3D Hybrid Nanofiber Aerogels Combining with Nanoparticles Made of a Biocleavable and Targeting Polycation and MiR‐26a for Bone Repair

Abstract

The healing of large bone defects represents a clinical challenge, often requiring some form of grafting. 3D nanofiber aerogels could be a promising bone graft due to their biomimetic morphology and controlled porous structures and composition. miR-26a has been reported to induce the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and facilitate bone formation. Introducing miR-26a with a suitable polymeric vector targeting BMSCs could improve and enhance the functions of 3D nanofiber aerogels for bone regeneration. Herein, the comb-shaped polycation (HA-SS-PGEA) is first developed, carrying a targeting component, biocleavable groups, and short ethanolamine (EA)-decorated poly(glycidyl methacrylate) (PGMA) (abbreviated as PGEA) arms as miR-26a delivery vector. Thereafter, the cytotoxicity and transfection efficiency of this polycation and cellular response to miR-26a-incorporated nanoparticles (NPs) are assessed in vitro. HA-SS-PGEA exhibits a stronger ability to transport miR-26a and exert its functions than the gold standard polyethyleneimine (PEI) and low-molecular-weight linear PGEA. The efficacy of HA-SS-PGEA/ miR-26a NPs loaded 3D hybrid nanofiber aerogels showing a positive effect on the cranial bone defect healing is finally examined. Together, the combination of 3D nanofiber aerogels and functional NPs consisting of a biodegradable and targeting polycation and therapeutic miRNA could be a promising approach for bone regeneration.

Freeze‐Casting with 3D‐Printed Templates Creates Anisotropic Microchannels and Patterned Macrochannels within Biomimetic Nanofiber Aerogels for Rapid Cellular Infiltration

“…[ 35–38 ] One technique to produce such materials, directional ice‐templating, is widely used for generating short nanofiber aerogels with controlled porous architectures. [ 29–31 ] In this study, we attempted to create both macro‐ and microchannels in nanofiber aerogels by combining the 3D‐printed sacrificial template and freeze‐casting process. Figure S1A (Supporting Information) shows a schematic representation of isotropic freezing, illustrating that cold ethanol (−80 °C) provides a spatially uniform freezing environment surrounding the side and bottom of the Cu mold during freeze‐casting.…”

“…[ 24 ] Specifically, aerogels made of short electrospun nanofibers have been subjected to research in several innovative areas including pressure sensing, [ 25 ] thermal insulation, [ 26 ] protein separation, [ 27 ] oil–water separation, [ 28 ] bone regeneration, [ 29 ] and tissue repair studies. [ 30,31 ]…”

Biomaterials with structural hierarchy and controlled 3D nanotopography guide endogenous bone regeneration

“…To test the bone regeneration efficacy of RAS and VAS, we implanted these scaffolds into the critical-sized (8 mm in diameter) calvarial bone defects in rats (Fig. 3A) (22)(23)(24). The schematic diagrams indicate the open pores on the side of the RAS facing the bone marrow (Fig.…”

3D PCL/Gelatin/Genipin Nanofiber Sponge as Scaffold for Regenerative Medicine

“…A possible solution is the production of highly porous three-dimensional (3D) nanofiber sponges or aerogels from short nanofibrous building blocks using a self-assembly process in combination with subsequent freeze drying and cross-linking steps [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ] or the combination of electrospinning and 3D printing [ 41 ]. Recently, several approaches of using preformed nanofibers to assemble 3D nanofiber scaffolds for tissue engineering, in particular for bone, have been reported [ 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ]. This is in contrast to alternative approaches for porous 3D scaffolds, e.g., using sol–gel processes [ 52 ].…”