Smart Materials in Medicine最新文献

Excessive local movement and inflammation are common problems in the process of wound repair, which lead to failure of later repair. In order to solve this problem, inspired by the octopus sucker structure, we successfully developed a photocrosslinked hydrogel that can adsorb skin surface fascia. In addition, extracellular vesicles from human bone marrow mesenchymal stem cells are encapsulated in the octopus like sucker structure. The morphology and structure of extracellular vesicles in bone marrow mesenchymal stem cells were detected by scanning electron microscopy and particle size analysis. Through iTRAQ, we tested the expression of angiogenesis related proteins contained in extracellular vesicles. Design small interfering RNA to verify its impact on angiogenic related genes and proteins. Macrophage polarization was detected by immunofluorescence. The expression of new blood vessels was detected by constructing a skin defect model and injecting microfil contrast agent into the heart. When the sucker is firmly adsorbed on the damaged wound, the sucker will slowly degrade. Using its delivery system, it is observed that the extracellular vesicles are released in the wound. Through iTRAQ, it was found that the angiogenesis regulator (angiopoietin-like 4, angiopoietin-like 3 and aminopeptidase N) released in the extracellular vesicles regulates collagen deposition, angiogenesis, and inhibits macrophage aggregation. In addition, the slowly released extracellular vesicles will further inhibit the polarization of proinflammatory macrophages. This biological behavior can provide an adaptive microenvironment for skin regeneration at an early stage. This new bionic octopus sucker structure gel creates a good microenvironment for wound repair and shortens the wound healing time. Therefore, this hydrogel inspired by the octopus sucker structure may provide a good strategy and commercial value for promoting wound repair treatment in clinical practice.

Three-dimensional (3D) printing is emerging as an innovative technology, which is widely used in cardiovascular disease at bench and bedside. During the last decade, with the development of 3D printing industry, many 3D printed models have been used in clinic, because it can provide the advantage of haptic feedback, direct manipulation, and enhanced doctors’ understanding of cardiovascular anatomy and underlying pathologies. In addition to the preparation of 3D printed models, 3D printing technology also shows great application potential in cardiovascular regenerative medicine because it has the advantages of integrating cells, cytokines and materials. Although cardiovascular regenerative medicine application still has a gap between bench and bedside, this gap is gradually narrowing with the development of new materials and new technology of 3D printing recently. In this review, we firstly analyze the characteristics and clinical needs of cardiovascular diseases, and introduce the concept and category of 3D printing technology. Secondly, we summarize the application of 3D printed models, stents, vascular graft, vascular network, and heart organs at bench and bedside. In the end, we discuss the challenges and future perspectives of 3D printing in cardiovascular diseases.

Magnetosurgery, the guidance or actuation of surgical instruments during operations using magnetic forces, has become a global trend in minimally invasive surgeries performed remotely. Despite the promise of the magnetosurgery platform, only select surgeries are compatible with this technology, and issues related to the engineering, materials used, and applications are still not fully understood. In this review, we focus on the engineering and material basis of magnetosurgery in order to summarize and expand existing knowledge to create a versatile platform with multiple surgical applications.

Carbon dots (CDs) are carbon-based zero-dimensional nanomaterials with characteristic sizes of less than 10 ​nm. Recently, bioactive CDs have made remarkable achievements in wound healing, bone and cartilage repair, neural regeneration, and myocardium regeneration owing to their unique physicochemical properties and excellent biocompatibility, which have significantly promoted the advancement of tissue engineering. Herein, we summarize the applications of bioactive CDs in tissue engineering. First, we briefly introduce the characteristics and synthesis methods of bioactive CDs. Subsequently, we review the applications of bioactive CDs in wound healing, bone and cartilage tissue engineering, neural tissue engineering, and cardiac tissue engineering in detail. Finally, we discuss the challenges and prospects of bioactive CDs in tissue engineering.

Facial paralysis is a highly burdening condition, resulting in a patient's inability to move his mimic musculature on one or both sides of his face. This condition compromises the patient's communication and facial expressions, and thus dramatically reduces his quality of life. The current treatment for chronic facial paralysis relies on a complex reconstructive surgery. This publication proposes a novel, less invasive approach for dynamic facial reanimation. The use of a smart material, namely a Dielectric Elastomer Actuator (DEA) is proposed for facial motion restoration, thus avoiding the traditional two-stage free muscle transfer procedure and allowing for a faster recovery of the patient. DEAs are a type of electroactive polymers, showing promising properties similar to natural muscles such as the fact that they are soft, lightweight and allow for large displacements. As a result, a study of the facial muscles and neural interfaces, notably the ones responsible for mouth movement, was performed, in order to implement a realistic setup. In this paper, a non-invasive neural interface based on myoelectric signal is used in order to establish a real-time control of the actuator. Visible motion of a skin model is produced in real time, by synchronizing the actuator to the activity of a healthy muscle, with a maximal delay of 108 ​ms resulting from the signal processing and a delay of less than 30 ​ms related to the actuation of the DEA. This shows that the usage of DEA combined with a neural interface presents a promising approach for treatment of facial paralysis.

Hydrogel-based burn wound dressings with excellent antibacterial, antifungal, and mechanical properties are ideal biomaterials to promote infected large burn wound healing. In this study, the hydrogel synthesized by repetitive freezing-thawing consists of poly (vinyl alcohol) (PVA), silk sericin (SS), and azithromycin (AZM), with genipin (GNP) as crosslinker. The FTIR showed that all hydrogel components were successfully blended. The swelling ratio, porosity, cell attachment, and proliferation improved with SS incorporation, while increased PVA content enhanced the mechanical performance of the hydrogel. The inclusion of AZM improved the antimicrobial property of the hydrogel towards Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The hydrogel showed sustained SS and AZM releases as well as cytocompatibility on keratinocytes and fibroblasts. Furthermore, the hydrogel displays skin adhesion ability when freeze-dried. In the in vivo study using an infected mouse full-thickness burn model with a 10% total body surface area, it was shown that burn injury led to increased inflammatory cytokine responses and macroscopic and microscopic alterations in the spleen and liver. The kidneys, on the other hand, revealed neither change. Interestingly, the prepared hydrogel had a better burn wound healing effect than the commercial Tegaderm™ film dressing, minimizing systemic burn effects. Hence, this novel hydrogel is projected to be a promising candidate for accelerated healing of infected burn wounds.

Metal materials have been widely applied clinically due to their superior mechanical properties. However, the integration of metallic implants with surrounding soft tissue remains challenging and may lead to severe infections and failure of treatments. Development of natural exemplar suggests that the establishment of the soft tissue integration around hard surfaces is a complex scenario associated with the coordination of epithelial tissue, connective tissue and immune cells. In addition, the influence of the peri-implant immune microenvironment on soft tissue integration reparative process has received increasing attention. Given that the properties of the metal implant could effectively modulate immune response, it is predictable to regulate the immune microenvironment around metal implants for optimized soft tissue integration. This review firstly compared the establishment of natural biological hard surface-soft tissue integration with metal implants, in which the important role of epithelial tissue, connective tissue and immune cells were emphasized. Furthermore, up-to-date research outcomes in the closely connections between the immune microenvironment and soft tissue integration were discussed and summarized. From the view of natural soft-hard tissue integration development and reparative process, the immunomodulation-based strategy is proposed to manipulate the immune microenvironment for the enhancement of soft tissue-metal implant integration.

Peripheral nerve injury (PNI) is a common surgical disease. In recent years, with the development of tissue engineering materials, nerve guidance conduit (NGC) is expected to replace autologous nerve transplantation and become a new method for the treatment of PNI. In this work, we developed a multifunctional silk fibroin (SF)/gelatin-tyramine (GT) composite hydrogel conduit with flexible adjustable size by using a diffusion-driven cross-linking method. Furthermore, the ZIF-8 nanoparticles loaded with miR-29a (miR-29a@ZIF-8) delivery system was constructed and compounded into SF/GT hydrogel conduit to enhance its bioactivity and neural repair effects through sustained miR-29a release. In vitro cell experiments showed that SF/GT hydrogel conduit could significantly promote the myelination of Schwann cells (SCs), neuronal differentiation and axon extension of PC12 ​cells. In addition, it was worth mentioning that SF/GT hydrogel conduit could also regulate the immune microenvironment of nerve regeneration by promoting the transformation of macrophages from M1 phenotype to M2 phenotype, indicating a potential application as nerve guidance conduit in peripheral nerve repair.

Aberrant activation of cell cycle proteins leads to tumor progression in most cancer types. While 5-fluorouracil (5-Fu)-based chemotherapy remains the first-line treatment strategy for colorectal cancer (CRC), more than 40% of patients with advanced CRC do not benefit from the regimen. Herein, a chemically modified curcumin (mCur) was developed to explore its curative effect on CRC and reveal its potential role in cell cycle regulation. Amphiphilic mCur could self-assemble into positively charged nano-micelles, hence facilitating high cellular uptake and anticancer activity. Multi-phase cell cycle arrest, induced by both mCur and Cur, was first observed in HCT 116 ​cells. This phenomenon was mainly attributed to the Cur/mCur mediated downregulation of cyclin-dependent kinases (CDKs) and their direct interactions. Moreover, mCur and Cur treatments generated distinct phenotypic signatures. In particular, mCur induced distinct dynamic fluctuations in cell cycle and a relatively higher proportion of cells in the G2/M phase than Cur, and specifically triggered the impaired expression of polo-like kinase 1 (PLK1). An in vivo evaluation using a CRC patient-derived tumor xenograft (PDX) model indicated that mCur exhibited better antitumor effects via more significant downregulation of PLK1 in PLK1^high PDX, with no obvious systemic toxicity. Collectively, our study revealed a unique multi-phase cell cycle arrest effect of Cur-based antitumor agents and highlighted the potential of mCur as a PLK1-targeted inhibitor for CRC therapy.