An injectable and self-healing hydrogel with dual physical crosslinking for in-situ bone formation.

Although hydrogels have been widely studied because of their satisfactory biocompatibility and plasticity, their application is limited in bone tissue engineering (BTE) owing to their inadequate mechanical properties and absence of osteogenic activity. To address this issue, we developed an updated alendronate (ALN)-Ca/Mg-doped supramolecular (CMS) hydrogel based on our previously developed mechanically resilient "host-guest macromer" (HGM) hydrogel to improve the hydrogel's mechanical properties and osteogenic activity. The CMS hydrogel was prepared by introducing a new physical crosslinking comprising the strong chelation of the comonomer acrylate alendronate (Ac-ALN) and Ca/Mg in the HGM hydrogel.

Functional Trachea Reconstruction Using 3D-Bioprinted Native-Like Tissue Architecture Based on Designable Tissue-Specific Bioinks.

Functional segmental trachea reconstruction remains a remarkable challenge in the clinic. To date, functional trachea regeneration with alternant cartilage-fibrous tissue-mimetic structure similar to that of the native trachea relying on the three-dimensional (3D) bioprinting technology has seen very limited breakthrough. This fact is mostly due to the lack of tissue-specific bioinks suitable for both cartilage and vascularized fibrous tissue regeneration, as well as the need for firm interfacial integration between stiff and soft tissues.

Hierarchical porous bacterial cellulose scaffolds with natural biomimetic nanofibrous structure and a cartilage tissue-specific microenvironment for cartilage regeneration and repair.

The limited three-dimensional (3D) nano-scale pore structure and lack of biological function hamper the application of bacterial cellulose (BC) in cartilage tissue engineering. To address this challenge, 3D hierarchical porous BC/decellularized cartilage extracellular matrix (DCECM) scaffolds with structurally and biochemically biomimetic cartilage regeneration microenvironment were fabricated by freeze-drying technique after EDC/NHS chemical crosslinking. The BC/DCECM scaffolds exhibited excellent mechanical properties, water superabsorbency and shape-memory properties.

A Biomimetic Biphasic Scaffold Consisting of Decellularized Cartilage and Decalcified Bone Matrixes for Osteochondral Defect Repair.

It is challenging to develop a biphasic scaffold with biomimetic compositional, structural, and functional properties to achieve concomitant repair of both superficial cartilage and subchondral bone in osteochondral defects (OCDs). This study developed a biomimsubchondraletic biphasic scaffold for OCD repair via an iterative layered lyophilization technique that controlled the composition, substrate stiffness, and pore size in each phase of the scaffold. The biphasic scaffold consisted of a superficial decellularized cartilage matrix (DCM) and underlying decalcified bone matrix (DBM) with distinct but seamlessly integrated phases that mimicked the composition and structure of osteochondral tissue, in which the DCM phase had relative low stiffness and small pores (approximately 134 μm) and the DBM phase had relative higher stiffness and larger pores (approximately 336 μm).