V5 王蕊 声望 48 医学 2021-08-20 00:14:03 上传
A doxorubicin delivery platform using engineered natural membrane vesicle exosomes for targeted tumor therapy
Targeted drug delivery vehicles with low immunogenicity and toxicity are needed for cancer therapy. Here we show that exosomes, endogenous nano-sized membrane vesicles secreted by most cell types, can deliver chemotherapeutics such as doxorubicin (Dox) to tumor tissue in BALB/c nude mice. To reduce immunogenicity and toxicity, mouse immature dendritic cells (imDCs) were used for exosome produc- tion. Tumor targeting was facilitated by engineering the imDCs to express a well-characterized exosomal membrane protein (Lamp2b) fused to av integrin-specific iRGD peptide (CRGDKGPDC). Purified exo- somes from imDCs were loaded with Dox via electroporation, with an encapsulation efficiency of up to 20%. iRGD exosomes showed highly efficient targeting and Dox delivery to av integrin-positive breast cancer cells in vitro as demonstrated by confocal imaging and flow cytometry. Intravenously injected targeted exosomes delivered Dox specifically to tumor tissues, leading to inhibition of tumor growth without overt toxicity. Our results suggest that exosomes modified by targeting ligands can be used therapeutically for the delivery of Dox to tumors, thus having great potential value for clinical applications.
V5 王蕊 声望 48 医学 2021-08-19 14:25:43 上传
Copper-containing mesoporous bioactive glass scaffolds with multifunctional properties of angiogenesis capacity, osteostimulation and antibacterial activity
It is of great importance to develop multifunctional bioactive scaffolds, which combine angiogenesis capacity, osteostimulation, and antibacterial properties for regenerating lost bone tissues. In order to achieve this aim, we prepared copper (Cu)-containing mesoporous bioactive glass (Cu-MBG) scaffolds with interconnective large pores (several hundred micrometer) and well-ordered mesopore channels (around 5 nm). Both Cu-MBG scaffolds and their ionic extracts could stimulate hypoxia-inducible factor (HIF)-1a and vascular endothelial growth factor (VEGF) expression in human bone marrow stromal cells (hBMSCs). In addition, both Cu-MBG scaffolds and their ionic extracts significantly promoted the oste- ogenic differentiation of hBMSCs by improving their bone-related gene expression (alkaline phosphatase (ALP), osteopontin (OPN) and osteocalcin (OCN)). Furthermore, Cu-MBG scaffolds could maintain a sus- tained release of ibuprofen and significantly inhibited the viability of bacteria. This study indicates that the incorporation of Cu2þ ions into MBG scaffolds significantly enhances hypoxia-like tissue reaction leading to the coupling of angiogenesis and osteogenesis. Cu2þ ions play an important role to offer the multifunctional properties of MBG scaffold system. This study has demonstrated that it is possible to develop multifunctional scaffolds by combining enhanced angiogenesis potential, osteostimulation, and antibacterial properties for the treatment of large bone defects.
V5 路漫漫 声望 155 生物医学 2021-08-18 19:48:53 上传
Key issues surrounding the health impacts of electronic nicotine delivery systems (ENDS) and other sources of nicotine
Over the last decade, the use of electronic nicotine delivery systems (ENDS), including the electronic cigarette or e-cigarette, has grown rapidly. More youth now use ENDS than any tobacco product. This extensive research review shows that there are scientifically sound, sometimes competing arguments about ENDS that are not immediately and/or completely resolvable. However, the preponderance of the scientific evidence to date suggests that current-generation ENDS products are demonstrably less harmful than combustible tobacco products such as conventional cigarettes in several key ways, including by generating far lower levels of carcinogens and other toxic compounds than combustible products or those that contain tobacco. To place ENDS in context, the authors begin by reviewing the trends in use of major nicotine-containing products. Because nicotine is the common core—and highly addictive—constituent across all tobacco products, its toxicology is examined. With its long history as the only nicotine product widely accepted as being relatively safe, nicotine-replacement therapy (NRT) is also examined. A section is also included that examines snus, the most debated potential harm-reduction product before ENDS. Between discussions of NRT and snus, ENDS are extensively examined: what they are, knowledge about their level of “harm,” their relationship to smoking cessation, the so-called gateway effect, and dual use/poly-use. CA Cancer J Clin 2017;67:449-471. © 2017 American Cancer Society.
V5 王蕊 声望 48 医学 2021-08-18 10:05:36 上传
A review of the biomaterials technologies for infection-resistant surfaces
Anti-infective biomaterials need to be tailored according to the specific clinical application. All their properties have to be tuned to achieve the best anti-infective performance together with safe biocom- patibility and appropriate tissue interactions. Innovative technologies are developing new biomaterials and surfaces endowed with anti-infective properties, relying either on antifouling, or bactericidal, or antibiofilm activities. This review aims at thoroughly surveying the numerous classes of antibacterial biomaterials and the underlying strategies behind them. Bacteria repelling and antiadhesive surfaces, materials with intrinsic antibacterial properties, antibacterial coatings, nanostructured materials, and molecules interfering with bacterial biofilm are considered. Among the new strategies, the use of phages or of antisense peptide nucleic acids are discussed, as well as the possibility to modulate the local im- mune response by active cytokines. Overall, there is a wealth of technical solutions to contrast the establishment of an implant infection. Many of them exhibit a great potential in preclinical models. The lack of well-structured prospective multicenter clinical trials hinders the achievement of conclusive data on the efficacy and comparative performance of anti-infective biomaterials.
V5 王蕊 声望 48 医学 2021-08-17 14:06:53 上传
The future of biologic coatings for orthopaedic implants
Implants are widely used for orthopaedic applications such as fixing fractures, repairing non-unions, obtaining a joint arthrodesis, total joint arthroplasty, spinal reconstruction, and soft tissue anchorage. Previously, orthopaedic implants were designed simply as mechanical devices; the biological aspects of the implant were a byproduct of stable internal/external fixation of the device to the surrounding bone or soft tissue. More recently, biologic coatings have been incorporated into orthopaedic implants in order to modulate the surrounding biological environment. This opinion article reviews current and potential future use of biologic coatings for orthopaedic implants to facilitate osseointegration and mitigate possible adverse tissue responses including the foreign body reaction and implant infection. While many of these coatings are still in the preclinical testing stage, bioengineers, material scientists and surgeons continue to explore surface coatings as a means of improving clinical outcome of patients undergoing orthopaedic surgery
V5 王蕊 声望 48 医学 2021-08-17 08:13:24 上传
Curcumin nanoformulations: A review of pharmaceutical properties and preclinical studies and clinical data related to cancer treatment
Curcumin, a natural yellow phenolic compound, is present in many kinds of herbs, particularly in Cur- cuma longa Linn. (turmeric). It is a natural antioxidant and has shown many pharmacological activities such as anti-inflammatory, anti-microbial, anti-cancer, and anti-Alzheimer in both preclinical and clinical studies. Moreover, curcumin has hepatoprotective, nephroprotective, cardioprotective, neuroprotective, hypoglycemic, antirheumatic, and antidiabetic activities and it also suppresses thrombosis and protects against myocardial infarction. Particularly, curcumin has demonstrated efficacy as an anticancer agent, but a limiting factor is its extremely low aqueous solubility which hampers its use as therapeutic agent. Therefore, many technologies have been developed and applied to overcome this limitation. In this re- view, we summarize the recent works on the design and development of nano-sized delivery systems for curcumin, including liposomes, polymeric nanoparticles and micelles, conjugates, peptide carriers, cy- clodextrins, solid dispersions, lipid nanoparticles and emulsions. Efficacy studies of curcumin nano- formulations using cancer cell lines and in vivo models as well as up-to-date human clinical trials are also discussed.
V5 王蕊 声望 48 医学 2021-08-16 22:22:30 上传
The 3D printing of gelatin methacrylamide cell-laden tissue-engineered constructs with high cell viability
In the present study, we report on the combined efforts of material chemistry, engineering and biology as a systemic approach for the fabrication of high viability 3D printed macroporous gelatin methacrylamide constructs. First, we propose the use and optimization of VA-086 as a photo-initiator with enhanced biocompatibility compared to the conventional Irgacure 2959. Second, a parametric study on the printing of gelatins was performed in order to characterize and compare construct architectures. Hereby, the influence of the hydrogel building block concentration, the printing temperature, the printing pressure, the printing speed, and the cell density were analyzed in depth. As a result, scaffolds could be designed having a 100% interconnected pore network in the gelatin concentration range of 10e20 w/v%. In the last part, the fabrication of cell-laden scaffolds was studied, whereby the application for tissue engineering was tested by encapsulation of the hepatocarcinoma cell line (HepG2). Printing pressure and needle shape was revealed to impact the overall cell viability. Mechanically stable cell-laden gelatin meth- acrylamide scaffolds with high cell viability (>97%) could be printed.
V5 王蕊 声望 48 医学 2021-08-16 01:53:32 上传
Dual and multi-stimuli responsive polymeric nanoparticles for programmed site-specific drug delivery
In the past decades, polymeric nanoparticles have emerged as a most promising and viable technology platform for targeted and controlled drug delivery. As vehicles, ideal nanoparticles are obliged to possess high drug loading levels, deliver drug to the specific pathological site and/or target cells without drug leakage on the way, while rapidly unload drug at the site of action. To this end, various “intelligent” polymeric nanoparticles that release drugs in response to an internal or external stimulus such as pH, redox, temperature, magnetic and light have been actively pursued. These stimuli-responsive nanoparticles have demonstrated, though to varying degrees, improved in vitro and/or in vivo drug release profiles. In an effort to further improve drug release performances, novel dual and multi-stimuli responsive polymeric nanoparticles that respond to a combination of two or more signals such as pH/temperature, pH/redox, pH/magnetic field, temperature/reduction, double pH, pH and diols, tem- perature/magnetic field, temperature/enzyme, temperature/pH/redox, temperature/pH/magnetic, pH/redox/magnetic, temperature/redox/guest molecules, and temperature/pH/guest molecules have recently been developed. Notably, these combined responses take place either simultaneously at the pathological site or in a sequential manner from nanoparticle preparation, nanoparticle transporting pathways, to cellular compartments. These dual and multi-stimuli responsive polymeric nanoparticles have shown unprecedented control over drug delivery and release leading to superior in vitro and/or in vivo anti-cancer efficacy. With programmed site-specific drug delivery feature, dual and multi-stimuli responsive nanoparticulate drug formulations have tremendous potential for targeted cancer therapy. In this review paper, we highlight the recent exciting developments in dual and multi-stimuli responsive polymeric nanoparticles for precision drug delivery applications, with a particular focus on their design, drug release performance, and therapeutic benefits.
V5 User6128 声望 95 生物医学工程 2021-08-16 01:05:26 上传
Nanoparticle-triggered in situ catalytic chemical reactions for tumour-specific therapy
Tumour chemotherapy employs highly cytotoxic chemodrugs, which kill both cancer and normal cells by cellular apoptosis or necrosis non-selectively. Catalysing/triggering the specific chemical reactions only inside tumour tissues can generate abundant and special chemicals and products locally to initiate a series of unique biological and pathologic effects, which may enable tumour-specific theranostic effects to combat cancer without bringing about significant side effects on normal tissues. Nevertheless, chemical reaction-initiated selective tumour therapy strongly depends on the advances in chemistry, materials science, nanotechnology and biomedicine. This emerging cross-disciplinary research area is substantially different from conventional cancer-theranostic modalities in clinics. In response to the fast developments in cancer theranostics based on intratumoural catalytic chemical reactions, this tutorial review summarizes the very-recent research progress in the design and synthesis of representative nanoplatforms with intriguing nanostructures, compositions, physiochemical properties and biological behaviours for versatile catalytic chemical reaction-enabled cancer treatments, mainly by either endogenous tumour microenvironment (TME) triggering or exogenous physical irradiation. These unique intratumoural chemical reactions can be used in tumour-starving therapy, chemodynamic therapy, gas therapy, alleviation of tumour hypoxia, TME-responsive diagnostic imaging and stimuli-responsive drug release, and even externally triggered versatile therapeutics. In particular, the challenges and future developments of such a novel type of cancer-theranostic modality are discussed in detail to understand the future developments and prospects in this research area as far as possible. It is highly expected that this kind of unique tumour-specific therapeutics by triggering specific in situ catalytic chemical reactions inside tumours would provide a novel but efficient methodology for benefiting personalized biomedicine in combating cancer.
V6 答魔君 声望 56 2018-04-16 18:07:10 上传
PLGA/β-TCP composite scaffold incorporating salvianolic acid B promotes bone fusion by angiogenesis and osteogenesis in a rat spinal fusion model
Spinal disorders often require surgical treatment called spinal fusion to restore a stabilized spine where bone grafts are implanted for the fusion of adjacent vertebras. In this study, we developed a bioactive composite scaffold incorporated with salvianolic acid B (SB), an active component extracted from Danshen. This study aimed to evaluate the effects of SB-incorporated porous scaffold on spinal fusion models. The composite scaffolds composed of poly (lactic-co-glycolic acid) and tricalcium phosphate (PLGA/β-TCP) were fabricated with low-temperature rapid prototyping technique, which incorporated SB at low (SB-L), middle (SB-M), high (SB-H) doses, and pure PLGA/β-TCP as blank control (Con). The release profile of SB from the scaffolds was determined by high performance liquid chromatography. Osteoconductive and osteoinductive properties of the scaffolds were reflected by the osteogenic differentiation ability of rat primary mesenchymal stem cells. The angiogenesis was determined by the forming of tube-like structures resembling capillaries using endothelial cell line (EA hy9.26). A well-established spinal fusion model was used to evaluate the in vivo bony fusion. Animals were transplanted with scaffolds, or autografts from iliac crest as positive controls. Micro-computed tomography (CT) analysis, CT-based angiography, manual palpation test, histomorphometry, and histology were performed after 8 weeks of transplantation. Results revealed that incorporated SB was steadily released from the scaffolds. The aliquot of released SB promoted osteogenesis and angiogenesis in vitro in a dose-dependent manner. In animal study, a dose-dependent effect of SB on new bone formation, mineral apposition rate, and vessel density within the scaffold were demonstrated. Manual palpation test showed little numerical improvement in fusion rate when compared with the blank controls. In summary, our results suggested that SB-incorporated PLGA/β-TCP composite scaffold could enhance bony fusion through the promotion of osteogenesis and angiogenesis.

生物医学工程(Biomedical Engineering,简称BME)是结合物理、化学、数学和计算机与工程学原理,从事生物学、医学、行为学或卫生学的研究;提出基本概念,产生从分子水平到器官水平的知识,开发创新的生物学制品、材料、加工方法、植入物、器械和信息学方法,用与疾病预防、诊断和治疗,病人康复,改善卫生状况等目的