Mebiol® Gel Frequently Asked Questions

 

Questions regarding Physical Properties of Mebiol Gel®
Questions regarding Mebiol Gel® and compatible cell types
Other Questions

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Questions regarding Physical Properties of Mebiol Gel®

Question	When the temperature is above 37°C (or even higher up to 60°C) , what happens to the gel?
Answer	The gel becomes harder as temperature elevates

Question	What is the phase state of the sol/gel/hydrogel at the temp between 0°C to 60°C? What is the temp range can the gel phase reversible?
Answer	0°C-15°C:　Sol 15°C-20°C: Intermediate of sol and gel 20°C:　Temperature transition point Over 20°C:　Gel Over 37°C: The gel becomes harder as temperature elevates.

Question	How are the Carbon Dioxide gas and nutrients supplied to cells? Can they dissolve into the cells at hydrogel state?
Answer	Nutrition and CO2 enter cells by diffusion in the gel from a multilayer nutrient medium.

Question	How is the structure strength of the gel at the temp 37°C?
Answer	Please see the following paper. Yoshioka H et al, A Synthetic Hydrogel with Thermoreversible Galation and Rheological Properties, Journal of Macromolecular Science, Part A: Pure and Applied Chemistry Volume 31, Issue 1, 1994

Question	Are there some holes in the hydrogel?
Answer	There is no gap or hole in the hydrogel.

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Question	Is the gel permeable of CO2, N2 and O2?
Answer	Yes, the gel is permeable of CO2, N2 and O2.

Question	When Mebiol Gel® is in the gel state, cells will be surrounded by hydrogel. Is there enough space for cell growth?
Answer	Mebiol Gel®'s cross-linked points are reversible even in it's gel state (i.e 37°C). The surrounding gel can change shape in accordance with the cell growth without any gap/spaces.

Question	How long does it take for Mebiol Gel® to become a gel form from solution when in appropriate temperature?
Answer	3 msec

Question	How many times can we repeat switching sol-gel state?
Answer	The sol - gel switch can be repeated until Mebiol gel is broken down chemically. The limit of sol - gel repeat depends on the temperature or the oxygen density after dilution. Normally, it is stable for 1-2 months if stored in refrigerator. For longer storage, keep dispensed liquid under -20°C to -80°C in multi-well plate.

Question	How much molecular weight of nutrient can go from top into the gel? And what is the relevance between the distant and molecular weight?
Answer	The biggest particle size which can diffuse through the 37℃ gel should be sized around molecular weight of around 10,000‐90,000 (the exact size unknown). Particle sizes with molecular weights in their thousands, i.e 1,000‐9,000 don't have a problem diffusing through the gel, but when it gets bigger than this, there are problems. If the molecular size is smaller, diffusive distance will be longer.

Question

I would like to know the porosity of the gel at cell culture conditions (37°C).

Answer

Unfortunately, there isn't any data for gel porosity. However, we have information about "gel diffusive speed in different materials" in the Discussion section of the following paper. Takao et al., Novel drug delivery system using thermoreversible gelation polymer for malignant glioma Journal of Neuro-Oncology (2005) Generally, when the gel concentration is low, gel "diffusive speed" in materials is high. It means when the gel concentration is low, gel porosity is thought to be high. However, it doesn't become gel when the gel concentration is low like 5%.

Question	What is the minimum gelling wt% of Mebiol Gel®.
Answer	The minimum concentration for gelling is around 7 wt%. We recommend that adding 1g of polymer into 10 g medium. This will make a concentration of 9 wt%.

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Questions regarding Mebiol Gel® and compatible cell types

Question	Can we exchange the medium when cell growing at 37°C?
Answer	The gel doesn't dissolve in excessive water at 37°C. Thus, you can layer medium on the gel. And you can exchange this layered medium.

Question	Do cells experience any resistance when cells grow in contact with the edge of the hydrogel?
Answer	No

Question	Is the gel suitable for culturing of T cells or MSC Cells?
Answer	We do not have any data or experience culturing T cells in Mebiol Gel®. Regarding MSC cells, please refer to the following paper Yuguo Lei et al., PNAS PLUS E5039E5048 doi: 10.1073/pnas.1309408110

Question	Which kind of cells have been successfuly cultured with Mebiol Gel®?
Answer	Please refer to our references and citations list to see published papers using Mebiol Gel® to culture cells.

Question	Can you use this gel to culture human lung epithelial cells? Do you have data for this?
Answer	No, unfortunately we do not have any data available.

Question	Has Mebiol Gel® been used to culture intestinal cells? Is there any data available?
Answer	No, unfortunately we do not have any data available.

Question	Is there any damage to cells when they are harvested (in solution state)?
Answer	No

Question	Can Mebiol Gel® be used for FACS (Flow Cytometry)? Which state does the Gel have to be in?
Answer	Yes, it can be used for FACS in its Sol state (low temperature).

Question

Can Mebiol Gel® be used in vivo? How long can it remain inside a mouse?

Answer

Yes, it can be used in vivo (not for human). Mebiol remained in rat brain for more than 28 days as a gel form. You can refer to the following paper for further information. T. Ozeki, K. Hashizawa, D. Kaneko, Y. Imai, H. Okada, “Treatment of rat brain tumors using sustained-release of camptothecin from poly(lactic-co-glycolic acid) microspheres in a thermoreversible hydrogel”, Chem. Pharm. Bull. 58 (9), 1142-1147 (2010)

Question	Can Mebiol Gel® be toxic to certain types of cells? If so, which types of cells would that be?
Answer	Mebiol Gel® is non-toxic to cells.

Question	Is there any data for Mebiol Gel® with Thyroid cells (normal or cancer)?
Answer	Yes, there is. Please refer to the following: Production of hepatitis C viruses (HCV) by 3-D culture of human hepatocyte cell line・ “Production of infectious hepatitis C virus particles in three-dimensional cultures of the cell line carrying the genome-length dicistronic viral RNA of genotype 1b“ Virology, 351 (2), 381-392 (2006)

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Other Questions

Question	Can the Mebiol Gel powder be stored at the room temp?
Answer	Yes, Mebiol Gel (powder) should be stored at RT.

Question	How long is the shelf life of Mebiol Gel®?
Answer	Expiry date is 1 year after date shipped

Question	I have some remaining gel after using a portion of it. How long can the remaining gel be stored at refrigeration?
Answer	Roughly 1 month. For longer desired storage, freeze at -20°C or -80°C.

Question	I am interested in trying out Mebiol Gel® for my first time. Could I have a sample for Mebiol Gel®?
Answer	We are sorry, we do not provide samples for Mebiol Gel®.

Question	How is Mebiol Gel® sterilized? Is there a possibility that there are some living organisms in the gel?
Answer	By EOG sterilization. There should not be any living organisms in the gel.

Question	What size flask is used for the 10ml and 50ml Mebiol Gel® product?
Answer	T-25 and T-75 Flask is used, respectively.

Question	Can I reconstitute it at 20% instead of 10% for stock storage? I would like to be able to dilute it later with a different type of medium.
Answer	There is no problem to reconstitute it at 20% instead of 10% for stock storage. However, please note that 20% high-concentration reconstitution has a high degree of viscosity and has low flowability even under low temperature.

Question	Mebiol Gel® (MBG-PMW20-1001) is said to be dissolved in 10ml culture media. Can it be dissolved in bigger volume of culture media?
Answer	We usually recommend 10ml of Mebiol to be dissolved in 10ml of culture medium. (when you would like to dissolve 50ml of MebiolGel, you should add 50ml of culture medium) If you make low concentration of MebiooGel solution, the solution cannot be gel state. For example, it is difficult to make gel sate if you dissolve 10ml MebiolGel into 20ml culture medium.

Question	How many grams of Mebiol Gel® are there in each container?
Answer	As for 10ml of dilution use, there is 1.0g Mebiol Gel®. As for 50ml of dilution use, there is 5.0g Mebiol Gel®.

Question	What is the Pink Tablet?
Answer	It is oxygen detection agent. And Oxygen and Moisture Absorbent that is also supplied with with Mebiol Gel®. They are not parts of the product.

Question	How many grams of Mebiol Gel® are there in each container?
Answer	As for 10ml of dilution use, there is 1.0g Mebiol Gel®. As for 50ml of dilution use, there is 5.0g Mebiol Gel®.
Question	What the highest concentration you can make mebiol gel?
Answer	Approximately 15wt% is the highest concentration.Viscosity is too high at 20wt% even at low temperature and can not be used.

To be used for research only. DO NOT use for human gene therapy or clinical diagnosis.