Degradable multi(aryl azide) star copolymer as universal photo-crosslinker for elastomeric scaffolds. (June 2019)

• Record Type: Journal Article
• Authors: Gangolphe, L.; Déjean, S.; Bethry, A.; Hunger, S.; Pinese, C.; Garric, X.; Bossard, F.; Nottelet, B.
• Is Part Of: Materials today chemistry. Volume 12(2019)
• Page Start: 209
• Page End: 221
• Publication Date: 2019-06
• Subjects: Degradable elastomers -- Tissue engineering scaffolds -- Electrospinning -- UV photo-crosslinking -- Polyester; PHBV polyhydroxybutyrate-co-hydroxyvalerate -- BA 2, 6-bis(4-azidobenzylidene)-4-methylcyclohexanone -- PMMA poly(methyl methacrylate) -- PLA poly(lactide) -- PEG poly(ethylene glycol) -- PEG8arm10k 8-arm poly(ethylene glycol) (tripentaerythritol) -- PEO poly(ethylene oxide) -- Pluronic®F127 poloxamer -- Tetronic®1107 poloxamine -- Sn(Oct)2 tin(II) 2-ethylhexanoate -- DCM dichloromethane -- Et2O diethylether -- DCC N, N-dicyclohexyl-carbodiimide -- DMAP 4-(dimethylamino)pyridine -- DMF N, N-dimethylformamide -- THF tetrahydrofuran -- PLA50PLU PLA50-Pluronic®-PLA50 -- s-PLA PEG8arm10k-PLA94 -- s-PLA-fN3 PEG8arm10k-PLA94-fN3 -- FSs (micro)fibrous scaffolds -- dispersities Ð average molecular weights -- SEC size exclusion chromatography -- NMR nuclear magnetic resonance -- CDCl3 deuterated chloroform -- DMSO-d6 dimethyl sulfoxide -- TMS tetramethylsilane -- DSC differential scanning calorimetry -- SEM scanning electron microscope -- MB mercury bulb -- MHB metal halide bulb -- E Young modulus -- σy stress at yield -- εy strain at yield -- σbreak stress at break -- εbreak strain at break -- Na2CO3 sodium bicarbonate -- MgSO4 magnesium sulfate -- PBS phosphate buffered saline -- Wi initial weight -- Ww weight of the wet samples -- Wx dry weight after x time -- ZDBC dibutyldithiocarbamate -- LDH lactate dehydrogenase -- Tm melting temperature -- Hm enthalpy of melting -- FDA Food and Drug Administration; Chemistry -- Periodicals; Materials -- Research -- Periodicals; Materials science -- Periodicals; Chemistry; Materials -- Research; Electronic journals; Periodicals; 660.282
• DOI: 10.1016/j.mtchem.2018.12.008
• Languages: English
• ISSNs: 2468-5194

Abstract

Abstract: Degradable elastomers with elastic properties close to those of soft tissues are necessary for tissue engineering. Most degradable elastomers developed so far are based on functional low–molecular-weight prepolymers that are combined with molecular crosslinkers to yield the elastomeric three-dimensional networks. To overcome this limitation, we present in this work the concept of star-shaped macromolecular multi(aryl azide) photo-crosslinker that has the ability to efficiently cross-link any polymer containing C-H bonds independently of its molecular weight and without the need for prefunctionalization. This concept of universal crosslinking agent is illustrated with a star-shaped block copolymer composed of an 8-arm poly(ethylene glycol) core and poly(lactide) side arms functionalized with aryl azide moieties (PEG8arm -PLA-fN3 ). It was selected due to its macromolecular nature that allows for an easy processing of electrospun photo-crosslinked scaffolds, while making it possible to adapt its chemical nature with one of the polymer matrices. A parameter study is first carried out on PEG8arm -PLA-fN3 /PLA-Pluronic ® -PLA films to evaluate the impact of the polymers' molecular weight, PEG/PLA ratios, and UV irradiation conditions on the crosslinking efficiency. This study confirms that high crosslinking efficiencies can be obtained with PEG8arm -PLA-fN3 (60%) compared with commercially available bis(aryl azide) photo-crosslinker (below 15%). Optimal conditions are then used to yield electrospun microfibers (1–2 μm) crosslinked with PEG8arm -PLA-fN3, resulting in biocompatible and highly elastomeric scaffolds ( ε y > 100 % ) compared with uncrosslinked scaffolds ( ε y < 10 % ). In addition, we show that the degradation rate can be controlled overtime depending on the blend content of PEG8arm -PLA-fN3 . Taken together, these results demonstrate the potential of macromolecular multi(aryl azide) photo-crosslinkers to develop original degradable elastomeric scaffolds for soft tissue reconstruction. Highlights: Star-shaped multi(aryl azide) copolymers as universal macromolecular photo-crosslinkers. Polymer-independent photo-crosslinker turns polymers into degradable network. Crosslinked electrospun fibers are easily generated yielding elastomer scaffolds. Mechanical and degradation properties are modulated by the content of the macromolecular photo-crosslinker.