Rapid and Efficient Optimization of Poly(1,2-Ethanediol Citrate) Synthesis Based on Magic Squares’ Various Methods

New biomaterials among aliphatic polyesters are in demand due to their potential applications in tissue engineering. There is a challenge not only to design scaffolds to regenerate defects in load-bearing tissues but also to ensure a proper blood supply to the reconstructed tissues. Poly-(1,2-ethanediol citrate) is one of the novel citrate-based polymers that could have the desired properties for cell scaffold fabrication and for enhancing cell adhesion. Both citric acid and 1,2-ethanediol are used in medicine and are fully resorbable by cells. This work aimed to synthesize poly(1,2-ethanediol citrate) in a catalyzed reaction with water removed by the Dean–Stark apparatus. The polyester structure was characterized by FTIR and NMR spectroscopy, and the HMBC experiment was performed to support the theory of successful polymer synthesis. The molecular weight was determined for the products obtained at 140 °C. The process was described via non-linear mathematical models. The influence of temperature and catalyst content on the degree of esterification and the conversion of acid groups in citric acid is described. The optimal process parameters are determined at 140 °C and 3.6% of p-toluenesulfonic acid content. The presented results are the starting point for scaffold design and scaling-up the process

Optimizing the conditions of PGSu synthesiswith simplex method

Poly(glycerol succinate) – PGSu – is one of glycerol polyesters which has focused nowadays the interestof scientists developing new biomaterials. Probably the polyester could be used as a drug carrier or asa cell scaffold in tissue engineering. Due to its potential use in medicine, it is extremely important todevelop a synthesis and then optimize it to obtain a material with desired properties. In this work oneflask two-step polycondensation of glycerol and succinic anhydride to PGSu is presented. Synthesiswas optimized with the simplex method and also described using a second-degree equation with twovariables (temperature and time) to better find the optimum conditions. PGSu was characterized byFTIR spectroscopy, NMR spectroscopy, degree of esterification was determined, and also molecularweight was calculated for each experiment using Carothers equation. A new synthesis route wasdeveloped and optimized. Temperature and time influence on molecular weight and esterificationdegree of obtained polyester are presented. Based on experiments conducted in this work, it waspossible to obtain poly(glycerol succinate) with molecular weight of 6.7 kDa

The catalyst-free polytransesterification for obtaining linear PGS optimized with use of 22 factorial design

Poly(glycerol sebacate) (PGS) is a polyester that is particularly useful for tissue engineering appli- cations. Many researchers have focused on the application and characterization of materials made from PGS. Synthesis is often superficially described, and the prepolymer is not characterized before crosslinking. Considering the different functionality of each monomer (glycerine – 3, sebacic acid – 2), materials with a branched structure can be obtained before the crosslinking process. Branched struc- tures are not desirable for elastomers. In this work, method to obtain linear PGS resins is presented. Moreover, synthesis was optimized with the use of the Design of Experiments method for minimizing the degree of branching and maximizing the molecular weight. The process was described via mathe- matical models, which allows to the association of process parameters with product properties. In this work ca. 1kDa and less than 10% branched PGS resin was produced. This resin could be used to make very flexible elastomers because branching is minimized

Exploring the application of poly(1,2-ethanediol citrate)/polylactide nonwovens in cell culturing

Biomaterials containing citric acid as a building unit show potential for use as blood vessel and skin tissue substitutes. The success in commercializing implants containing a polymer matrix of poly(1,8-octanediol citrate) provides a rationale for exploring polycitrates based on other diols. Changing the aliphatic chain length of the diol allows functional design strategies to control the implant’s mechanical properties, degradation profile and surface energy. In the present work, poly(1,2-ethanediol citrate) was synthesized and used as an additive to polylactide in the electrospinning process. It was established that the content of polycitrate greatly influences the nonwovens’ properties: an equal mass ratio of polymers resulted in the best morphology. The obtained nonwovens were characterized by surface hydrophilicity, tensile strength, and thermal properties. L929 cell cultures were carried out on their surface. The materials were found to be non-cytotoxic and the degree of porosity was suitable for cell colonization. On the basis of the most important parameters for assessing the condition of cultured cells (cell density and viability, cell metabolic activity and lactate dehydrogenase activity), the potential of PLLA + PECit nonwovens for application in tissue engineering was established