Biomimetic polymer scaffolds

Besides traditional 3-D scaffolds fabrication methods, electrospinning and molecular self-assembly are newly developed techniques to construct biomimetic polymer scaffolds. Scaffolds fabricated by those techniques are mainly used in four tissue engineering areas skin, cartilage, blood vessel, and nerve. 

Keywords Bioactive Biomaterials Biomimetic Cellular infiltration Electrospinning Extracellular matrix Hydrogels Nanofibers Polymer scaffolds Tissue... 

Potential applications of peptide-polymer conjugates include drug delivery materials, optoelectronics, biosensors, tissue scaffolds, tissue replacement materials, hydrogels, adhesives, biomimetic polymers, lithographic masks, and templates for metallic or silica nanostructures. 

R. Zhang, PX. Ma, Biomimetic polymer/apatite composite scaffolds for mineraUzed tissue engineering, Macromol. Biosci. 4 (2)... 

For fabrication of biomimetic hydrogel for biomedical and pharmaceutical applications, a range of synthetic and protein-based polymer scaffolds, such as albumin, collagen, gelatin, elastin, proteoglycan, hyaluronan, laminin, silk fibroin, soybean, fibrinogen, and fibrin have been widely used (Rajangam and An, 2013). 

Techniques to produce multiscale biomaterial scaffolds with designer geometries are the need of the hour to provide improved biomimetic properties for functional tissue replacements. While micrometer fibers generate an open pore stnicture, nanofibers support cell adhesion and facilitate cell-cell interactions. This was further proven by cell penetration studies, which showed superior ingrowth of cells into hierarchical structures. Mixed bimodal scaffolds of two different polymers are another promising approach, because they exhibit hierarchical pore/ surface systems and combine the beneficial properties of both polymers at two different scales. Vaiious 3D micro- and nanoscale multiscale scaffolds have been fabricated through various techniques and were found to have the potential to essentially recreate natural bone, cardiac, neural, and vascular tissues. 

The use of double hydrophilic block copolymers in biomimetic mineralization processes has been investigated in recent years. In contrast to rigid templates (like carbon nanotubes and porous aluminum templates which predefine the final structure) water soluble polymers could be used as soluble species at various hierarchy levels. Usually, in the case of DHBCs, one of the block acts as scaffold for the development of the crystal, while the other acts as a soluble-stabilizing matrix. Therefore, both of the blocks play a crucial role on the development of the crystals. There is a plethora of reports on the emerging bio-inspired mineralization field. Various crystal structures have been presented during the last years, following versatile synthetic routes. A very detailed and illustrious review has been recently given by Colfen [3]. The above review describes in detail all aspects of the specific field. Herein, we present just a few selected examples. 

Tissue engineering scaffold for DNA delivery by cationic polymers. Biomimetic scaffolds can be encapsulated with growth factors and MSCs are seeded onto their surface [top]. Polymeric release bottom left) consists in the entrapment of the complexes between cationic polymers and DNA within the biomaterial for release into the environment. Conversely, substrate-mediated delivery bottom right), also termed reverse transfection delivery, employs the immobilization of complexes to the biomaterial. MSCs can internalize the complexes either directiy or by degrading the linkage between the biomaterial and DNA complexes. 

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