Xenoimplant of Collagen Matrix Scaffold in Liver Tissue as a Niche for Liver Cells.

Hepatitis C virus-induced liver damage, chronic liver damage due to alcohol, and non-alcoholic liver disease-induced cellular alterations promote fibrosis, cirrhosis, and/or hepatocellular carcinoma. The recommended therapeutic option for advanced liver damage is liver transplantation. Extracellular matrix scaffolds have been evaluated as an alternative for tissue restoration. Studies on the biocompatibility and rejection of synthetic and natural scaffolds as an alternative to organ transplantation have been evaluated. Our group has recently described the xenoimplant of collagen matrix scaffold (CMS) in a rat model. However, no complete macroscopic and histological description of the liver parenchyma at the initial (day 3), intermediate (day 14), and advanced (day 21) stages has been obtained. In this study, we described and compared liver tissue from the CMS zone (CZ, CMS, and liver parenchyma), liver tissue from the normal zone (liver parenchyma close to the CMS), and basal tissue (resected tissue from the CMS implantation site). Our data strongly suggest that the collagen matrix xenoimplant is a good niche for hepatocytes, with no rejection, and does not affect liver function tests. The liver can regenerate after damage, but this capacity is inhibited in a chronic injury. At present, the use of CMS after liver damage has not been reported. This biomaterial could be a novel alternative in the field of regenerative medicine for liver diseases.

Three-Dimensional Collagen Matrix Scaffold Implantation as a Liver Regeneration Strategy.

Liver diseases are the leading cause of death worldwide. Excessive alcohol consumption, a high-fat diet, and hepatitis C virus infection promote fibrosis, cirrhosis, and/or hepatocellular carcinoma. Liver transplantation is the clinically recommended procedure to improve and extend the life span of patients in advanced disease stages. However, only 10% of transplants are successful, with organ availability, presurgical and postsurgical procedures, and elevated costs directly correlated with that result. Extracellular matrix (ECM) scaffolds have emerged as an alternative for tissue restoration. Biocompatibility and graft acceptance are the main beneficial characteristics of those biomaterials. Although the capacity to restore the size and correct function of the liver has been evaluated in liver hepatectomy models, the use of scaffolds or some kind of support to replace the volume of the extirpated liver mass has not been assessed. Partial hepatectomy was performed in a rat liver with the xenoimplantation of a collagen matrix scaffold (CMS) from a bovine condyle. Left liver lobe tissue was removed (approximately 40%), and an equal proportion of CMS was surgically implanted. Liver function tests were evaluated before and after the surgical procedure. After days 3, 14, and 21, the animals were euthanized, and macroscopic and histologic evaluations were performed. On days 3 and 14, adipose tissue was observed surrounding the CMS, with no clinical evidence of rejection or infection, as was vessel neoformation and CMS reabsorption at day 21. There was histologic evidence of an insignificant inflammation process and migration of adjacent cells to the CMS, observed with the hematoxylin and eosin (H&E) and Masson's trichrome staining. The CMS was shown to perform well in liver tissue and could be a useful alternative for studying tissue regeneration and repair in chronic liver diseases.

Biosafety of an entomopathogenic fungus Isaria fumosorosea in an acute dermal test in rabbits.

Isaria fumosorosea (formerly Paecilomyces fumosoroseus) is an entomopathogenic fungus that has been proposed as a low risk environmental alternative to the use of chemical insecticides to control agricultural pests and disease vectors. Although there are some mycoinsecticides already being marketed in many countries, not all their biosafety protocols have been published. The acute dermal toxicity test in an animal model is one in a series of biosafety protocols that must be developed, in order to provide information on health hazards, while taking into consideration the periods that the workers are in direct contact with the microbial agent when applied for the control of pests. For this test, we used I. fumosorosea monospore culture EH-506/3, isolated in Mexico from the Bemisia tabaci whitefly, applying a dose of 2 g/kg of animal body weight, on the shaved skin of 16 New Zealand rabbits, with an exposure time of 24 h. Clinical observations were conducted to evaluate the presence of erythema, edema and other alterations in the skin, as well as the behavior and health of the animals, for a period of 14 days. None of the rabbits showed clinical signs of any disease and their body weight corresponded to the expected weight for a healthy rabbit. The test showed no inflammatory reactions in the skin, supporting the safety of a single dose of this fungus in dermal exposure. Therefore, these data support the safety of I. fumosorosea EH-506/3 when applied to the skin.

Absorbable bioprosthesis for the treatment of bile duct injury in an experimental model.

INTRODUCTION: Cholecystectomy is a common surgical procedure in which complications may occur, such as injury to the biliary tract, which are associated with high morbidity. The aim of this study was to demonstrate the efficacy of a polymer-based absorbable bioprosthesis with bone scaffold for the treatment of bile duct injury in an animal model. MATERIALS AND METHODS: An absorbable bioprosthesis was used to replace the common bile duct in 15 pigs which were divided into 3 groups with different follow-ups at 1, 3 and 6 months. The animals were anesthetized at these time points and laboratory tests, Magnetic Resonance Cholangiopancreatogram [MRCP], Choledochoscopy using Spyglass and Endoscopic retrograde Cholangiopancreatogram [ERCP] were performed. After radiological evaluation was complete, the animals were euthanized and histological and immunohistochemical analyses were performed. RESULTS: Liver function tests at different time points demonstrated no significant changes. No mortality or postoperative complications were found in any of the experimental models. Imaging studies ([MRCP], [ERCP] and Choledochoscopy with SpyGlass(™)) showed absence of stenosis or obstruction in all the experimental models. DISCUSSION: Histological and immunohistochemical staining (CK19 and MUC5+) revealed the presence of biliary epithelium with intramural biliary glands in all the experimental models. There was no stenosis or obstruction in the bile duct. CONCLUSIONS: The bioprosthesis served as scaffolding for tissue regeneration. There was no postoperative complication at 6 months follow-up. This bioprosthesis could be used to replace the bile duct in cancer or bile duct injury. The bioprosthesis may allow different modeling depending on the type of bile duct injury.

[Comparative study of the cost/effectiveness of surgical wash with various antiseptics].

BACKGROUND: "Surgical scrub" of the hands and arms is a fundamental procedure for reducing infection risk. We undertook this study in order to compare different antiseptics and their microbicidal effects, costs and times of the procedures. METHODS: Thirty students followed the surgical scrub procedure using benzalkonium chloride. Seven days later the students used povidone-iodine and, 7 days after that, they used chlorhexidine/alcohol. After the surgical scrub, cultures were obtained from the palms of their hands and from their nail beds. The students wore sterile gloves, which were removed 30 min later to obtain new cultures from the same sites. The cost of the products was calculated in Mexican pesos and the time of each procedure was measured in minutes. RESULTS: There was a statistically significant difference in the number of colony-forming units (CFUs). The number of CFUs was lower in the groups of students who used chlorhexidine/alcohol and povidone-iodine as compared to the benzalkonium chloride group. There was no difference between chlorhexidine/alcohol and povidone-iodine. Costs were higher for povidone-iodine and benzalkonium chloride compared to chlorhexidine/alcohol. Procedure times were similar with povidone-iodine and benzalkonium chloride but the time was reduced approximately five times when using chlorhexidine/alcohol. CONCLUSIONS: It is a proven fact that the lack of surgical scrub favors wound infections, longer hospital stays and increased costs. Therefore, further studies are needed to determine the best antiseptic according to cost/benefit. Chlorhexidine/alcohol proved to be the superior antiseptic in terms of cost/benefit compared to povidone-iodine and benzalkonium chloride.

[Bone loss treatment, pseudoarthrosis, arthrodesis and benign tumors using xenoimplant: clinical study].

BACKGROUND: Bone loss as a result of arthrodesis, pseudarthrosis, benign tumors and bone defects was treated using a xenoimplant (Nukbone). METHODS: The effectiveness of the material was evaluated through a longitudinal and observational study at the Hospital Regional "General Ignacio Zaragoza" (HRGIZ) ISSSTE. The Mexican xenoimplant is a patent of the National Autonomous University of Mexico (UNAM). RESULTS: Fifty two patients were considered regardless of age or gender. Of these patients, 28 were male and 24 female. Average age of the patients was 47.7 years (9-84 years). Twenty eight patients had arthrodesis, 16 were treated with pseudarthrosis, three patients had benign tumors and five patients presented bone defects, which were implanted with Nukbone at the site and was the correct treatment for the problem. The xenoimplant is fully integrated during a period of 3-18 months, depending on the size of the pathology and the region where it was placed. Fracture healing was evaluated radiographically according to the classification of Montoya. No patient had clinical signs of rejection. CONCLUSIONS: In Mexico, bony xenoimplants (osseous) have been used, all of foreign origin due to the high degree of technological dependence in this country. In this study we describe the use, for the first time, of a Mexican xenoimplant with a patent from the Universidad Nacional Autónoma de México (UNAM). The Mexican xenoimplant is biocompatible and can be adapted to treat pathologies where bony (osseous) material is needed.

Tratamiento de pérdidas óseas, pseudoartrosis, artrodesis y tumores óseos benignos con un xenoimplante mexicano (estudio clínico) / Bone loss treatment, pseudoarthrosis, arthrodesis and benign tumors using xenoimplant: clinical study

Objetivo: Se trataron pérdidas óseas, artrodesis, pseudoartrosis, tumores benignos y defectos óseos con un xenoimplante. Material y métodos: Se evaluó la eficacia del material mediante un estudio observacional y longitudinal en el Hospital Regional “General Ignacio Zaragoza” del ISSSTE. Resultados: Fueron considerados 52 pacientes, 28 masculinos y 24 femeninos, de los cuales a 28 se les practicó artrodesis, 16 fueron tratados por pseudoartrosis, tres presentaron tumores óseos benignos y cinco defectos óseos, a los cuales se les colocó el xenoimplante en el sitio y forma adecuada según el problema por tratar. El promedio de edad de los pacientes fue de 47.7 años, con un rango de nueve a 84 años. Se presentó consolidación ósea entre los tres y ocho meses después de la cirugía; el xenoimplante se integró totalmente en un periodo de tres a 18 meses dependiendo del tamaño de la patología y la región donde fue colocado. La consolidación ósea fue valorada radiográficamente de acuerdo con la clasificación de Montoya. Ningún paciente presentó signos clínicos de rechazo. Conclusiones: En México se han empleado xenoimplantes óseos de origen extranjero debido a la gran dependencia tecnológica del país. Por primera vez se utiliza un xenoimplante producido en el país y cuya patente es de la Universidad Nacional Autónoma de México. El xenoimplante Nukbone® fue biocompatible y resultó adecuado para tratar patologías donde se requiere aporte óseo.

BACKGROUND: Bone loss as a result of arthrodesis, pseudarthrosis, benign tumors and bone defects was treated using a xenoimplant (Nukbone). METHODS: The effectiveness of the material was evaluated through a longitudinal and observational study at the Hospital Regional "General Ignacio Zaragoza" (HRGIZ) ISSSTE. The Mexican xenoimplant is a patent of the National Autonomous University of Mexico (UNAM). RESULTS: Fifty two patients were considered regardless of age or gender. Of these patients, 28 were male and 24 female. Average age of the patients was 47.7 years (9-84 years). Twenty eight patients had arthrodesis, 16 were treated with pseudarthrosis, three patients had benign tumors and five patients presented bone defects, which were implanted with Nukbone at the site and was the correct treatment for the problem. The xenoimplant is fully integrated during a period of 3-18 months, depending on the size of the pathology and the region where it was placed. Fracture healing was evaluated radiographically according to the classification of Montoya. No patient had clinical signs of rejection. CONCLUSIONS: In Mexico, bony xenoimplants (osseous) have been used, all of foreign origin due to the high degree of technological dependence in this country. In this study we describe the use, for the first time, of a Mexican xenoimplant with a patent from the Universidad Nacional Autónoma de México (UNAM). The Mexican xenoimplant is biocompatible and can be adapted to treat pathologies where bony (osseous) material is needed.