Biohybridized materials

Besides the previously mentioned collagen, a wide variety of natural polymers have been involved in the synthesis of bio-nanohybrid materials with potential application in bone repair and dental prostheses. For instance, some recent examples refer to bionanocomposites based on the combination of HAP with alginate [96,97], chitosan [98,99], bovine serum albumin (BSA) [100], sodium caseinate [101], hyaluronic acid [102], silk fibroin [103,104], silk sericin [105], or polylactic add (PLA) [106,107]. These examples illustrate the increasing interest in the subject of HAP-based biohybrid materials, which has led to almost 400 articles appeared in scientific journals in 2006 alone. 

Tab. 15.4 Adsorption and structural data for a-ZrP-protein biohybrid material from Kumar et al. [136].

The most commonly used protein, often ultilized as a versatile supramolecular building block for the synthesis of biohybrid materials, is probably streptavidin. Streptavidin was discovered in the bacterium Streptomyces avidinii 241-242-243 and is an homo-tetrameric protein with a 2-fold symmetry, and molecular weight of 60 kDa.244,245,246... 

Keywords Tissue engineering Cell culture Poly(A-isopropyl acrylamide) Biohybrid material Heparin Star-poly(ethylene glycol) Angiogenesis... 

These results clearly demonstrate how cell adhesion onto the developed set of biohybrid materials can be easily timed through the choice of PEG-content and biomolecular functionalisation. More advanced functionalisation schemes additionally utilize non-covalent loading of growth and differentiation factors to locally induce the formation of capillary endothelial cell networks. Based on that, the novel biohybrid hydrogel can be expected to offer valuable extensions of various tissue engineering strategies. 

Some of these basic strategies can be also adapted to create biohybrid materials consisting of peptides or proteins and synthetic organic polymer units (Section 5.5.3). 

In the following we will briefly describe some selected examples of biohybrid structures and networks consisting of synthetic organic polymers and polynucleotides, polypeptides/proteins, and/or polysaccharides with focus on biomedical applications. In order to provide multifunctional biohybrid materials with the optimal combination of mechanical, biological, and stmctural properties for particular purposes, different design aspects must be considered. 

Weber and coworkers developed a hydrogel for time-scheduled vaccination that consists of biohybrid materials cross-linked via multiple supramolecular interactions [283]. The hydrogel is based on two eight-arm PEG species with end groups that are either functionalized with fluorescein or with a humanized single-chain... 

Ruiz-Hitzky E, Darder M, Aranda P, Ariga K (2010) Advances in biomimetic and nano-structured biohybrid materials. Adv Mater 22 323-336... 

Ruiz-Hitzky E, Darder M, Wicklein B, Fernandes FM, Castro-Smimov FA, del Burgo MAM, del Real G, and Aranda P (2012) Advanced biohybrid materials based on nanoclays for biomedical applications. In Choi SH, Choy JH, Lee U, Vaiadan VK (eds) Nanosystems in engineering and medicine, vol 8548. SPIE-Int Soc Optical Engineering, Bellingham... 

Nanoclays can be categorized into cationic and anionic types. Cationic nanoclays are based on smectite clays. An example is montmorillonite (MMT), a hydrated Al, Mg silicate that may contain cations such as Na+ and Ca++ between the anionic layers. In contrast, anionic clays contain cationic layers and anions such as Cr and in the interlayer space. Typical examples include layered double hydroxides (LDH) and hydrotalcite (HT), a mostly synthetic hydrated magnesium and aluminum carbonate salt. Whereas MMT is commonly used as a nanofiller to improve thermal, mechanical, and barrier properties, LDHs have many attractive properties that lead to application as surfactant adsorbents, biohybrid materials, antacid food formulations, acid neutralizers, and active pharmaceutical ingredients excipients [37, 13, 28, 14, 35]. 

Broyer RM, Quaker GM, Maynard HD (2008) Designed amino acid ATRP initiators for the synthesis of biohybrid materials. J Am Chem Soc 130 1041-1047... 

Biohybrid Materials from Bioinspired Mineralization Strategies 631... 

---