Porous Copolymers of ε-Caprolactone as Scaffolds for Tissue Engineering

Abstract

A series of random copolymers were synthesized via the copolymerization of a carbohydrate lactone, acetic acid 5-acetoxy-6-oxotetrahydropyran-2-yl methyl ester (1), and ε-caprolactone. The copolymers were characterized by nuclear magnetic resonance (NMR) spectroscopy, size exclusion chromatography (SEC), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). Copolymers (P1–P4) were produced with typical carbohydrate ester compositions of 1–4 mol %. These copolymers are semicrystalline and can be processed into thin films with Young’s moduli of 300–420 MPa, values that exceed that for polycaprolactone (PCL). The copolymers were processed using supercritical carbon dioxide (scCO2, 35 °C, 200 bar) into foamed, porous scaffolds, which were characterized by dynamic mechanical thermal analyses (DMTA), mercury porosimetry, and scanning electron microscopy (SEM). The copolymer foams showed increased pore size with increasing carbohydrate ester content. The average pore size increased from 71 μm (PCL) to 319 μm (P4). The foamed scaffolds have normalized storage moduli ranging from 37 MPa cm3 g–1 (P4) to 109 MPa cm3 g–1 (P1). A representative copolymer foamed scaffold, tested according to ISO 10993-5 criteria, was cytocompatible for cell culture. MC3T3 cells cultured on a film of this copolymer showed increased relative metabolic activities compared to cells cultured on a PCL film. When primary bovine chondrocytes were cultured on the foamed scaffolds, increased cell penetration into the random copolymer foam was observed compared to PCL foams.

Functional Brush-Decorated Poly(globalide) Films by ARGET-ATRP for Bioconjugation

“…Aliphatic polyesters are widely used in various medical applications, such as sutures, stents, bone screws, tissue engineering scaffolds, and drug delivery systems . Depending on the choice of (co)monomers, aliphatic polyesters exhibit tunable thermal and mechanical properties, hydrophilicity and degradation rate, but often lack functional groups for bioconjugation, for example, with peptide ligands or growth factors to improve cell adhesion and enhance cell growth.…”

Itaconic acid used as a versatile building block for the synthesis of renewable resource‐based resins and polyesters for future prospective: a review

“…58 Comparable results were also reported for the polymerization of itaconic anhydride with 1,2-epoxybutane in the presence of catalysts Mg(OEt) 2 , Al(OiPr) 3 , bis(nonafluorobutanesulfonyl) imide and Sc(OTf ) 3 . 59,60 Although, in this method, the polymerization was followed by isomerization of itaconate to cytraconate. This process facilitates the synthesis of polymers of molar mass up to 50 kg mol −1 .…”

“…61,62 For all the methods analysed, still at low concentration of IA, crosslinked polymers can be prepared. In earlier studies, Tang et al 60 first copolymerized a polyester containing IA, maleate and 3-methyl-1,5-pentanediol and then operated a specific photo-crosslinking of the exo-type double bonds of itaconate, while the double bonds of maleate remained intact.…”

“…Nf 2 NH-catalysed polycondensation reaction at low temperature. 60 it is an interesting approach for obtaining biomaterials. A photoinitiator, diethoxyacetophenone, is used for the UV-curing of synthesized materials.…”

Changes in the morphology of poly( l ‐lactide‐ ran ‐δ‐valerolactone) following supercritical carbon dioxide processing

“…Controlled‐release materials can be obtained by impregnating biodegradable polymers, using scCO 2 to soften the polymers at low temperatures . CO 2 has a critical temperature of 31.1°C and a critical pressure of 7.38 MPa, such that scCO 2 can be readily generated for the processing of polymers . This technology allows the spontaneous release of compounds from the polymer through hydrolysis, and is often used in conjunction with poly(lactide) or its copolymers.…”