3 N. Pallua and C.V. Suschek (eds.), Tissue Engineering, DOI: 10.1007/978-3-642-02824-3_1, © Springer-Verlag Berlin Heidelberg 2011 1.1 Introduction Tissue engineering (TE) is a rapidly growing scien- tific area [129] that aims to create, repair, and/or replace tissues and organs by using combinations of cells, biomaterials, and/or biologically active mole- cules [42, 119]. In this way, TE intends to help the body to produce a material that resembles as much as possible the body’s own native tissue. By doing so, TE strategies promise to revolutionize current thera- pies and significantly improve the quality of life of millions of patients. The classical TE strategy consists of isolating spe- cific cells through a biopsy from a patient, growing them on a biomimetic scaffold under controlled cul- ture conditions, delivering the resulting construct to the desired site in the patient’s body, and directing the new tissue formation into the scaffold that can be degraded over time [42, 119]. Most of the presently existing TE techniques rely on the use of macrostructured porous scaffolds, which act as supports for the initial cell attachment and sub- sequent tissue formation, both in vitro and in vivo [88, 102, 113]. This kind of approach has been successful to a certain extent in producing relatively simple con- structs relying on the intrinsic natural capability of cells and tissues to self-regenerate, remodel, and adapt. For this reason, cells have been the most significant factor in the generation of the tissue itself [33]. However, this natural capability of cells for adapting to its surrounding environment has limitations and that is the main reason why TE has not been able to generate complex thick tissues so far [47]. In fact, one of the most important drawbacks of the currently available constructs in TE approaches is related to the lack of means to generate effective oxygen and nutrient dis- persion pathways that can reach a whole construct homogenously and, therefore, enable the functionality/ viability of the construct upon implementation. In order to generate constructs capable of accurately mimicking/replacing structures as defined and organized as complex tissues and organs, novel kinds of scaffolds and devices have lately been developed, which poten- tially allow obtaining a fine control over the cellular positioning, organization, and interactions [36]. For this, much has contributed the continuous technological development in the areas of micro- and nanotechnolo- gies, both in terms of production methods and in analy- sis tools [107]. Developments in these areas may allow a finer control over the architecture of scaffolds, making them no longer simple substrates for cellular adhesion and proliferation, but most importantly, active agents in the process of tissue development [37]. Micropatterning integrated in a TE approach is a result of the combina- tion of micro- and nanofabrication techniques with materials science and surface engineering, which results in a deep exploration of the microenvironment where cells are embedded [37, 90]. In TE, micro- and nano- technologies can also be applied to fabricate biomimetic scaffolds with increased complexity to promote, for example, vascularization, also enabling to perform a series of high-throughput experiments (Fig. 1.1). Micro- and Nanotechnology in Tissue Engineering Daniela Coutinho, Pedro Costa, Nuno Neves, Manuela E. Gomes, and Rui L. Reis D. Coutinho, P. Costa, N. Neves, M.E. Gomes (), and R.L. Reis 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, Department of Polymer Engineering, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark, 4806-909 Taipas, Guimarães, Portugal and PT Government Associated Laboratory, IBB – Institute for Biotechnology and Bioengineering, Braga, Portugal e-mail: megomes@dep.uminho.pt 1