Inspired by the relatively simple morphological blueprint provided by batoid fish such as stingrays and skates, we created a biohybrid system that enables an artificial animal—a tissue-engineered ...ray—to swim and phototactically follow a light cue. By patterning dissociated rat cardiomyocytes on an elastomeric body enclosing a microfabricated gold skeleton, we replicated fish morphology at 1/10 scale and captured basic fin deflection patterns of batoid fish. Optogenetics allows for phototactic guidance, steering, and turning maneuvers. Optical stimulation induced sequential muscle activation via serpentine-patterned muscle circuits, leading to coordinated undulatory swimming. The speed and direction of the ray was controlled by modulating light frequency and by independently eliciting right and left fins, allowing the biohybrid machine to maneuver through an obstacle course.
Bioprocessing applications that derive meat products from animal cell cultures require food-safe culture substrates that support volumetric expansion and maturation of adherent muscle cells. Here we ...demonstrate scalable production of microfibrous gelatin that supports cultured adherent muscle cells derived from cow and rabbit. As gelatin is a natural component of meat, resulting from collagen denaturation during processing and cooking, our extruded gelatin microfibers recapitulated structural and biochemical features of natural muscle tissues. Using immersion rotary jet spinning, a dry-jet wet-spinning process, we produced gelatin fibers at high rates (~ 100 g/h, dry weight) and, depending on process conditions, we tuned fiber diameters between ~ 1.3 ± 0.1 μm (mean ± SEM) and 8.7 ± 1.4 μm (mean ± SEM), which are comparable to natural collagen fibers. To inhibit fiber degradation during cell culture, we crosslinked them either chemically or by co-spinning gelatin with a microbial crosslinking enzyme. To produce meat analogs, we cultured bovine aortic smooth muscle cells and rabbit skeletal muscle myoblasts in gelatin fiber scaffolds, then used immunohistochemical staining to verify that both cell types attached to gelatin fibers and proliferated in scaffold volumes. Short-length gelatin fibers promoted cell aggregation, whereas long fibers promoted aligned muscle tissue formation. Histology, scanning electron microscopy, and mechanical testing demonstrated that cultured muscle lacked the mature contractile architecture observed in natural muscle but recapitulated some of the structural and mechanical features measured in meat products.
Wounds in the fetus can heal without scarring. Consequently, biomaterials that attempt to recapitulate the biophysical and biochemical properties of fetal skin have emerged as promising ...pro-regenerative strategies. The extracellular matrix (ECM) protein fibronectin (Fn) in particular is believed to play a crucial role in directing this regenerative phenotype. Accordingly, Fn has been implicated in numerous wound healing studies, yet remains untested in its fibrillar conformation as found in fetal skin. Here, we show that high extensional (∼1.2 ×105 s−1) and shear (∼3 ×105 s−1) strain rates in rotary jet spinning (RJS) can drive high throughput Fn fibrillogenesis (∼10 mL/min), thus producing nanofiber scaffolds that are used to effectively enhance wound healing. When tested on a full-thickness wound mouse model, Fn nanofiber dressings not only accelerated wound closure, but also significantly improved tissue restoration, recovering dermal and epidermal structures as well as skin appendages and adipose tissue. Together, these results suggest that bioprotein nanofiber fabrication via RJS could set a new paradigm for enhancing wound healing and may thus find use in a variety of regenerative medicine applications.
Cells regulate adhesion to the fibrillar extracellular matrix (ECM) of which fibronectin is an essential component. However, most studies characterize cell adhesion to globular fibronectin substrates ...at time scales long after cells polarize and migrate. To overcome this limitation, a simple and scalable method to engineer biomimetic 3D fibrillar fibronectin matrices is introduced and how they are sensed by fibroblasts from the onset of attachment is characterized. Compared to globular fibronectin substrates, fibroblasts accelerate adhesion initiation and strengthening within seconds to fibrillar fibronectin matrices via α5β1 integrin and syndecan‐4. This regulation, which additionally accelerates on stiffened fibrillar matrices, involves actin polymerization, actomyosin contraction, and the cytoplasmic proteins paxillin, focal adhesion kinase, and phosphoinositide 3‐kinase. Furthermore, this immediate sensing and adhesion of fibroblast to fibrillar fibronectin guides migration speed, persistency, and proliferation range from hours to weeks. The findings highlight that fibrillar fibronectin matrices, compared to widely‐used globular fibronectin, trigger short‐ and long‐term cell decisions very differently and urge the use of such matrices to better understand in vivo interactions of cells and ECMs. The engineered fibronectin matrices, which can be printed onto non‐biological surfaces without loss of function, open avenues for various cell biological, tissue engineering and medical applications.
Biomimetic fibrillar fibronectin matrices are engineered using 3D‐printed microgrids and simple solution shearing. Attaching to fibrillar fibronectin matrices, fibroblasts strengthen adhesion initiation within seconds and enhance long‐term migration and proliferation by employing β1 integrin and syndecan‐4. This rapid and continual fibrillar mechanosensing explains how fibrillar extracellular matrices modulate cell decisions in native tissues.
Engineered nanomaterials (ENMs) are increasingly used in consumer products due to their unique physicochemical properties, but the specific hazards they pose to the structural and functional ...integrity of endothelial barriers remain elusive. When assessing the effects of ENMs on vascular barrier function, endothelial cell monolayers are commonly used as
in vitro
models. Monolayer models, however, do not offer a granular understanding of how the structure-function relationships between endothelial cells and tissues are disrupted due to ENM exposure. To address this issue, we developed a micropatterned endothelial cell pair model to quantitatively evaluate the effects of 10 ENMs (8 metal/metal oxides and 2 organic ENMs) on multiple cellular parameters and determine how these parameters correlate to changes in vascular barrier function. This minimalistic approach showed concerted changes in endothelial cell morphology, intercellular junction formation, and cytoskeletal organization due to ENM exposure, which were then quantified and compared to unexposed pairs using a "similarity scoring" method. Using the cell pair model, this study revealed dose-dependent changes in actin organization and adherens junction formation following exposure to representative ENMs (Ag, TiO
2
and cellulose nanocrystals), which exhibited trends that correlate with changes in tissue permeability measured using an endothelial monolayer assay. Together, these results demonstrate that we can quantitatively evaluate changes in endothelial architecture emergent from nucleo-cytoskeletal network remodeling using micropatterned cell pairs. The endothelial pair model therefore presents potential applicability as a standardized assay for systematically screening ENMs and other test agents for their cellular-level structural effects on vascular barriers.
Micropatterned endothelial cell pairs enable the analysis of the impact of nanomaterial exposure on cellular-level remodeling processes and vascular barrier integrity.
Historically, soy protein and extracts have been used extensively in foods due to their high protein and mineral content. More recently, soy protein has received attention for a variety of its ...potential health benefits, including enhanced skin regeneration. It has been reported that soy protein possesses bioactive molecules similar to extracellular matrix (ECM) proteins and estrogen. In wound healing, oral and topical soy has been heralded as a safe and cost‐effective alternative to animal protein and endogenous estrogen. However, engineering soy protein‐based fibrous dressings, while recapitulating ECM microenvironment and maintaining a moist environment, remains a challenge. Here, the development of an entirely plant‐based nanofibrous dressing comprised of cellulose acetate (CA) and soy protein hydrolysate (SPH) using rotary jet spinning is described. The spun nanofibers successfully mimic physicochemical properties of the native skin ECM and exhibit a high water retaining capability. In vitro, CA/SPH nanofibers promote fibroblast proliferation, migration, infiltration, and integrin β1 expression. In vivo, CA/SPH scaffolds accelerate re‐epithelialization and epidermal thinning as well as reduce scar formation and collagen anisotropy in a similar fashion to other fibrous scaffolds, but without the use of animal proteins or synthetic polymers. These results affirm the potential of CA/SPH nanofibers as a novel wound dressing.
A plant‐based biomimetic cellulose/soy protein nanofibrous wound dressing is fabricated using rotary jet spinning. Its physicochemical properties mimic native extracellular matrix in skin and exhibit a high water‐retaining capability for enhanced wound healing. The plant hybrid wound dressing accelerates in vitro dermal fibroblast proliferation, spreading, and migration. Furthermore, it promotes re‐epithelialization and reduces epidermal thickness and scar area in mouse model.
Cells assemble fibronectin, the major extracellular matrix (ECM) protein, into fibrillar matrices, which serve as 3D architectural scaffolds to provide, together with other ECM proteins ...tissue-specific environments. Although recent approaches enable to bioengineer 3D fibrillar fibronectin matrices in vitro, it remains elusive how fibronectin can be co-assembled with other ECM proteins into complex 3D fibrillar matrices that recapitulate tissue-specific compositions and cellular responses. Here, we introduce the engineering of fibrillar fibronectin-templated 3D matrices that can be complemented with other ECM proteins, including vitronectin, collagen, and laminin to resemble ECM architectures observed in vivo. For the co-assembly of different ECM proteins, we employed their innate fibrillogenic mechanisms including shear forces, pH-dependent electrostatic interactions, or specific binding domains. Through recapitulating various tissue-specific ECM compositions and morphologies, the large scale multi-composite 3D fibrillar ECM matrices can guide fibroblast adhesion, 3D fibroblast tissue formation, or tissue morphogenesis of epithelial cells. In other examples, we customize multi-composite 3D fibrillar matrices to support the growth of signal propagating neuronal networks and of human brain organoids. We envision that these 3D fibrillar ECM matrices can be tailored in scale and composition to modulate tissue-specific responses across various biological length scales and systems, and thus to advance manyfold studies of cell biological systems.
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•We engineer 3D multi-composite fibrillar ECMs of well-defined compositions of key ECM proteins (including fibronectin, laminin, collagen, or vitronectin) such as needed by various tissues.•The multi-composite ECMs are free-standing, easy-to-produce, scalable, transferable for surface functionalization, and mimic the nano-and micro-fibrillar architecture of native ECMs.•The multi-composite ECMs can evoke cellular responses across various biological and temporal scales, from single cells to complex multicellular structures like tissues or organoids, spanning from initial cell attachment to extended culture periods of weeks.
Recent reports suggest the utility of extracellular matrix (ECM) molecules as raw components in scaffolding of engineered materials. However, rapid and tunable manufacturing of ECM molecules into ...fibrous structures remains poorly developed. Here we report on an immersion rotary jet-spinning (iRJS) method to show high-throughput manufacturing (up to ∼1 g/min) of hyaluronic acid (HA) and other ECM fiber scaffolds using different spinning conditions and postprocessing modifications. This system allowed control over a variety of scaffold material properties, which enabled the fabrication of highly porous (70–95%) and water-absorbent (swelling ratio ∼2000–6000%) HA scaffolds with soft-tissue mimetic mechanical properties (∼0.5–1.5 kPa). Tuning these scaffolds’ properties enabled the identification of porosity (∼95%) as a key facilitator for rapid and in-depth cellular ingress in vitro. We then demonstrated that porous HA scaffolds accelerated granulation tissue formation, neovascularization, and reepithelialization in vivo, altogether potentiating faster wound closure and tissue repair. Collectively, this scalable and versatile manufacturing approach enabled the fabrication of tunable ECM-mimetic nanofiber scaffolds that may provide an ideal first building block for the design of all-in-one healing materials.
Alfalfa Nanofibers for Dermal Wound Healing Ahn, Seungkuk; Ardoña, Herdeline Ann M; Campbell, Patrick H ...
ACS applied materials & interfaces,
09/2019, Letnik:
11, Številka:
37
Journal Article
Recenzirano
Engineering bioscaffolds for improved cutaneous tissue regeneration remains a healthcare challenge because of the increasing number of patients suffering from acute and chronic wounds. To help ...address this problem, we propose to utilize alfalfa, an ancient medicinal plant that contains antibacterial/oxygenating chlorophylls and bioactive phytoestrogens, as a building block for regenerative wound dressings. Alfalfa carries genistein, which is a major phytoestrogen known to accelerate skin repair. The scaffolds presented herein were built from composite alfalfa and polycaprolactone (PCL) nanofibers with hydrophilic surface and mechanical stiffness that recapitulate the physiological microenvironments of skin. This composite scaffold was engineered to have aligned nanofibrous architecture to accelerate directional cell migration. As a result, alfalfa-based composite nanofibers were found to enhance the cellular proliferation of dermal fibroblasts and epidermal keratinocytes in vitro. Finally, these nanofibers exhibited reproducible regenerative functionality by promoting re-epithelialization and granulation tissue formation in both mouse and human skin, without requiring additional proteins, growth factors, or cells. Overall, these findings demonstrate the potential of alfalfa-based nanofibers as a regenerative platform toward accelerating cutaneous tissue repair.
Abstract Tissue engineered scaffolds have emerged as a promising solution for heart valve replacement because of their potential for regeneration. However, traditional heart valve tissue engineering ...has relied on resource-intensive, cell-based manufacturing, which increases cost and hinders clinical translation. To overcome these limitations, in situ tissue engineering approaches aim to develop scaffold materials and manufacturing processes that elicit endogenous tissue remodeling and repair. Yet despite recent advances in synthetic materials manufacturing, there remains a lack of cell-free, automated approaches for rapidly producing biomimetic heart valve scaffolds. Here, we designed a jet spinning process for the rapid and automated fabrication of fibrous heart valve scaffolds. The composition, multiscale architecture, and mechanical properties of the scaffolds were tailored to mimic that of the native leaflet fibrosa and assembled into three dimensional, semilunar valve structures. We demonstrated controlled modulation of these scaffold parameters and show initial biocompatibility and functionality in vitro. Valves were minimally-invasively deployed via transapical access to the pulmonary valve position in an ovine model and shown to be functional for 15 h.
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