The Regulatory Effect of Braided Silk Fiber Skeletons with Differential Porosities on In Vivo Vascular Tissue Regeneration and Long-Term Patency.

The development of small-diameter vascular grafts that can meet the long-term patency required for implementation in clinical practice presents a key challenge to the research field. Although techniques such as the braiding of scaffolds can offer a tunable platform for fabricating vascular grafts, the effects of braided silk fiber skeletons on the porosity, remodeling, and patency in vivo have not been thoroughly investigated. Here, we used finite element analysis of simulated deformation and compliance to design vascular grafts comprised of braided silk fiber skeletons with three different degrees of porosity.

Distinct patterns of responses in endothelial cells and smooth muscle cells following vascular injury.

Vascular smooth muscle cells (SMCs) are heterogeneous, and their differential responses to vascular injury are not well understood. To address this question, we performed single-cell analysis of vascular cells to a ligation injury in mouse carotid arteries after 3 days. While endothelial cells had a homogeneous activation of mesenchymal genes, less than 30% of SMCs responded to the injury and generated 2 distinct clusters - i.

Intramuscular delivery of neural crest stem cell spheroids enhances neuromuscular regeneration after denervation injury.

Background: Muscle denervation from trauma and motor neuron disease causes disabling morbidities. A limiting step in functional recovery is the regeneration of neuromuscular junctions (NMJs) for reinnervation. Stem cells have the potential to promote these regenerative processes, but current approaches have limited success, and the optimal types of stem cells remain to be determined.

Neural crest-like stem cells for tissue regeneration.

Neural crest stem cells (NCSCs) are a transient population of cells that arise during early vertebrate development and harbor stem cell properties, such as self-renewal and multipotency. These cells form at the interface of non-neuronal ectoderm and neural tube and undergo extensive migration whereupon they contribute to a diverse array of cell and tissue derivatives, ranging from craniofacial tissues to cells of the peripheral nervous system. Neural crest-like stem cells (NCLSCs) can be derived from pluripotent stem cells, placental tissues, adult tissues, and somatic cell reprogramming.

Three-dimensional Imaging Coupled with Topological Quantification Uncovers Retinal Vascular Plexuses Undergoing Obliteration.

Murine models provide microvascular insights into the 3-D network disarray seen in retinopathy and cardiovascular diseases. Light-sheet fluorescence microscopy (LSFM) has emerged to capture retinal vasculature in 3-D, allowing for assessment of the progression of retinopathy and the potential to screen new therapeutic targets in mice. We hereby coupled LSFM, also known as selective plane illumination microscopy, with topological quantification, to characterize the retinal vascular plexuses undergoing preferential obliteration.

Cellular remodeling of fibrotic conduit as vascular graft.

The replacement of small-diameter arteries remains an unmet clinical need. Here we investigated the cellular remodeling of fibrotic conduits as vascular grafts. The formation of fibrotic conduit around subcutaneously implanted mandrels involved not only fibroblasts but also the trans-differentiation of inflammatory cells such as macrophages into fibroblastic cells, as shown by genetic lineage tracing.

Three-dimensional silk fibroin scaffolds incorporated with graphene for bone regeneration.

Porous three-dimensional (3D) silk fibroin (SF) scaffolds were widely applied for bone regeneration and showed excellent biocompatibility and biodegradability. Recently graphene was developed for bone scaffolds due to its osteogenic properties. Thus, we combine the SF and graphene to improve the osteogenic properties of SF scaffolds.

Matrix stiffness regulates SMC functions via TGF-β signaling pathway.

The stiffness change of the vessel wall is involved in many pathological processes of the blood vessel. However, how stiffness changes regulate vascular cell phenotype is not well understood. In this study, we investigated the effects of matrix stiffness on the phenotype and functions of vascular smooth muscle cells (SMCs).

Biomechanical and mechanical behavior of the plantar fascia in macro and micro structures.

Plantar fascia (PF) is a heterogeneous thickness structure across plantar foot. It is important significance to investigate the biomechanical behavior of the medial, middle and lateral PF regions. To investigate the non-uniform macro/micro structures of the different PF regions, the uniaxial tensile test of PF strips were performed to assess the mechanical behavior of PF.

The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters.

Aliphatic biodegradable polyesters have been the most widely used synthetic polymers for developing biodegradable devices as alternatives for the currently used permanent medical devices. The performances during biodegradation process play crucial roles for final realization of their functions. Because physiological and biochemical environment significantly affects biodegradation process, large numbers of studies on effects of mechanical loads on the degradation of aliphatic biodegradable polyesters have been launched during last decades.

Effects of different fluid shear stress patterns on the in vitro degradation of poly(lactide-co-glycolide) acid membranes.

The applications of poly (lactide-co-glycolide) acid (PLGA) for coating or fabricating polymeric biodegradable stents (BDSs) have drawn more attention. The fluid shear stress has been proved to affect the in vitro degradation process of PLGA membranes. During the maintenance, BDSs could be suffered different patterns of fluid shear stress, but the effect of these different patterns on the whole degradation process is unclear.

Shear stress with appropriate time-step and amplification enhances endothelial cell retention on vascular grafts.

Endothelial cells (ECs) are sensitive to changes in shear stress. The application of shear stress to ECs has been well documented to improve cell retention when placed into a haemodynamically active environment. However, the relationship between the time-step and amplification of shear stress on EC functions remains elusive.

Silk fibroin scaffold as a potential choice for female pelvic reconstruction: A study on the biocompatibility in abdominal wall, pelvic, and vagina.

The aim of this study was to compare the tissue reactions to silk fibroin scaffolds in the abdominal wall, vagina, and pelvic vesico-uterine of rats. Silk fibroin scaffolds were implanted subcutaneously in the abdominal, pelvic vesico-uterine space, and under the vaginal mucosa of 16 rats. The animals were euthanized at 2, 4, 8, and 12 weeks postoperatively.

Graphene-Based Materials in Regenerative Medicine.

Graphene possesses many unique properties such as two-dimensional planar structure, super conductivity, chemical and mechanical stability, large surface area, and good biocompatibility. In the past few years, graphene-based materials have risen as a shining star on the path of researchers seeking new materials for future regenerative medicine. Herein, the recent research advances made in graphene-based materials mostly utilizing the mechanical and electrical properties of graphene are described.

Delivery of demineralized bone matrix powder using a salt-leached silk fibroin carrier for bone regeneration.

Demineralized bone matrix (DBM) has been widely used for bone regeneration due to its osteoinductivity and osteoconductivity. However, the use of DBM powder is limited due to the difficulties in handling, the tendency to migrate from graft sites and the lack of stability after surgery. In this study, a mechanically stable, salt-leached porous silk fibroin carrier was used to improve the handling properties of DBM powder and to support the attachment, proliferation and osteogenic differentiation of rat bone marrow derived mesenchymal stem cells (rBMSCs).

Physiological pulsatile flow culture conditions to generate functional endothelium on a sulfated silk fibroin nanofibrous scaffold.

Many studies have demonstrated that in vitro shear stress conditioning of endothelial cell-seeded small-diameter vascular grafts can improve cell retention and function. However, the laminar flow and pulsatile flow conditions which are commonly used in vascular tissue engineering and hemodynamic studies are quite different from the actual physiological pulsatile flow which is pulsatile in nature with typical pressure and flow waveforms. The actual physiological pulsatile flow leading to temporal and spatial variations of the wall shear stress may result in different phenotypes and functions of ECs.

Comparison of cellular responses of mesenchymal stem cells derived from bone marrow and synovium on combined silk scaffolds.

As a brand new member in mesenchymal stem cells (MSCs) families, synovium-derived mesenchymal stem cells (SMSCs) have been increasingly regarded as a promising therapeutic cell species for musculoskeletal regeneration. However, there are few reports mentioning ligamentogenesis of SMSCs and especially null for their engineering use towards ligament regeneration. The aim of this study was to investigate and compare the cellular responses of MSCs derived from bone marrow and synovium on combined silk scaffolds that can be used to determine the cell source most appropriate for tissue-engineered ligament.

In vitro evaluation of combined sulfated silk fibroin scaffolds for vascular cell growth.

A combined sulfated silk fibroin scaffold is fabricated by modifying a knitted silk scaffold with sulfated silk fibroin sponges. In vitro hemocompatibility evaluation reveals that the combined sulfated silk fibroin scaffolds reduce platelet adhesion and activation, and prolong the activated partial thromboplastin time (APTT), thrombin time (TT), and prothrombin time (PT). The response of porcine endothelial cells (ECs) and smooth muscle cells (SMCs) on the scaffolds is studied to evaluate the cytocompatibility of the scaffolds.

Lipid resuscitation of bupivacaine toxicity: long-chain triglyceride emulsion provides benefits over long- and medium-chain triglyceride emulsion.

Background: The superiority of Intralipid, a long-chain triglyceride (LCT) emulsion versus Lipovenoes, a long- and medium-chain triglyceride (LCT/MCT) emulsion, in reversing local anesthetic-induced cardiac arrest is poorly defined and needs to be determined.

Methods: The study included two parts: in experiment A, bupivacaine (20 mg/kg) was injected to produce asystole. Either Intralipid 20% (LCT group, n = 30) or Lipovenoes 20% (LCT/MCT group, n = 30) with epinephrine was infused immediately.