Effect of Ethyl Ester L-Lysine Triisocyanate addition to produce reactive PLA/PCL bio-polyester blends for biomedical applications

Abstract

Citation: VISCO, A. ...et al., 2017. Effect of Ethyl Ester L-Lysine Triisocyanate addition to produce reactive PLA/PCL bio-polyester blends for biomedical applications. Journal of the Mechanical Behavior of Biomedical Materials, 68, pp. 308 317.Additional Information:• This paper was accepted for publication in the journal Journal of the

Effect of the configuration of poly(lactic acid) and content of poly(oxyethylene) blocks to the structure and functional properties of poly(lactic acid)‐block‐poly(oxirane)‐based nanofibrous electrospun polyester–ether–urethanes used as potential drug‐delivery system

“…Accordingly, (i) might reflect the ability of PLA blocks to crystalize when in extended conformations (induced by electrospinning); (ii) may result from the dilution effect of the added VAC. Due to the lower concentration of the polymer in the drug-loaded and to the increased conductivity of the electrospun solution, the diameters of the fibers should decrease 19,20,26,30 ; (iii) and the fact that PEU6 forms no nanofibres indicate that the highly flexible POE blocks under the applied processing conditions show the characteristic feature of the electrospinning process: chaotic oscillations of the electrospinning jet preventing fiber formation. [31][32][33][34] The data on VAC encapsulation efficiency (E e ) was determined by HPLC using known mehod.…”

“…The undesirable brittleness of PLA s can be decreased by incorporating low‐molar‐mass poly(oxyethylene) ( POE ) subchains attached to the PLA chains by esterification of their carboxy end‐groups with hydroxy end‐groups of oligomeric POE . The POE subchains are not only flexible but also hydrophilic ( POE is water‐soluble polymer), and so they also increase not only hydrophilicity but also processability of so chain‐extended PLA ‐based polymers . Since POE is a polymer of the polyether class, the resulting combined polymers (segmented copolymers) are usually referred to as polyesteretherurethanes.…”

“…However, the products of the degradation of urethane linkages might be problematic. This toxicity can be reduced by using lysine ethyl ester diisocyanate ( LEDI ) as the linking agent that gives units that provide non‐toxic degradation products . In this context, we recently described the successful synthesis of the PEUs based on short PLA / POE chains linked to longer chains by LEDI , studied them mainly in the form of nanoparticles in nano‐encapsulation and only partly as electrospun nanofibres and then proposed as carriers for the sustainable delivery of bioactive‐compounds and tissue‐engineering materials (Scheme ) …”

“…The POE subchains are not only flexible but also hydrophilic (POE is water-soluble polymer), and so they also increase not only hydrophilicity but also processability of so chain-extended PLA-based polymers. [16][17][18][19][20] Since POE is a polymer of the polyether class, 9 the resulting combined polymers (segmented copolymers 9 ) are usually referred to as polyesteretherurethanes.…”

“…This toxicity can be reduced by using lysine ethyl ester diisocyanate (LEDI) as the linking agent that gives units that provide non-toxic degradation products. 16,19 In this context, we recently described the successful synthesis of the PEUs based on short PLA/POE chains linked to longer chains by LEDI, 16,20 studied them mainly in the form of nanoparticles in nano-encapsulation and only partly as electrospun nanofibres and then proposed as carriers for the sustainable delivery of bioactivecompounds and tissue-engineering materials (Scheme 2). 21 Surprisingly, the knowledge on the modification of PEU properties through the crystallinity of its PLA prepolymer is quite limited, although the impact of configurational isomerism on the properties of pure PLAs has been extensively studied.…”