Amino-acid based biodegradable

R. Katsarava, Active polycondensation from peptide chemistry to amino acid based biodegradable polymers, Macromol. Symp. 199 (2003) 419-429. 

Metselaar, J.M. et al, 2003. A novel family of L-amino acid-based biodegradable polymer-lipid conjugates for the development of long-circulating liposomes with effective drug-targeting capacity. Bioconjugate Chemistry, 14(6), 1156-1164. 

Amino-acid based biodegradable elastomeric poly(ester amide) fibers... 

Even though other amino acid-based biodegradable carrier systems are described, some of them targeted, among others the earlier developed amphoteric branched peptide carriers... 

A series of biodegradable functional amino acid-based PEAs were designed and synthesized by the solution copolycondensation of antino add (L-phenylalanine and DL-2-allylglycine)- and dicarboxylic acid-based monomers... 

G. Tsitlanadze, M. Machaidze, T. Kviria, N. DjavakhishviU, C.C. Chu, R. Katsarava, Biodegradation of amino-acid-based polyfester amide)s in vitro weight loss and preUminary in vivo studies, J. Biomater. Sci. Polym. Ed. 15 (2004) 1-24. 

J.A. Horwitz, K.M. Shum, J.C. Bodle, M. Deng, C.C. Chu, C.A. Reinhart-King, Biological performance of biodegradable amino acid-based poly (ester amide)s endotheUal cell adhesion and inflammation in vitro, J. Biomed. Mater. Res. A 95 (2) (2010) 371-380. 

Tsitlanadze G, Machaidze M, Kviria T, Djavakhishvili N, Chu C C and Katsarava R (2004a), Biodegradation of amino acid based poly(ester amide)s in vitro weight loss and prehminary in vivo study , J Biomater Sci Polym Ed, 15(1), 1-24. 

Chu C C Novel biodegradable functional amino acid-based poly(ester amide) biomaterials design, synthesis, property and biomedical applications , I Fiber Bioeng Informatics (In Press). 

Chu C C, Song H and Spruiell J E (2012), Novel biodegradable amino acid-based poly(ester-amide)s fibers melt-spinning, characterization and in vivo biocompatibility , 9th World Biomaterials Congress, Cheng-Du, China, 1-5 June. 

Amino acids are natural nutrients. Polymers derived from amino acids may have advantageous biocompatibility, as demonstrated by PLA. However, amino acid based polymers often do not have good material properties. They are often difficult to process into 3-D structure, and possess poor mechanical properties. Tyrosine-derived polymers have been developed in the Kohn group as biodegradable polymers, which have shown certain promising properties (56), and have been used for bone tissue engineering research (57). 

Contrarily to fatty add salts (i.e., sodium laurate soap), the long-chain iV -acyl amino adds have excellent water solubility (due to the presence of additional CO-NH linkages), quick biodegradability and good lime resistance (i.e., caldum ion tolerance) [11]. The surfactant properties of pure sodium salts of iV -acyl amino acids (anionic surfactants) with different alkyl chains (saturated and unsaturated with 10-18 carbon atoms) and amino acid residues have been described and compared with those of sodium lauryl sulfate (SLS) and sodium laurate [11-14]. The authors showed that the critical micelle concentration (CMQ of the amino acid-based surfactants was lower than that of the SLS but higher than that of sodium laurate. The surface activity increased and the CMC decreased by raising the alkyl chain... 

One important milestone in our research is the design and development of new amino acid-based surfactants with antimicrobial properties, which mimic natural amphiphilic cationic peptides [42,43]. To this end, Lys and Arg derivatives of long-chain A -acyl, COO-ester, and A-alkyl amide have been prepared. In particular, the A -acylarginine methyl ester derivatives series 1 (Scheme 1) have turned out to be an important class of cationic surface active compounds with a wide bactericidal activity, high biodegradability, and low toxicity profile. We have shown that essential structural factors for their antimicrobial activity include both the length of the fatty residue (akin with their solubility and surface activity) and the presence of the protonated guanidine function [43,44]. 

By certain physical factors like thermal, ultraviolet irradiation, high pressure and other chemical parameters like organic solvents the helical pol5mers are easily denaturalized. A variety of helical polymers are synthesized, which include polyisocyanates, polyisocyanides, polychloral, polymethacrylates, polysilanes, polythiophenes, poly (p-phenylene)s, poly(l-methylpropargyl-ester)s, poly(phenylacetylene)s and poly (-unsaturated ketone) [18-24] (Fig. 1). Other polymers are whose optical activity is main chain or side chain chirality dependent e.g. amino-acid-based polymers are nontoxic, biocompatible and biodegradable. 

PA-7A (Figure 5.13) polymers obtained employing DBTL and TEA as catalysts, respectively. The authors claim that since these polymers are optically active and have amino acids in the polymer architecture, they are likely biodegradable, and are therefore classified as environmentally friendly polymers. Potential application can be found for the amino acid based pol)miers as the chiral stationary phases for the resolution of enantiomers in chromatographic techniques, drug delivery and biomaterials. 

---