Smart Materials in Medicine最新文献

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.

Burns not only damage the skin barrier, but also cause a series of inflammatory reactions and oxidative stress states. Among them, elderly patients are prone to suffer severe burns due to degenerative changes of their skin caused by aging factors, such as atrophy and thinning, etc. After burns, the body will continuously release inflammatory factors, resulting in systemic inflammatory response syndrome (SIRS) and oxidative stress, which are related to the poor treatment effect and the poor prognosis of elderly burn patients. It seems to be difficult for conventional treatments to control the disease development of elderly burn patients effectively. Considering the rapidly increasing elderly population, it is priority to understand the pathological process and the mechanisms to formulate more appropriate treatment strategies for elderly burn patients. In recent years, owing to considerable advances in nanotechnology, a variety of nanomaterials have been developed for wound healing and inflammation regulation. Its good biocompatibility, cell proliferation stimulation and antibacterial properties make the clinical treatment strategy more optimized. Concurrently, mesenchymal stem cells (MSCs) have also been used in the burns field and have been proven effective in not only controlling the level of inflammation and regulating the systemic immune balance, but also promoting wound healing and vascularization. Here, this review covers burns classification, the pathological process of elderly burn patients, and the research progress of nanotechnology and MSCs in burns. Eventually, we summarize the advantages and challenges of emerging strategies such as nanotechnology and MSCs in the treatment of elderly burn patients, expecting to promote the clinical transformation.

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Due to the lack of agreement on affiliation format between authors and the owner of the journal, this article has been retracted at the request of all authors, the Editors-in-Chief and the owner of the journal.

Nanoscale metal is considered the backbone of biomedical nanotechnology. Recently, there has been an exponential increase in nanoscale materials’ biomedical applications. These nanomaterials have mainly been employed in drug delivery systems, prosthetic implants, diagnostics, and therapeutics of various diseases, including cancer. Nanoscale materials have two major classes, namely organic and inorganic nanomaterials. Given the merit of excellent biocompatibility, facile synthesis, target recognition, prolonged circulation half-life, and deference to surface functionalization, the inorganic (metallic) nanoparticles hold promising applications in biomedicine. Their biomedical properties may vary based on their type, size, shape, structure, functionalization, and origin. This review will enlighten the recent advances in nanoscale materials applications as nanoscale-knife in cancer theranostics. Moreover, the external assisted technologies and metallic nanoparticle surface decoration will also be highlighted.

Liposome surface potential effect on cellular uptake and cytotoxicity is evaluated using liposomes, modified with cationic lipid DOTAP, a series of cationic gemini surfactants with two carbamate fragments, and an amphiphilic peptide SSRGD. The surfactants used are novel representatives of the gemini family with improved self-assembling activity coupled with potential biodegradable properties and displayed increasing antibacterial activity and cytotoxicity with the shortening of hydrophobic alkyl tails. The longest alkyl tail surfactant, 14-6-14(Et), was the most biocompatible of the series, which was chosen for liposome modification. Prepared liposomes of various compositions are characterized from morphological and physicochemical standpoints in order to optimize their biocompatibility and stability. The carbamate gemini surfactants were also twice as effective at providing positive charge to liposomes and less toxic compared to DOTAP. On their own, carbamate surfactants were able to increase cellular uptake of liposomes by 190%. The mixed composition of 14-6-14(Et) surfactant and SSRGD amphiphilic peptide was the most readily absorbed formulation among different tested neutral, cationic and RGD-modified liposomes. The comparison between the cellular uptake promotion is conducted as to what is the most selective and efficient approach to enhance lipid nanoparticle uptake by cancerous cells.

Nanosized drug delivery systems typically enter the cell via endocytosis. However, a significant amount of the endocytosed cargo cannot effectively escape from the endosome, resulting in drug degradation. Therefore, there are several ongoing efforts to develop transmembrane delivery systems that could circumvent endocytosis. In this study, phospholipid nanotube nanodrills (LDs) were formed onto the surface of a human serum albumin nanoparticle via self-assembling phospholipids. The nanodrill technology enhanced the intracellular uptake efficiency of nanoparticles via energy-independent direct cell membrane permeation. The length of the nanodrills according to the DSPE-PEG to DSPC ratio was investigated both experimentally and theoretically. Our findings demonstrated that longer nanodrills were formed on the surface of the nanoparticles as the ratio of DSPC (i.e., a strongly hydrophobic lipid) in the two phospholipids increases. Moreover, the intracellular uptake efficiency increased as the length of phospholipid nanodrills increased. In addition to enhancing intracellular delivery, the phospholipid nanodrills could penetrate the extracellular matrix and enable the introduction of nanoparticles, thus highlighting the promising tissue penetration capacity of phospholipid nanodrill technology. The improved cell permeability of LD technology was demonstrated by effectively inhibiting specific genes via siRNA-based therapeutic delivery. Moreover, this approach enhanced the efficacy of chemotherapeutics against chemo-resistant cancer cells. Therefore, LD technology could be used to deliver genetic materials and chemical-based therapeutics both in vitro and in vivo.

Bone repair processes are tightly affected by fiber topographies of scaffolds and can be promoted by coupling with chemotactic and/or angiogenic molecules. Here, we developed polycaprolactone (PCL) and collagen-based fibrous scaffolds expressing various architectures via a modified electrospinning set up. We conjugated the as-spun scaffolds with caffeic acid (CA) and/or a cartilage oligomeric matrix protein of angiopoietin 1 (COMP-Ang1). The CA-coupled PCL/collagen scaffold (PCL/col/CA) exhibited greater treatment efficacies for biomimetic and cellular mineralization, expression of osteogenic and chemotactic molecules, and cell migration than did the PCL/col treatment alone. Among the PCL/col/CA scaffolds, the radially symmetric grid-patterned scaffold (rG-PCL/col/CA) showed the greatest bioactivities. The linking of the rG-PCL/col/CA with COMP-Ang1 increased the expression of vascular endothelial growth factor by cells. The COMP-Ang1-linked rG-PCL/col/CA formed more new blood vessels and expressed more chemotactic molecules in a rat model of femoral defects than did the scaffold alone. Compared with PCL/col/CA scaffolds, the COMP-Ang1-coupled rG-PCL/col/CA scaffold stimulated faster and greater healing of femoral defects. Collectively, this study demonstrates that the coupling of a radially grid-patterned fibrous scaffold with CA and COMP-Ang1 greatly enhances scaffold-mediated bone healing via synergistic improvements in vascularization, cell migration, and formation and maturation of new bones in defected regions.