Tissue engineering articles within Nature Communications

It remains unclear how cells respond to complex extracellular geometries at the mesoscale. Here, the authors study the organization of bone cells in landscapes with varying curvatures, observing a preference for local concavities, multicellular bridging, and collective stress fiber orientation.

Bioengineered livers using decellularized scaffolds have been considered as an alternative to donor organs. Here, the authors modulate biophysical properties of decellularized scaffolds by crosslinking with nano-graphene oxide, thereby greatly enhancing therapeutic efficacy of bioengineered livers.

The mechanical properties of biological tissues are key to their integrity and function. Here, the authors engineer 3D microtissues from optogenetically modified fibroblasts and use light to quantify tissue elasticity and strain propagation using their own constituent cells as internal actuators.

Volumetric additive manufacturing of protein scaffolds has a wide range of possible biomedical applications. Here the authors report on the bioprinting of unmodified silk sericin and silk fibroin inks with shape-memory and tuneable mechanical properties and demonstrate the potential of the inks in different applications.

Islet transplantation for type 1 diabetes management is hindered by the life-long need for immunosuppressive medications. Here, the authors report an islet encapsulation device with local anti-rejection drug release that achieves long-term diabetes reversal in male rats and reduces drug-related toxicity.

Current mesenchymal stem cell (MSC) transplantation practices are limited by the loss or reduced performance of MSCs. Here the authors develop a bead-jet printer for intraoperative formulation and printing of MSCs-laden Matrigel beads to improve skeletal muscle and hair follicle regeneration.

Host versus graft reaction is a major impediment to CAR-T cell immune therapy in allogeneic settings. Authors show here that CAR-T cells, engineered to be deficient in MHC I expression but to express the NK inhibitor HLA-E, are resistant to destruction by both T and NK cells of the host.

Soft tissue fabrication using digital light processing remains challenging. Here the authors present a molecular cleavage approach to achieve high-performance bioprinting of constructs with tissue-matching mechanical properties and structural complexity.

Limited stem cells and mismatched interface fusion have plagued biomaterial-mediated cranial reconstruction. Here, the authors engineer an instantly fixable and self-adaptive scaffold to promote calcium chelation and interface integration, regulate macrophage M2 polarization, and recruit endogenous stem cells.

Protoissues have received a lot of attention for studying cell interaction and for biomedical engineering. Here, the authors demonstrate a high-throughput, bottom-up approach to assemble spatial programmable prototissues based on the magnetic Archimedes affect and demonstrate biomedical application for producing NO for vasodilation.

Mechanical forces in lungs facilitate breathing motions. Here the authors use a microfluidic human lung alveolus chip to study influenza infection and find that mechanical forces from active chips also induce innate inflammatory responses via, at least partially, signaling from TRPV4 and RAGE, thereby implicating them as potential therapeutic targets for lung inflammation.

The culture of gastrointestinal organoids relies on Matrigel that has several drawbacks for clinical application. Here, the authors report the feasibility of gastrointestinal tissue-mimetic matrices as effective alternatives to Matrigel for organoid culture and transplantation.

How double strand breaks (DSBs) are repaired within the plant 45S rDNA repeats is unclear. Here, the authors show that Cas9-mediated DSBs in 45S rDNA are mainly repaired by cNHEJ and describe CRISPR-Kill as a tool for organ-specific cell elimination by targeting functional repetitive DNA in Arabidopsis.

Vascularization is critical for cranial bone growth, maintenance, and healing, but it remains unknown how blood vessels are spatially distributed in the calvarium, and how they interact with skeletal progenitors during these processes. Here, the authors apply a quantitative light-sheet imaging platform to visualize and analyze the relationship between blood vessels and skeletal progenitors throughout the murine calvarium.

Mammalian cell-based cultured meat has mostly been unstructured, leaving a demand for artificial steak-like meat. Here the authors present an assembled steak-like tissue of bovine skeletal muscle, adipose tissue, and blood capillary tissue fabricated by tendon-gel integrated printing technology.

Developing effective treatments for noncompressible hemorrhages remains a challenge. Here the authors engineer alkylated chitosan sponges with highly interconnective microchannels and demonstrate anti-infective activity, as well as higher pro-coagulant, hemostatic and wound healing capacities compared to clinically-used materials in rat and pig liver models.

Brain organoids derived from human pluripotent stem cells can model human brain development and disease, though current culture systems fail to ensure reliable production of high-quality organoids. Here the authors combine human brain extracellular matrix and culture in a microfluidic device to promote structural and functional maturation of human brain organoids.

Shape memory scaffolds are needed for minimally invasive tissue repair and void filling. Here the authors report on the development of 4D printed polycarbonate-based scaffolds with surface degradation properties which fill voids without deforming tissue and allow for tissue ingrowth with reduced immune response.

Current methods for the modular assembly of biomaterials are associated with limitations. Here the authors implement vapor-phase deposition to fabricate 3D polymeric materials that permit biomolecule functionalization, tunable mass transport and mechanical properties, as well as control over boundaries between compartments, and analyze the behavior of 3D encapsulated cells.

Existing methods for tissue dissociation are inefficient and lead to variable outcomes and biases. Here, the authors present a microfluidic platform that combines digestion, disaggregation and filtration of tissue to allow single cell analysis and RNA sequencing.

Fabrication of dynamic, reversible and biocompatible scaffolds with non-invasive external triggers has so far been limited. Here, the authors report on the creation of 3D printed scaffolds with Janus structure that produce nanovibrations when exposed to ultrasound, promoting bone regeneration.

The creation of biomaterials which are resorbable and have biomimetic mechanical properties is key to successful tissue engineering. Here the authors report on the creation of a new biopolymer where the mechanical properties can be tuned by changing the ratios of cis:trans double bonds in the backbone.

Large-scale meat production can have negative impacts on public health, the environment and animal welfare. In this Review, the authors consider plant-based and cell-based approaches to meat production and the challenges they face.

Human microphysiological systems (MPS) have some advantages over animal models to study the mechanisms of disease. Here the authors use a tissue-engineered blood vessel MPS to create a model of early stage atherosclerosis and assess the effect of several drugs.

Brain organoids are important tools to study early development and disease but little is known of their network activity and plasticity. Here the authors generate iPSC-derived neuronal organoids that display early network formation and maturation with evidence for a GABA polarity switch and long-term potentiation.

3D liver organoids hold great promise for regenerative medicine but the use of ill-defined matrices limits their potential. Here, the authors generate human and mouse liver organoids using a chemically defined matrix, and reveal a link between matrix stiffness and organoid growth that does not require acto-myosin contraction.

In vitro models of the human mammary gland have struggled to mimic the 3D morphogenic processes that occur in vivo. Here the authors develop a 3D microfluidic platform of a vascularized human mammary duct that simulates diverse morphogenic transitions and paracrine crosstalk.

Acellular tissue engineered vessels functionalised with VEGF are coated with a layer of endothelial cells after in vivo implantation, but the source of the cells are unknown. Here the authors provide evidence that monocytes expressing VEGF receptors can transdifferentiate into endothelial cells via a macrophage intermediate.

Regeneration of corneal stroma has been a challenge due to its sophisticated structure and the easy transformation of the keratocyte. Here, the authors use a hydrogel reinforced with orthogonally aligned fibres and serum free medium to maintain keratocyte phenotype for the in vivo stromal regeneration.

3D bioprinting of skeletal muscle using primary human muscle progenitor cells results in correct muscle architecture, but functional restoration in rodent models is limited. Here the authors include human neural stem cells into bioprinted skeletal muscle and observe improved architecture and function in vivo.

Mesenchymal stromal cells enhance bone and cartilage repair, but are limited by poor survival and retention after transplantation. Here, the authors show that synthetic hydrogels presenting integrin-specific peptides enhance the survival and persistence of human mesenchymal stromal cells after transplant, as well as bone repair.

The cellular composition of previous engineered heart tissue is often heterogeneous. Here, the authors create chamber-specific human pluripotent stem cell-derived cardiomyocytes to form both ventricular and atrial cells before embedding in collagen-based matrix to form ring-shaped engineered heart tissue.

Extracellular matrix (ECM) is an ideal scaffold for tissue engineering but tends to lack hierarchical structure. Here the authors implant sacrificial templates subcutaneously to build an organised ECM scaffold, and following template removal and decellularisation use these scaffolds to create functionally integrated muscle, nerve and artery in vivo.

The success of engineered tissue depends on the integration of a dense vascular network to supply nutrients and remove waste products. Here the authors design high density microvascular meshes made through an anchored self-assembly mechanism, and use these meshes to support subcutaneous pancreatic islet survival in a mouse diabetes model.

The brain extracellular matrix (ECM) is altered in brain tumors, but its role in cancer progression and drug sensitivity are difficult to study. Here the authors develop a 3D bioengineered brain tissue model using patient-derived samples and tunable brain-derived ECM to examine the interplay between cells and the ECM.

Islet transplantation is a feasible approach to treat type I diabetes, however inflammation and poor vascularisation impair long-term engraftment. Here the authors show that incorporating human amniotic epithelial cells into islet organoids improves engraftment and function of organoids, through enhanced revascularisation.

Controlled patterning of functionality within hydrogels typically involves complex chemistry. Here, the authors report on a simple competitive binding strategy using avidin and biotin analogs in an injectable biomaterial for spatiotemporally controlled presentation of biochemical stimuli to cells.

Injectable hydrogels could be used to repair bone defects. Here the authors incorporate nanoclay particles into chitosan creating an interconnected microporous hydrogel and show that this hydrogel can support MSC proliferation and differentiation in vitro, and support the recruitment of native cells and bone regeneration in a mouse calvarial defect model.

Bone tissue is a complex organic-inorganic nanocomposite and strategies that replicate the characteristics of bone tissue are scarce. Here the authors demonstrate the deposition of nanoscale apatite in collagen embedded with mesenchymal, vascular and nerve cells, using a protein-guided biomineralization approach.

Bioengineering of small diameter vascular grafts that recapitulate the features of native vessels is extremely challenging. Here the authors present a combined dip-spinning and blow-spinning technology to fabricate multi-layered cell-embedded grafts with native mechanical properties.

The development of tissue-engineered vascular grafts heavily relies on the availability of large animal models that allow long-term assessment of graft patency. Here Itoh et al. propose a novel model of immunodeficient pigs that allows long-term accommodation of human cell-derived three-dimensional bioprinted vascular tubes.

Blood clotting is a complex process involving platelet adhesion and clot stiffening. Here the authors present a microfluidic system to recapitulate the dynamic changes in clot mechanics under physiological shear.

Injectable hydrogels have gained significant interest; yet, due to high viscosity, many are unsuitable for catheter delivery. Here, the authors report on cyclic peptides with low viscosity for catheter delivery, which form self-assembled peptide hydrogels following enzymatic cleavage and demonstrated delivery in vivo.

Engineering 3D tissues faces the challenge of adequate vascularisation for nutrient delivery and gas exchange deep inside the construct. Here the authors use surface acoustic waves to create an aligned array of blood vessels in a hyaluronic acid hydrogel and use it to improve function in a mouse hindlimb ischemia model.

A bioengineering approach to enhance the regeneration of large bone defects is lacking. Here, the authors show that a biomaterial scaffold with a channel-like pore architecture enables organized endochondral ossification through directional cell recruitment and extracellular matrix alignment.

Combining decellularised scaffolds with patient-derived cells holds promise for bioengineering of functional tissues. Here the authors develop a two-stage approach to engineer an oesophageal graft that retains the structural organisation of native oesophagus.

To improve trauma survival and surgical outcomes, hemostatic agents are needed. Here, the authors report on the development of injectable, biocompatible carbon nanotube reinforced quaternized chitosan cryogels with shape memory, conductivity and antibacterial properties for hemostatic control.

A bottleneck in developing new anti-fibrosis therapies is the absence of suitable in vitro models that recapitulate key features of fibrogenesis. Here the authors develop a tissue-on-a-chip model of lung fibrosis and test the therapeutic efficacy of two recent FDA-approved drugs.

Although 3D bioprinting technology has gained much attention in the field of tissue engineering, there are still several significant challenges that need to be overcome. Here, the authors present silk fibroin bioink with printability and biocompatibility suited for digital light processing 3D printing.