Biomedical Technology - Science topic

It is necessary to improve the systems of controlling children's use of various technological innovations. It is necessary to improve parental control systems and on the part of teachers. Of course, new information technologies are also very helpful in education processes, but the use of smartphones and laptops by children should not dominate everyday life. Unfortunately, e-learning, which was developed during the SARS-CoV-2 (Covid-19) coronavirus pandemic, meant that children and adolescents spend much more time using laptops, smartphones through which they use the Internet a lot, browsing social networking sites and playing computer games.

Best wishes,

Dariusz Prokopowicz

Dear Khushwant Singh many thanks for your very interesting technical question. It is well established that a variety of other metal complexes exhibit high cytotoxicity against cancer cells, including complexes of gallium, tin, titanium, palladium, gold etc. However, most of these have been studied only in a single lab, while cis-platin has undergone all clinical trials and has been approved as anti-cancer metallodrug. There are various useful articles available in which potential alternatives are described. However, most of them are still awaiting clinical trials. For more information about this issue please have a look at the following relevant articles:

1. Anticancer Applications and Recent Investigations of Metallodrugs Based on Gallium, Tin and Titanium

This review article has been published Open Access (see attached pdf file)

2. Palladium-Based Anti-Cancer Therapeutics

3. Novel Metals and Metal Complexes as Platforms for Cancer Therapy

and various others.

Myles Joshua Toledo Tan dear, I don't think medical students need to study math or physics as they already has to acquire a good basics on them to qualify for the admission test. In MBBS level they have to cover a vast and extensive curriculum. If you want to add something to them you can add--English language, Behavioral science and Psychology.

Thanks to Mohamad -Hani Temsah for your response.

We usually use 100 mM CaCl2 and 1.5% alginate (Pronova UPLVG) for cell encapsulation. The particles are stable without any need of further coating. Critical points may be the lenth of alginate chains you are using (low, medium, hi viscosity), the impurities (you'd better use ultrapure alginate), the Mannuronic/Guluronic acid monomers ration (the higher content in G, the higher strength), the medium where you dissolve the alginate, the inclusion of other ions on your hardening solution... It is of great importance what Evi Lippens points out. The gellation is based on ion exchange, so if you transfere your beads to any medium or buffer w/o Ca++, your beads will desappear rapidly. Make sure also all your solutions maintain a suitable tonicity and pH.

Final comment

The questions of risk associated with tissue engineering have recently been discussed in detail by a committee of the European Commission, culminating in a report on this subject¹⁴. The following is a summary of the main issues.

The basis of the report is the perception of the need for a careful analysis of the risk-benefit equation whenever a new concept of medical therapy is introduced into health care practice, such that this analysis can inform the development of regulatory control and clinical experimentation.

It is, of course, necessary to put this into perspective. Tissue engineering does not carry the same level of risk as xenotransplantation since the risks are confined to the patients themselves and not to the community at large, as may be the case when live, potentially infectious animal cells are used. It may also be argued that tissue engineering could be associated with less risk than conventional medical devices or medicinal products, since the latter are mass-produced and the hazards related to defective products or unforeseen mechanisms can affect thousands of patients. Tissue engineering is essentially a customized process that, although involving some commercial components, is directed towards individual patients, minimizing the scale of the hazard.

On the other hand, tissue engineering, as with cell and gene therapy, involves the manipulation of live cells and the interaction of these cells with substrates and biomolecules in unusual circumstances, leading to the possibilities of contamination, process errors, and as yet unknown cell-substrate interactions that could have serious consequences. The analysis of risks and benefits has to take into account the fact that some applications carry very high risks for the patient but address immensely important clinical conditions, while others are aimed at non-life-threatening conditions for which there are already adequate treatment methods available. In other words, both risks and benefits vary considerably. The nature of these risks to patients may be enumerated and summarized as follows:

Microbiological contamination associated with source materials, including the possibility of latent viruses, which may give rise to infectious diseases. This may have to be addressed by the exclusion of certain types of donor for allogeneic products and the archiving of source material will be important.

Disease transmission, where some disease states such as cancer, blood disorders, and genetic conditions will have to be considered.

Contamination associated with the production process, generally of low risk and addressed by standard operating procedures and quality systems.

The delivery of unwanted cells, especially in coculture situations, resulting in ineffective products.

The risk of mix-ups, especially with the use of autologous cells and the delivery of the resulting tissue to the wrong recipient.

Risks associated with the modification of cells during the processes of cell amplification or differentiation, especially those involving genetic manipulation.

Risks inherently associated with the scaffold and with as yet unknown cell-scaffold interactions. It has to be said here that the development of scaffold materials has tended to follow on from the applications of materials in implantable medical devices, which is not necessarily the best approach. There are still many risks of underachievement with respect to the quality of regenerated tissue because of failures to understand the specific biocompatibility requirements of tissue engineering scaffolds¹⁵.

Risks associated with the achievement of sterility of the final product, which may be a complex combination of cells, materials, and biologically active agents.

Risks associated with the potential toxicity of cryopreservatives, process additives, and other residues, as well as patient-specific responses such as allergies to antibiotics or other substances.

Risks associated with the performance of the final product. There are risks that the regeneration process may not yield tissue with adequate mechanical or physical properties, which could result in life-threatening situations, for example with tissue-engineered blood vessels or valves.

The combination of risks identified above contributes to the uncertainty that currently exists with respect to the commercial and clinical exploitation of tissue engineering. It should be noted that, during the last decade, a number of companies have been formed with the objective of commercializing tissue engineering and at one time investment in these companies looked attractive. However, that tide has profoundly turned and there have been a number of high profile bankruptcies and changes in company positions over the last few years, with little hope of recovering initial investments. Two fundamental issues are at play here¹⁶. On the one hand, the research and development costs are extremely high. On the other, there is little prospect of these companies being able to sell their products and processes for a reasonable sum. Even when they are in the market, the treatments are usually labeled ‘investigational’ or ‘experimental’, which means that the treatments may not be reimbursable under most insurance schemes. The question arises as to whether tissue engineering will ever be deemed cost effective. It is likely, for example, that the cost of treating diabetic foot ulcers through a tissue engineering approach will run into the tens of thousands of dollars. The cost of alternative treatments, i.e. keeping the wound clean and applying wound dressings, may amount to a few dollars per week. We have, therefore, a situation in which the costs of the development of tissue engineering and regenerative medicine will have pharmaceutical dimensions, but with rewards that will be similar to those associated with the conventional medical devices they are replacing. The dilemma is easy to see. The solutions lie within a complex array of technological, political, and socio-economic factors, the evolution of and interaction between which will be interesting to watch over the next few years.

You can use http://sfepy.org/dicom2fem/ to generate FE meshes from CT scans. It is an application for semi-automated segmentation base on the graph-cuts method. I think that HU data are not sufficient to determine the bone mechanical properties because they usually depend on a bone internal structure.

Dear Sunita Mehta,

When you say substrates used for cell growth in tissue engineering, are you asking for substrates used to expand cells before seeding them on a scaffold or are you asking about typical materials used for preparing scaffolds?

Very briefly.

Typically, T flasks are used (attached link) for cell expansion, which are made of polystyrene with a treated bottom surface to allow cell adherence.

Regarding substrate culture conditions, there are 2 types of cells: adherent (the big majority) and non-adherent. The first group of cells does not survive if they do not have a surface that allows them to adhere. This big group of different cell types has proteins on their membrane called cell adhesion molecules that allows them to anchor to the substrate (if it is compatible). The nutrients that they consume are provided by the culture medium you add to the flask, there are many kinds, and it should be also compatible with the cell type being cultured.

Regarding materials used to produce scaffolds, there are many to say the least, from natural to synthetic origin, from hydrogels to ceramics...

I wish I could help you more, but you have to be more specific. I advise you to get a book on tissue engineering and start from there.

Best regards and the best of luck with your research,

Sebastião van Uden

The original SBF solution, which can be named c-SBF, is a TRIS-HCl pH-buffered solution (pH = 7.40 at 37 ºC) that can be prepared as indicated at Table 5.1 (p. 206) of the following reference: 

Hi Andishe!

The precise value remains unknown to me. However, I found a good reference illustrating how to perform that procedure (clic the link above)

I hope it helps (please upvote if it did)

Best!

I am not sure if the electric field has effect on PH. But if you consider that PH is actually the availability of the H+ ions its safe to assume that there would be certain effect from the electric fields. 

but more importantly there is constant supply of C02 in the incubator that also acts like a buffer and maintain PH, unless you are using a different buffering approach than the carbonate buffering system. 

A health educator who specializes in patient education needs to understand biomedical technology but is not a specialist in biomedical technology.  Public health educators use educational, behavioral and social science to design programs to improve the health of the population.   Medical devices are used to improve the health of an individual patient.  I am puzzled how you expect to combine the two.

Of course it depends on the kind of drug and the kind of carrier you are using, but I won't be that alarmed... It is rare to see high entrapment efficiency, and I think I would not be too far from reality saying that achieving a 5-6% EE is considered a success by most of us working in the field.

Don't despair, though. Sometimes it is not necessary to have an extremely high EE as long as the delivery is successful.

Yes right its a good point; its difficult to specifically tag a phosphorylated protein, but not its unphosphorylated counterpart (if I understand correctly your problem). 

One solution that I would maybe investigate is to try to use a mutant with an acidic amino acid in place of the phosphorylated residue to try mimicking the phosphate:

Lets say that you protein is phosphorylated on a serine or a threonine, you could mutate that residue for an aspartate or glutamate and fused this mutated protein to a YFP or GFP and transfect in your cell of interest and see if its transfer to the second cell. A good negative control would then be the Wt or a mutant in which the phosphorylated residue would be mutated for an unphosphorylable amino acid such as an alanine for serine or threonine or phenylalanine for tyrosine. The comparison of the localization of the three variant of your protein of interest could be helpful to adress the question you are raising.

NAL has evaluated Bernafon's Symbio, which uses a FIR filter bank and a processing strategy that operates in the time-domain, against four advanced hearing aids of the time that used the traditional multiple channels and FFT signal processing. The following paper does not high-light the difference in processing strategies but presents the subjective and objective results of the evaluation: Dillon H, Keidser G, O’Brien, A, Silberstein H. (2003). Sound quality comparisons of advanced hearing aids. Hearing Journal 56(4):30-40.

The radiation must be causing the material to expand. Often radiolysis of polymers can result in the decomposition and the production of gases that might exert a force on the polymer causing it to expand. This would be seen in XRD as a shift to smaller theta values. The peaks might broaden slightly as well. 

In the last 70 years or so, the longevity of life has exponentially  increased,  thanks to the developments in the medical science. Any research of this type is a must for sustainability, and we must provide for this social expenditure happily. Otherwise, society will stagnate. Especially, developing countries have to resolve these dilemmas--whether to focus on uplifting people out of more manifest problems or spending more on research so that it helps us  remain a modern and progressive nation. These are always difficult decisions, and which way to go depends upon so many considerations.

To preciptiate proteins within a sucrose-containing fraction I use methanol/chloroform precipitation. Then no sucrose will co-precipitate with the proteins.

150µL fraction + 600µL methanol. MIX. Add 150µL chloroform. VORTEX. Add 450µL water. VORTEX. Spinn maxspeed (eg. 14000xg) 5min. A white disc of proteins is formed between the organic and the aqueous phases - remove upper phase. Add 650µL methanol. INVERT tubes 3 times. Spinn maxspeed 5min. Remove solvent. Protein precipitate as a pellet.

My reference: http://www.mitosciences.com/PDF/sg.pdf