ABSTRACT
Developments in adult stem cell (ASC) potentiation have contributed to excitement in the field of stem cell-based therapy. Not only the use of ASCs increases therapeutic treatment possibilities but also the successful use of multipotent cells for gene therapy has been demonstrated in animal models (Rizvi et al. 2006). The concurrent ability of stem cells (SCs) to either contribute to disease development, as identified in cancer SCs (CSCs), or to replace diseased tissue by induced differentiation using selected growth factors has highlighted the intricate molecular and cellular mechanisms. Adipose-derived SCs (ADSCs) are capable of self-renewal and respond well to induced differentiation (Tarnok, Ulrich, and Bocsi 2010). Autoimmunity and transplant rejection may become limitations when selective induction of immunological nonresponsiveness to specific antigens or tissues becomes possible using autologous cell sources (Ichim et al. 2010). CSCs can initiate tumorigenesis, generate differentiated daughter cells, or undergo self-renewal and are thought to instigate tumor recurrence posttreatment. Therapy targeting CSCs have failed to provide feasible alternatives to conventional cancer treatment. Low-intensity laser irradiation (LILI) induces a biostimulatory response in several tissue types in addition to a dose-response effect to the detriment of cellular degeneration. LILI has been applied clinically for the treatment of a variety of disorders including, pain, inflammation, cancer, skin diseases, soft tissue injuries, and many more. It includes the use of low-intensity
light devices delivering light in the visible to near-infrared wavelength of approximately 400 to 1000 nm. LILI of different intensities can either inhibit or stimulate cellular processes, activating signaling cascades that ultimately lead to cellular modulation. Light energy is absorbed by light-absorbing molecules called chromophores in the cells, which direct and convert the light energy to be harvested in the form of chemical energy through the photochemical synthesis of adenosine triphosphate (ATP) (Gao and Xing 2009). The mechanism whereby this occurs is not well understood but is thought to be facilitated by the mitochondrial respiratory complexes resulting in production of reactive oxygen species, cyclic adenosine monophosphate (cAMP) synthesis, and influx of intracellular calcium. A significant increase in ATP production has been identified using a range of different wavelengths including 632.8, 830, and 904 nm and LILI and in a number of different cell types such as fibroblasts, keratinocytes, osteoblasts, lymphocytes, and endothelial cells (Drochioiu 2010; Gao and Xing 2009). The augmentation of SC-based therapies to potentially modulate regenerative processes using noninvasive methods such as LILI holds great potential (Lin et al. 2010). The study and development of SC therapy coincide with the development of other highly investigative and therapeutic disciplines such as tissue and genetic engineering, molecular biology, and biocompatible polymer synthesis leading to significant advances in the field of regenerative medicine. Peptide-based biopolymers are emerging as a new class of biomaterials due to their unique chemical, physical, and biological properties. Applications of
57.1 Introduction ............................................................................................................................ 663 57.2 Stem Cells ................................................................................................................................. 664
57.4 Lasers and SCs ......................................................................................................................... 673 ADSC Applications • ADSCs Differentiated into SMCs
57.5 SCs and TE ................................................................................................................................678 57.6 SCs and Cancer ....................................................................................................................... 679 57.7 Ethical Considerations ........................................................................................................... 679 57.8 Concluding Remarks .............................................................................................................. 679 References ............................................................................................................................................ 680
these engineered biomolecules include tissue engineering (TE) where they serve as injectable scaffolds that form gels in vivo via physical or chemical means and provide a minimally invasive route to deliver tissue scaffolds.
