ABSTRACT
Abstract Purpose: This study assessed the regeneration potential of mesenchymal stem cells (MSC) from adipose tissue associated with platelet-rich plasma (PRP) in bone regeneration. Methods: Thirty Wistar rats (Rattus norvegicus albinos) were divided into five groups (according to the grafting material and time to euthanasia): (1) autograft - 14 days (control), (2) autograft - 28 days (control), (3) MSC + PRP - 14 days, (4) MSC + PRP + papaverine - 14 days and (5) MSC + PRP + papaverine - 28 days. After euthanasia, the graft was removed and histological slides were prepared. They were assessed by a blinded pathologist using a previously published histological scale as parameter. Results: There was some degree of neoformed bone trabeculae (NBT) in 93.3% of the samples, as well as osteoblastic activity (OA). The autograft groups (14 and 28 days) had higher levels in the formation of bone trabeculae. Nonparametric data were analyzed using the Wilcoxon-Mann-Whitney test and proved not to be statistically significant at p < 0.05. Conclusions: Experimental parietal bone reconstruction, combining MSC, PRP and papaverine presented regeneration in all groups with no significant difference among them.
Subject(s)
Animals , Rats , Platelet-Rich Plasma , Mesenchymal Stem Cells , Parietal Bone/surgery , Bone Regeneration , Rats, WistarABSTRACT
Neste estudo é apresentado um modelo experimental de defeito agudo em nervo periférico para avaliação da regeneração nervosa mediante técnica de tubulização associada à inoculação de células-tronco autólogas de medula óssea. Foram utilizados 12 coelhos Nova Zelândia albinos, submetidos à secção bilateral e ao afastamento de 5mm do nervo tibial e posterior reparo mediante utilização de câmara de silicone. Internamente à prótese de tubulização do nervo tibial esquerdo em todos os animais, foram inoculadas células-tronco autólogas de medula óssea, coletadas a partir do úmero. Como grupo controle (nervo tibial direito), mediante aplicação da mesma técnica de reparo, solução de NaCl 0,9 por cento foi administrada internamente à prótese. Após 30 dias de observação, os animais foram eutanasiados e foi realizada a avaliação histológica dos segmentos nervosos por meio das colorações de hematoxilina-eosina, luxol fast blue e azul de toluidina. Com os resultados, foi possível concluir que o transplante de células-tronco autólogas associado à técnica de tubulização apresenta vantagens no processo de regeneração nervosa periférica.
This study presents an experimental model of an acute deffect in a peripheral nerve to evaluate neural regeneration using a tubulization technique associated with the inoculation of autologous stem cells from bone marrow. A total of 12 New Zealand white rabbits underwent a bilateral dissection of the tibial nerve followed by repair with silicone tubulization. On the left tibial nerve of all animals, the tube was filled with autologous bone marrow-derived stem cells collected from the humerus. For control, using the same repair technique, the tubes were filled with a NaCl solution in the right tibial nerve. After 30 days of observation, the animals were euthanized and a histological evaluation of the collected nerve segments was performed by staining with hematoxylin-eosin, luxol fast blue, and toluidine blue. From the results it is possible to conclude that the transplanted autologous stem cells associated with the tubulization technique present an advantage in the peripheral nerve regeneration process.
ABSTRACT
Embryonic stem cells are pluripotent cell lines with the capacity of self-renewal and a broad differentiation plasticity. They are isolated from preimplantation embryos and can be cultured in vitro for long time without losing their pluripotency. Embryonic stem cells can also differentiate in vitro with the proper combination of growth and differentiation factors, cells will differentiate into more advanced stages of embryogenesis generating different adult cell type. In the present study, we induced the in vitro differentiation of mouse embryonic stem cells (line R1) into cardiomyocytes and neuronal cells. These differentiations were evaluated by reverse transcription-polymerase chain reaction to verify presence of tissue-specific markers.
Células-tronco embrionárias são linhagens celulares pluripotentes capazes de se multiplicar indefinidamente e com grande capacidade de diferenciação celular. São isoladas de embriões em estágio pré-implantacional e podem ser cultivadas por longo tempo em laboratório sem perder sua pluripotencialidade. Células-tronco embrionárias podem, ainda, se diferenciar in vitro através da adição de fatores de crescimento e diferenciação ao meio de cultivo. As células se diferenciarão em estágios mais avançados de embriogênese, gerando tipos diferentes de células adultas. No presente estudo, induzimos a diferenciação in vitro de células-tronco embrionárias de camundongos (linhagem R1) em células de tecido cardíaco e nervoso. A diferenciação foi avaliada pela reação em cadeia da polimerase precedida de transcrição reversa para verificar a presença de marcadores tecido-específicos.
Subject(s)
Animals , Guinea Pigs , Mice , Embryonic Stem Cells/cytology , Cell Differentiation/genetics , In Vitro Techniques , Myocardium/cytology , Nerve Tissue/cytology , Cell Culture Techniques/methodsABSTRACT
An alternative approach to somatic gene therapy is to deliver the therapeutic protein by implanting genetically modified cells that could overexpress the gene of interest. Microencapsulation devices were designed to protect cells from host rejection and prevent the foreign cells from spreading while allowing protein secretion. Alginate microcapsules form a semi-permeable structure that is suitable for in vivo injection. In this study, we report an effective laboratory protocol for producing calcium alginate microcapsules, following optimization of uniformly shaped and sized particles containing viable cells. Encapsulation of baby hamster kidney (BHK) cells in alginate microcapsules was performed using a simple device consisting of a cylinder of compressed air and a peristaltic pump. A cell suspension flow of 100 mL h-1 and an air jet flow of 10 L min-1 produced the best uniformity of microcapsule size and shape. Cells maintained viability in culture for 4 weeks without any signs of necrosis, and protein diffusion was observed during this period. Our results clearly demonstrated that microisolation of BHK cells in alginate using a simple assembly device could provide an environment that is capable of preserving live cells. In addition, encapsulated cells under the conditions described were able to secrete an active enzyme even after four weeks, thus becoming potentially compatible with therapeutic protein delivery.