Smart Materials in Medicine最新文献

Mesenchymal stem cell exosomes (MSC-Exos) are a type of cell vesicle with biological function secreted by mesenchymal stem cells (MSCs). In tissue repair, MSC-Exos are more effective than MSCs, and they can be used as a cell-free alternative therapy to MSCs. This therapeutic system has a stable membrane structure that is coated with proteins, miRNAs, mRNA, lncRNA, DNA, and other macromolecular active substances. These molecules have a powerful effect on tissue regeneration. MSC-Exos can regulate the biological function of target cells through direct recognition, membrane fusion, and secretion of communication mediators. Skin wound healing consists mainly of blood coagulation, inflammation response, cell proliferation, and tissue remodeling. By regulating the four stages of wound healing, MSC-Exos effectively reduce tissue inflammation, reduce the immune response, promote enhanced cell migration and angiogenesis and regulate tissue remodeling, thus shortening the healing time and reducing scar formation. A variety of biological factors, genetic material and signaling pathways are involved in this process. This article reviews the efficacy and mechanism of MSC-Exos in promoting skin tissue repair.

Bacterial cellulose (BC) possesses the desirable properties of biocompatibility, high porosity, high surface area and noticeable mechanical strength as a scaffold in bone tissue engineering. However, the lack of osteogenic activity restricts its application. In this study, gold nanoparticles (GNPs) with excellent osteogenic differentiation ability were incorporated into the network of BC hydrogel (Au/BC hydrogels) by the in-situ fermentation. The effects of GNPs on physicochemical properties of BC hydrogel and subsequently in vitro osteogenic differentiation and in vivo bone regeneration of Au/BC hydrogels were comprehensively investigated. The results showed that the increased feeding amounts of GNPs could remarkablly enhance the Au/BC hydrogels with better mechanical properties, higher porosity, larger surface area, and biocompatibility. The sustainable release of GNPs endowed the hydrogels with an outstanding biological activity in facilitating osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). Mechanism research showed that autophagy might be a potential pathway for Au/BC hydrogels-induced osteogenic differentiation of hBMSCs. In addition, Au/BC hydrogel exhibited an excellent in vivo bone repair performance in a rabbit model of femoral defect, which was evidenced by the significant newly bone formation. Overall, the multifunctional Au/BC hydrogels fabricated by in-situ fermentation could serve as a good scaffold for promoting bone tissue regeneration in clinic.

Bone regeneration scaffolds loaded with osteoblast-related cells or cytokines exhibit outstanding therapeutic potential during large-scale bone defect repair. However, limited sources of cells, opportune choosing of growth factors and their concentration, as well as immunological rejection, seriously hinder its clinical application. Developing a scaffold that can effectively recruit MSCs in situ and achieve endogenous bone regeneration is a viable strategy. Herein, we report a chitosan-calcium carbonate scaffold with high mineral content and centripetal pore arrangement using a simple in situ mineralization method. In vivo results first time demonstrate that the scaffold with high calcium carbonate content can effectively recruit MSCs near the defect area, induce their osteogenic differentiation, and ultimately accelerate the process of bone regeneration. Considering the accessible preparation and excellent osteogenicity, the chitosan-calcium carbonate scaffold possesses high potential for the therapeutics of massive bone defects.

The study of synthetic biology focusing on biosensor systems has resulted from a growing interest in developing customized biological devices with desired cellular functions. Recently, biosensors have been used for a variety of medical applications such as disease diagnosis, prevention, rehabilitation, patient health monitoring, and human health management. Meanwhile, the ability to track biomarkers based on biosensors allows researchers and medical practitioners to provide patients with individualized treatment regimens and health management. Biosensors that respond to electrochemical, optical, thermal, piezoelectric and magnetic signals have been developed and utilized for various disease therapies and biomedical applications. This study reviews recent developments in biosensor-based therapeutic tools by sensing diverse biomarkers in many diseases (e.g. cancer, infections, metabolic diseases), such as physical biomarkers (e.g. pressure, temperature) and chemical biomarkers (e.g. dissolved oxygen, glucose). Additionally, we highlight the challenges and problems of biosensor-based therapeutics and possible solutions for biosensor engineering thereof. Current biosensors enable for coarsely programable personal treatment and health management, however, new sensors with optimized dose-response functions, for example, fast response and tight-control performances, could significantly boost versatile uses in medical treatment in the coming future.

Rapid hemostasis and effective healing for the non-compressible liver wounds which are not able to be sewn, especially for those large-area wounds, remain great clinical challenges. In this study, we fabricated epidermal growth factor (EGF)-loaded chitosan microspheres (CM) and then incorporated them into a photo-crosslinking gelatin methacryloyl (GelMA) hydrogel. The results showed that the EGF-loaded CM/GelMA precursor solution could transform into a hydrogel and cease bleeding at laceration sites without external stress. Subsequently, the sustained release of EGF accelerated wound closure and promoted liver regeneration. The in vitro experiments demonstrated that the microsphere/hydrogel composite could promote the proliferation and migration of L02 ​cells. Moreover, the histological and immunohistological analyses indicated that EGF-CM/GelMA composite could alleviate inflammation in the mouse liver and promote liver remodeling. Overall, this multi-functional microsphere/hydrogel composite will inspire the development of clinical applications for noncompressible hemostasis and successive wound closure.

With the advent of nanotechnology, incorporating nanoscale fillers in dental resins seems promising to improve therapeutic features and provide more excellent physicochemical properties for dental materials. The use of nanotubes has been raised due to their excellent mechanical properties, carry and delivery of drugs capabilities, and bioactive properties. These features depend on the composition of nanotubes and their application. This scoping review aims to describe previous studies about incorporating nanotubes in restorative resin-based materials. The main goals here addresses are: (1) to identify which are the most used nanotubes in the development of these dental materials; (2) to verify which the molecules/particles associated with these nanotubes; (3) to report the objectives of the incorporation of nanotubes to these dental materials and main results. The searches were performed using PubMed and Scopus databases in December 2022, identifying 534 manuscripts. After the selection process, 43 studies were included in the review. We mainly analyzed and discussed the nanotubes' composition, the parental materials in which the nanotubes were incorporated, the purposes of adding these particles to the dental materials, how the materials were analyzed, and the primary studies' outcomes. The outcomes are stimulating and reveal a promising advance in dental resins with the possibility of improving the maintenance of restorations and patients' quality of life. Further studies should address the abovementioned topics to expand the understanding and options of using nanotubes in resin-based restorative materials.

Peripheral nerve injury (PNI) is a common and complex clinical disease with high morbidity, limited treatment options and poor clinical outcomes. Several million cases of PNI in the world every year have brought a heavy burden to the patients and the social economy. Autologous nerve grafting has long been the “gold standard” in the treatment of PNI repair, but it still has some shortcomings, such as donor area injury, limited graft source and mismatch of nerve thickness after transplantation. In recent years, many artificial nerve guidance conduits (NGCs) have emerged for replacing autologous nerve grafts, and their effectiveness has been proven. Currently, there are already clinical products obtained from the European CE Certification, and approved by the Food and Drug Administration (FDA), China Food and Drug Administration (CFDA), Therapeutic Goods Administration (TGA) in Australia, etc. The preparation of NGCs requires interdisciplinary studies and has received considerable attention from researchers in recent years. At present, among emerging and mature manufacturing technologies, textile methods to prepare NGCs are relatively simple and have wide material sources, which has become a hotspot in textile research. This paper mainly reviewed the current situation and recent technological achievements of NGCs that were prepared by textile methods. Several other common methods were also briefly summarized. Furthermore, current NGCs products and their clinical applications were reported. Finally, the future development direction of textile-based NGCs is discussed in this review.

With the development of modern medicine, the research methods of occurrence, development and treatment of orthopedic diseases are developing rapidly. The microenvironment provided by traditional orthopedic research methods differ considerably from the human body, resulting in poor or inconsistent conclusions in previous studies. Microfluidic technology has shown its advantages in the field of orthopedic research, especially in providing bionic mechanical stimulation environment. The microfluidic device can simulate the complex internal environment through the fine and complex structure and perfusion control system, and provide a stable, controllable and efficient culture system. Moreover, it can serve as a manufacturing device, which can produce bone grafts or bone like organs for tissue engineering with bionic structure. It can also simultaneously act as a detection device, which can realize high-throughput detection of small samples at low cost. In addition, we can establish in vitro physiological or pathological models on microfluidic systems to assist in the diagnosis and treatment of orthopedic diseases. This paper reviews the medical application of microfluidic devices in orthopedics.

Effective wound care is a major concern as many conventional wound healing methods and materials have failed in facilitating proper healing, instead disrupts the overall healing process, leading to the development of chronic wounds. Advancement in tissue engineering has led to the development of scaffolds; a 3D construct which can be utilized as a template for cell growth and regeneration while preventing infection along with acceleration of the wound healing process. Natural and synthetic polymers are used extensively for scaffold production and hybrid scaffolds are also introduced which constitutes a combination of natural and synthetic polymers. This review highlights the design of scaffolds using different kinds of polymers for skin tissue engineering.