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Pseudo-Proteins and Related Synthetic Amino Acid-Based Polymers Promising for Constructing Artificial Vaccines
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
Interestingly, even acidic products, released after ester-bond’s hydrolysis of PP-PEUs before the ultimate biodegradation, did not cause inflammation that was ascribed to the self-buffering property of PEU preventing significant pH drop during the degradation process (Stakleff et al. 2013). Many PPs are amorphous and that provides smooth biodegradation of devices made of them. Other advantages of PPs over aliphatic polyesters, especially over the polyesters obtained via ROP are (Katsarava and Gomurashvili 2011; Katsarava, Kulikova, and Puiggalí 2016): Polycondensation synthesis without using toxic catalystsSynthesis under atmospheric conditions at moderate temperatures (20–80˚C)Tunable hydrophobicity/hydrophilicity balanceHigher affinity (owing to NHCO bonds) and better compatibility with tissuesSolubility in common organic solvents (ethanol, isopropanol, THF, acetone, etc.)Longer shelf-life
Lactic acid-based polymers in depth
Published in Yoshinobu Onuma, Patrick W.J.C. Serruys, Bioresorbable Scaffolds, 2017
Like polyesters in general, lactic acid-based polymers can be synthesized by polycondensation, i.e., by formation of ester links between the alcohol and the carboxylic acid function present in the lactic acid molecule. In general, this route does not lead to high molecular mass macromolecules and thus corresponding polymers are rather weak, though that high molecular mass lactic acid-based polycondensates have been reported in the literature [3]. The use of PLAs obtained by the polycondensation route has not been prospected for biomedical applications yet.
Elements of Polymer Science
Published in E. Desmond Goddard, James V. Gruber, Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
E. Desmond Goddard, James V. Gruber
Carothers, in 1929, classified synthetic polymers into two classes, according to the method of their preparation, i.e., condensation polymers and addition polymers. In polycondensation, or step-growth polymerization, polymers are obtained by reaction between two poly-functional molecules and elimination of a small molecule, for example water. Typical condensation polymers are shown in Figure 2. Addition (or chain reaction) polymers are formed from unsaturated monomers in a chain reaction. Examples of addition polymers are shown in Figure 2.
Synthetic biodegradable polyesters for implantable controlled-release devices
Published in Expert Opinion on Drug Delivery, 2022
Jinal U. Pothupitiya, Christy Zheng, W. Mark Saltzman
PCL can be synthesized from CL or 6-hydroxyhexanoic acid, which are both intermediates in the oxidation of cyclohexanol to adipic acid in microorganisms. Polycondensation of 6-hydroxyhexanoic acid to yield PCL requires harsh temperature and pressure conditions in the absence of catalysts [126]. The polymerization is feasible in the presence of catalysts at low temperatures; however, PCL formation proceeds sluggishly. ROP of CL is the preferred route to produce PCL. CL is commercially produced from the oxidation of cyclohexanone and subjected to ROP to yield high molecular weight PCL. ROP allows for fine tuning of molecular weight and produces polymers with low polydispersity in molecular weight; the polydispersity, or polydispersity index (PDI), is defined as the ratio of weight average molecular weight (Mw) and the number average molecular weight (Mn), PDI = Mw/Mn [126].
Ficus carica extract impregnated amphiphilic polymer scaffold for diabetic wound tissue regenerations
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Jia Feng, Yu Niu, Yi Zhang, Hong Zuo, Shujin Wang, Xufeng Liu
Polymerization of xylitol, adipic acid and l-glutamic acid was carried out by the polycondensation reactions with the previous report's slightly modified procedure [28]. The 1:1:1 stoichiometric ratio of xylitol, adipic acid, l-glutamic acid monomers is accurately weighed 1 g and dissolved in a 1:1 ratio of DD water–ethanol solution, and these solutions were made up to 20 mL. The solutions were then taken in an RB flask to heat 120 °C with constant stirring (150 rpm) for 5 h to get a transparent solution of the PXAG prepolymer. The transparent solution was heated in a micro oven at 150 W for about 10 min to form the pale yellow solution of PXAG polymers. The polymer viscosity was elevated slowly with the cumulative reaction period. Finally, the PXAG polymeric solution was kept a room temperature (25 °C) for 24 h to get a solid palm leaves structure of PXAG copolymer. The formation of palm leaves structure polymer of PXAG polymer, which has an ester bond between the monomers of xylitol and adipic acid and the amide bonds between adipic acid and l-glutamic acid monomers (Scheme 1), was confirmed by FT-IR, 1H and 13C NMR spectroscopy. The synthetic procedure of PXAG synthesis is shown in Supplementary Figure 1.
Fluorescent melamine-formaldehyde/polyamine coatings for microcapsules enabling their tracking in composites
Published in Journal of Microencapsulation, 2022
Christian Neumann, Sophia Rosencrantz, Andreas Schmohl, Latnikova Alexandra
The polycondensation reaction of MF prepolymer and PEI (Table 1) took place in the aqueous phase yielding a suspension. After the end of the reaction (2 h), the suspension was left to stand for 10 min at room temperature and the filtrate was isolated by vacuum filtration (4–7 µm cellulose filter paper) and washed three times with 100 ml deionised water. The filter cake was quantitatively transferred to a glass vessel and allowed to dry overnight at room temperature. The weight of the white/yellow powder allowed to calculate the yield based on the amount of solids content of the starting materials used.