Biomedical product polymers

At present these materials are too expensive to be considered as viable alternatives to the commodity plastics in packaging but they do have potential applications in biomedical products such as orthopaedic implants and even as temporary replacements for parts of the pericardium during open-heart surgery. In this kind of application, performance is much more important than cost. However, Biopol may be able to replace non-biodegradable polymers in paper coating which would then allow paper composite materials to biodegrade much more rapidly in compost and similar environments. 

Bock, N., M.A. Woodruff, D.W. Hutmacher, and T.R. Dargaville. Electrospraying, a reproducible method for production of polymeric microspheres for biomedical applications. Polymers 3(1) (2011) 131-149. 

Versatile, malleable Pasteurella synthases have been harnessed as useful catalysts for the creation of a variety of defmed GAG or GAG-like polymers ranging in size from small oligosaccharides to huge polysaccharides. These materials should be useful for a wide spectrum of potential biomedical products for use in the areas of cancer, coagulation, infection, tissue engineering, drug delivery, surgery, and viscoelastic supplementation. 

The majority of synthetic pol)miers showing biodegradability are aliphatic polyesters. Among them, PLA, PGA, and polycaprolactone (PCL) are arguably the most commonly used biodegradable polymers in the development of biomedical products. These polymers are generally insoluble in water, while with the exception of PGA, other polymers in this family are soluble in many common organic solvents and thus can be processed by a variety of thermal and solvent-based methods. 

In addition to polyesters, other types of biodegradable polymers such as polyurethanes, polyanhydrides, poly(amino acids), poly(vinyl alcohol), and poly(ester amide), are generally processable by conventional processing techniques for plastics. Their physical properties can be expected to be comparable, and sometimes can be used to supplement biodegradable polyesters. Although these polymers are more likely used in niche applications or incorporated with other polymers by making composite materials, they obviously provide more material choices in the design and manufacture of various biomedical products. 

HA is the most expensive bacterial polysaccharide, a medical grade HA sells at US 40,000-60,000 per kg. The HA industry is worth an estimated US 1000million per year. The first hyaluronan biomedical product, Hyalon, was developed in 1970s. The polymer from Streptococcus epizooticus or related species is identical to HA from the human and animal body. 

Cappello,]. and Crissman, J.VV. (1990) The Design and Production of Bioactive Protein Polymers for Biomedical Applications. Polymer JSeprints, 31. 193. 

The surface characterization tools that provide qualitative and quantitative information about wettability, morphology, and elemental and molecular surface chemistry are outlined in this section. These tools can provide a comprehensive view of the surface (10-100 A) from which a model of interfacial behavior can be developed. The model of the working surface can be utilized to understand fundamental structure-property relations and thus used in general problem solving. It is important to remember that no one surface tool is an end in itself [28j. It is important to correlate information from all sources to build a working model of behavior. The understanding of the surface structure allows one to apply the appropriate surface modification and to follow the modification as a function of polymer processing. Thus, assessment of the real-world surface chemistry in a deliverable biomedical product is necessary and prudent. 

Classification of biomedical products made with bioabsorbable polymers... 

These considerations may be applicable to biomedical products made with polymers. In particular, they apply to absorbable polymer products, wherein there could be doubts about the mechanism of action, which may influence the metabolism of the polymer. The basic requirement for the development of biomedical products made from resorbable polymers is therefore to clarify how the absorption of the polymer participates to achieve the pmpose of use of the product. This aspect is discriminative for the correct classification of the product as an MD or as a drug. 

Although the MEDDEVs and manual do not constitute rules with binding nature, these inputs should be taken into careful consideration in the classification of a biomedical product based on absorbable polymers, to determine whether they are drugs or MDs. 

Table 6.10 presents an example of risk analysis applied to a biomedical product based on a resorbable polymer. Whether it is a dmg or an MD is not relevant the objective of the example is to highlight the main target of the analysis ... 

This review highlights the uses of chitosan-based derivatives for various biomedical applications. Chitosan has offered itself as a versatile and promising biodegradable polymer. In addition, chitosan possesses immense potential as an antimicrobial packaging material owing to its antimicrobial activity and non-toxicity. The functional properties of chitosan films can be improved when chitosan films are combined with other film forming materials such as SF, alginate and other biopolymers. All these studies indicate that, in the near future, several commercial biomedical products based on silk fibroin and chitosan will be available in the world market. 

Biomedical Applications of Poly (a-hydroxy acid)s Hydroxy acids derived from natural resources such as lactic and glycolic acid have been employed to synthesize a wide variety of useful biodegradable polymers for large number and type of biomedical product applications. As an example, bioresorbable surgical sutures made form poly(a-hydroxy acid)s have been in clinical use since 1970. 

The same papei describes a conjugate derived from a dihydroxyl-fimctional-ized carrier prepared by an ester-amine polycondensation process from diethyl tartrate and 4,7,10-trioxa-l,13-tridecanediamine. With 1.8 mol of ferrocenylation agent used in the feed for every carrier base mole, the water-soluble product polymer 27 is obtained in a composition corresponding to x/y=4 (Scheme 16). For all conjugates here described the x y ratios, determined by NMR spectroscopy, reflect ferrocene contents of approximately 10-25 mol%, a range considered convenient for biomedical applications. 

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