Evaluation of biological integration and inflammatory response to blood vessels produced by tissue engineering: experimental model in rabbit

The cardiovascular disease is the main cause of mortality in the western population and the Peripheral Arterial Disease (PAD) evolves, in large proportion, to the amputation of the affected limb. This study aimed to synthesize blood vessels using scaffolds of rabbit’s Inferior Vena Cava (IVC) and test its interaction with the receiver tissue and test inflammatory responses. Methods: The IVC were obtained from 8 rabbits to decellularization or in natura veins. The descellularized veins (DV) were obtained through protocols of decellularization established previously, using sodium dodecyl sulfate 1% (SDS) and mechanical agitation for 2 hours.12 animals were used to the experiment in vivo (3 animals in each group), being the product implanted in the interescapular dorsal area of each animal. The established groups are: Group 1- in natura allogeneic vein; Group 2- DV-SDS no cells added; Group 3- DV- SDS with 1x105 adipose tissue allogeneic Mesenchymal Stem Cells (MSC) added; Group 4- DV-SDS + autologous MSC. The (MSC) of the autologous receptors were collected 21 days before the implant and expanded in vitro. The explants were analyzed by histomorphological/immunohistochemistry and the peripheral blood was collected in the pre operatory in 1d, 7d, 14d, 30d and 60 day post operatory to dose the inflammatory and anti-inflammatory interleukins. Results: IL-10 and PDGF levels were significantly higher in group 4, which also showed neovascularization and large endothelial reconstruction. We may conclude the existence of an inflammatory response to the use of allogeneic grafts, which is lower when associated with autologous MSC

Private umbilical cord blood banks for family use, in Brazil: technical, legal and ethical issues for an implementation analysis

Os bancos de sangue de cordão umbilical e placentário foram criados a partir da comprovação de que o sangue de cordão umbilical e placentário (SCUP) é uma fonte rica em células progenitoras hematopoéticas (CPH) e alternativa às células provenientes da medula óssea para transplante, fato que gerou o interesse pelo armazenamento das células nele contidas. A legislação brasileira distingue bancos para uso alogênico não aparentado (públicos) e para uso exclusivamente autólogo (privados). Por sua vez, o armazenamento de SCUP para uso familiar (doação dirigida) pode ser realizado em bancos de sangue de cordão umbilical e placentário públicos, serviços de hemoterapia ou centros de transplante, quando há um membro da família do nascituro com doença diagnosticada e que necessite de transplante de CPH como tratamento. Apesar de a legislação ser clara, a Anvisa tem identificado o interesse sobre a possibilidade da liberação de unidades de SCUP, armazenadas em bancos autólogos, para a utilização de outrem, familiar, além do recém-nascido beneficiário. O objetivo do trabalho visa promover a reflexão sobre uma possível modificação dos parâmetros legais nacionais que regem os bancos de SCUP autólogo, tornando-os bancos com vistas ao uso familiar, por meio da exposição dos principais elementos relacionados ao tema. O estudo analisou os critérios técnico-sanitários legais para regulamentação dos bancos; descreveu as características das CPH de diversas fontes e tipos de doação para transplante; contextualizou a relação com os princípios da Bioética; avanços sobre terapia e pesquisas relativas às CPH; e discutiu possíveis riscos envolvidos no processo.Umbilical cord blood banks have been created worldwide after the discovery that umbilical cord blood (UCB) is a rich source of Hematopoietic Stem Cells (HSC) and an alternative to HSC from bone marrow for allogeneic transplantation. According to Brazilian legislation, banks for allogeneic use (government services) and exclusively autologous use (private services) can be created in the country. The storage of UCB units for direct donation (family use) can occur in public cord blood banks, hemotherapy services and transplant centers when there is a specific need to treat a known patient that is a member of the newborn's family. Even with the legislation being quite clear about the creation of cord blood banks and distribution of UCB units, ANVISA has identified an interest, demonstrated by the population and regulated sector, in the possibility of releasing UCB units, stored in autologous cord blood banks, with the purpose of clinical applicability to another family member other than the newborn owner of the cells. The objective of this study is to promote a discussion on a possible alteration in the legal parameters that support the implementation of autologous cord blood banks, towards the constitution of private banks for family use, pointing out the main issues. The study analyzed the technical and legal criteria related to cord blood banks, described the characteristics of HSC from different sources and types of transplant donations and procedures; discussed concerns related to Bioethical principles, current and potential clinical HSC applications, and possibly risks and benefits

Treatment of osteochondral injuries with platelet gel

OBJECTIVES: Treatments for injured articular cartilage have not advanced to the point that efficient regeneration is possible. However, there has been an increase in the use of platelet-rich plasma for the treatment of several orthopedic disorders, including chondral injuries. Our hypothesis is that the treatment of chondral injuries with platelet gel results in higher-quality repair tissue after 180 days compared with chondral injuries not treated with gel. METHODS: A controlled experimental laboratory study was performed on 30 male rabbits to evaluate osteochondral injury repair after treatment with or without platelet gel. Osteochondral injuries were surgically induced in both knees of each rabbit at the medial femoral condyle. The left knee injury was filled with the platelet gel, and the right knee was not treated. Microscopic analysis of both knee samples was performed after 180 days using a histological grading scale. RESULTS: The only histological evaluation criterion that was not significantly different between treatments was metachromasia. The group that was treated with platelet gel exhibited superior results in all other criteria (cell morphology, surface regularity, chondral thickness and repair tissue integration) and in the total score. CONCLUSION: The repair tissue was histologically superior after 180 days in the study group treated with platelet gel compared with the group of untreated injuries

Immunosensor for the Diagnostics of Autoimmune Hemolytic Anemia (AIHA) Based on Immobilization of a Monoclonal Antibody on a Layer of Silk Fibroin

European Regional Development Fund (ERDF)The diagnostics of the autoimmune hemolytic anemia (AIHA), a rare disease caused by autoantibody-induced hemolysis, is still prone to false positives for it is based on visual observation in the so-called Direct Coombs test. In this study, we developed a specific IgG hemolysis immunosensor produced with layer-by-layer (LbL) films containing a monoclonal antibody against human immunoglobulin (mAbIMUG) deposited along with a layer of silk fibroin (SF) derived from Bombyx mori cocoons. Adsorption of mAbIMUG on a SF layer was confirmed by the fluorescence emission band at 326 nm. Immunosensors were prepared with LbL films deposited on interdigitated gold electrodes for impedance spectroscopy and on screen printed carbon electrodes for electrochemical measurements. When the SF/mAbIMUGLbL film was exposed to healthy red blood cells (RBCs), no cell binding was observed by the optical microscopy images. In addition, no major changes were observed in the signals of the square wave voltammogram and in the impedance spectra. In contrast, the electrochemical signal was significantly increased and the dielectric loss curve shifted for the sensing units containing RBCs with the antibody attached on the surface (“sick cells”). Furthermore, cell attachment was so strong that optical images still showed covered electrodes even after washing in PBS buffer. The detection with two distinct methods seems promising for an effective diagnosis of AIHA

Fat grafting: Lipofragmentation X Liposuction

Introduction: Aiming to obtain autogenous and injectable lipografts from resected tissues in dermolipectomies, this study proposes a new method for harvesting and processing adipose tissue through a specific fragmenting device. The main objective was to establish a comparative analysis of the quality and viability characteristics of the new lipofragmentation technique and those of the well-known liposuction technique, widely accepted as a viable source of fat grafting. In vivo and in vitro assays were designed to evaluate the biological behavior of the samples to guide new and possible human studies with clinical applications. Methods: A post-bariatric patient who underwent abdominal dermolipectomy had her surgical specimen resected, which was divided into four parts that underwent liposuction and lipofragmentation, with and without prior infiltration. All samples were centrifuged and distributed for assays with assessments involving histological analysis, immunohistochemistry, flow cytometry, cell culture, and xenograft injection on the back of 10 Wistar rats, which was evaluated after six weeks for mass, volume, and histological features. Results: The structural characteristics and biological behaviors of fragmented, dry, and infiltrated fat samples were similar to those of liposuction samples. Conclusions: Fat fragmentation transformed the subcutaneous cellular tissue of dermolipectomies into a new, viable injectable lipograft variant, with biological characteristics similar to those of traditional liposuction. Although still preliminary, our results support further investigations to optimize the technique and improve fat grafting and its possible applications in regenerative medicine

Organosilylated complex [Eu(TTA)₃(Bpy-Si)]: a bifunctional moiety for the engeneering of luminescent silica-based nanoparticles for bioimaging

A new highly luminescent europium complex with the formula [Eu(TTA)₃(Bpy-Si)], where TTA stands for the thenoyltrifluoroacetone, (C₄H3S)COCH₂COCF₃, chelating ligand and Bpy-Si, Bpy-CH₂NH(CH₂)₃(OEt)₃, is an organosilyldipyridine ligand displaying a triethoxysilyl group as a grafting function has been synthesized and fully characterized. This bifunctional complex has been grafted onto the surface of dense silica nanoparticles (NPs) and on mesoporous silica microparticles as well. The covalent bonding of [Eu(TTA)₃(Bpy-Si)] inside uniform Stöber silica nanoparticles was also achieved. The general methodology proposed could be applied to any silica matrix, allowed high grafting ratios that overcome chelate release and the tendency to agglomerate. Luminescent silica-based nanoparticles SiO₂-[Eu(TTA)₃(Bpy-Si)], with a diameter of 28 ± 2 nm, were successfully tested as a luminescent labels for the imaging of Pseudomonas aeruginosa biofilms. They were also functionalized by a specific monoclonal antibody and subsequently employed for the selective imaging of Escherichia coli bacteria