Poly(ester amide)s: recent insights into synthesis, stability and biomedical applications

Abstract

Recent progress in polyesteramides, which are important polymers that can combine the properties of polyesters and polyamides, is described with a focus on synthesis and their application as biomaterials.

TBD‐Catalyzed Ring‐Opening Polymerization of Alkyl‐Substituted Morpholine‐2,5‐Dione Derivatives

“…Poly(ester amide)s (PEA)s feature a rather similar degradation behavior as they contain hydrolysis‐sensitive ester moieties alongside more stable amide bonds . The complete degradation of PEAs yields biocompatible hydroxy acids and amino acids, making them highly interesting for application in the field of drug delivery …”

“…[4] The complete degradation of PEAs yields biocompatible hydroxy acids and amino acids, making them highly interesting for application in the field of drug delivery. [5] www.advancedsciencenews.com www.mrc-journal.de have been investigated for the ROP of morpholine-2,5-diones with varied success. [29,30] However, to the best of our knowledge, a mild polymerization procedure of these cyclic monomers toward well-defined PEAs is missing to date.…”

“…[18][19][20][21][22] Although this approach helps to overcome the comparably low reactivity of the morpholine-2,5-diones, [23] these Sn(Oct) 2 -catalyzed bulk polymerizations still have to be performed at 120 °C due to the low activity of the catalyst.On the other hand, highly potent organocatalysts for the ROP of cyclic esters or lactones in solution have been developed within the last decade. [24] 1,5,.0]dec-5-ene (TBD), [25][26][27] 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), or 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) represent heterocyclic guanidine-based organobases suitable for this purpose. Among these, TBD is the most active catalyst [28] and could, therefore, be able to compensate the relatively low reactivity of the morpholine-2,5-dione derivatives.…”

How Strong is Hydrogen Bonding to Amide Nitrogen?

“…Despite the information abundance on the amide functionality, [1][2][3] there is a continued interest in chemical synthesis, [4][5][6][7][8][9] biosynthesis [10][11][12] and reactivity [13][14][15][16][17][18][19] of amides due to their importance in medicine, biology, chemistry and other related interdisciplinary sciences. [20][21][22][23][24][25][26][27][28][29][30][31][32] This relevance encourages the research of the amide group's fundamental characteristics, e. g. the cis-trans isomerization barrier, [33][34][35][36] the resonance energy [37][38][39] or acid-base properties. The latter are especially important to ensure further progress in all areas of research listed above, specifically in the understanding of biochemical hydrolysis [40] and isomerization, [41][42][43] protein tertiary structure stabilisation, [44,45] structure and principle of action for ...…”

Antimicrobial Electrospun Fibers of Polyester Loaded with Engineered Cyclic Gramicidin Analogues

“…Although recent advances have facilitated the use of different stimuli, such as light, magnetic and electric fields, ultrasounds and electrochemical signals, to trigger drug release from smart material formulations (e.g., films, micro-and nanoparticles, and implant devices) [3][4][5][6], traditional systems based on the biodegradability of polymeric vehicles remain the most employed technology because of its efficiency, simplicity, and low cost [7][8][9][10][11][12][13][14]. Biodegradable polyester particles and fibers are widely employed for controlled and sustained targeted release of hydrophobic and poorly-water soluble drugs [15][16][17][18][19][20][21].…”