Common calcaneal tendon repair with glycerin-preserved carotid artery xenografts and autologous bone marrow mononuclear cells in rabbits

Fifteen adult rabbits were used to evaluate the repair of experimental common calcaneal tendon defects treated with glycerin-preserved canine carotid artery xenografts alone or associated with autologous mononuclear bone marrow cells (AMCs). Rabbits were submitted to daily clinical examination; implanted sites were analyzed under light microscopy within 15, 30 and 60 days of surgery. Pelvic limbs receiving xenografts associated with AMCs had better physical performance as well as higher collagen fiber, fibroblast, lymphocyte and new vessel counts at all postoperative time points considered. Glycerin-preserved canine carotid artery xenografts associated with AMCs constituted an effective method for common calcaneal tendon repair in rabbits. Utilizou-se 15 coelhos adultos para avaliar o reparo de lesão do tendão calcanear comum com implante de artéria carótida de cães, preservada em glicerina, associado ou não a células mononucleares autólogas da medula óssea (CMAs). Os animais foram observados diariamente por meio de avaliações clínicas e o local do implante foi analisado sob microscopia de luz decorridos 15, 30 e 60 dias de pós-operatório. Notou-se em todos os períodos de observação, com o implante associado às CMAs, melhor desempenho físico dos membros pélvico e maior intensidade de fibras colágenas, fibroblastos e linfócitos e neovascularização. A utilização de xenoimplante de artéria carótida de cães preservada em glicerina associado à administração de células mononucleares da medula óssea foi eficiente no reparo do tendão calcanear comum de coelhos

Common calcaneal tendon repair with glycerin-preserved carotid artery xenografts and autologous bone marrow mononuclear cells in rabbits

Fifteen adult rabbits were used to evaluate the repair of experimental common calcaneal tendon defects treated with glycerin-preserved canine carotid artery xenografts alone or associated with autologous mononuclear bone marrow cells (AMCs). Rabbits were submitted to daily clinical examination; implanted sites were analyzed under light microscopy within 15, 30 and 60 days of surgery. Pelvic limbs receiving xenografts associated with AMCs had better physical performance as well as higher collagen fiber, fibroblast, lymphocyte and new vessel counts at all postoperative time points considered. Glycerin-preserved canine carotid artery xenografts associated with AMCs constituted an effective method for common calcaneal tendon repair in rabbits

Comparison of palmar digital neurectomy by the guillotine technique and palmar digital neurotomy associated with end-to-side neurorrhaphy in mares

O nervo digital palmar (NDP) lateral do membro torácico direito (MTD) de cinco equinos fêmeas foi submetido à neurectomia pela técnica da guilhotina, e o do membro torácico esquerdo (MTE) à neurotomia e neurorrafia término-lateral. Os animais foram avaliados a cada 15 dias quanto ao teste de sensibilidade cutânea com pressão local com pinça de casco e de claudicação, não sendo notados sinais clínicos de neuroma doloroso. Aos 60 dias pós-cirurgia coletou-se segmentos dos cotos proximais dos NDPs. Os dos MTDs apresentavam em média, a espessura de 7,16 mm e aos dos MTEs de 5,96 mm. Nos cotos proximais dos nervos dos membros direito e esquerdo notou-se predominância de células de Schwann à grande quantidade de tecido conjuntivo cicatricial. Os do MTEs apresentavam estruturas de nervo típico, bem constituídas, com maior organização do tecido nervoso e predomínio de fibras nervosas orientadas paralelamente. A neurorrafia termino-lateral apresentou tendência a ocasionar maior organização entre as estruturas analisadas, o que lhe conferiu menor potencial em desenvolver neuromas dolorosos.Five mares were submitted to palmar digital neurectomy by the guillotine technique and palmar digital neurotomy followed by end-to-side neurorrhaphy (right and left thoracic limbs, respectively). Mares were checked for local pain sensation using hoof tester and submitted to lameness workup at 15-day intervals. No evidence of painful neuroma formation was detected. Palmar digital nerve (PDN) stump segments were collected within 60 days of surgery. Mean left and right limb PDN stump thickness corresponded to 5.96 mm and 7.16 mm, respectively. Schwann cells prevailed over connective healing tissue in all PDN stumps studied. Well-formed nerve-like structures with better organized nervous tissue and predominance of parallel nerve fiber orientation were documented in left limb PDN stumps. End-to-side neurorrhaphy tended to promote tissue organization, potentially reducing the chances of neuroma formation

Adesão e modulação da progênie hepatocitária de células-tronco embrionárias de camundongos sobre a matriz extracelular placentária de camundongos

Researches from different fields around the world are searching for both new sources of biomaterials and potential hepatocytes in order to supply drug tests, cell therapies, and cell transplantation as alternative therapeutic support to liver diseases and injuries. Placenta may be eligible as a new model in tissue engineering due to its rich extracellular matrix (ECM) and availability after birth. Placental scaffolds were produced by decellularization with 0.01, 0.1 and 1% SDS, and 1% Triton X-100 which were valued by means of structure and composition. Afterwards, placental scaffolds were co-cultured with mouse embryonic fibroblasts in a tridimensional (3D) rotating system. Placental scaffolds presented a well-preserved acellular ECM containing 9.42 ± 5.2 ng dsDNA per mg of ECM. Weak collagen I of the natives clearly appears in decellularized ECM while the collagen III, once well observed in native placenta, it was absent on scaffolds. This interesting observation may have been due to the solubilization SDS-induced of the collagen III fibrils during decellularization. Fibronectin was well-observed in placental scaffolds whereas laminin and collagen IV were strongly stained. Recellularized with fibroblasts by a 3D culture system, placental scaffolds showed potential for repopulation, with cells adhered throughout its acellular ECM. Placental scaffolds were then newly recellularized, aiming now for differentiation of mouse embryonic stem cells into hepatic cells. In a protocol of 23 days, it was simulated major events of liver embryonic development by adding growth factors. As result, a high index of cells adhered, proliferated and migrated throughout outer and inner scaffolds ECM surface. Absence of Oct4 and Nanog showed that Activin A and Wnt3a (d0-6) induced primitive endoderm fate, and negative label for Foxa2 and Sox17 representing BMP4 and FGF2 (d6-10) differentiation-induced generating definitive endoderm cells. Also, FGF1, FGF4 and FG8b (d10-14) induced hepatoblast phenotype cells, that were observed positive for AFP and CK7 markers. Finally, HGF and FS-288 (d14-23) induced to hepatocyte-like cells, positive for CK18 and Alb markers. The hepatocyte-like cells functional aspects were observed by glycogen storage. Though a heterogeneous cell hepatic lineage was confirmed, mouse placental scaffolds shown a useful model to support recellularization with simultaneous differentiation into hepatic fate simulating phases of embryonic development.Pesquisas de diferentes campos ao redor do Mundo estão em busca de novas fontes tanto de biomateriais, quanto de potenciais hepatócitos, a fim de suprir testes de drogas, terapias celulares e transplante de células, como suporte terapêutico alternativo para doenças e lesões hepáticas. Placentas podem ser elegíveis como um novo modelo em Engenharia Tecidual em decorrência de sua rica matriz extracelular (ECM), e disponibilidade após o nascimento. Os scaffolds placentários foram produzidos por decelularização com SDS 0,01, 0,1 e 1% e Triton X-100 1%, os quais foram avaliados por meio da estrutura e composição. Posteriormente, os scaffolds placentários foram co-cultivados com fibroblastos embrionários de camundongos em um sistema rotativo tridimensional (3D). Os scaffolds placentários apresentaram uma MEC acelular bem conservada, contendo 9,42 ± 5,2 ng/dsDNA/mg/MEC. O fraco colágeno I nos nativos aparece claramente na MEC descelularizada, enquanto o colágeno III bem visível na placenta nativa estava ausente nos scaffolds. Esta observação interessante pode decorrido da solubilização das fibrilas de colágeno III, induzida pelo SDS durante a decelularização. A fibronectina foi bem observada nos scaffolds placentários, enquanto a laminina e o colágeno IV estiveram fortemente marcados. Recelularizados com fibroblastos por um sistema de cultura 3D, os scaffolds placentários mostraram potencial para repovoamento, com células aderidas ao longo de sua MEC acelular. Os scaffolds placentários foram então novamente recelularizados, visando agora a diferenciação de células tronco-embrionárias de camundongos em células hepáticas. Em um protocolo de 23 dias, foram simulados os grandes eventos do desenvolvimento embrionário do fígado, pela adição de fatores de crescimento. Como resultado, um alto índice de células aderiu, proliferou e migrou através das superfícies externa e interna dos scaffolds. A ausência de Oct4 e Nanog demostraram que o Activin A e o Wnt3a (d0-6) induziram o destino endoderma primitivo, e a marcação negativa para Foxa2 e Sox17 representaram a geração de células endodermais definitivas pela diferenciação induzida por BMP4 e FGF2 (d6-10). Ainda, FGF1, FGF4 e FG8b (d10-14) induziram células do fenótipo hepatoblasto, que foram observadas positivas para os marcadores AFP e CK7. Finalmente, HGF e FS-288 (d14-23) induziram as células hepatocyte-like, positivas para os marcadores CK18 e Alb. The hepatocyte-like cells functional aspects were observed by glycogen storage. Though a heterogeneous cell hepatic lineage was confirmed, mouse placental scaffolds shown a useful model to support recellularization with simultaneous differentiation into hepatic fate simulating phases of embryonic development. Os aspectos funcionais das células hepatocyte-like foi observada pelo armazenamento de glicogênio. Embora uma linhagem hepática formada por células heterogêneas tenha sido confirmada, os scaffolds placentários de camundongos se mostraram um modelo útil para sustentar a recelularização com simultânea diferenciação em destino hepático, simulando fases do desenvolvimento embrionário

Common calcaneal tendon repair with glycerin-preserved carotid artery xenografts and autologous bone marrow mononuclear cells in rabbits

Fifteen adult rabbits were used to evaluate the repair of experimental common calcaneal tendon defects treated with glycerin-preserved canine carotid artery xenografts alone or associated with autologous mononuclear bone marrow cells (AMCs). Rabbits were submitted to daily clinical examination; implanted sites were analyzed under light microscopy within 15, 30 and 60 days of surgery. Pelvic limbs receiving xenografts associated with AMCs had better physical performance as well as higher collagen fiber, fibroblast, lymphocyte and new vessel counts at all postoperative time points considered. Glycerin-preserved canine carotid artery xenografts associated with AMCs constituted an effective method for common calcaneal tendon repair in rabbits