Cadmium-containing quantum dots: properties,applications, and toxicity

The marriage of biology with nanomaterials has significantly accelerated advancement of biological techniques, profoundly facilitating practical applications in biomedical fields. With unique optical properties (e.g., tunable broad excitation, narrow emission spectra, robust photostability, and high quantum yield), fluorescent quantum dots (QDs) have been reasonably functionalized with controllable interfaces and extensively used as a new class of optical probe in biological researches. In this review, we summarize the recent progress in synthesis and properties of QDs. Moreover, we provide an overview of the outstanding potential of QDs for biomedical research and innovative methods of drug delivery. Specifically, the applications of QDs as novel fluorescent nanomaterials for biomedical sensing and imaging have been detailedly highlighted and discussed. In addition, recent concerns on potential toxicity of QDs are also introduced, ranging from cell researches to animal models.

     

经皮给药纳米载体及靶向系统治疗类风湿关节炎研究进展

类风湿关节炎(RA)是全世界难治性自身免疫疾病,其治疗药物虽不断发展,但病灶药物浓度达不到有效水平导致药物疗效不理想或存在各种毒副反应,因此,基于新技术、新方法研究开发针对RA的安全、高效新型制剂是必要的.研究表明,纳米技术的运用可提高药物生物利用度,经皮给药可改善口服和注射带来的毒副作用.对近年来基于经皮给药系统治疗...     

Three-dimensional biomaterial degradation — Material choice,design and extrinsic factor considerations

The apparent difficulty to precisely control fine-tuning of biomaterial degradation has initiated the recent paradigm shift from conventional top-down fabrication methods to more nature-inspired bottom-up assemblies. Sophistication of material fabrication techniques allows today's scientists to reach beyond conventional natural materials in order to synthesise tomorrow's ‘designer material’. Material degradation into smaller components and subsequent release of encapsulated cells or cell-signalling agents have opened medically exploitable avenues, transforming the area of regenerative medicine into a dynamic and self-propagating branch of modern medicine. The aim to synthesise ever more refined scaffolding structures in order to create micro- and nanoenvironments resembling those found in natural tissues now represents an ever growing niche in the materials sciences. Recently, we have developed and conducted the world's first in-human tracheal transplantation using a non-degradable completely synthetic biomaterial. Fuelled by such clinical potential, we are currently developing a biodegradable version suitable for skin tissue engineering and paediatric applications. However, despite enormous efforts, current, as yet insurmountable challenges include precise biomaterial degradation within pre-determined spatial and temporal confines in an effort to release bio-signalling agents in such orchestrated fashion as to fully regenerate functioning tissues. In this review, the authors, almost anti-climactically, ask the readers to step out of the artificially over-constructed spiral of ever more convoluted scaffold fabrication techniques and consider the benefits of controllable bottom-up scaffold fabrication methods. It will further be investigated how scaffold designs and fabrication methods may influence degradation and subsequent release of incorporated elements. A focus will be placed on the delivery of growth factors, stem cells and therapeutic agents alone or in parallel. The difficulties of designing a delivery vehicle capable of delivering multiple factors whilst maintaining distinct release kinetics will be highlighted. Finally, this review will be rounded off with an insight into current literature addressing the recurring issues of degradation product toxicities and suggests means of overcoming those.     

Gold nanomaterials as key suppliers in biological and chemical sensing,catalysis, and medicine

BackgroundGold nanoparticles (AuNPs) with unique physicochemical properties have received a great deal of interest in the field of biological, chemical and biomedical implementations. Despite the widespread use of AuNPs in chemical and biological sensing, catalysis, imaging and diagnosis, and more recently in therapy, no comprehensive summary has been provided to explain how AuNPs could aid in developing improved sensing and catalysts systems as well as medical settings.Scope of reviewThe chemistry of Au-based nanosystems was followed by reviewing different applications of Au nanomaterials in biological and chemical sensing, catalysis, imaging and diagnosis by a number of approaches, and finally synergistic combination therapy of different cancers. Afterwards, the clinical impacts of AuNPs, future application of AuNPs, and opportunities and challenges of AuNPs application were also discussed.Major conclusionsAuNPs show exclusive colloidal stability and are considered as ideal candidates for colorimetric detection, catalysis, imaging, and photothermal transducers, because their physicochemical properties can be tuned by adjusting their structural dimensions achieved by the different manufacturing methods.General significanceThis review provides some details about using AuNPs in sensing and catalysis applications as well as promising theranostic nanoplatforms for cancer imaging and diagnosis, and sensitive, non-invasive, and synergistic methods for cancer treatment in an almost comprehensive manner.     

Wacław Szybalski's contribution to immunotherapy: HGPRT mutation & HAT selection as first steps to gene therapy and hybrid techniques in mammalian cells

In this report we describe Wac?aw Szybalski's fundamental contribution to gene therapy and immunotherapy. His 1962 PNAS paper (Szybalska and Szybalski, 1962) documented the first successful gene repair in mammalian cells. Furthermore, this was also the first report on the HAT selection method used later in many applications. Most importantly, somatic cell fusion and HAT selection were subsequently used to develop monoclonal antibody technology, which contributed significantly to the progress of today's medicine.     

Nanoporous protein matrix made of amyloid fibrils of β2‐microglobulin

Amyloid fibrils are considered as novel nanomaterials because of their nanoscale width, a regular constituting structure of cross β‐sheet conformation, and considerable mechanical strength. By using an amyloidogenic protein of β₂‐microglobulin (β₂M) related to dialysis‐related amyloidosis, nanoporous protein matrix has been prepared. The β₂M granules made of around 15 monomers showed an average size of 23.1 nm. They formed worm‐like fibrils at pH 7.4 in 20 mM sodium phosphate containing 0.15 M NaCl following vigorous nondirectional shaking incubation, in which they became laterally associated and interwound to generate the porous amyloid fibrillar matrix with an average pore size of 30–50 nm. This nanoporous protein matrix was demonstrated to be selectively disintegrated by reducing agents, such as tris‐(2‐carboxyethyl) phosphine. High surface area with nanopores on the surface has been suggested to make the matrix of β₂M amyloid fibrils particularly suitable for applications in the area of nanobiotechnology including drug delivery and tissue engineering. © 2010 American Institute of Chemical Engineers Biotechnol. Prog., 2010     

Do you have any regrets about entering medicine?

Do today''s students have any second thoughts about their decision to pursue a career in medicine? Gabriel Leung, who graduates in June from the University of Western Ontario, considers the problems and dilemmas that have confronted him and his classmates during their short careers and muses on the uncertain future today''s physicians face.     

Nanobiotechnology: From Molecules to Systems

Nanobiotechnology is a key enabling multidisciplinary field for medical, technological and biological research and development, medicine, pharmaceutical development, and analytical sciences. Its foundation is the selective integration of a multitude of endeavours, such as biotechnology, chemical and physical nanotechnology, materials sciences, chemistry, engineering, electronics and optronics targeting the construction of micro‐ and nano‐arrays for analyzing complex mixtures of DNA, RNA, proteins, metabolites as well as the design of ultra‐sequencing devices, microbial fuel cells, implantates, molecular motors, artificial organs, and nanorobots. The developments in nanobiotechnology benefit from and contribute to the scientific advances in the chemical and physical nanotechnologies, in particular with respect to materials, composites, nanostructuring techniques, carbon nanotubes, and nanoelectronics.     

Nanobiotechnologies for the detection and reduction of pathogens

Advances in the manipulation of nanomaterials has permitted the development of nanobiotechnology with enhanced sensitivities and improved response times. Low levels of infection of the major pathogens require the need for sensitive detection platforms and the properties of nanomaterials make them suitable for the development of assays with enhanced sensitivity, improved response time and increased portability. Nanobiotechnologies focusing on the key requirements of signal amplification and pre-concentration for the development of sensitive assays for food-borne pathogen detection in food matrices will be described and evaluated. The potential that exists for the use of nanomaterials as antimicrobial agents will also be examined.     

孕妇不良情绪、生活事件与妊娠结局以及分娩方式的关系研究

目的:探讨孕妇不良情绪、生活事件对妊娠结局以及分娩方式的影响。方法:选择2017年3月至2018年7月在海南省三亚市人民医院进行分娩的孕妇232例,搜集孕妇的基本资料,调查孕妇的生活事件及抑郁、焦虑状态,并记录孕妇的妊娠结局以及分娩方式,分析孕妇不良情绪、生活事件与妊娠结局以及分娩方式之间的关系。结果:在232例孕妇中,焦虑情绪孕妇有24例,占10.34%;抑郁孕妇有86例,占37.07%;发生生活事件的孕妇有69例,占29.74%。受到生活事件刺激、存在抑郁及焦虑的孕妇出现不良妊娠结局的概率均高于正常孕妇(P0.05)。剖宫产孕妇负性生活事件发生次数高于自然分娩的孕妇,而正性生活事件发生次数低于自然分娩的孕妇(P0.05)。剖宫产孕妇焦虑、抑郁的发生率均高于自然分娩的孕妇(P0.05)。结论:孕妇的不良情绪及生活事件普遍存在,可导致不良妊娠结局的发生并且对分娩方式产生一定的影响,应引起家庭及社会的重视。     

Liposomes in the Treatment of Parasitic,Viral, Fungal and Bacterial Infections

Abstract

The applicability of liposomes as carriers of immunomodulatory agents or antibiotics for improvement of treatment of severe infections is under investigation. The use of “classical'’ liposomes for targeting of macrophage modulators to enhance non-specific host resistance to infections caused by a variety of micro-organisms shows good results. The therapeutic prospects of “classical'’ liposomes as carriers of antibiotics are good, however are limited to the treatment of intracellular infections in mononuclear phagocyte system (MPS) tissues. The recent development of liposome formulations with reduced affinity to the MPS and long circulation half-lives creates new possibilities for obtaining improved delivery of antibiotics to infected tissues in general including infections in non-MPS tissues.     

Strategies of enzyme immobilization on nanomatrix supports and their intracellular delivery

Abstract

Enzymes are one of the foundations and regulators for all major biological activities in living bodies. Hence, enormous efforts have been made for enhancing the efficiency of enzymes under different conditions. The use of nanomaterials as novel carriers for enzyme delivery and regulating the activities of enzymes has stimulated significant interests in the field of nano-biotechnology for biomedical applications. Since, all types of nanoparticles (NPs) offer large surface to volume ratios, the use of NPs as enzyme carriers affect the structure, performance, loading efficiency, and the reaction kinetics of enzymes. Hence, the immobilization of enzymes on nanomatrices can be used as a useful approach for direct delivery of therapeutic enzymes to the targeted sites. In other words, NPs can be used as advanced enzyme delivery nanocarriers. In this paper, we present an overview of different binding of enzymes to the nanomaterials as well as different types of nanomatrix supports for immobilization of enzymes. Afterwards, the enzyme immobilization on nanomaterials as a potential system for enzyme delivery has been discussed. Finally, the challenges associated with the enzyme delivery using nano matrices and their future perspective have been discussed.

Communicated by Ramasamy H. Sarma     

Radioiodination of extravesicular surface constituents to study the biocorona,cell trafficking and storage stability of extracellular vesicles

BackgroundExtracellular vesicles (EVs) are produced by all cell types and serve as biological packets delivering a wide variety of molecules for cell-to-cell communication. However, the biology of the EV extravesicular surface domain that we have termed EV ‘biocorona’ remains underexplored. Upon cell secretion, EVs possess an innate biocorona containing membrane integral and peripheral constituents that is modified by acquired constituents post secretion. This distinguishes EVs from synthetic nanoparticulate biomaterials that are limited to an adsorption-based, acquired biocorona.MethodsThe EV biocorona molecular constituents were radiolabeled with ¹²⁵I to study biocorona constituents and its surface dynamics. As example toolset applications, ¹²⁵I-EVs were utilized to study EV cell trafficking and the stability of the EV biocorona during storage.ResultsThe biocorona of EVs consisted of proteins, lipids, DNA and RNA. The cellular uptake of ¹²⁵I-EVs was temperature dependent and internalized ¹²⁵I-EVs were rapidly recycled by cells. When ¹²⁵I-EVs were stored in a purified state, they exhibited time and temperature dependent biocorona shedding and proteolytic degradation that was partially inhibited in the presence of serum.ConclusionThe EV biocorona is complex and dynamic. Radiolabeling of the EV biocorona enables a unique platform methodology to study the biocorona and will facilitate unlocking EV's full clinical translation potential.General significanceThe EV biocorona affects EV mediated biological processes in health and disease. Acquiring knowledge of the EV biocorona composition, dynamics, stability and structure not only informs the diagnostic and therapeutic translation of EVs but also aids in designing biomimetic nanomaterials for drug delivery.     

Device Attitude and Real-Time 3D Visualization: An Interface for Elderly Care

Objectivethis paper presents an innovative graphical user interface to visualize the attitude of a sensing device in a three-dimensional space, serving a wide-range of medical applications.Material and methodsbased on inertial measurement units (IMU) or on magnetic, angular rate and gravity (MARG) sensors, a processing unit provides Euler angles using a sensor fusion technique to display the orientation of the device relative to the Earth frame in real-time. The device is schematized by linking six polygonal regions, and is subject to sequential rotations by updating the graph each 350 ms. We conduct comparative studies between the two sensing devices, i.e. IMUs and MARGs, as well as two orientation filters, namely Madgwick's algorithm and Mahony's algorithm.Resultsthe accuracy of the system is reported as a function of (i) the sampling frequency, (ii) the sensing unit, and (iii) the orientation filter, following two elderly care applications, namely fall risk assessment and body posture monitoring. The experiments are conducted using public datasets. The corresponding results show that Madgwick's algorithm is best suited for low sampling rates, whereas MARG sensors are best suited for the detection of postural transitions.Conclusionthis paper addresses the different aspects and discusses the limitations of attitude estimation systems, which are important tools to help clinicians in their diagnosis.     

何氏益气养血补肾方治疗气血亏虚型类风湿关节炎并血液系统受累患者的效果分析

摘要 目的：探讨何氏益气养血补肾方治疗气血亏虚型类风湿关节炎并血液系统受累患者的治疗效果。方法：选取我院2020年10月到2022年10月收治的60例气血亏虚型类风湿关节炎并血液系统受累患者作为研究对象,分为观察组与对照组,每组30例。对照组采取常规本病治疗与对症治疗,观察组采取何氏益气养血补肾方与本病治疗,对比两组患者临床疗效,治疗前后中医证候积分变化,血红蛋白（Hb）、白细胞计数（WBC）、超敏C反应蛋白（hsCRP）及血沉（ESR）相关血液指标水平变化,CD4⁺、CD3⁺、CD4⁺/ CD8⁺相关T淋巴细胞亚群水平变化,并应用谷丙转氨酶（ALT）表达水平、谷草转氨酶（AST）评价患者治疗前后肝功能,应用血肌酐（Scr）、尿素氮(BUN)来评价患者肾功能变化。结果：观察组总有效率为93.33%明显高于对照组总有效率86.66%（P<0.05）;治疗后,两组患者神疲乏力、心悸气短、自汗、头晕眼花、怕冷、睡眠障碍相关中医证候积分均降低,且观察组低于对照组（P＜0.05）;治疗后两组患者Hb、WBC升高,观察组较对照组高,ESR、hsCRP降低,且观察组低于对照组（P＜0.05）;治疗后两组患者CD4⁺、CD3⁺和CD4⁺/ CD8⁺数值均升高,且观察组高于对照组（P＜0.05）;治疗后两组患者ALT、AST水平无明显变化,但两组患者SCr、BUN水平降低,观察组低于对照组（P＜0.05）。结论：何氏益气养血补肾方治疗气血亏虚型类风湿关节炎并血液系统受累疗效显著,可改善患者相关中医症状,提升血红蛋白和白细胞计数,提高患者免疫功能,且不对肝肾功能造成损伤,能够轻度提升患者肾功能水平,值得临床应用推广。     

Tailored carbon nanotubes for tissue engineering applications

A decade of aggressive researches on carbon nanotubes (CNTs) has paved way for extending these unique nanomaterials into a wide range of applications. In the relatively new arena of nanobiotechnology, a vast majority of applications are based on CNTs, ranging from miniaturized biosensors to organ regeneration. Nevertheless, the complexity of biological systems poses a significant challenge in developing CNT‐based tissue engineering applications. This review focuses on the recent developments of CNT‐based tissue engineering, where the interaction between living cells/tissues and the nanotubes have been transformed into a variety of novel techniques. This integration has already resulted in a revaluation of tissue engineering and organ regeneration techniques. Some of the new treatments that were not possible previously become reachable now. Because of the advent of surface chemistry, the CNT's biocompatibility has been significantly improved, making it possible to serve as tissue scaffolding materials to enhance the organ regeneration. The superior mechanic strength and chemical inert also makes it ideal for blood compatible applications, especially for cardiopulmonary bypass surgery. The applications of CNTs in these cardiovascular surgeries led to a remarkable improvement in mechanical strength of implanted catheters and reduced thrombogenecity after surgery. Moreover, the functionalized CNTs have been extensively explored for in vivo targeted drug or gene delivery, which could potentially improve the efficiency of many cancer treatments. However, just like other nanomaterials, the cytotoxicity of CNTs has not been well established. Hence, more extensive cytotoxic studies are warranted while converting the hydrophobic CNTs into biocompatible nanomaterials. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009     

Implications of molecular diversity of chitin and its derivatives

Chitin is a long unbranched polysaccharide, made up of β-1,4-linked N-acetylglucosamine which forms crystalline fiber-like structure. It is present in the fungal cell walls, insect and crustacean cuticles, nematode eggshells, and protozoa cyst. We provide a critical appraisal on the chemical modifications of chitin and its derivatives in the context of their improved efficacy in medical applications without any side effect. Recent advancement in nanobiotechnology has helped to synthesize several chitin derivatives having significant biological applications. Here, we discuss the molecular diversity of chitin and its applications in enzyme immobilization, wound healing, packaging material, controlled drug release, biomedical imaging, gene therapy, agriculture, biosensor, and cosmetics. Also, we highlighted chitin and its derivatives as an antioxidant, antimicrobial agent, anticoagulant material, food additive, and hypocholesterolemic agent. We envisage that chitin and chitosan-based nanomaterials with their potential applications would augment nanobiotechnology and biomedical industries.

     

A recent update on the use of Chinese medicine in the treatment of inflammatory bowel disease

BackgroundInflammatory bowel disease (IBD) is a chronic idiopathic disease that is characterized by inflammation of the gastrointestinal tract. Proper management of IBD requires both early diagnosis and novel therapies and management programs. Many reports have suggested that Chinese medicine has unique properties favorable to the treatment of IBD. However, there are no systematic analyses on this topic.PurposeThis review summarizes recent studies that assessed the effects and mechanisms of Chinese medicine in the treatment of IBD in order to fully understand the advantages of Chinese medicine in the management of IBD.MethodsA literature search was conducted using peer-reviewed and clinical databases, including PubMed, Web of Science, ClinicalTrials.gov, MEDLINE, EMBASE, Springer LINK, Wan-fang database, the Chinese Biomedicine Database, and the China National Knowledge Infrastructure (CNKI). Keywords used were inflammatory bowel disease (including Ulcerative colitis or Crohn's disease) and Chinese medicine. All selected articles were from 1997 to 2021, and each were assessed critically for our exclusion criteria. Studies describing the pathogenesis of IBD, the effects and mechanisms of Chinese medicine in the treatment of IBD, in particular their roles in immune regulation, intestinal flora regulation, and improvement of intestinal barrier function, were included.ConclusionThis review highlights recent progress in the use of Chinese medicine in the treatment of IBD. It also provides a reference for further evaluation and exploration of the potential of classical multi-herbal Chinese medicine in the treatment of IBD.     

THE SCOPE AND RESPONSIBILITY OF MEDICINE—A Forum with a Purpose

To engender discussion of what the scope and responsibility of medicine ought to be in today''s society, California Medicine printed in its June issue six essays by authors known to have keen if various interest in the subject.In presenting the essays the editors expressed hope that they would be the beginning of a forum from which a definition of our profession''s responsibilities may be distilled. Readers were invited to take part in a continuation of the forum in succeeding issues. Following are three contributions selected from those received to date. Others will be published in the months ahead.If you have thoughts on the subject, just address them to the editors of California Medicine, 693 Sutter Street, San Francisco, California 94102. Keep your essays short, please.