Naturally-derived scaffolds

L.E. Flynn, G.D. Prestwich, J.L. Semple, K.A. Woodhouse, Proliferation and differentiation of adipose-derived stem cells on naturally derived scaffolds. Biomaterials 29 (2008) 1862-1871. 

Flynn L, Prestwich G D, Semple J L and Woodhouse K A (2008), Adipose tissue engineering in vivo with adipose-derived stem cells on naturally derived scaffolds , J Biomed Mater Res A, 89, 929 1. 

There are several ways to prepare libraries of natural product derivatives on a solid phase. These include (a) total synthesis on the resin (b) derivation of supported natural products and (c) syntheses of analogs based on a natural product scaffold. This review will provide examples of all these approaches. 

In order to functionalize scaffolds to mimic the native cell environment, different strategies are available. Recombinant DNA technology can be used to design artificial ECM proteins to avoid the aforementioned complications that can arise with naturally derived materials [60], However, there is little known about the long-term... 

Contributions by R. Joseph and P. Arya as well as M. A. Koch and H. Waldmann focus on synthetic aspects towards lead structures originating from natural product-derived scaffolds. R. Joseph and P. Arya refer to two complementary approaches, the synthetic access to focussed libraries around bioactive natural product cores, and diversity-oriented synthesis aiming at 3D scaffold diversity for hit generation, respectively. On the other hand, M. A. Koch and H. Waldmann emphasise the correlation of natural product-based library concepts with structural features of targeted protein domains, thus strengthening the privileged structure concept from a bioorganic viewpoint. 

Samiulla et u/. report the design of natural product scaffolds that were then used in a small library of vasicinone derivatives. A key aspect of the design was the incorporation of parameters intended to result in improved ADME properties by including the filters proposed by Lipinski" and Veber et BCUTs were used to optimize the diversity of the scaffolds while Unity fingerprints were used in the diversity optimization of the vasicinone library. The measured solubility, permeability in MDCK cells and CYP inhibition were measured for the scaffolds. The resulting libraries demonstrated favorable distributions of each of the measured ADME properties. 

Selection of a tissue engineering substrate includes a choice between absorbable and nonabsorbable material, as well as a choice between synthetic and naturally derived materials. The most common synthetic polymers used for fibrous meshes and porous scaffolds include polyesters such as polylactide and polyglycolide and their copolymers, polycaprolactone, and polyethylene glycol. Synthetic polymers have advantages over natural polymers in select instances, such as the following i... 

The embossing ice particulate template method has also been used to prepare porous scaffolds of other naturally derived polymers such as chitosan, HA and GAGs [19-21]. The funnel-like porous scaffolds of chitosan and HA and collagen-GAG composite prepared by this method also show the hierarchical two-layer pore structures (Fig. 3.1.4). Depending on the type of naturally derived polymers, the cross-linking method is different. The... 

The embossing ice particulates can be used to control the surface pore structures and to create micropatterned structures in porous scaffolds of naturally derived biodegradable polymers. When free ice particulates that are not embossed on a substrate are used, the inner body pore structures of biodegradable polymers can be controlled. In this case, preprepared ice particulates are used as a porogen material. The ice particulates are mixed with precooled polymer solution. The mixture is subsequently frozen slowly and freeze-dried. This method has been used to prepare porous scaffolds of biodegradable synthetic polymers and biodegradable naturally derived polymers [16-18,22]. 

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