Synthesis of functionalized triblock copolyesters derived from lactic acid and macrolactones for bone tissue regeneration

Synthetic and functional grafts are a great alternative to conventional grafts. They can provide a physical support and the precise signaling for cells to heal damaged tissues. In this study, a novel RGD peptide end-functionalized poly(ethylene glycol)-b-poly(lactic acid)-b-poly(globalide)-b-poly(lactic acid)-b-poly(ethylene glycol) (RGD-PEG-PLA-PGl-PLA-PEG-RGD) is synthetized and used to prepare functional scaffolds. The PGl inner block is obtained by enzymatic ring-opening polymerization of globalide. The outer PLA blocks are obtained by ring-opening polymerization of both, l-lactide or a racemic mixture, initiated by the a-¿-telechelic polymacrolactone. The presence of PGl inner block enhances the toughness of PLA-based scaffolds, with an increase of the elongation at break up to 300% when the longer block of PGl is used. PLA-PGl-PLA copolymer is coupled with a-¿-telechelic PEG diacids by esterification reaction. PEGylation provides hydrophilic scaffolds as the contact angle is reduced from 114° to 74.8°. That difference improves the contact between the scaffolds and the culture media. Moreover, the scaffolds are functionalized with RGD peptides at the surface significantly enhancing the adhesion and proliferation of bone marrow-derived primary mesenchymal stem cells and MC3T3-E1 cell lines in vitro. These results place this multifunctional polymer as a great candidate for the preparation of temporary grafts.The authors would like to acknowledge AGAUR for the financial support by the Doctorats Industrials grant (Project No. 2018 DI 003) and the Ministerio de Ciencia, Innovación y Universidades of Spain (MCIU/AEI/FEDER, UE) (Project No. RTI2018-095041-B-C33). This research was also supported by grants PDC2021-121776-I00 and PID2020-117278GB-I00 from MCIN/AEI/10.13039/501100011033, co-funded by FEDER “Una manera de hacer Europa” or “NextGenerationEU”/PRTR. Globalide, l-lactide/d,l-lactide, and N435 biocatalyst were kindly provided by Symrise, Corbion, and Novozymes, respectively.  Peer ReviewedPostprint (published version

Electrohilado de microfibras de poli(éster amida) y poli(éster urea) derivadas de la L-leucina

Estudio y caracterización de microfibras de poli(éster amida) y poli(éster urea) derivadas de la L-leucina obtenidas por la técnica de electrohilado. Para su caracterización se determinan distintas propiedades físicas y químicas, así como su morfología. Se estudia también la variación de dichas propiedades según la composición en cada uno de los polímeros. Finalmente, se evalúa la degradación enzimática de las microfibras y el perfil de liberación de distintas drogas cargadas en ellas

Electrohilado de microfibras de poli(éster amida) y poli(éster urea) derivadas de la L-leucina

Estudio y caracterización de microfibras de poli(éster amida) y poli(éster urea) derivadas de la L-leucina obtenidas por la técnica de electrohilado. Para su caracterización se determinan distintas propiedades físicas y químicas, así como su morfología. Se estudia también la variación de dichas propiedades según la composición en cada uno de los polímeros. Finalmente, se evalúa la degradación enzimática de las microfibras y el perfil de liberación de distintas drogas cargadas en ellas

Enzymatic recycling of polymacrolactones

The use of renewable monomers to make new polyesters which could replace the ones obtained from petrochemical resources employing green processes is attracting a lot of attention these days. With this in mind, three different macrolactones, ¿-pentadecalactone, globalide and 6-hexadecenlactone, have been polymerized in bulk by enzymatic ring opening polymerization (e-ROP) using immobilized Candida antarctica lipase B to give their corresponding polymacrolactones (PMLs). For the first time, these PMLs have been depolymerized enzymatically in solution with the concourse of the same enzyme and at mild temperatures. GPC, NMR and ESI MS demonstrated that the main products recovered after the enzymatic processive recycling were cyclic monomers and dimers, with a small amount of higher size macrocyclic oligoesters (MCOs). It was observed that these depolymerizations followed a Michaelis–Menten kinetic model. Finally it was shown that these MCOs could be repolymerized. This research provides a biosynthetic method for chemical recycling of these interesting polymeric materials providing a pathway towards a circular economy.Peer ReviewedPostprint (author's final draft

Espacios y destinos turísticos en tiempos de globalización y crisis

2 volúmenesXII Coloquio de Geografía del Turismo, Ocio y Recreación de la Asociación de Geógrafos Españoles. Colmenarejo (Madrid), del 17 al 19 de junio de 2010.Este libro ha sido editado con la colaboración económica del Ministerio de Ciencia e Innovación (ref. CS02010-10416-E)

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

non present