Novel materials, biomaterials

Figure 7.5 Production of xanthan gum in batch culture using X. campestris. Bacterial dry weight ( ) xanthan gum ( ) residual glucose ( ) residual glutamate (A). Adapted from Microbial exopolysaccharide, Yenton etai pp 217-261. In biomaterials Novel Materials from Biological Sources, D Byrom (Ed), MacMillan Academic Professional Ltd, 1991.

Steinbuchel A (1991) Polyhydroxyalkanoic acid. In Byrom D (ed) Biomaterials. Novel materials from biological sources. Macmillan, Basingstoke, p 123... 

Byrom D (1991) Biomaterials novel materials from biological sources. Stockton, New York... 

In dentistry, silicones are primarily used as dental-impression materials where chemical- and bioinertness are critical, and, thus, thoroughly evaluated.546 The development of a method for the detection of antibodies to silicones has been reviewed,547 as the search for novel silicone biomaterials continues. Thus, aromatic polyamide-silicone resins have been reviewed as a new class of biomaterials.548 In a short review, the comparison of silicones with their major competitor in biomaterials, polyurethanes, has been conducted.549 But silicones are also used in the modification of polyurethanes and other polymers via co-polymerization, formation of IPNs, blending, or functionalization by grafting, affecting both bulk and surface characteristics of the materials, as discussed in the recent reviews.550-552 A number of papers deal specifically with surface modification of silicones for medical applications, as described in a recent reference.555 The role of silicones in biodegradable polyurethane co-polymers,554 and in other hydrolytically degradable co-polymers,555 was recently studied. 

Marques, A. R., Reis, R. L., Hunt, J. A. (2001). In vitro evaluation of the biocompatibility of novel starch based polymeric and composite material. Biomaterials., 21,1471-1478. 

Abstract Carbohydrates have been investigated and developed as delivery vehicles for shuttling nucleic acids into cells. In this review, we present the state of the art in carbohydrate-based polymeric vehicles for nucleic acid delivery, with the focus on the recent successes in preclinical models, both in vitro and in vivo. Polymeric scaffolds based on the natural polysaccharides chitosan, hyaluronan, pullulan, dextran, and schizophyllan each have unique properties and potential for modification, and these results are discussed with the focus on facile synthetic routes and favorable performance in biological systems. Many of these carbohydrates have been used to develop alternative types of biomaterials for nucleic acid delivery to typical polyplexes, and these novel materials are discussed. Also presented are polymeric vehicles that incorporate copolymerized carbohydrates into polymer backbones based on polyethylenimine and polylysine and their effect on transfection and biocompatibility. Unique scaffolds, such as clusters and polymers based on cyclodextrin (CD), are also discussed, with the focus on recent successes in vivo and in the clinic. These results are presented with the emphasis on the role of carbohydrate and charge on transfection. Use of carbohydrates as molecular recognition ligands for cell-type specific dehvery is also briefly... 

Steinbuchel, A. (1991), in Biomaterials Novel Materials from Biological Sources, Byrom, D., ed., Macmillan, New York, NY, pp 123-213. 

Polyanhydrides are promising as biomaterials because they possess a unique combination of properties that include hydrolytically labile backbone, hydrophobic bulk, and chemistry that can be easily combined with other functional groups to design novel materials. These materials are primarily surface-erodible and offer the potential to stabilize protein drugs and sustain release from days to months. The microstructure characteristics of copolymer systems can be exploited to tailor drug release profiles. The versatility of polyanhydride chemistry promises a new class of drug release systems for specific applications. 

With the recent advances in the development of novel polymeric biomaterials along with surface modification techniques, significant research effort has been devoted toward fabrication of fully polymeric valves as an attractive alternative to mechanical and bioprosthetic valves [128]. Development of these types of valves is specifically appealing, since polymeric materials offer significant flexibility in terms of material properties and manufacturing process to achieve reduced thrombogenicity and improved durability and biocompatibility [127,128]. However, fully poly-... 

In the search for novel materials it is sometimes pointed out that biology is far ahead of chemistry and that we chemists can find inspiration and exemplary materials in biology. An imitation of living tissues and processes is called bi-omimetics (see box). However, there are three essential differences between biomaterials and synthetic ones ... 

D. L. Kaplan and co-workers, in D. Byrom ed.. Biomaterials Novel Materials from Biological Sources, Stockton Press, New York, 1991, p. 1. 

Apart from PLA-based polymers, amphiphilic polymers containing fluorinated blocks are also favorable materials for biomedical applications. Due to their antifouling properties, fluorinated polymers are feasible materials for coatings in biomaterials science. However, their inert nature hampers chemical modification for the development of novel materials. In order to alter the properties of fiuorinated polymers, rather harsh conditions have to be employed. 

Gmunder, F.K. Cogoli, A. Appl. Microgravity Techn. 1988,1,115 Doi, Y. Microbial Polyesters VCH, New York 1990 Steinbiichel, A. in Biomaterials Novel Materials from Biological Sources (ed. D. Byrom) Macmillan Publishers Ltd. London 1991, 123 Huisman, G.W. Wonink, E. Meima, R. Terpstra, P. Witholt, B.. I.Biol.Chem. 1991, 266(4), 2191... 

---