Osteoconductive and Antibacterial Poly(lactic acid) Fibrous Membranes Impregnated with Biobased Nanocarbons for Biodegradable Bone Regenerative Scaffolds

Abstract

Carbonaceous nanostructures featuring unique structural characteristics and high cytocompatibility offer a wealth of possibilities to impart enhancements of mechanical properties and biological activities for osteogenic tissue scaffolds. Here, we unveil the fabrication of osteoconductive and antibacterial porous poly­(lactic acid) (PLA) membranes by direct electrospinning of microfibers impregnated with coffee-ground-derived quantum dots (QDs). It enabled a straightforward pathway to regulate the diameter and its distribution for the electrospun PLA microfibers, as well as the improved hydrophilicity. The QDs exhibited high affinity to the PLA matrix, permitting remarkable promotion of tensile strength and elastic modulus for the QD-modified PLA membranes while maintaining comparable extensibility. More importantly, osteoblast adhesion and stretching on the electrospun membranes were significantly enhanced with the existence of QDs, as exemplified by the nearly 1.8-fold increase in cell viability cultured onto the composite membrane loaded with 1.5% QDs compared to that of pure PLA. This was accompanied by rapid biomimetic mineralization and uniform apatite formation in an osteo-friendly manner. Unexpectedly, immediate and broad-spectrum antibacterial performance was achieved for the composite membranes, likely arising from the synergistic effects of QD-imparted membrane stress and oxidative stress. The unusual combination of mechanical, biomineralization, biological, and antibacterial performances makes the biodegradable membrane scaffolds promising for guided bone/tissue regeneration therapy.

A review: studying the effect of graphene nanoparticles on mechanical, physical and thermal properties of polylactic acid polymer

“…Huan et al 197 observed in Fig. 17 that the tensile strength during fracture and the tensile modulus improved with increasing nanocarbons.…”

Graphene Oxide/RhPTH(1-34)/Polylactide Composite Nanofibrous Scaffold for Bone Tissue Engineering

“…These results suggest that the electrostatic force may improve the interaction between the polylactic acid matrix and the GO strengthening nanofillers during the electrospinning process, and that the size effect in nanofibers may also contribute to the improvement of mechanical properties, which is a positive phenomenon. It was in line with the definition of scaffolds in bone tissue engineering, as the scaffolds should have high mechanical strength and stiffness [ 41 , 42 ]. However, limited by the mechanical properties of electrospun membranes, the strength of pure PLA membranes are characterized by a strength of about 1.0 MPa, because the width and thickness of the membranes are greatly related to the mechanical properties.…”

Synthesis of Fluorine‐Containing, UV‐Responsive PLA‐Based Materials by Means of Functionalized DOX Monomer

“…[16] Besides poor mechanical properties, PLA's in vivo applicability is often limited by inadequate surface properties and hydrophobicity and low surface energy, as well as the lack of surface functional groups, likely hindering proper cell adhesion. [17,18] A partial fluorination of the surface has been recently reported as a possible improvement, as it was demonstrated that partially fluorinated surfaces can promote the cells' adhesion and proliferation, thanks to the formation of favorable dipoles. [19][20][21] To this regard, it is important to balance properly the fluorination degree, in order to avoid an increased hydrophobicity that would hinder proper in vivo interactions.…”