Reverse Reconstruction and Bioprinting of Bacterial Cellulose‐Based Functional Total Intervertebral Disc for Therapeutic Implantation

Abstract

The degradation of intervertebral discs (IVD), a typical hierarchical structured tissue, causes serious neck and back pain. The current methods cannot fully reconstitute the unique structure and function of native IVD. In this study, by reverse reconstruction of the structure of native IVD and bioprinting bacterial cellulose (BC) nanofibers with a high-throughput optimized micropattern screening microchip, a total IVD is created that contained type II collagen-based nucleus pulposus (NP) and hierarchically organized and micropatterned BC-based annulus fibrosus (AF), mimicking native IVD tissue. The artificial NP contains rat NP cells, whereas the AF contains concentrically arranged BC layers with aligned micropatterns and attached AF cells in +/-30° alternate directions between adjacent layers. Long-term (3 months) implantation experiments on rats demonstrate the excellent structural (shape maintenance, hydration, tissue integration) and functional (mechanical support and flexibility) performance of the artificial IVD. This study provides a novel strategy for creating highly sophisticated artificial tissues.

Latest Advances on Bacterial Cellulose‐Based Materials for Wound Healing, Delivery Systems, and Tissue Engineering

“…In a distinct study, Yang et al . developed a new strategy for the preparation of 3D structures mimicking intervertebral discs ( Figure ).…”

“…Subsequently the bacteria were cultured in the PDMS template and the micropatterned BC membrane was created at the liquid‐PDMS template interface. Reproduced with permission . Copyright 2018, Wiley‐VCH.…”

Biomaterials for intervertebral disc regeneration: Current status and looming challenges

“…(c) The disc composite, composed of demineralised bone matrix gelatin, was seeded with the AF cells, and the Collagen II/hyaluronate/chondroitin‐6‐sulfate scaffold was seeded with the NP cells (Zhuang et al, ). (d) The IVD composite was created using collagen Type II seeded with the NP cells and the hierarchically organised and micropatterned bacterial cellulose seeded with the AF cells (Yang et al, ). (e) The AF cells and chondrocytes were seeded onto the silk scaffold and fibrin/HA gel, respectively, to generate the AF and NP‐like tissues (Park et al, ).…”

“…For example, chondrocytes and AF cells were respectively seeded into a scaffold consisting of a central hydrogel and an outer silk protein ring to generate a disc composite (Park, Gil, Cho, et al, 2012). A similar composite was fabricated and implanted in the subcutaneous space of athymic mice or in the rat tails, suggesting that this disc-like structure shared similar morphological, biochemical, and functional properties to the native IVD (Yang, Wang, Zhang, et al, 2017;Zhuang, Huang, Li, et al, 2011). This composite replacement method was demonstrated to be effective at increasing disc hydration using an ex-vivo rat tail model (Sloan Jr., Galesso, et al, 2017a).…”

Biomimetic intestinal barrier based on microfluidic encapsulated sucralfate microcapsules

“…Benefiting from their capability to separate liquid cargo and solid encapsulant as well as high cargo content, microcapsules have been widely applied in encapsulation, delivery, and release of actives in the fields of agriculture, cosmetics, drug delivery, detergents, and food additives [14][15][16][17][18]. A variety of techniques, such as spray drying, interfacial polymerization, complex coacervation, and microfluidics, have been employed for the preparation of functional microcapsules [19][20][21][22][23][24][25][26]. Among these methods, the microfluidics technologies can overcome limitations associated with variability during microcapsule production and generate functional microcapsules with fine-tuned chemical compositions, shell thicknesses, and encapsulant volume ratios by the precise control of their multiphasic flow [15][16][17][27][28][29][30][31][32] considerable challenges [16,33,34].…”