3 Scenarios When Density of Microspheres Matters in Research

Does Density of Microspheres Matter for Fluid Suspension?

When is the density of microspheres important? Density of microspheres controls the buoyancy of each particle and its behavior in a system or process. Let’s look at three scenarios: (1) suspension of microspheres in a specific fluid, (2) fluid flow, performing flow visualizations, or particle image velocimetry, and (3) simulation or modeling of objects with specific density.

Suspension of Hydrophobic Particles in Aqueous Solution – Density Gradients

Hydrophobic Particles in Solution

Fortunately, there is a simple way to overcome the hydrophobic effect. It is called a surfactant, a detergent, or simply ?soap.? Surfactant is a magical molecule that has both hydrophobic and hydrophilic properties, which coats the particles and helps them mix into water. The same mechanism applies when we use soap to wash greasy dishes or stained clothes.

Microspheres in Drug Delivery Systems – 2 Essential Uses

Polystyrene Microspheres

Benefits of Microspheres in Drug Delivery There are numerous benefits of using microspheres in drug delivery due to their precise uniform dimensions, larger surface area per unit volume, as well as the ability to be surface-functioalized or loaded with active compounds and other additives. Typically microspheres in drug delivery are manufactured out of biodegradable materials … Read more

Negatively-charged Yellow Microparticles – Back in Stock

Cospheric’s neutrally-buoyant highly charged yellow microspheres have a strong negative charge and are used by scientists in medical technology, biotechnology, applied physics and research. Precise particles with known density of 1.0g/cc that behave in a known way are useful as a model particles in simulation experiments.? Particles in a range of diameters from 5micron to … Read more

BioCompatability of Metal Coated Spheres

For those scientists?who are looking to use silver coated materials?such as silver coated microspheres in biomedical applications, it is important to understand whether they are bio-compatable.? A selection of abstracts and article references related to the biocompatability of silver follow:

The Biocompatibility of Silver2

The experiments reported have referred to some of the characteristics of the biocompatibility of Ag. Silver has been shown to display interactions with albumin, as an example of a plasma protein, quite different from those of most metals. Such studies shed further light on the complex issue of protein adsorption on biomaterials. It has also been demonstrated that Ag at concentrations < 1 ppm exerts a considerable influence on the activity of lactate dehydrogenase, this effect being reversed in the presence of albumin. A significant but transient increase in blood levels of Ag following intramuscular implantation of the metal has been observed. This is not reflected in any raised urine level. It is proposed that the richly vascular tissue immediately surrounding the implant in the acute phase of the response gives rise to the transient increase, but a subsequent decrease in vascularity reduces this possibility. It appears that Ag released from implants following this initial period substantially remains in the local area.2

Lack of toxicologocial side-effects in silver-coated megaprostheses in humans1

Deep infection of megaprostheses remains a serious complication in orthopedic tumor surgery. Furthermore, reinfection gets a raising problem in revision surgery of patients suffering from infections associated with primary endoprosthetic replacement of the knee and hip joint. These patients will need many revision surgeries and in some cases even an amputation is inevitable. Silver-coated medical devices proved their effectiveness on reducing infections, but toxic side-effects concerning some silver applications have been described as well. Our study reports about a silver-coated megaprosthesis for the first time and can exclude side-effects of silver-coated orthopedic implants in humans. The silver-levels in the blood did not exceed 56.4 parts per billion (ppb) and can be considered as non-toxic. Additionally we could exclude significant changes in liver and kidney functions measured by laboratory values. Histopathologic examination of the periprosthetic environment in two patients showed no signs of foreign body granulomas or chronic inflammation, despite distant effective silver concentrations up to 1626 ppb directly related to the prosthetic surface. In conclusion the silver-coated megaprosthesis allowed a release of silver without showing any local or systemic side-effects.1

Specific Article?References for the biocompatability of silver are below:

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Microspheres in Medical Devices – MDDI Magazine

What are Microspheres?

The Microsphere of Influence

Published on MDDI Magazine
By: Yelena Lipovetskaya

Why Use Microspheres in Medical Devices?

Properties of Microspheres - Composition
Microspheres in Medical Devices

Microspheres are round microparticles that typically range from 1 to 1000 micron in diameter. Benefits of microspheres in medical devices, pharmaceuticals, and cosmetics are well known due to the microspheres’ ability to encapsulate and deliver active materials. However, there are many other lesser known advantages and functionalities of using micropsheres in medical device design, quality control, manufacturing, and testing.

The typical manufacturing process involves the microencapsulation of a drug or an active cosmetic ingredient to protect it from the deteriorating effects of the environment or for optimal release and performance in the final product. Active ingredients are released by dissolution of the capsule walls, mechanical rupture (rubbing, pressure, or impact), melting, or digestion processes. The resulting particles are often called microcapsules, which are different from solid, non-deformable microspheres.

Solid microspheres are widely used as fillers and spacers in a variety of industries. Microspheres that are used to manufacture and test medical devices are typically solid particles that are made from robust and stable raw materials such as polymers, glass, and in some cases, ceramics. Different types and grades of microspheres are available and selected based on specific application requirements.

Solid microspheres in medical devices are often used as tracers and challenge particles. In these situations, it is beneficial to use larger microspheres with sphere diameters greater than 50 micron that are vividly colored (red, blue, black, yellow, or green), since they provide contrast with the background material and visibility to the naked eye in daylight.

Colored microspheres are typically used in the testing of filtration media and systems, vial and container cleaning evaluations, flow tracing and fluid mechanics, centrifugation and sedimentation processes, pharmaceutical manufacturing, and contamination control.

Fluorescent microspheres are recommended for applications that require the use of particles that emit distinctive colors when illuminated by UV light and offer additional sensitivity for observation through the use of microscopes, lasers, and other analytical methods. Examples include microcirculation and biological research, imaging, and flow cytometry. Fluorescent microspheres can be excited and detected by a wide range of methods and are useful as experimental particles for acoustical and optical analytical systems.

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Technical Properties of PMMA Microspheres

PMMA Microspheres - Technical Specifications

In this article we will discuss the applications and technical properties of PMMA microspheres. What are PMMA Microspheres? PMMA micropsheres are also known as Poly(methyl methacrylate) or acrylic microspheres. PMMA, an ester of methacrylic acid (CH2=C[CH3]CO2H), is a synthetic resin produced from the polymerization of methyl methacrylate. Ever since PMMA resin was discovered and first … Read more

Fluorescent Tracer Microspheres – Properties and Applications

Fluorescent Tracer Particles

Fluorescent microspheres are round spherical particles that emit bright colors when illuminated by UV light. Ability to emit intense color under UV (black light) illumination provides contrast and visibility of microspheres relative to background materials.