Electrospun Scaffolds from Low Molecular Weight Poly(ester amide)s Based on Glycolic Acid, Adipic Acid and Odd or Even Diamines

Abstract

Electrospinning of regular poly(ester amide)s (PEAs) constituted by glycolic acid, adipic acid and diamines with five and six carbon atoms has been carried out. Selected PEAs were constituted by natural origin products and could be easily prepared by a polycondensation method that avoids tedious protection and deprotection steps usually required for obtaining polymers with a regular sequence. Nevertheless, the synthesis had some limitations that mainly concerned the final low/moderate molecular weight that could be attained. Therefore, it was considered interesting to evaluate if electrospun scaffolds could still be prepared taking also advantage of the capability of PEAs to establish intermolecular hydrogen bonds. Results indicated that the crucial factor was the control of polymer concentration in the electrospun solution, being necessary that this concentration was higher than 40% (w/v). The PEA with the lowest molecular weight (Mw close to 8000 g/mol) was the most appropriate to obtain electrospun samples with a circular cross-section since higher molecular sized polymers show solvent retention problems derived from the high viscosity of the electrospun solution that rendered ribbon-like morphologies after the impact of fibers into the collector. The studied PEAs were semicrystalline and biodegradable, as demonstrated by calorimetric and degradation studies. Furthermore, the new scaffolds were able to encapsulate drugs with anti-inflammatory and bacteriostatic activities like ketoprofen. The corresponding release and bactericide activity was evaluated in different media and against different bacteria. Finally, biocompatibility was demonstrated using both fibroblast and epithelial cell lines. OPEN ACCESSFibers 2015, 3 152

Ductile gas barrier poly(ester–amide)s derived from glycolide

“…39,40 In 2005, Vera et al reported inspiring work that poly(ester-amide)s containing glycolate were degradable in enzymatic media and hydrolytic conditions. [41][42][43][44] Since materials containing glycolate units typically exhibit low gas permeability, we anticipated that these degradable poly(ester-amide)s derived from glycolide would have both promising mechanical and gas barrier properties (Chart 1C).…”