Xenoinjertos de piel de tilapia en quemaduras cutáneas. Una revisión exploratoria / Tilapia skin xenografts in skin burns. An exploratory review

Introducción y objetivo: El tratamiento de heridas, y en particular el de las quemaduras es complejo, son lesiones de alto costo e implican amplios periodos de hospitalización, además de incapacidades físicas, laborales y alteraciones emocionales. Existen diferentes tratamientos para su manejo, entre ellos, recientemente, los xenoinjertos de piel de tilapia, del Nilo (Oreochromis niloticus), un pez de agua dulce nativo de África que se encuentra y cultiva comúnmente en diferentes países tropicales y subtropicales. Es un tejido rico en fibras de colágeno tipo I y III, con resistencia a la humedad y estructura similar a la piel humana. Usada como xenoinjerto, posee propiedades antiinflamatorias y antibacterianas que apoyan y mejoran la cicatrización. Evaluamos la eficacia de los injertos de piel de tilapia en comparación con técnicas alternativas para el tratamiento de quemaduras. Material y método: Búsqueda bibliográfica sistemática en las bases de datos PubMed y ScienceDirect, utilizando los términos MeSH, con la ecuación de búsqueda (tilapia skin) AND (burns), incluyendo estudios de casos y controles, reportes de caso y ensayos controlados aleatorios. Resultados: Analizamos 5 trabajos para el estudio final; 4 eran de Brasil (país que actualmente tiene más experiencia en el uso de piel de tilapia en regeneración tisular) y el quinto de Indonesia. Todos en inglés. Conclusiones: De nuestra revisión podemos concluir que, en la actualidad, no existe una técnica estándar para tratar heridas, sin embargo, los injertos de piel de tilapia demostraron una mejor y más rápida cicatrización de heridas, menos cambios de apósitos, menos dolor y costos más bajos, en comparación con las técnicas convencionales.Nivel de evidencia científica 5c Terapéutico.(AU)

Background and objective: Treatment of wounds, and burns in particular, is complex, they are high-cost injuries, imply long periods of hospitalization, additionally physical and work disabilities and emotional disturbances. There are different treatments available for its management, recently including tilapia skin xenografts. Nile tilapia (Oreochromis niloticus) is a fresh water fish, native to Africa and commonly found and farmed in different tropical and subtropical countries. The skin It is a tissue rich in type I and III collagen fibers and has resistance to moisture and skin alterations similar to human skin. Used as a xenograft, it possess anti-inflammatory and antibacterial properties that support and enhance healing. In this study, we evaluate the efficacy of tilapia skin grafts in comparison with alternative techniques for the treatment of burns. Methods: A systematic bibliographic search was carried out using the PubMed and ScienceDirect data bases, MeSH terms were used with the search equation (tilapia skin) AND (burns), including case-control studies, case reports, and randomized controlled trials. Results: Five papers were included for the final study; 4 were from Brazil (the country that currently has the most experience in the use of tilapia skin in tissue regeneration) and 1 from Indonesia, all of them were written in English. Conclusions: There is currently no standard technique for treating wounds, however, fish skin grafts demonstrated faster and improved wound healing, fewer dressing changes, less pain, and lower costs, compared with conventional techniques. Level of evidence 5c Terapeutic.(AU)

In-depth characterization of a new patient-derived xenograft model for metaplastic breast carcinoma to identify viable biologic targets and patterns of matrix evolution within rare tumor types

Metaplastic breast carcinoma (MBC) is a rare breast cancer subtype with rapid growth, high rates of metastasis, recurrence and drug resistance, and diverse molecular and histological heterogeneity. Patient-derived xenografts (PDXs) provide a translational tool and physiologically relevant system to evaluate tumor biology of rare subtypes. Here, we provide an in-depth comprehensive characterization of a new PDX model for MBC, TU-BcX-4IC. TU-BcX-4IC is a clinically aggressive tumor exhibiting rapid growth in vivo, spontaneous metastases, and elevated levels of cell-free DNA and circulating tumor cell DNA. Relative chemosensitivity of primary cells derived from TU-BcX-4IC was performed using the National Cancer Institute (NCI) oncology drug set, crystal violet staining, and cytotoxic live/dead immunofluorescence stains in adherent and organoid culture conditions. We employed novel spheroid/organoid incubation methods (Pu·MA system) to demonstrate that TU-BcX-4IC is resistant to paclitaxel. An innovative physiologically relevant system using human adipose tissue was used to evaluate presence of cancer stem cell-like populations ex vivo. Tissue decellularization, cryogenic-scanning electron microscopy imaging and rheometry revealed consistent matrix architecture and stiffness were consistent despite serial transplantation. Matrix-associated gene pathways were essentially unchanged with serial passages, as determined by qPCR and RNA sequencing, suggesting utility of decellularized PDXs for in vitro screens. We determined type V collagen to be present throughout all serial passage of TU-BcX-4IC tumor, suggesting it is required for tumor maintenance and is a potential viable target for MBC. In this study we introduce an innovative and translational model system to study cell–matrix interactions in rare cancer types using higher passage PDX tissue.

Microtomographic reconstruction of mandibular defects treated with xenografts and collagen-based membranes: A pre-clinical minipig model / Reconstrucción microtomográfica de defectos mandibulares tratados con Xenoinjertos y membranas a base de colágeno: un modelo preclínico de minicerdo

Background: The goal of this study was to evaluate hard tissue response following guided bone regeneration us-ing commercially available bovine bone grafts and collagen membranes; bilayer collagen membrane and porcinepericardium-based membrane, by means of a non-destructive three-dimensional (3D) computerized volumetricanalysis following microtomography reconstruction.Material and Methods: Bone regenerative properties of various bovine bone graft materials were evaluated in theGöttingen minipig model. Two standardized intraosseous defects (15mm x 8mm x 8mm) were created bilaterallyof the mandible of eighteen animals (n=72 defects). Groups were nested within the same subject and randomlydistributed among the sites: (i) negative control (no graft and membrane), (ii) bovine bone graft/bilayer collagenmembrane (BOB) (iii) Bio-Oss® bone graft/porcine pericardium-based membrane (BOJ) and (iv) cerabone® bonegraft/porcine pericardium-based membrane (CJ). Samples were harvested at 4, 8, and 12-week time points (n=6animal/time point). Segments were scanned using computerized microtomography (μCT) and three dimensionallyreconstructed utilizing volumetric reconstruction software. Statistical analyses were performed using IBM SPSSwith a significance level of 5% Results: From a temporal perspective, tridimensional evaluation revealed gradual bone ingrowth with the presenceof particulate bone grafts bridging the defect walls, and mandibular architecture preservation over time. Volumetricanalysis demonstrated no significant difference between all groups at 4 weeks (p>0.127). At 8 and 12 weeks therewas a higher percentage of new bone formation for control and CJ groups when compared to BOB and BOJ groups(p<0.039). The natural bovine bone graft group showed more potential for graft resorption over time relative to bo-vine bone graft, significantly different between 4 and 8 weeks (p<0.003)...(AU)

A systematic review and meta-analysis on the effectiveness of xenograft to prevent periodontal defects after mandibular third molar extraction / Una revisión sistemática y un metanálisis sobre la eficacia del xenoinjerto para prevenir defectos periodontales después de la extracción del tercer molar mandibular

Background: To evaluate the use of guided bone regeneration with xenograft to prevent periodontal defect in thedistal aspect of the second molar after the surgical removal of the mandibular third molar.Material and Methods: Three electronic databases (Pubmed, Cochrane Library and Scopus) were searched inApril 2020. Randomized clinical trials in non-smokers and healthy patients, with at least six months follow-up, comparing periodontal probing depth, clinical attachment level, alveolar bone level and adverse events wereselected by two independent investigators. The risk of bias assessment of the selected studies was evaluated bymeans of the Cochrane Collaboration’s Tool. Finally, a meta-analysis of the outcomes of interest was performed.Results: Despite 795 articles were found in the initial search, only three randomized controlled clinical trials wereincluded. Pooled results favoured the use of the xenograft plus collagen membrane over the spontaneous healingin terms of periodontal probing depth gain (MD=2.36; 95% CI 0.69 to 4.03; P=0.005) and clinical attachment levelgain (MD=2.52; 95% CI 0.96 to 4.09; P=0.002). No other statistically significant differences were found.Conclusions: Within the limitations of the present review, the xenograft plus collagen membrane exhibited betterperiodontal results than spontaneous healing without increasing postoperative complications. However, future well-designed studies with larger samples are required to confirm our results.(AU)

Coberturas transitorias en quemaduras / Temporary coverage in burns

En numerosas ocasiones, los pacientes con quemaduras profundas recientemente sometidos a escarectomías no pueden recibir una cobertura inmediata con autoinjertos debido a las condiciones locales del lecho de la herida, a la no disponibilidad de áreas donantes o porque el procedimiento en sí mismo pueda resultar arriesgado para la supervivencia del paciente. En estas circunstancias es necesario cubrir temporalmente la herida para mantener su viabilidad y reducir las infecciones y el estrés metabólico secundarios a la pérdida de fluidos y al dolor. Los homoinjertos están considerados como la mejor cobertura transitoria, pero su disponibilidad y costo hacen que su uso sea limitado; en segundo lugar, y aunque su calidad es inferior a la de los homoinjertos, los heteroinjertos proveen también una cobertura cutánea adecuada en muchos de estos casos. Asistimos en la actualidad a un desarrollo constante de productos biosintéticos útiles para este mismo fin; sin embargo, hasta la fecha, no existe ningún producto que podamos considerar como patrón o modelo de elección. Este artículo revisa los productos actualmente dispo¬nibles y las situaciones clínicas en las cuales pueden ser utilizados

Sometimes excised burn wounds cannot be covered immediately with autologous skin grafts, due to local wound conditions, unavailability of donor areas, or because the procedure itself may be risky for patient sur¬vival. In these circumstances a temporary coverage is desirable to maintain wound viability, reduce infections, metabolic stress and pain. Allografts have always been considered the best temporary coverage, but availability and cost are of concern. Xenografts can provide temporary coverage, even though its quality is clearly inferior to allograft. Although there is a constant evolution in the development of skin substitutes, no single product can be considered as the gold standard. This article reviews currently available products and clinical situations in which they can be used

Historia del soporte de la experimentación animal en el desarrollo de los trasplantes / History of the support of animal experimentation in the development of transplants

Se realiza en el trabajo una descripción histórica del empleo de otras especies especial animales, como soporte de la experimentación en el desarrollo y puesta a punto de las diferentes trasplantes. La mayoría de las aportaciones referenciadas constituyen a hitos en relación a la realización de forma pionera de las técnicas. En otros casos el apunte histórico se refiere a experimentos realizados de forma rutinaria que sirvieron para lograr aportaciones en algún campo puntual y también en el adiestramiento técnico quirúrgico para realizar los trasplantes. Hay referencia también al empleo de animales para la obtención de las vísceras como injertos en su aplicación en el ser humano lo que constituyen los xenoinjertos

A historical description of the use of other animals species, is carried out in the work as a support for the experimentation in the development and implementation of the different transplants. The majority of the referenced contributions constitute milestones in relation to the realization of a pioneering technique. In other cases the historical record refers to routinely performed experiments that served to achieve contributions in a specific field and also in the surgical technical training to perform the transplants. There is also reference to the use of animals for obtaining the viscera as grafts in their application in the human being what constitute the xenografts

Magnetic resonance imaging of tumor angiogenesis using dual-targeting RGD10-NGR9 ultrasmall superparamagnetic iron oxide nanoparticles

Objective. Using RGD10-NGR9 dual-targeting superparamagnetic iron oxide nanoparticles to evaluate their potential value in tumor angiogenesis magnetic resonance imaging (MRI) and the biodistribution in vitro and in vivo. Materials and methods. Dual-targeting RGD10-NGR9 ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles were designed and synthesized in our previous study. In vitro, prussian blue staining and phenanthroline colorimetry were conducted to evaluate binding affinity and adsorption of dual-targeting USPIO nanoparticles to αvβ3-integrin/APN positive cells. In vivo, a xenograft mouse tumor model was used to evaluate the potential of the dual-targeting nanoparticles as an MRI contrast agent. After intravenous injection, the contrast-to-noise ratio (CNR) values of MR images obtained were calculated at predetermined time-points. The iron level was detected to access the biodistribution and plasma half-time. Results. In vitro, dual-targeting USPIO nanoparticles bound to proliferating human umbilical vein endothelia cells with high specificity. In vivo, contrast MRI of xenograft mice using dual-targeting nanoparticles demonstrated a significant decrease in signal intensity and a greater increase in CNR than standard MRI and facilitated the imaging of tumor angiogenesis in T2*WI. In terms of biodistribution, dual-targeting USPIO nanoparticles increased to 1.83 times in tumor lesions as compared to the control. And the plasma half-time was about 6.2 h. Conclusion. A novel RGD10-NGR9 dual-targeting USPIO has a great potential value as a contrast agent for the identification of tumor angiogenesis on MRI, according to the high specific affinity in vitro and in vivo

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Estudio ultraestructural del comportamiento de xenoinjertos vasculares sometidos a dietas hiperlipídicas / Ultrastructural study about the effect of the hiperlipidic diets on criopreserved vascular xenografts

Se ha procedido al análisis ultraestructural de la pared de la aorta nativa y de xenoinjertos criopreservados implantados en ratas de la raza Wistar-Lewis sometidas a dietas aterogénicas. Para ello se han establecidos distintos grupos de estudio, iguales en número y con una distribución al azar de los individuos. Se trata de determinar si las lesiones ateromatosas inducidas por la alimentación hiperlipídica son idénticas en ambos tipos de vasos arteriales o presentan diferencias significativas. Una vez finalizado el período de investigación, los resultados obtenidos sugieren que los injertos heterólogos son más sensibles a la acción pató- gena de las dietas ricas en grasas. La aplicación de la microscopía electrónica, tanto de transmisión como de barrido, ha permitido valorar de forma idónea el comportamiento de los implante (AU)

One proceeds to the ultrastructural analysis of the wall of the native aorta and the criopreserved xenografts, implanted in Wistar-Lewis rats submitted to aterogenic diets. For this, different groups of study are established, in equal number and with a distribution of the individuals at random. It is a question of determining if the injuries induced by the hiperlipidic nourishment are identical in both types of arterial vessels or if they present significant differences. Once the period of investigation is finished, the obtained results suggest that the heterologous grafts are more sensitive to the pathogenic action of the diets rich in fats. The application of the electronic microscopy, both of transmission and of sweep, has allowed to value the behaviour of the implants in a suitable form (AU)