Biological properties copolymers

Etrych, T., Jelinkova, M., Rihova, B., and Ulbrich, K. New HPMA copolymers containing doxorubicin bound via pH-sensitive linkage Synthesis and preliminary in vitro and in vivo biological properties. J. Contr. Rel. 73(1) 89-102. 2001. 

The importance of surface enrichment in the determination of copolymer surface properties is demonstrated by a number of surface analysis studies of polyurethanes [22,27-29], The versatility of polyurethanes as biomaterials is derived from the ability to control physicochemical and biological properties of the material by altering the proportions of hard and soft segments. 

Dr. Isao Noda has been working on the family of PHA called Nodax that consists of f/ j-3-hydroxyalkanoate comonomer units with medium size chain side groups and j-3-hydroxybutyrate. Because of the unique design of their molecular structure, the Nodax class PHA copolymers have a set of useful attributes, including polyolefin-like thermo-mechanical properties, polyester-like physicochemical properties, and interesting biological properties. Therefore, a broad range of industrial and consumer product applications are anticipated. 

A particularly interesting feature of these hybrid block copolymers is that the aggregation number and pH sensitivity of the nanoobjects can be controlled via direrted single and double mutations of the peptide primary structure. This may be relevant in light of possible biomedical applications because preliminary experiments have shown that the biological properties of the PEGylated coiled coils correlate to their self-assembly behavior. Another example that is worth mentioning is the work by Velonia et who studied the... 

Both blocky and random poly(p-dioxanone-co-c-caprolactone) copol mers were prepared and extruded into monofilaments to study their physical and biological properties (Bezwada, Shalaby, and Erneta, 1991). Random copolymers were prepared by pol)Tnerizing the desired proportions of p-dioxanone and c-caprolactone in a single step process in the presence of an organometallic catah st and an initiator at elevated temperatures as described above for p-dioxanone. 

The mechanical and biological properties are described in the literature (Bezwada, Shalaby and Erneta, 1991) and show that a surgical filament prepared from a block copolymer of c-caprolactone and p-dioxanone has equivalent straight and knot tensile strength to p-dioxanone homopolymer, but has significantly enhanced flexibility as demonstrated by the reduction in Young s Modulus. 

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