Smart Materials in Medicine最新文献

To optimize synergistic breast cancer treatment, a nanocomposite was fabricated with pH-temperature responsive and chemo-photothermal combination therapy. Herein, gold nanorods (AuNRs) are coated with [poly[(N-isopropylacrylamide)-co-(methacrylic acid)] (p(NIPAM-co-MAA)) modified mesoporous silica (MS) for Doxorubicin (DOX) delivery (AuNR@DOX-MS@p(NIPAM-co-MAA)). Upon NIR radiation, the AuNR core induced hyperthermia via generating heat. Simultaneously, the polymer layer collapsed in response to high temperature/low pH, which allowed the triggering of DOX release from the MS shell at the tumor site. With this nanocomposite, nearly zero premature release of DOX at physiological pH/temperature was detected, while effective DOX release was reported at higher temperature/lower pH values. In addition, in vitro studies demonstrated that the nanocomposite has a substantial uptake efficiency of MDA-MB-231 breast cancer cells, with a significant increase in suppressing MDA-MB-231 ​cell proliferation in response to laser irradiation. The in vivo experiments further verified the high efficiency of the fabricated nanocomposite in accumulating at the tumor site and the good capability in suppressing tumor growth in the mice upon intravenous injection, while exhibiting good biosafety in relation to major organs in the body. Thus, the synthesized nanocomposite could be a potential nanocarrier for breast cancer treatment with synergistic chemo-photothermal therapeutic capability.

With the increasing demand for innovative therapies, biodegradable magnesium has attracted more and more attention, which could avoid secondary surgery and reduce complications. Until now, plenty of researchers take part in the research & development of this field, and many articles have been published every year. However, it is a huge challenge to predict research trends and definite topics for researchers, which could result in low research value, wasted resources and even slowed medical device transformation. Usually, reviews summarize a specific topic, such as alloy elements, coating designs, degradable properties, etc. Deriving key indicators from a large amount of data with the help of statistical analysis, make a historical review, current situation analysis, and future prediction more convincing. Herein, it has been conducted a bibliometric study according to 2669 publications collected from the Web of Science (WOS) database from 2005 to 2021. By analyzing some key factors, including annual publications, keywords, country contributions, authors as well as institutions, the evolution of biodegradable magnesium is objectively studied. The research trends of biodegradable magnesium alloys are corrosion resistance, the influence of microstructural control on mechanical behavior and bio-functions of implants in a chronological manner. The co-occurrence mapping of the countries and authors suggests that current in-depth research and development of magnesium is more emphasis on institutional and international cooperation.

This review paper deals with the advancements of composites to shape memory alloys. The journey of smart materials from conventional composites to advance shape memory alloys and their application is described in this literature. Classification of smart materials such as smart composites, shape memory alloys, polymer composite and various other types of materials that are intelligent are explained briefly. Different manufacturing and developing techniques to manufacture smart materials and characterization of conventional composites is compared with advance modern day shape memory alloys. Shape memory effect such as one way and two-way shape memory effect are depicted. However, the most important of all the applications and extensive use of smart materials in health care sector for implants and various other uses with uses in aerospace and automotive industries are reviewed.

The thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) is widely applied in the biomedical field particularly as thermoresponsive substrate for culture of cells. To be used as a stimuli-responsive coating for cell culture, combining PNIPAM with glycosaminoglycans might be an effective approach to improve its bioactivity. In this study, chitosan is grafted with PNIPAM moieties (PCHI) possessing a cloud point at 31 ​°C and used as a polycation to fabricate thermoresponsive polyelectrolyte multilayers (PEM) with the bioactive polyanion chondroitin sulfate (CS) at pH 4 by layer-by-layer technique. The in-situ investigation by surface plasmon resonance and quartz crystal microbalance with dissipation monitoring confirms that the formation of PEMs with CS can be achieved despite the bulky structure of PCHI at 25 ​°C. The stability of the PEMs is further improved at physiological pH 7.4 by chemical crosslinking using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide. Moreover, these PEMs exhibit de-swelling and swelling ability with different surface wettability in response to temperature, which triggers the adsorption and desorption of adhesive protein vitronectin on the PEMs. At 37 ​°C, the PEMs containing PNIPAM particularly associated with CS terminal layer supports protein adsorption and consequently enhances cell adhesion using multipotent murine stem cells. Overall, due to improved stability, crosslinked PNIPAM-modified biogenic multilayers are cytocompatible and hold great potential as culture substrate for different tissue cells and application in tissue engineering.

The over-accumulation of ROS during prolonged in vitro expansion could negatively affect the properties of stem cells. This leads to a reduced capacity for self-renewal and a lower potential for multiple differentiation, ultimately hindering their applicability in regenerative medicine. Herein, we fabricated platinum nanoparticles (PtNPs) as a potential biocompatible antioxidant to efficiently eliminate the ROS accumulation in human dental follicle stem cells (hDFSCs) during in vitro expansion, thereby enhancing hDFSCs proliferation and osteogenic differentiation. Transcriptome analysis revealed that PI3K/AKT signaling pathway was activated in PtNPs-treated hDFSCs. Transplantation of PtNPs-treated rDFSCs could facilitate new bone formation compared to transplantation of PBS or un-treated rDFSCs, leading to efficient regeneration of bone tissue in rat mandibular bone defect models. In conclusion, PtNPs offered a novel antioxidative strategy to improve stem cell properties and stem-cells-based alveolar bone regeneration.

Excessive scar tissue formation along with bacterial infection, hemorrhage, and oxidative wound microenvironment pose adverse physiological and psychological effects on patients, which necessitate the advent of innovative anti-inflammatory, anti-bacterial, and anti-oxidative multifunctional wound dressings. The overarching objective of this study was to exploit bioactive glass (BG) and a natural anti-bacterial component namely “oregano essential oil (OEO)” to impart multifunctionality to poly(L-lactide-co-glycolide)/Gelatin (PLGA/Gel)-based nanofibrous dressings for excisional wound management. We performed a series of structural, morphological, and release studies as well as delineated angiogenic, hemostatic, anti-bacterial, and anti-oxidative properties of these bioactive dressings in vitro, which altogether revealed the beneficial effects of BG and OEO in terms of rapid hemostasis, improved chemotactic response, diminished bacterial colonization, and anti-inflammatory response. Impressively, in multiple injury models, including a rat tail-amputation model, an ear artery injury model, and a liver trauma model in rabbit in vivo, we reported BG-mediated rapid hemostasis. Moreover, dressings containing BG showed improved hemocompatibility and suppressed coagulation as revealed by activated partial thromboplastin assay (APTT) in vitro. In addition, the transplantation of these nanofibrous dressings in a full-thickness excisional wound model in rats showed significant tissue regeneration as evidenced by the more number of blood vessels, glands, and hair follicles, re-epithelialization, diminished inflammatory response, and less fibrotic tissue formation. Taken together our approach of simultaneously harnessing economical BG and OEO to enable multifunctionality to nanofibrous dressings for tissue repair may hold great promise for wound healing as well as other bio-related disciplines.

Alleviating excessive inflammation while accelerating chronic wound healing to prevent wound infection has remained challenging, especially during the coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 when patients experienced difficulties with receive appropriate healthcare. We addressed this issue by developing handheld electrospun aloe-nanofiber membranes (ANFMs) with convenient, environmentally friendly properties and a therapeutic capacity for wound closure. Our results showed that ANFMs fabricated with high molecular weight polyvinyl alcohol (PVA) to form fibers during electrospinning had uniform fibrous architecture and a porous structure. Given the value of aloe gel in accelerating wound healing, liquid extracts from ANFMs significantly downregulated the expression of the pro-inflammatory genes, interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS), and markedly suppress the generation of reactive oxygen species (ROS) induced by lipopolysaccharide in RAW264.7 macrophages. These results indicated the excellent antioxidant and anti-inflammatory effects of ANFMs. After implantation into a mouse diabetic wound model for 12 days in situ, ANFMs notably expedited chronic wound healing via promoting angiogenesis and enhancing cell viability. Our ANFMs generated by handheld electrospinning in situ healed chronic wounds offer a convenient and promising alternative for patients to heal their own wounds under variable conditions.

Dental resin adhesives and composites are the most prevailing dental restorative materials used to treat cavitated tooth decay. These materials are challenged inside the mouth by bacterial acid attack, lack of bioactivity, and the scarcity of alternatives maintaining the mechanical properties over the lifetime service of these materials. Core-shell nanostructures are composed of various materials surrounded by a protective shell. They are acquiring considerable attention as innovative multipurpose carriers that show great potential in restorative dentistry. Herein, we systematically reviewed the recent studies on core-shell nanostructures incorporated into dental resin-based materials, their intended properties, synthesis methods, and assessment tests employed. This study used scoping review method, following Arksey and O'Malley's five stages framework using PubMed and Scopus (Elsevier) databases. From 149 initially identified manuscripts, 20 studies were eligible for full-text screening, and 15 were included for data extraction. The majority of included studies have used resin composite as parental material. Silica oxide was the most prevailing shell incorporated into dental resins. Almost all core-shell nanostructures were added to improve the material's strength and impart antibacterial properties. Designing strategies and drug release behaviors were discussed. In the end, current challenges and prospects in this promising field were highlighted.

The impaired osteogenic ability and excessive accumulation of reactive oxygen species (ROS) under osteoporosis severely weaken repair performance of biomimetic bone grafts. Currently, biomimetic bone grafts, capable of highly simulating bone hierarchy, could remarkably promote bone regeneration without systemic disease. Decorating biomimetic bone grafts with bioactivities without compromising hierarchical biomimicry stands as a feasible approach to treat the osteoporotic bone defect. Herein, through mineralizing decellularized collagen lamellae via strontium (Sr)- amorphous calcium phosphate and further modifying with tannic acid (TA), TA modified Sr-doped biomimetic bone lamellae was engineered. The physicochemical properties, ROS scavenging capacity and pro-osteogenic effect on osteoporotic bone marrow mesenchymal stem cells of construct were systemically evaluated. The results showed that TA and Sr can be successfully decorated without impairing the nano- and micro-architecture of biomimetic bone lamellae. The construct not only exhibited a potent and long-standing performance to eliminate ROS, but also effectively fostered the proliferation and osteogenic differentiation of osteoporotic bone marrow mesenchymal stem cells under oxidative stress environment. After implantation in the critical-sized bone defect of osteoporotic rat, it potently facilitated bone regeneration via synergistically activating PI3K/AKT signaling pathway. Hence, this construct is projected to be candidate for further engineering biomimetic bone grafts with more complicated hierarchy for accelerated healing of the osteoporotic bone defect.

Metabolic intermediates serve as precursors for bioactive molecule synthesis, the energy source for life activities, and signals for environmental adaptation. Ketone bodies are important metabolic intermediates produced in the liver by the degradation of fatty acids, acting as an alternative energy source for extrahepatic tissues when glucose is short in supply (especially during starvation). β-hydroxybutyric acid, with its conjugate base β-hydroxybutyrate, constitutes approximately 70% of ketone bodies. A growing number of studies have demonstrated the beneficial effects of β-hydroxybutyrate, especially in delaying aging, intervening in aging-related disease, and promoting longevity. This review systematically reviews the role of β-hydroxybutyrate in aging hallmarks, shedding light on the possible molecular mechanism by which β-hydroxybutyrate supports healthy aging. Higher circulating β-hydroxybutyrate can be achieved by lifestyle modification (ketogenic diet or caloric restriction) or exogenous β-hydroxybutyrate (or β-hydroxybutyrate precursors, derivates and agonists) supplementation. We will also discuss the pros and cons of different ways to upregulate β-hydroxybutyrate, emphasizing the promising future clinical use of poly-β-hydroxybutyrate, the polymers of β-hydroxybutyrate, which can be easily produced via a microbial platform and synthetic biology.