ABSTRACT
Abstract Oral mucosa has been highlighted as a suitable source of epidermal cells due to its intrinsic characteristics such as its higher proliferation rate and its obtainability. Diabetic ulcers have a worldwide prevalence that is variable (1%-11%), meanwhile treatment of this has been proven ineffective. Tissue-engineered skin plays an important role in wound care focusing on strategies such autologous dermal-epidermal substitutes. Objective The aim of this study was to obtain autologous dermal-epidermal skin substitutes from oral mucosa from diabetic subjects as a first step towards a possible clinical application for cases of diabetic foot. Material and Methods Oral mucosa was obtained from diabetic and healthy subjects (n=20 per group). Epidermal cells were isolated and cultured using autologous fibrin to develop dermal-epidermal in vitro substitutes by the air-liquid technique with autologous human serum as a supplement media. Substitutes were immunocharacterized with collagen IV and cytokeratin 5-14 as specific markers. A Student´s t- test was performed to assess the differences between both groups. Results It was possible to isolate epidermal cells from the oral mucosa of diabetic and healthy subjects and develop autologous dermal-epidermal skin substitutes using autologous serum as a supplement. Differences in the expression of specific markers were observed and the cytokeratin 5-14 expression was lower in the diabetic substitutes, and the collagen IV expression was higher in the diabetic substitutes when compared with the healthy group, showing a significant difference. Conclusion Cells from oral mucosa could be an alternative and less invasive source for skin substitutes and wound healing. A difference in collagen production of diabetic cells suggests diabetic substitutes could improve diabetic wound healing. More research is needed to determine the crosstalk between components of these skin substitutes and damaged tissues.
Subject(s)
Humans , Male , Female , Adult , Middle Aged , Aged , Skin, Artificial , Cell Transplantation/methods , Diabetes Mellitus, Type 2 , Epidermis/cytology , Epithelial Cells/transplantation , Mouth Mucosa/cytology , Skin Ulcer/therapy , Time Factors , Transplantation, Autologous , Wound Healing , Biocompatible Materials , Case-Control Studies , Keratinocytes/cytology , Cells, Cultured , Reproducibility of Results , Collagen/analysis , Cell Culture Techniques , Cell Proliferation , Diabetes Mellitus, Type 2/therapy , FibroblastsABSTRACT
Anterior segment stem cell technology, due to its already well-defined corneal limbal stem cells with greater ease of evaluation, has been at the forefront of ophthalmic stem cell treatment and technology since 1997. This paper provides an overview of the current standard of care for treatment of limbal stem-cell deficient conditions and reviews recent treatment technologies using ex vivo expansion of cultivated limbal stem cells of the cornea
Subject(s)
Humans , Limbus Corneae/cytology , Epithelium, Corneal/cytology , Stem Cell Transplantation , Transplantation, Homologous , Epithelial Cells/transplantation , Amnion/transplantationABSTRACT
Lesões na superfície ocular podem atingir as células-tronco do limbo e causar deficiência límbica. A deficiência límbica é caracterizada pela conjuntivalização, que pode ser definida como a invasão do epitélio conjuntival sobre a córnea. Este processo é acompanhado por graus variáveis de alterações corneanas, como neovascularização, inflamação, erosões recorrentes, defeitos epiteliais persistentes, destruição da membrana basal do epitélio e cicatrização estromal. Frequentemente, estas alterações estão associadas à diminuição da acuidade visual, fotofobia e desconforto ocular. O melhor tratamento para essa afecção não é conhecido e possibilidades variam em casos uni ou bilaterais. Entre os tratamentos disponíveis, o transplante de limbo autólogo ou alógeno é um dos mais utilizados. Para melhorar os resultados dos transplantes alógenos, alguns pesquisadores utilizam o transplante de epitélio da córnea cultivado em laboratório pela expansão ex vivo de células-tronco epiteliais límbicas. Mas devido à limitada disponibilidade de tecido autólogo do limbo e o risco de complicações associadas à imunossupressão em transplante de tecido alógeno, pesquisas de outras opções de células-tronco cultivadas ex vivo têm sido descritas em fase experimental e clínica. Essa revisão descreve os novos tipos de células-tronco cultivadas ex vivo, seus resultados atuais e potencialidades futuras.
Lesions on the ocular surface can destroy the stem cells from the limbus and cause limbal stem cell deficiency. The limbal stem cell deficiency is marked by conjunctivalization, which can be defined as the invasion of conjunctival epithelium over the cornea. This process is accompanied by varying degrees of corneal changes such as neovascularization, inflammation, recurrent erosions, persistent epithelial defects, destruction of basement membrane of epithelium and stromal healing. Often, these changes are associated with poor visual acuity, photophobia and ocular discomfort. The best treatment for this disease is not known and varies in unilateral or bilateral cases. Among the treatments available, transplantation of limbal autograft or allograft is one of the most used. To improve the outcome of allotransplantation, some researchers use the transplantation of corneal epithelium cultured in the laboratory by ex vivo expansion of limbal stem cells, but due to limited availability of autologous tissue from the limbus and the risk of complications associated with immunosuppression in allogeneic tissue transplantation, researches of others options of stem cell cultured ex vivo have been described in experimental and clinical stage. This review describes the new types of stem cells cultured ex vivo, their current results and future potential.
Subject(s)
Humans , Corneal Diseases/therapy , Limbus Corneae/cytology , Stem Cell Transplantation/methods , Cell Culture Techniques/methods , Epithelial Cells/transplantationABSTRACT
Paciente apresentou falência de transplante de limbo e conjuntiva de doador vivo alógeno no olho direito após ceratoconjuntivite epidêmica. Após alguns meses, foi submetida a transplante de células-tronco epiteliais límbicas alógenas cultivadas ex vivo sobre membrana amniótica (primeiro caso no Brasil), tendo evoluído com epitelização total da córnea e melhora da acuidade visual. Após o 3º mês da cirurgia, iniciou-se neovascularização superficial periférica com piora da transparência corneana. A visão manteve-se 0,1 após um ano de cirurgia.
Case report of a patient who developed failure of an allogenic living related conjunctival limbal transplantation in the right eye after an episode of epidemic keratoconjunctivitis. After a few months, she underwent transplantation of allogenic limbal epithelial stem cells cultivated ex vivo on amniotic membrane (first case in Brazil). The patient evolved with total corneal epithelialization and improvement of the visual acuity. Three months after the surgery, peripheral superficial neovascularization with worsening of the corneal transparency was observed. The vision remained 0.1 after one year of the transplantation.
Subject(s)
Female , Humans , Male , Middle Aged , Amnion , Adult Stem Cells/transplantation , Epithelial Cells/transplantation , Keratoconjunctivitis/surgery , Limbus Corneae/cytology , Cell Culture Techniques/methods , Transplantation, Homologous , Treatment OutcomeABSTRACT
The cornea, conjuctiva and the limbus comprise the tissues at the ocular surface. All of them are covered by stratified, squamous, non-keratinizing epithelium and a stable tear film. The ocular surface health is ensured by intimate relationship between ocular surface epithelia and the preocular team film. There are two types of ocular surface failure. The first one is characterized by squamous metaplasia and loss of goblet cells and mucin expression. This is consistent with unstable tear film which is the hallmark of various dry-eye disorders. The second type of ocular surface failure is characterized by the replacement of the normal corneal epithelium in a process called limbal stem cell deficiency. It is essential to establish accurate diagnosis for appropriate management of complex ocular surface disorders. There has been considerable advancement in the understanding of the pathophysiology of ocular surface disease. Management has improved with introduction of the limbal stem cell concept and use of amniotic membrane transplantation.
Subject(s)
Amnion/transplantation , Biological Dressings , Conjunctival Diseases/diagnosis , Corneal Diseases/diagnosis , Dry Eye Syndromes/diagnosis , Epithelial Cells/transplantation , Humans , Limbus Corneae/cytology , Ophthalmologic Surgical Procedures/methods , Severity of Illness Index , Stem Cell Transplantation/methodsABSTRACT
El entendimiento en profundidad de los diferentes mecanismos de daño, defensa y reparación que toman lugar en una causticación ocular, ha permitido tratar en mejor forma a estos pacientes. En la etapa aguda, la medida más importante continúa siendo la irrigación profusa del ojo en el mismo lugar del accidente. Lisis de adherencias, antibióticos, corticoides, hipotensores y citrato de sodio deben emplearse. En la etapa subaguda nuestro norte será promover la epitelización (lente de contacto blanda terapéutica, tarsorrafía) y, evitar y tratar la ulceración. En la etapa tardía deberemos tratar las complicaciones y uno de los procedimientos empleados es la rehabilitación de la superficie ocular, con el transplante de células epiteliales sanas; puede hacerse tan precozmente como cuatro semanas despúes de la causticación, siempre que la isquemia limbar haya pasado y el limbo se encuentre vascularizado
Subject(s)
Humans , Burns, Chemical , Caustics/adverse effects , Eye Burns/chemically induced , Epithelial Cells/transplantation , Contact Lenses/statistics & numerical data , Eye Burns/complications , Eye Burns/drug therapy , Eye Burns/therapy , Eye/blood supply , Ophthalmologic Surgical Procedures , Corneal Ulcer/prevention & controlABSTRACT
O presente experimento foi desenvolvido com o objetivo de obter novas informaçöes a respeito do processo de reconstruçäo biológica de enxertos autógenos livres de gengiva conjuntivo-epiteliais e de conjuntivo. Este propósito se baseou no fato de que trabalhos recentes praticamente objetivaram a validade inconteste da influência da interaçäo ectomesenquimal no estabelecimento das características finais dos tecidos enxertados. Para tanto foram executados 64 enxertos autógenos livres de gengiva em 28 cäes, sendo 32 de conjuntivo e 32 conjuntivo-epitelial. Em linhas gerais os enxertos conjuntivo-epiteliais seguiram os princípios de SULLIVAN & ATKINS 125, enquanto que os de conjuntivo seguiram os de EDEL 49, destacando-se como alteraçäo procedural para melhor visualizar a análise histológica o preparo de área receptora com dimensöes de 10x15mm para receber enxerto de 3 x 6mm, de modo a deixar uma área cruenta em toda extensäo periférica dos enxertos. Os animais foram sacrificados mediante perfusäo com tinta naquim, executada através das carótidas comuns, de maneira a fornecer amostras de períodos pós-operatórios de 0, 1, 2, 4, 7, 14, 30 e 60 dias. Os espécimes foram processados histologicamente até a coloraçäo por HE e Tricrômico de Masson, em cortes semi-seriados de 7µm. Os resultados mostraram reconstruçäo da lâmina própria gengival por fibrogênese, permitindo a uniäo de ambos os tipos de enxertos aos tecidos subjacentes e a preservaçäo das características do tecido conjuntivo de mucosa ceratinizada. Por outro lado, em ambos os tipos de enxertos a reepitelizaçäo evoluiu até à ceratinizaçäo, sendo mais rápida no enxerto conjuntivo-epitelial do que no de conjuntivo, todos sugerindo a influência da interaçäo ectomesenquimal, pois a reepitelizaçäo se processou a partir do epitélio circunjacente do leito receptor. Diferentes fases sequenciais foram identificadas durante a "pega" desses enxertos de gengiva, a saber: "circulaçäo plasmática" revascularizaçäo precose, reepitelizaçäo e incorporaçäo e maturaçäo e/ou remodelamento. Finalmente, há que se destacar que todos os enxertos mostraram sucesso e se apresentaram imóveis após a "pega" dos mesmos