization of microanatomy in morphological and pathological morphology protocols / Micro-plastinación: técnica para la obtención de cortes inferiores a 250 µm para la visualización de la microanatomía en protocolos experimentales de morfología y patología

Plastination has revolutionized the study and research of anatomy, thanks to the biosecurity and indefinite preservation of human and animal bodies and organs. This paper presents the concept of Micro-Plastination, an ultra-thin sheet plastination technique, to obtain ultra-thin slices, of a thickness of less than 250 µm, for the identification and visualization of the microanatomy of any anatomical region in morphological and pathological experimental protocols.

La plastinación ha revolucionado el estudio y la investigación de la anatomía, gracias a la conservación biosegura y por tiempo indefinido de cadáveres y órganos humanos y animales. En este trabajo se presenta el concepto de Micro-Plastinación, técnica de plastinación de cortes ultrafinos para la obtención de cortes ultradelgados, de un grosor inferior a los 250 µm, para la identificación y visualización de la microanatomía de cualquier región anatómica en protocolos de morfología experimental.

Fibrous configuration of the fascia iliaca compartment: An epoxy sheet plastination and confocal microscopy study.

BACKGROUND AND OBJECTIVES: The underlying anatomical mechanism of the ultrasound-guided fascia iliaca compartment (FIC) block for anaesthesia and analgesia in the lower limb has not been illuminated and numerous variations were attempted to achieve an optimal needle placement. This study aimed to define the fibrous configuration of the FIC. METHODS: A total of 46 adult cadavers were studied using dissection, latex injection, epoxy sheet plastination and confocal microscopy. RESULTS: (1) The fascia iliaca originated from the peripheral fascicular aponeurotic sheet of the iliopsoas. (2) The FIC was a funnel-shaped adipose space between the fascia iliaca and the epimysium of the iliopsoas, had a superior and an inferior opening and contained the femoral and lateral femoral cutaneous nerves but not obturator nerve. (3) The estimated volume of the FIC in the cadavers was about 23 mls, of which about one third was below the level of the anterior superior iliac spine. CONCLUSIONS: This study revealed that the fascia iliaca was aponeurotic and may be less permeable for the local anesthetics. CONCLUSIONS: The FIC contained only the femoral and lateral femoral cutaneous nerves and communicated with the extraperitoneal space and femoral triangle adipose space via its superior and inferior opening, respectively.

Development of an ultrathin sheet plastination technique in rat humeral joints with osteoarthritis induced by monosodium iodoacetate for neovascularization study.

Injection with monosodium iodoacetate (MIA) is widely used to produce osteoarthritis (OA). Ultrathin sheet plastination has been used to study the morphology of structures, with strong application in anatomical education and research. Our aim was to carry out, for the first time, ultrathin sheet plastination of rat humeral joints to observe the neovascularization provoked by OA. We injected 0.1 mL of MIA into the left humeral joints of ten Sprague-Dawley rats. The right shoulders of the same rats were used as control. Sixteen weeks after the injection, the animals were euthanized and were given an immediate red epoxy resin injection through the thoracic aorta. The samples were fixed in 10% formalin, prior to the plastination process, without decalcification. Samples were dehydrated with acetone (100%) at - 25 °C, for 10 days. Later, for degreasing, samples were immersed in methylene chloride at room temperature during 1 week. Forced impregnation was performed inside a stove within a vacuum chamber. The plastinated blocks obtained were cut with a slow velocity diamond blade saw. Slices were placed in curing chambers to achieve curing and final tissue transparentation. 230 µm thickness slices were obtained. The slices were analyzed under magnifying glass and microscope, achieving visualization of OA neovascularization. The cartilage affected by OA loses its ability to remain avascular, and blood vessels invade it from the subchondral bone to the calcified and uncalcified cartilage. Ultra-thin sheet plastination is useful to observe articular cartilage neovascularization, caused by OA induced with MIA in humeral rat joint.

Desarrollo de un protocolo de plastinación de cortes con resina poliéster aplicado a secciones de cerebro humano / Development of a sheet plastination protocol with polyester resin applied to human brain slices

La plastinación es una técnica anatómica de conservación cadavérica creada en 1977 por Gunther von Hagens, en Heidelberg, Alemania, y que sustituye los líquidos biológicos y/o de fijación por acetona, para luego impregar las muestras con distintas resinas, dependiendo de la técnica de plastinación desarrollada, para finalmente llevar a cabo la polimerización de los componentes incorporados a las muestras, para obtener muestras biológicas secas y totalmente duraderas. El objetivo de este trabajo consistió en desarrollar un protocolo de plastinación de cortes con resina poliéster (Biodur® P40) en secciones de 3 mm de espesor de cerebro humano. La muestras fueron fijadas y conservadas con formalina al 10 %. Los cerebros luego fueron seccionados con una maquina cortadora de tejidos, obteniéndose láminas delgadas de 3 mm de espesor. Inmediatamente los cortes de cerebro fueron colocados en deshidratación en acetona al 100 %, a -25 ºC, durante 7 días el primer baño de acetona, y durante otros 3 días más, para el segundo baño de acetona. Una vez deshidratados los cortes, estos fueron colocados en resina poliéster Biodur® P40 y se llevó a cabo la impregnación forzada de los cortes, en cámara de vacío a temperatura ambiente (20 ºC). Una vez finalizada la impregnación forzada, se procedió a la etapa de curado, la cual en primer lugar consiste en el armado de las cámaras de curado dentro de las cuales se colocaran los cortes con resina poliéster. Las cámaras de curado fueron colocadas bajo luz UV para acelerar la polimerización del poliéster y finalizar el proceso de plastinación. Se logró desarrollar satisfactoriamente en el Laboratorio de Plastinación y Técnicas Anatómicas de la Universidad de La Frontera un protocolo de plastinación de cortes con resina poliéster, obteniendo una excelente conservación de cortes de cerebro, con diferenciación de sustancias gris y blanca, y conservación de todas las características morfológicas.

Plastination is an anatomical technique of cadaveric conservation created in 1977 by Gunther von Hagens, in Heidelberg, Germany, and that substitutes biological and / or fixation fluids with acetone, to then impregnate the samples with different resins, depending on the developed plastination technique, to finally carry out the polymerization of the components incorporated into the samples, to obtain dry and totally durable biological samples. The aim of this work was to develop a sheet plastination protocol with polyester resin (Biodur® P40) in 3 mm thick slices of human brain. The samples were fixed and preserved with 10 % formalin. The brains were sectioned with a slice cut machine, obtaining thin sheets of 3 mm thick. Immediately the slices of brain were placed in dehydration in 100 % acetone, at -25 °C, for 7 days the first acetone bath, and for another 3 more days, for the second acetone bath. Once the cuts were dehydrated, they were placed in Biodur® P40 polyester resin and the forced impregnation was carried out in a vacuum chamber at room temperature (20 °C). Once the forced impregnation was finished, the curing stage was carried out, which first consists in the assembly of the curing chambers within which the slices with polyester resin were placed. The curing chambers were placed under UV light to accelerate the polymerization of the polyester and finished the plastination process. A sheet plastination protocol with polyester resin was successfully developed in the Laboratory of Plastination and Anatomical Techniques of Universidad de La Frontera, obtaining excellent conservation of brain slices, with differentiation of gray and white substances, and conservation of all morphological characteristics.

Room temperature/Corcoran/Dow Corning™-Silicone plastination process.

For 20 years, the cold temperature/S10/von Hagens' plastination technique was used to preserve biological specimens without challenge. It became the "gold standard" for preservation of beautiful, dry biological specimens. Near the end of the 21st century, a group from the University of Michigan and environs and Dow Corning™, USA, combined silicone ingredients, similar to the von Hagens' plastination products, however in a different sequence. The new polymer (Cor-tech) was combined with the cross-linker to design the "impregnation mix" which would invade the cellular structure of the specimen and yet was stable at room temperature. Later, curing would be by application of the catalyst onto the impregnated specimen. This unique sequencing of products would become the "Room temperature/Dow Corning™/Corcoran-Silicone plastination technique." The results of this room temperature technique provided similar plastinates, beautiful and practical for demonstration, containing no toxic chemical residues and forever preserved. As the name implies, impregnation of this silicone mix could be done at room temperature, without having to be kept cold. Both processes (cold and room temperature) required the same four basic steps for plastination. As well, both processes used similar basic polymers and additives to produce plastinates. However, they were combined in a different sequence. Cold temperature combines polymer and catalyst/chain extender, which is not stable and therefore must be kept colder than -15°C, while room temperature combines polymer with cross-linker which is stable, and likely forever.

Coloring plastinated specimens.

In the early days of plastination, plastinate Color was the usual grey/brown familiar to formalin-fixed biological specimens. Initially, trials with Kaiserling's, Klotz, Jore's and McCormick's fixative solutions were disappointing. Vascular injections with Colored epoxy were a great breakthrough in the 1980s. Biodur AC10® stain was the first stain of note to be applied to gross specimens to be plastinated and was applied in the last acetone bath. As plastination became more popular, specimen Color became an important and necessary aspect. Reactivation of the normal Color of red blood cells within a formalin-fixed specimen was introduced as a mechanism to restore Color to plastinated specimens. Painting of plastinated vessels was tried with some success, and finally, a superior new proprietary type of silicone coloration was developed. More recently, a versatile red pigment stain was developed. All of these have added aesthetically to the plastination processes and will certainly be a reality in the years to come. The various methodologies to Color plastinates are presented. Time will tell how effective these may or may not be.

Plastination-A scientific method for teaching and research.

Over the last four decades, plastination has been one of the best processes of preservation for organic tissue. In this process, water and lipids in biological tissues are replaced by polymers (silicone, epoxy, polyester) which are hardened, resulting in dry, odourless and durable specimens. Nowadays, after more than 40 years of its development, plastination is applied in more than 400 departments of anatomy, pathology, forensic sciences and biology all over the world. The most known polymers used in plastination are silicone (S10), epoxy (E12) and polyester (P40). The key element in plastination is the impregnation stage, and therefore depending on the polymer that is used, the optical quality of specimens differs. The S10 silicone technique is the most common technique used in plastination. Specimens can be used, especially in teaching, as they are easy to handle and display a realistic topography. Plastinated silicone specimens are used for displaying whole bodies, or body parts for exhibition. Transparent tissue sections, with a thickness between 1 and 4 mm, are usually produced by using epoxy (E12) or polyester (P40) polymer. These sections can be used to study both macroscopic and microscopic structures. Compared with the usual methods of dissection or corrosion, plastinated slices have the advantage of not destroying or altering the spatial relationships of structures. Plastination can be used as a teaching and research tool. Besides the teaching and scientific sector, plastination becomes a common resource for exhibitions, as worldwide more and more exhibitions use plastinated specimens.

E12 technique: Conventional epoxy resin sheet plastination.

Epoxy plastination techniques were developed to obtain thin transparent body slices with high anatomical detail. This is facilitated because the plastinated tissue is transparent and the topography of the anatomical structures well preserved. For this reason, thin epoxy slices are currently used for research purposes in both macroscopic and microscopic studies. The protocol for the conventional epoxy technique (E12) follows the main steps of plastination-specimen preparation, dehydration, impregnation and curing/casting. Preparation begins with selection of the specimen, followed by freezing and slicing. Either fresh or fixed (embalmed) tissue is suitable for epoxy plastination, while slice thickness is kept between 1.5 and 3 mm. Impregnation mixture is made of epoxy E12 resin plus E1 hardener (100 ppw; 28 ppw). This mixture is reactive and temperature sensitive, and for this reason, total impregnation time under vacuum at room laboratory temperature should not last for more than 20-24 hr. Casting of impregnated slices is done in either flat chambers or by the so-called sandwich method in either fresh mixture or the one used for impregnation. Curing is completed at 40°C to allow a complete polymerization of the epoxy-mixture. After curing, slices can be photographed, scanned or used for anatomical study under screen negatoscope, magnification glass or fluorescent microscope. Based on epoxy sheet plastination, many anatomical papers have recent observations of and/or clarification of anatomical concepts in different areas of medical expertice.