Hybrid Membranes of PLLA/Collagen for Bone Tissue Engineering: A Comparative Study of Scaffold Production Techniques for Optimal Mechanical Properties and Osteoinduction Ability

Abstract

Synthetic and natural polymer association is a promising tool in tissue engineering. The aim of this study was to compare five methodologies for producing hybrid scaffolds for cell culture using poly-l-lactide (PLLA) and collagen: functionalization of PLLA electrospun by (1) dialkylamine and collagen immobilization with glutaraldehyde and by (2) hydrolysis and collagen immobilization with carbodiimide chemistry; (3) co-electrospinning of PLLA/chloroform and collagen/hexafluoropropanol (HFP) solutions; (4) co-electrospinning of PLLA/chloroform and collagen/acetic acid solutions and (5) electrospinning of a co-solution of PLLA and collagen using HFP. These materials were evaluated based on their morphology, mechanical properties, ability to induce cell proliferation and alkaline phosphatase activity upon submission of mesenchymal stem cells to basal or osteoblastic differentiation medium (ODM). Methods (1) and (2) resulted in a decrease in mechanical properties, whereas methods (3), (4) and (5) resulted in materials of higher tensile strength and osteogenic differentiation. Materials yielded by methods (2), (3) and (5) promoted osteoinduction even in the absence of ODM. The results indicate that the scaffold based on the PLLA/collagen blend exhibited optimal mechanical properties and the highest capacity for osteodifferentiation and was the best choice for collagen incorporation into PLLA in bone repair applications.

Biofabrication of bundles of poly(lactic acid)-collagen blends mimicking the fascicles of the human Achille tendon

“…Theisen et al tested the same blend in electrospun scaffolds, and demonstrated a good proliferation of human tenoblasts from long biceps tendons [33]. Conçalves et al studied the morphology, mechanical properties and osteoblastic differentiation of random electrospun fiber scaffolds mats made by five different kinds of PLLA/Coll blends and solvents systems, confirming their good biocompatibility [34].…”

“…Because of their inherent properties of biological recognition, natural polymers have therefore been proposed in combination with synthetic polymers for tendon reconstruction: for instance poly(L-lactide-co-ε-caprolactone) copolymer has been blended with either collagen [29] or silk [30] and chitosan and gelatin have been used in combination with poly(L-lactic acid) (PLLA) [28]. While blends of collagen and PLLA have been investigated in the past [31][32][33][34] they have never been manufactured to produce bundles for tendon reconstruction. Moreover, the effect of the amount of the natural component on the mechanical properties of the bundle and on cell behaviour, as well the stability of bundle composition under physiological condition have never been deeply investigated.…”

Characterization of maghemite (γ-Fe2O3)-loaded poly-l-lactic acid/thermoplastic polyurethane electrospun mats for soft tissue engineering

“…Many researchers had tried to report the application of PLLA for soft tissue such as heart valve and blood vessel but all of them failed. Several works have been done on fabricating polymer blends such as PLLA/ PCL [32], PLLA/chitosan [33], PLLA/collagen [34], PLA/PLGA [19], and polymer composites like PLLA/hydroxyapatite (HA) and PLLA/carbon nanotubes (CNTs) [35,36], to enhance the flexibility and elasticity properties of scaffold.…”

Bone Morphogenetic Proteins

“…The porosity, orientation, and size of fibers and chemical affinity are essential to define the best materials to develop the ideal scaffold for optimum cells adhesion and/or BMPs adsorption. Several materials have been tested as carriers, from synthetic to natural sources, such as hydroxyapatite, bioglass, calcium sulfates, calcium phosphates, β-tricalcium phosphate, calcium carbonate, organic polymers, polylactic acid (PLA), polyglycolic acid (PGA), copolymers (such as polylactic-co-polyglycolic acid (PGLA)), methylmethacrylate, hyaluran, fibrina, alginate, silk, agarose and collagen (Carpena, Min, & Lee, 2015;Chen, Liu, Gu, Feng, & Yang, 2015;Dadsetan et al, 2015;Gonçalves et al, 2015;Margolin et al, 1998;Seeherman & Wozney, 2005). The choice of a biomaterial depends on a good compatibility, accessibility, and low immunogenicity.…”