BACKGROUND: Blood typing is an essential test for transfusion. Generally, blood typing is performed using a slide test, tube test or microcolumn agglutination test. The aims of this study were to develop a new blood typing kit using micromachining, microfluidics and microseparation methods, and to evaluate the clinical usefulness of the new blood typing kit. METHODS: We designed and manufactured a blood typing microchip using polydimethylsiloxane (PDMS), which contained a microchannel (25~200 micrometer). The blood sample and antisera to be tested were dropped on the microwell for movement and mixing by capillary action. Once agglutination occurred, the microchannel acts as a filter and the blood type was determined by observation by the naked eye. To evaluate the newtyping kit, we tested sensitivity using artificially diluted blood and compared the results of the new typing method with the slide and tube methods using 70 samples. RESULTS: The new blood typing kit could differentiate a +4~+2 agglutination reaction, but could not detect a +1 agglutination reaction as observed by the naked eye. Among 70 samples, the results of ABO and Rh typing by the new typing method (n=66, > or = +2 agglutination reaction by the column agglutination method) were in accord with the results of the tube and slide methods, but couldnot detect agglutination in all 4 clinical samples, below a +1 agglutination reaction. CONCLUSION: The new blood typing kit is inadequate for routine use in the clinical laboratory due to low sensitivity, but with further improvement, it can be used economically, conveniently and objectively for blood typing without any special equipment. Moreover, the microfludics and separation method may be broadly applicable in other tests using the hemagglutination method.
Agglutination ; Agglutination Tests ; Blood Grouping and Crossmatching* ; Capillary Action ; Hemagglutination ; Immune Sera ; Microfluidics* ; Microtechnology

From the perspective of Regenerative Medicine, the tissue generated in vitro can imitate the physiological and pathological tissue to a certain extent. However, the structures and functions of the in vitro tissue are very simple so that research on in vitro self-assembling and imitating of tissue development is necessary. The development of Nanotechnology and the technology of micro-structure makes the in vitro tissue assembling possible. As previous studies showed that, besides genetic material, tissue architecture and its micro-environment are closely related to morphogenesis of in vitro tissue. Thus, how to design and assemble microstructure to make the tissue molding still requires effort. How to predict and control the development mechanism in vitro is also a question needed to be resolved. In this essay, we reviewed the mechanism of assembling and imitating of in vitro tissue based on the theory of physics, biology and systemic integrated structure.
Animals ; Computer Simulation ; Humans ; Microtechnology ; methods ; Nanostructures ; chemistry ; Regenerative Medicine ; methods ; Tissue Engineering ; methods

A sub-microsecond pulse generation applied for electroporation effects of tumor cell is presented in this paper. The principle of the generator is that the expected pulse waveform is intercepted from the RC discharge curve by controlling the on-off states of two IGBT modules with a synchronous controller. Experimental tests indicate that the generator can produce adjustable pulse waveform parameters with 0.5-3.5kV amplitude, 300-800 ns pulse duration, 1-400Hz repetition frequency rate, and it is suitable for the study of the electroporation effect experiments.
Animals ; Cell Line, Tumor ; Cell Membrane ; Electricity ; Electroporation ; instrumentation ; methods ; Equipment Design ; Microtechnology ; instrumentation ; Neoplasms ; ultrastructure

PURPOSE: The spreading, orientation, and chemotaxis with the gradient of a chemoattractant of smooth muscle cells (SMCs) were studied on the micro-grooved substrata by the light, fluorescence and scanning electron microscopy. METHOD: Vertical-walled grooves were produced in silicon wafers by the micromachining technique. All grooves were 4~20micrometer deep and 10~80 micrometer wide. SMCs were cultured on each microgroove and examined under stereo-microscope. RESULT: Cell clusters were markedly oriented by all the grooved substrata examined. Time-lapse images acquired from CCD (Charge Coupled Device) showed that the grooves directed the migration of SMCs. There was no prominent difference in the migration speed of SMCs according to the grooves. All the cytoskeletal fibers were reorganized in the same direction with grooves. Especially the alignments of microtubule and intermediate filaments were distinguished in the SMCs on the micro grooves. CONCLUSION: These results could be applied to the analysis of vascular restenosis and the development of artificial blood vessels.
Blood Substitutes ; Chemotaxis ; Fluorescence ; Intermediate Filaments ; Microscopy, Electron, Scanning ; Microtechnology ; Microtubules ; Muscle, Smooth* ; Myocytes, Smooth Muscle* ; Silicon

BACKGROUND: Latest tissue engineering strategies for musculoskeletal tissues regeneration focus on creating a biomimetic microenvironment closely resembling the natural topology of extracellular matrix. This paper presents a novel musculoskeletal tissue scaffold fabricated by hybrid additive manufacturing method. METHODS: The skeleton of the scaffold was 3D printed by fused deposition modeling, and a layer of random or aligned polycaprolactone nanofibers were embedded between two frames. A parametric study was performed to investigate the effects of process parameters on nanofiber morphology. A compression test was performed to study the mechanical properties of the scaffold. Human fibroblast cells were cultured in the scaffold for 7 days to evaluate the effect of scaffold microstructure on cell growth. RESULTS: The tip-to-collector distance showed a positive correlation with the fiber alignment, and the electrospinning time showed a negative correlation with the fiber density. With reinforced nanofibers, the hybrid scaffold demonstrated superior compression strength compared to conventional 3D-printed scaffold. The hybrid scaffold with aligned nanofibers led to higher cell attachment and proliferation rates, and a directional cell organization. In addition, there was a nonlinear relationship between the fiber diameter/density and the cell actinfilament density. CONCLUSION: This hybrid biofabrication process can be established as a highly efficient and scalable platform to fabricate biomimetic scaffolds with patterned fibrous microstructure, and will facilitate future development of clinical solutions for musculoskeletal tissue regeneration.
Biomimetics ; Extracellular Matrix ; Fibroblasts ; Humans ; Methods ; Microtechnology ; Nanofibers ; Printing, Three-Dimensional ; Regeneration ; Skeleton ; Tissue Engineering ; Tissue Scaffolds

The loss of urinary bladder control/sensation, also known as urinary incontinence (UI), is a common clinical problem in autistic children, diabetics, and the elderly. UI not only causes discomfort for patients but may also lead to kidney failure, infections, and even death. The increase of bladder urine volume/pressure above normal ranges without sensation of UI patients necessitates the need for bladder sensors. Currently, a catheter-based sensor is introduced directly through the urethra into the bladder to measure pressure variations. Unfortunately, this method is inaccurate because measurement is affected by disturbances in catheter lines as well as delays in response time owing to the inertia of urine inside the bladder. Moreover, this technique can cause infection during prolonged use; hence, it is only suitable for short-term measurement. Development of discrete wireless implantable sensors to measure bladder volume/pressure would allow for long-term monitoring within the bladder, while maintaining the patient's quality of life. With the recent advances in microfabrication, the size of implantable bladder sensors has been significantly reduced. However, microfabricated sensors face hostility from the bladder environment and require surgical intervention for implantation inside the bladder. Here, we explore the various types of implantable bladder sensors and current efforts to solve issues like hermeticity, biocompatibility, drift, telemetry, power, and compatibility issues with popular imaging tools such as computed tomography and magnetic resonance imaging. We also discuss some possible improvements/emerging trends in the design of an implantable bladder sensor.
Aged ; Biocompatible Materials ; Catheters ; Child ; Hostility ; Humans ; Magnetic Resonance Imaging ; Microtechnology ; Quality of Life ; Reaction Time ; Reference Values ; Renal Insufficiency ; Sensation ; Telemetry ; Urethra ; Urinary Bladder* ; Urinary Incontinence

Porous surfaces have an important effect on bioactivity of titanium implants. In this study, two micro/nanostructural titanium surfaces were prepared by chemical and electrochemical method. The two samples had different diameters of nanotubes. Tests of biomineralization and codeposition in simulated body fluid and bovine serum albumin (BSA) were carried out in order to evaluate the bioactivity of micro/nanostructural titanium surfaces. The information of the surfaces was detected using scanning electron microscope and X-ray diffractometer. The results showed that the bioactivity of micro/nanostructural titanium increased with the diameter of nanotubes. Furthermore, the existence of BSA can accelerate biomineralization and decrease the crystallinity of hydroxyapatite coating.
Biocompatible Materials ; Coated Materials, Biocompatible ; chemistry ; Materials Testing ; Microscopy, Electron, Scanning ; Microtechnology ; Nanostructures ; chemistry ; Porosity ; Prostheses and Implants ; Surface Properties ; Titanium ; chemistry

Since microdroplets are able to be generated rapidly in large amount and each droplet can be well controlled as an independent micro-cultivator, droplet microfluidic technology can be potentially used in the culture of microorganisms, and provide the microbial culture with high throughput manner. But its application mostly stays in the laboratory-level building and using for scientific research, and the wide use of droplet microfluidics in microbial technology has been limited by the key problems that the operation for microdroplets needs high technical requirements with wide affecting factors and the difficulties in integration of automatic microdroplet instrumentation. In this study, by realizing and integrating the complicated operations of droplet generation, cultivation, detection, splitting, fusion and sorting, we design a miniaturized, fully automated and high-throughput microbial microdroplet culture system (MMC). The MMC can be widely used in microbial growth curve test, laboratory adaptive evolution, single factor and multi-level analysis of microbial culture, metabolite detection and so on, and provide a powerful instrument platform for customized microbial evolution and screening aiming at efficient strain engineering.
Industrial Development ; Microfluidics

Paper-based analytical devices are fluidic chips fabricated with extremely inexpensive materials, namely paper, thereby allowing their use as a zero-cost analytical device in third-world countries that lack access to expensive diagnostic infrastructures. The aim of this review is to discuss: (1) microfluidic paper-based analytical devices (microPADs) for quantitative analysis, (2) fabrication of two- or three-dimensional microPADs, (3) analytical methods of microPADs, and (4) our opinions regarding the future applications of microPADs for quantitative urinalysis.
Developing Countries ; Methods ; Microfluidics ; Urinalysis*

Microalgae are a group of photosynthetic microorganisms, which have the general characteristics of plants such as photosynthesis, and some species have the ability of movement which resembles animals. Recently, it was reported that microalgae cells can be engineered to precisely deliver medicine-particles and other goods in microfluidic chips. These studies showed great application potential in biomedical treatment and pharmacodynamic analysis, which have become one of the current research hotspots. However, these developments have been rarely reviewed. Here, we summarized the advances in manageable movement exemplified by a model microalgae Chlamydomonas reinhardtii based on its characteristics of chemotaxis, phototaxis, and magnetotaxis. The bottlenecks and prospects in the application of microalgae-based tactic movement were also discussed. This review might be useful for rational design and modification of microalgal manageable movement to achieve targeted transport in medical and other fields.
Chlamydomonas reinhardtii ; Microalgae ; Microfluidics ; Photosynthesis