During the past several years, there has been intense research in the field of bone marrow-derived stem cell (BMSC) therapy to facilitate its translation into clinical setting. Although a lot has been accomplished, plenty of challenges lie ahead. Furthermore, there is a growing body of evidence showing that administration of BMSC-derived conditioned media (BMSC-CM) can recapitulate the beneficial effects observed after stem cell therapy. BMSCs produce a wide range of cytokines and chemokines that have, until now, shown extensive therapeutic potential. These paracrine mechanisms could be as diverse as stimulating receptor-mediated survival pathways, inducing stem cell homing and differentiation or regulating the anti-inflammatory effects in wounded areas. The current review reflects the rapid shift of interest from BMSC to BMSC-CM to alleviate many logistical and technical issues regarding cell therapy and evaluates its future potential as an effective regenerative therapy.

Dendrimers are a class of macromolecular materials with a highly branched three-dimensional structure. Since its inception in 1978, the dendrimers have attracted much attention for their biomedical applications. Structurally, dendrimers can be divided into three components: the core, the interior and the shell. The stepwise growth technique gives rise to nearly monodisperse polymeric tree-like macromolecules, which are essential for biological applications, since the monodispersity is a key factor for generation of reproducible structure that allows evaluation of the biological activity relating to specific structures. In addition, the reactive functional groups on the exterior give provision to modify its outer surface so as to achieve multivalent effects, such as improved pharmacokinetics, combined drug delivery, site specific delivery of therapeutics using targeting molecules, reduced cytotoxicity and limited long-term side effects. This chapter presents a basic concept of this evolving technology and explores the unique features of this nanomaterial for successful future applications as biotherapeutics.