Biological and mechanical properties of novel composites based on supramolecular polycaprolactone and functionalized hydroxyapatite

Abstract

Supramolecular polymers based on quadruple hydrogen-bonding ureido-pyrimidinone (UPy) moieties hold promise as dynamic/stimuli-responsive materials in applications such as tissue engineering. Here, a new class of materials is introduced: supramolecular polymer composites. We show that despite the highly ordered structure and tacticity-dependent nature of hydrogen-bonded supramolecular polymers, the bioactivity of these polymers can be tuned through composite preparation with bioceramics. These novel supramolecular composites combine the superior processability of supramolecular polymers with the excellent bioactivity and mechanical characteristics of bioceramics. In particular, the bioactive composites prepared from supramolecular polycaprolactone and UPy-grafted hydroxyapatite (HApUPy) are described that can be easily formed into microporous biomaterials. The compression moduli increased about 40 and 90% upon composite preparation with HAp and HApUPy, respectively, as an indication to improved mechanical properties. These new materials show excellent potential as microporous composite scaffolds for the adhesion and proliferation of rat mesenchymal stem cells (rMSCs) as a first step toward bone regeneration studies; rMSCs proliferate about 2 and 2.7 times faster on the conventional composite with HAp and the supramolecular composite with (HApUPy) than on the neat PCL1250(UPy)(2).

Polymeric scaffolds as stem cell carriers in bone repair

“…Surface changes can be induced by ion beam irradiation (Marletta et al ., ), forming He + ‐irradiated PCL scaffolds, and it is confirmed to improve the adhesion of MSCs and support their differentiation. Mineralization with CP or HA and CT1 was also shown to be suitable for bone tissue engineering (Chen and Chang, ; Edlund et al ., ; Guarino et al ., ; Phipps et al ., ; Scaglione et al ., ; Schantz et al ., ; Shokrollahi et al ., ; Weinand et al ., ; Yu et al ., ). Indeed, the effects of HA particle size and shape in the coating layer on the mechanical and biological properties of a biphasic calcium phosphate (BCP) scaffold were examined (Roohani‐Esfahani et al ., ): needle‐shaped coated HA/PCL particles induced the differentiation of primary human bone‐derived cells and possessed superior physical, mechanical, elastic and biological properties.…”

Biocomposites and hybrid biomaterials based on calcium orthophosphates

“…54 In this system, PCL as a coating component was able to improve the brittleness and low strength of the HA scaffolds, while the particles in the coating improved the osteoconductivity and bioactivity of the coating layer. More complex formulations, such as PDLLA/PCL/ HA, 439 PLLA/PCL/HA 440 and supramolecular PCL/functionalized HA 441 biocomposites, have been prepared as well. Further details on both the PCL/HA biocomposites and the processing methodologies thereof might be found in reference 328.…”

Degradable biocomposite of nano calcium- deficient hydroxyapatite-multi(amino acid) copolymer

“…[1][2][3] Hence, in designing a new inorganic/organic biocomposite, the choice of an inorganic component and a polymer are key to formulating a composite with favorable bioperformance. Nano hydroxyapatite biomaterials have being extensively developed for biomedical applications in recent decades because they have good biocompatibility and bioactivity, and can bond with host bone directly.…”