Smart Materials in Medicine最新文献

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.

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.

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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.

Biomaterials play a pivotal role in modern orthopedics. There are a plethora of functional issues with orthopedic implants. These issues include things like aseptic loosening, lack of osseointegration, biofilm formation, and infections. Researchers have devised several surface modification procedures, including coating the implant surfaces, to address these problems. Implant coatings serve as a bridge between the implant and the surrounding bio components. One of the creative methods is to modify surfaces using smart coatings. Smart coatings can detect environmental cues like temperature, pH, light, and so on and in turn react facultatively to the tissues. A particular stimulus and its specific role in orthopedic implant coatings are of our interest. Some coatings, known as dual-acting coatings, allow for the utilization of one or more stimuli in addition to the individual stimulus as a trigger. Based on the stimuli that they react to, we have highlighted the most cutting-edge smart orthopedic implant coatings in the current review.

Cancer remains the leading cause of death and an important barrier to increase life expectancy. It is desirable to develop therapeutics that can improve life quality and prolong the survival duration. Nano materials have long been considered as a potential tool for detection, diagnosis, and treatment of tumor. The application of nanotechnology for the treatment of cancer is highly based on nano drug delivery system. To meet specific clinical requirements in a superior degree, nanoparticles (NPs) with better biocompatibility, lower toxicity, and definite therapeutic effect are now being developed and designed for experiments and applications. This review presents an overview of the clinical application characteristics of NPs and summarizes the recent advances in the development of nano materials for cancer therapy.

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.

Cell sheet engineering is a rapidly growing field of tissue engineering and regenerative medicine. The ease of cell sheet obtainment techniques and the resulting unique characteristics and microenvironment of these multicellular structures give rise to the wide range of their in vivo application. At the same time, there are also macroscale cell sheet properties such as thickness, shrinkage after detachment due to cytoskeleton relaxation, and resulting mechanical characteristics. The main topic of this review is the discussion of these properties and how they define the need to use special approaches to manipulating cell sheets during stacking several structures, transferring them to surgical sites, or cryopreserving them. We aimed to systematize the existing techniques of cell sheet transferring, and describe their principles, advantages, and drawbacks regarding cell sheet application during surgical procedures on various tissues and organs. Attention is also paid to such aspects and details as cell sheet positioning in vivo, their ability to spontaneous adhesion, and the requirement for additional fixation at particular surgical sites. Finally, the last section of this review covers the subject of cell sheet cryopreservation – the discussion of freezing and thawing protocols, the variety of cryoprotectants and their mixtures, as well as special requirements such as cryoprotectant loading systems, and cell sheet supporting systems that also stem from their unique macroscale characteristics. Altogether, this systematized review of existing technological approaches related to cell sheet application in vivo can be potentially helpful for the new and expert researchers in this area of tissue engineering.

While a significant number of studies have focused on elucidating the functioning mechanisms of the Hepatocellular carcinoma (HCC) microenvironment, the intercellular crosstalk between multiple cells in the tumor microenvironment remains unclear. Here we co-cultured spheroids of HCC cells, hepatic stellate cells (HSCs), and hepatocytes in a biomimetic composite hydrogel to construct a 3D model of the HCC microenvironment in vitro. The model reproduced the major cellular components of early HCC in a biomimetic 3D microenvironment, realizing the visualization of the cellular interplay between cells and the microenvironment. Using this model, we showed that the HSCs were activated when co-cultured with HCC cells and deposed collagen to remodel the microenvironment, which in turn triggered higher EMT levels in HCC cells. The hepatocytes also responded to the existence of HCC cells and the activation of HSCs in co-culture, showing the downregulated expression level of ALB, AFP, and HNF4A. This model recapitulated the activation of HSCs in the HCC microenvironment and enabled visualization of multicellular interplay in 3D, providing a biomimetic platform to investigate mechanisms of HCC and related hepatic fibrosis.

Nowadays, malignant brain tumors are still mostly lethal diseases with poor prognosis and a clinical median survival rate of fewer than 2 years after therapeutic intervention. It is difficult to achieve complete remission of brain tumors due to blood-brain barrier (BBB) and a lack of efficient drug delivery systems to targeted transportation of brain tumor medicines. Nanoparticle delivery systems have shown merits including stability and high carrier capacity for the transportation of different drugs to treat brain tumors. The application of mRNA nanomedicines brings in great promise not only in COVID-19, but also for malignant brain tumor immunotherapy. The appropriate delivery system facilitates mRNA delivery efficiency and enhances the immune response successfully, for optimal treatment outcomes on malignant brain tumors. Herein, we do an updated review on the development of mRNA nanomedicines for malignant brain cancer treatment. We focus on how to design mRNA-loaded nanoparticle-based delivery systems with optimized pharmacokinetics and pharmacodynamics for efficient therapy of brain cancers. In addition, we point out the challenges and solutions for further development of mRNA nanomedicines for brain cancer therapy. We hope this review would stimulate interest among researchers with different backgrounds and expedite the translation from bench to bedside for the mRNA nanomedicines.