RESUMO A biologia das células-tronco é um dos campos mais dinâmicos e promissores das ciências biológicas, pois é a base do desenvolvimento dos organismos. Sua complexidade biológica demanda esforços de diversas linhas de pesquisa, visando principalmente à sua utilização terapêutica. A Nanotecnologia surge como um novo campo de estudo, o qual demonstra grande potencial no que tange ao tratamento de diversas doenças. Esta nova área da saúde vem sendo denominada “Nanomedicina” ou “Bionanotecnologia”, a qual pode ser aplicada na Medicina por meio da utilização de sistemas de transporte e liberação de fármacos, ferramentas robóticas a serem utilizadas em processos de diagnóstico e cirurgia, nanobiomateriais, terapias gênicas, dispositivos nanobiomédicos, entre outros. Em razão das células-tronco e a Nanotecnologia serem duas áreas da ciência extremante promissoras, um novo campo de estudo, denominado “Nanotecnologia das células-tronco”, surge gradativamente. Neste, a Nanotecnologia é utilizada de forma a auxiliar as células-tronco a exercerem seu potencial terapêutico no tratamento, na cura e na reparação dos tecidos lesionados, de forma eficaz e segura. A Nanotecnologia das células-tronco tem gerado grande interesse, podendo resultar em contribuições significativas na Medicina Regenerativa e na engenharia de tecidos. O presente trabalho teve por objetivo apresentar o estado da arte visando à sua utilização terapêutica na Medicina Humana.

ABSTRACT The biology of stem cells is one of the most dynamic and promising fields of the biological sciences, since it is the basis for the development of organisms. Its biological complexity demands efforts from several lines of research aimed mainly at its therapeutic use. Nanotechnology has been emerging as a new field of study, which shows great potential in the treatment of various diseases. This new area of health has been called “Nanomedicine” or “Bionanotechnology”, which can be applied in Medicine by transport and drug delivery systems, robotic tools to be used in diagnostic and surgical processes, nanobiomaterials, gene therapies, nanobiomedical devices, among others. Because stem cells and Nanotechnology are two areas of extremely promising science, a new field of study, called “stem cell Nanotechnology”, has gradually emerged. In this, Nanotechnology is used to help the stem cells apply their therapeutic potential in the treatment, cure, and repair of the damaged tissues, in an effective and safe way. In this way, stem cell Nanotechnology has generated great interest, since it may result in significant contributions to Regenerative Medicine and tissue engineering. The present work aims to present the state-of-the-art regarding its therapeutic use in Human Medicine.

We studied the karyotypes of three hybrid clones of mouse embryonic stem cells and murine splenocytes (two having near diploid and one having near tetraploid chromosome numbers) and the characteristics of their differentiation during the formation of embryoid bodies. The X chromosome originating from embryonic stem cells may be lost in hybrids with a near diploid chromosome number and reprogramming of the "somatic" X may occur. The morphological data we obtained using light and electron microscopy revealed a correlation between the karyotype constitution of hybrid cells and their differentiation during the formation of embryoid bodies. At the beginning of development, the embryoid bodies derived from hybrid cells already showed an advanced degree of differentiation. The production of significant quantities of cartilage was typical for hybrid cells with near tetraploid chromosome numbers. The hybrid cells showed restricted pluripotent capacity and were already committed when they started to differentiate into embryoid bodies.