Noémie-Manuelle Dorval Courchesne

Adaptive growth factor delivery from a polyelectrolyte coating promotes synergistic bone tissue repair and reconstruction

Significance A critical challenge in the field of tissue repair is effective bone repair and reconstruction. The clinical standard of extracting bone from another area in the body or from donors is severely hampered by short supply, pain, and concerns about disease transmission. In this study, we developed a polymer-based nanolayered coating that carries active biological drugs in physiologically relevant amounts for tissue repair, with tunable release properties to induce bone repair. Using a rodent model, we observed that these coatings yield mature, mechanically stable bone that bridges large defects and restores the native form. This system is a potent strategy for safe and precise tissue repair and has the potential to significantly boost successful outcomes for bone repair. Traumatic wounds and congenital defects that require large-scale bone tissue repair have few successful clinical therapies, particularly for craniomaxillofacial defects. Although bioactive materials have demonstrated alternative approaches to tissue repair, an optimized materials system for reproducible, safe, and targeted repair remains elusive. We hypothesized that controlled, rapid bone formation in large, critical-size defects could be induced by simultaneously delivering multiple biological growth factors to the site of the wound. Here, we report an approach for bone repair using a polyelectrolye multilayer coating carrying as little as 200 ng of bone morphogenetic protein-2 and platelet-derived growth factor-BB that were eluted over readily adapted time scales to induce rapid bone repair. Based on electrostatic interactions between the polymer multilayers and growth factors alone, we sustained mitogenic and osteogenic signals with these growth factors in an easily tunable and controlled manner to direct endogenous cell function. To prove the role of this adaptive release system, we applied the polyelectrolyte coating on a well-studied biodegradable poly(lactic-co-glycolic acid) support membrane. The released growth factors directed cellular processes to induce bone repair in a critical-size rat calvaria model. The released growth factors promoted local bone formation that bridged a critical-size defect in the calvaria as early as 2 wk after implantation. Mature, mechanically competent bone regenerated the native calvaria form. Such an approach could be clinically useful and has significant benefits as a synthetic, off-the-shelf, cell-free option for bone tissue repair and restoration.

Versatile Three-Dimensional Virus-Based Template for Dye-Sensitized Solar Cells with Improved Electron Transport and Light Harvesting

By genetically encoding affinity for inorganic materials into the capsid proteins of the M13 bacteriophage, the virus can act as a template for the synthesis of nanomaterial composites for use in various device applications. Herein, the M13 bacteriophage is employed to build a multifunctional and three-dimensional scaffold capable of improving both electron collection and light harvesting in dye-sensitized solar cells (DSSCs). This has been accomplished by binding gold nanoparticles (AuNPs) to the virus proteins and encapsulating the AuNP-virus complexes in TiO2 to produce a plasmon-enhanced and nanowire (NW)-based photoanode. The NW morphology exhibits an improved electron diffusion length compared to traditional nanoparticle-based DSSCs, and the AuNPs increase the light absorption of the dye-molecules through the phenomenon of localized surface plasmon resonance. Consequently, we report a virus-templated and plasmon-enhanced DSSC with an efficiency of 8.46%, which is achieved through optimizing both the NW morphology and the concentration of AuNPs loaded into the solar cells. In addition, we propose a theoretical model that predicts the experimentally observed trends of plasmon enhancement.

Assembly of a Bacteriophage-Based Template for the Organization of Materials into Nanoporous Networks

M13 bacteriophages are assembled via a covalent layer-by-layer process to form a highly nanoporous network capable of organizing nanoparticles and acting as a scaffold for templating metal-oxides. The morphological and optical properties of the film itself are presented as well as its ability to organize and disperse metal nanoparticles.

Assembly of Viral Hydrogels for Three-Dimensional Conducting Nanocomposites

M13 bacteriophages act as versatile scaffolds capable of organizing single-walled carbon nanotubes and fabricating three-dimensional conducting nanocomposites. The morphological, electrical, and electrochemical properties of the nanocomposites are presented, as well as its ability to disperse and utilize single-walled carbon nanotubes effectively.

Carbon nanotube–polyaniline core–shell nanostructured hydrogel for electrochemical energy storage

Conductive polymer hydrogels, which synergize the advantageous features of hydrogels and conductive materials, have been utilized in many electrochemical energy storage applications. Here, we introduce phytic acid as (1) a dispersing agent for pristine multi-walled carbon nanotubes (MWNTs) in aqueous solution containing aniline and as (2) a gelator to form polyaniline (PANI)-based hydrogels after polymerization. The PANI-based hydrogels exhibit nanowire-based mesoporous networks with high surface area and electrical conductivity. The nanostructured core (MWNT)–shell (PANI) hydrogels show an improvement on the electrical conductivity from 0.21 to 1.54 S cm−1 as the loading of MWNTs increases from 0 to 5.0 wt%. The conducting nanowire-based networks with MWNT loadings of 3.0 wt% in the hydrogel provide efficient electron transport pathways that exhibit a maximal specific capacity of 609 F g−1. The scalable and facile synthesis demonstrates excellent electrochemical performance, rendering it attractive for sensing, energy conversion, and energy storage applications.