Surface nanocrystallization of stainless steel for reduced biofilm adherence

Stainless steel is one of the most common metallic biomedical materials. For medical applications, its resistance to the adherence of biofilms is of importance to the elimination or minimization of bacterial infections. In this study, we demonstrate the effectiveness of a process combining surface nanocrystallization and thermal oxidation (or a recovery heat treatment in air) for reducing the biofilm's adherence to stainless steel. During this treatment, a target surface was sandblasted and the resultant dislocation cells in the surface layer were turned into nanosized grains by a subsequent recovery treatment in air. This process generated a more protective oxide film that blocked the electron exchange or reduced the surface activity more effectively. As a result, the biofilm's adherence to the treated surface was markedly minimized. A synthetic peptide was utilized as a substitute of biofilms to evaluate the adhesion between a treated steel surface and biofilms using an atomic force microscope (AFM) through measuring the adhesive force between the target surface and a peptide-coated AFM tip. It was shown that the adhesive force decreased with a decrease in the grain size of the steel. The corresponding surface electron work function (EWF) of the steel was also measured, which showed a trend of variation in EWF with the grain size, consistent with corresponding changes in the adhesive force.     

体医融合视角下慢性病移动医疗设计策略研究

目的在工业化、老龄化、生态环境恶化各种现实背景下,构思当代慢性病移动医疗服务的创新策略,重构慢性病患者的移动医疗服务体验。方法系统地研究了慢性病移动医疗服务的现状,分析慢性病治疗以及慢性病移动医疗平台在国内发展存在的各种问题,结合慢性病治疗本身独特的特点,在系统创新思维和服务设计理念的基础上,从体医融合的视角提出了具有针对性的慢性病移动医疗服务系统创新策略。结论指出当代慢性病移动医疗服务系统创新策略在于整合性的动态解决方案,站在时间和空间的纬度上,将体育与医疗资源跨界整合,缓解慢性病治疗面临的资源不足、断层、同质化等问题,构建新的服务流程系统与治疗体验,为慢性病移动医疗的发展,提供一种新的解决思路与发展方向。     

In vitro and in vivo microbial adhesion and growth on argon plasma-treated silicone rubber voice prostheses

Patients who undergo a total laryngectomy usually receive a silicone rubber voice prosthesis for voice rehabilitation. Unfortunately, biofilm formation on the esophageal side of voice prostheses limits their lifetime to 3–4 mon on average. The effects of repeated argon plasma treatment of medical grade, hydrophobic silicone rubber on in vitro adhesion and growth of bacteria and yeasts isolated from voice prostheses, as well as in vivo biofilm formation are presented here. In vitro experiments demonstrated that initial microbial adhesion over a 4 h time span to plasma-treated, hydrophilized, silicone rubber was generally less than on original, hydrophobic silicone rubber, both in the absence and presence of a salivary conditioning film on the biomaterial. Growth studies over a time period of 14 d at 37°C in a modified Robbins device, showed that fewer Candida cells adhered on plasma-treated, hydrophilized silicone rubber as compared to on original, hydrophobic silicone rubber. For the in vivo evaluation of biofilm formation on plasma-treated silicone rubber voice prostheses, seven laryngectomized patients received a partly hydrophilized Groningen Button voice prosthesis for a planned evaluation period of 4 wk. After removal of the voice prostheses, the border between the hydrophilized and the original, hydrophobic side of the prostheses was clearly visible. However, biofilm formation was, unexpectedly, less on the original, hydrophobic sides, although the microbial compositions of the biofilms on both sides were not significantly different. Summarizing, this study demonstrates that in vitro microbial adhesion and growth on silicone rubber can be reduced by plasma treatment, but in vivo biofilm formation on silicone rubber voice prostheses is oppositely enhanced by hydrophilizing the silicone rubber surface. Nevertheless, from the results of this study the important conclusion can be drawn that in vivo biofilm formation on voice prostheses is controlled by the hydrophobicity of the biomaterials surface used. © 1998 Chapman & Hall     

Kalte Plasmen in der Medizin

Cold Plasmas In Medicine Cold non‐equilibrium plasma at atmospheric pressure are excellently suited to stimulate, inactivate, or influence sensitive biological systems. Physical plasma generates reactive nitrogen or oxygen species that are also present in cell signalling processes, UV‐Radiation, electric fields and charges species. Possible future plasma medical therapies lie in the inactivation of pathogens, healing of chronic wounds, support in surgical procedures or prospectively also in the support of cancer therapy in localized tumors.     

基于SpringMvc架构模式的远程居家医疗系统设计

目的基于现实意义的基础上,利用SpringMvc架构模式建立软件程序,将医疗系统中的定性问题与患有慢性病的老年人用户需求结合起来,建立比较完善的远程就医系统,通过相应的媒介,解决患有慢性病的老年人日常体检和就医困难问题。方法通过针对性人群的问卷调查分析和采集数据分析,以患有慢性病老年人的体征数据为依据,挖掘其内在需求,发现健康医疗智能设备的问题,采用慢性病数据模型分析,提出具有现实意义的远程医疗系统设计。结论通过前期调研和设计实践证实,在我国现实医疗水平和科技水平的基础上,能够实现远程居家医疗系统与现代信息物理系统技术的结合,有效解决慢性病老年人的日常看病就医问题。     

Cultivation of human keratinocytes without feeder cells on polymer carriers containing ethoxyethyl methacrylate: in vitro study

The cell/tissue engineering therapy of extensive or chronic skin wounds is a highly topical task of the contemporary medicine. One of possible therapeutic approaches is grafting of in vitro cultured keratinocytes directly to the wound bed, where the cells colonize the wound, proliferate and improve the re-epithelization process. Because the successful cultivation of keratinocytes needs an application of feeder cells, the exclusion of these cells from the cultivation system is highly required. In this study we show a positive influence of 2-ethoxyethyl methacrylate as a component of cultivation support on growth of keratinocytes without feeder cells. Keratinocytes cultured on these surfaces are able to migrate to the model wound bed in vitro, where they form distinct colonies and have a normal differentiation potential.     

Small extracellular vesicles secreted by urine-derived stem cells enhanced wound healing in aged mice by ameliorating cellular senescence

Regeneration of chronic skin wounds in tissue is still a key challenge in regenerative medicine because of the accumulation of senescent cells and increasing secretion of s¨enescence-associated secretory phenotype(SASP)in the wound site.Recently,some studies have reported that small extracellular vesicles(sEVs)derived from stem cells can alleviate cellular senescence with very low risk of tumorigenesis and immune responses.As our previous studies have shown that urine-derived stem cells(USCs)can be obtained easily and noninvasively and sEVs derived from USCs(USC-sEVs)have capabilities of regenerating tissue injuries,using USC-sEVs to enhance chronic skin wound healing in aged tissue might be a feasible and efficient strategy.Therefore,in this study,the USC-sEVs were collected and firstly loaded in a human acellular amniotic membrane(HAAM)for controlled releasing and locating the USC-sEVs in the wound site before they were implanted into a chronic skin wound in aged mice.In vivo results showed that the USC-sEVs in HAAM could effectively accelerate the wound healing by ameliorating cellular senescence and reducing the secretion of SASP in the aged skin wounds.To elucidate the mechanism,USC-sEVs were used to in vitro culture human dermal fibroblasts(HDFs)and results showed that USC-sEVs could rejuvenate senescent fibroblasts by reversing the aging phenotypes of senescent HDFs and efficiently reducing the secretion of SASP after they activated the Sirt1 pathway.Therefore,USC-sEVs are efficient for enhancing wound healing in aged mice by ameliorating cellular senescence.     

Nanotechnological approaches for the development of herbal drugs in treatment of diabetes mellitus – a critical review

Diabetes mellitus (DM) is a chronic illness that requires continuing medical care and patient self‐management education to prevent acute complications and to reduce the risk of long‐term complications. The number of people with diabetes is increasing due to population growth, ageing, urbanisation and increasing prevalence of obesity and physical inactivity. Apart from currently available therapeutic options, many herbal medicines have been recommended for the treatment of diabetes. Herbal drugs are prescribed widely because of their effectiveness, less side effects and relatively low cost. Several pharmacopoeias have provided parameters to maintain quality and standardise procedures in identification/authentication of herbal inputs and their products. Available literature related to folklore medicine used in the treatment of diabetes extended to nanoformulation of herbal drugs up to date was cited. The use of bioactive compounds leads to new hope to improve the life expectancy and health status of the population for the formulation of novel drugs. Recently, many studies have shown that nanotechnology has the potential to be used in different biological and medical applications, mainly as targeted drug delivery systems to minimise and delay the chronic effects of diabetes. Herein, the authors presented a thorough review of the available herbal medicines and the possibilities of developing their nanoformulations in the treatment of DM.Inspec keywords: drugs, drug delivery systems, nanomedicine, reviews, diseases, patient careOther keywords: nanotechnological approaches, herbal drugs, diabetes mellitus treatment, critical review, chronic illness, medical care, patient self‐management education, long‐term complications, risk reduction, ageing, urbanisation, obesity, physical inactivity, pharmacopoeias, standardise procedures, herbal inputs identification‐authentication, folklore medicine, bioactive compounds, health status, biological applications, medical applications, targeted drug delivery systems, chronic effects, herbal medicines     

Complex wounds tend to develop more rapidly in patients receiving hemodialysis because of diabetes mellitus

The number of patients requiring dialysis because of diabetes mellitus is increasing and such patients often have complex chronic wounds, which are difficult to heal. However, there are few retrospective studies of wounds requiring surgical treatment. We evaluated 14 patients receiving hemodialysis (HD) (8 because of diabetes and 6 because of other diseases) who had extremity wounds and underwent surgical treatment in our unit from 2004 through 2007. We investigated differences in the cause of wounds, and in the interval between the start of HD and wound development. Wounds in patients undergoing HD because of diabetes originated due to ischemia in 2 cases (25%), trauma in 2 cases (25%), and infection in 4 cases (50%). Seven of 8 wounds developed infection with methicillin-resistant Staphylococcus aureus (MRSA). Wounds in patients undergoing HD because of other diseases developed due to ischemia in 2 cases (33%) and trauma in 4 cases (67%). Three of 6 wounds developed infection and MRSA were isolated from 2 wounds. The interval between the start of HD and wound development was significantly shorter in patients with diabetes than in patients without diabetes. All patients with infectious wounds required immediate debridement. We conclude that patients receiving HD because of diabetes are likely to have more severe and rapidly developing wounds due to infections. Thus, they usually require immediate debridement before blood access shunt infection occurs.     

The occurrence and fate of anti-inflammatory and analgesic pharmaceuticals in sewage and fresh water: treatability by conventional and non-conventional processes

The presence of pharmaceutical (PhAC) residues in the environment is an emerging issue due to their continuous and uncontrolled release (via excretion from medical care) to the water environment and detrimental effects on aquatic organisms at low concentrations. A large fraction of PhAC pollution in water is composed of anti-inflammatory (AI) and analgesic (AN) drugs, which are rapidly excreted in urine. The present review is aimed to emphasize the occurrence of AI/AN wastes in sewage and fresh water bodies, their impacts on non-target organisms, and conversion or elimination by chemical, biochemical and physical treatment methods. The first part of the study is devoted to a critical review of most common AI/AN drugs and the relative efficiency of some selected sewage and drinking water treatment operations for their elimination/separation from aqueous systems. The second part focuses on pilot- or lab-scale applications of various advanced oxidation processes that are promising solutions to the ultimate degradation and/or conversion of such medical residues in effluents of drinking water treatment plants (DWTPs) and wastewater treatment plants (WWTPs) to less harmful and non-toxic products.     

Construction of an Artificial Intelligence Traditional Chinese Medicine Diagnosis and Treatment Model Based on Syndrome Elements and Small-Sample Data

1.Introduction The combination of traditional Chinese medicine(TCM)and Western medicine has advantages in the treatment of chronic and complex diseases,for exam...     

Combating bacterial colonization on metals via polymer coatings: relevance to marine and medical applications

Metals are widely used in engineering as well as medical applications. However, their surfaces are easily colonized by bacteria that form biofilms. Among the numerous concerns with biofilm formation, biocorrosion is of particular importance in industry, because structural integrity may be compromised, leading to technical failures. In the food industry and medical field, biofilms also pose health risks. To inhibit bacterial colonization, the surfaces of metals can be coated with a polymeric layer which is antiadhesive and/or bactericidal. This article describes polymers that have these desired properties and the methodologies for immobilizing them on metal surfaces of relevance to the marine and medical fields. The focus is on polymer coatings that have a high degree of stability in aqueous medium and do not leach out. The efficacies of the different polymer coatings against bacteria commonly encountered in marine (Desulfovibrio desulfuricans) and medical applications (Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli) are demonstrated.     

Polymeric meshes for internal sutures with differentiated adhesion on the two sides

The aim of this work is to investigate the effects of different plasma treatments on ePTFE abdominal prostheses with the final goal of obtaining a new prosthesis, made of a single strand of ePTFE, with clearly differentiated adhesion properties on the two sides, which should be able to promote tissue ingrowth on one side and prevent post surgical visceral adhesions on the other.Samples obtained from ePTFE Bard Dulex Meshes have been treated sequentially with three different gases (N₂, O₂ and NH₃) in order to choose the optimal treatment conditions to improve ePTFE wettability. In particular, no modification was induced by N₂ treatment, while the full treatment after the final ammonia gas resulted in the best suitable candidate.As demonstrated by scanning electron microscopy, AFM analyses and contact angle measurements, ammonia plasma treatment increases ePTFE surface roughness and renders it more hydrophilic, thus promoting adhesion without any alteration of the materials bulk properties.The reported results also evidence the possibility to obtain the maximum wettability with a cheap treatment by optimizing plasma exposure time.As a preliminary cell adhesion study, Swiss 3T3 fibroblasts (mouse, embryo) have been seeded on the treated and untreated materials in order to assess whether there was any difference in terms of cell attachment and spreading. Cells seeded on the ammonia plasma treated material showed a better adhesion and spreading when compared to the untreated material.     

光照世界史坛的中医起源之谜

以疫病流行及其原型分析为线索，联系早期治法（如热熨、火灸、砭刺等）探讨了古代以腺鼠疫为代表的疫病流行与医学起源间的内在联系；以医源于疫的视野分析我国医史病史研究在出土文物、古文字和医学文献等方面丰富的信息资源与优势；分析解读疾病名实的古今变迁、比较中西医学及其在认识论与方法论上的差异，为审视我国传统医学在疫病防治方面的丰富经验与延至今日的独到成就与意义，疾病史研究成果与推广，实现古为今用，将为当今疫病防治的中西互补、中西医结合与比较提供宝贵的历史经验与借鉴。     

Cold atmospheric plasma delivery for biomedical applications

As the fourth state of matter, plasma’s unique properties and interactions with other states of matter offer many promising opportunities for investigation and discovery. In particular, cold atmospheric plasma (CAP), operating at atmospheric pressure and room temperature, has remarkable potential for biomedical applications through various delivery methods. These biomedical applications include sterilization, wound healing, blood coagulation, oral/dental diseases treatment, cancer therapy, and immunotherapy. Effective delivery of plasma constituents is critical to its efficacy for these applications. Therefore, this review presents the key research activities related to CAP delivery (including direct CAP delivery, delivery of plasma-activated media, biomedical device-assisted plasma delivery, and CAP delivery with other therapeutics) and needs for future research. This review will be of great interest for understanding the current state-of-the-art of biomedical applications of plasma medicine while also giving researchers from a broad range of communities insight into research efforts that would benefit from their contributions. Such communities include biomedicine, physics, biochemistry, material science, nanotechnology, and medical device manufacturing.     

Physical properties and biocompatibility of UHMWPE-derived materials modified by synchrotron radiation

The applications of synchrotron radiation (SR) in medical imaging have become of great use, particularly in angiography, bronchography, mammography, computed tomography, and X-ray microscopy. Thanks to recently developed phase contrast imaging techniques non-destructive preclinical testing of low absorbing materials such as polymers has become possible. The focus of the present work is characterization and examination of UHMWPE-derived materials widely used in medicine, before and after their exposure to SR during such testing. Physical properties, such as wettability, surface energy, IR-spectroscopy, roughness, optical microscopy, microhardness measurements of UHMWPE samples were studied before and after SR. The relationship between a growth of UHMWPE surface hydrophilicity after SR and surface colonization by stromal cells was studied in vitro. Obtained results demonstrate that SR may be used as prospective direction to examine bulk (porous) structure of polymer materials and/or to modify polymer surface and volume for tissue engineering.     

Increased response of Vero cells to PHBV matrices treated by plasma

The copolymers poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) (PHBV) are being intensely studied as a tissue engineering substrate. It is known that poly 3-hydroxybutyric acids (PHBs) and their copolymers are quite hydrophobic polyesters. Plasma-surface modification is an effective and economical surface treatment technique for many materials and of growing interest in biomedical engineering. In this study we investigate the advantages of oxygen and nitrogen plasma treatment to modify the PHBV surface to enable the acceleration of Vero cell adhesion and proliferation. PHBV was dissolved in methylene chloride at room temperature. The PHBV membranes were modified by oxygen or nitrogen-plasma treatments using a plasma generator. The membranes were sterilized by UV irradiation for 30 min and placed in 96-well plates. Vero cells were seeded onto the membranes and their proliferation onto the matrices was also determined by cytotoxicity and cell adhesion assay. After 2, 24, 48 and 120 h of incubation, growth of fibroblasts on matrices was observed by scanning electron microscopy (SEM). The analyses of the membranes indicated that the plasma treatment decreased the contact angle and increased the surface roughness; it also changed surface morphology, and consequently, enhanced the hydrophilic behavior of PHBV polymers. SEM analysis of Vero cells adhered to PHBV treated by plasma showed that the modified surface had allowed better cell attachment, spreading and growth than the untreated membrane. This combination of surface treatment and polymer chemistry is a valuable guide to prepare an appropriate surface for tissue engineering application.     

Microalgae-Based Biohybrid Microrobot for Accelerated Diabetic Wound Healing

A variety of wound healing platforms have been proposed to alleviate the hypoxic condition and/or to modulate the immune responses for the treatment of chronic wounds in diabetes. However, these platforms with the passive diffusion of therapeutic agents through the blood clot result in the relatively low delivery efficiency into the deep wound site. Here, a microalgae-based biohybrid microrobot for accelerated diabetic wound healing is developed. The biohybrid microrobot autonomously moves at velocity of 33.3 µm s⁻¹ and generates oxygen for the alleviation of hypoxic condition. In addition, the microrobot efficiently bound with inflammatory chemokines of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) for modulating the immune responses. The enhanced penetration of microrobot is corroborated by measuring fibrin clots in biomimetic wound using microfluidic devices and the enhanced retention of microrobot is confirmed in the real wounded mouse skin tissue. After deposition on the chronic wound in diabetic mice without wound dressing, the wounds treated with microrobots are completely healed after 9 days with the significant decrease of inflammatory cytokines below 31% of the control level and the upregulated angiogenesis above 20 times of CD31⁺ cells. These results confirm the feasibility of microrobots as a next-generation platform for diabetic wound healing.     

Ferulic acid‐loaded collagen hydrolysate and polycaprolactone nanofibres for tissue engineering applications

There is a great need for the progress of composite biomaterials, which are effective for tissue engineering applications. In this work, the development of composite electrospun nanofibres based on polycaprolactone (PCL) and collagen hydrolysate (CH) loaded with ferulic acid (FA) for the treatment of chronic wounds. Response Surface Methodology (RSM) has been applied to nanofibres factor manufacturing assisted by electrospinning. For wound healing applications, the authors have created the efficacy of CH, and PCL membranes can act as a stable, protective cover for wound, enabling continuous FA release. The findings of the RSM showed a reasonably good fit with a polynomial equation of the second order which was statistically acceptable at P  < 0.05. The optimised parameters include the quantity of hydrolysate collagen, the voltage applied and the distance from tip‐to‐collector. Based on the Box–Behnken design, the RSM was used to create a mathematical model and optimise nanofibres with minimum diameter production conditions. Using FTIR, TGA and SEM, optimised nanofibres were defined. In vitro, cytocompatibility trials showed that there was an important cytocompatibility of the optimised nanofibres, which was proved by cell proliferation and cell morphology. In this research, the mixed nanofibres of PCL and CH with ferulic could be a potential biomaterial for wound healing.Inspec keywords: tissue engineering, polymer fibres, wounds, electrospinning, nanofibres, response surface methodology, cellular biophysics, proteins, molecular biophysics, scanning electron microscopy, biomedical materials, nanomedicine, nanocomposites, nanofabrication, Fourier transform infrared spectraOther keywords: wound healing applications, PCL membranes, stable cover, protective cover, continuous FA release, RSM, optimised parameters, hydrolysate collagen, mathematical model, optimised nanofibres, polycaprolactone nanofibres, tissue engineering applications, composite biomaterials, composite electrospun nanofibres, collagen hydrolysate, ferulic acid, chronic wounds, Response Surface Methodology, nanofibres factor     

Nanocapsules: coating for living cells

One of the most promising tools for future applications in science and medicine is the use of nanotechnologies. Especially self-assembly systems, e.g., polyelectrolyte (PE) capsules prepared by means of the layer-by-layer technique with tailored properties, fulfill the requirements for nano-organized systems in a satisfactory manner. The nano-organized shells are suitable as coating for living cells or artificial tissue to prevent immune response. With these shells, material can be delivered to predefined organs. In this paper, some preliminary results are presented, giving a broad overview over the possibilities to use nano-organized capsules. Based on the observations that the cells while duplicating break the capsule a mutant yeast strain (Saccharomyces cerevisiae), which express GFP-tubulin under galactose promotion, was investigated by means of confocal laser scanning microscopy. The measurements reveal an increased surface charge in the region of buds developed prior encapsulation. In order to test the used PE pair for cytotoxicity, germinating conidia of the fungi Neurospora crassa were coated. The investigation with fluorescence microscopy shows a variation in the surface charge for the growing region and the conidium poles. The capsules exhibit interesting properties as valuable tool in science and a promising candidate for application in the field of medicine.