[Music] hi welcome to this particular module and we'll be learning in this module what our tissue and cell culture techniques so it's very important because for our course electronic system for cancer diagnosis we need to understand how the cancer occurs in in a human body right and what exactly a cancer is so when you will understand in detail about Xillia cancer is you will find that it is nothing but a group of cells dividing unevenly and that causes the problem in the human body all right so when we talk about cell dividing unevenly what exactly we mean right and how you are culturing those cells how to culture within the body so what is the environment within the body and how we are how these cells accumulate together to form our tissues how tissue sacrament together to form an organ right so let us see today what our cell means and then few cell culture techniques or you can set the super-g techniques when there is a culturing that means that your culturing in the laboratory alright so there are several terms that we'll be learning today one of those terms is called in vivo techniques the another one is called ex vivo techniques and the final one is called in vitro techniques so we will learn how those techniques are and how we can take advantage of the existing cell and tissue culture to learn about the progression of cancer and to learn about how we can design electronic system if we want to address the problem which are tissue related cancers all right so with that particular goal let us start over this particular module and like I said we are here interested in understanding tissue and cell culture techniques so when you talk about tissue and cell culture techniques it's a combination of engineering it's combination of biology is a combination of medicine okay so when you talk about engineering and biology and medicine that combination it's very interesting because you can talk about cell engineering you can talk about bioreactor you can talk about how to monitor and control you can understand what is cell stability and selection you can understand what exactly a tissue engineering means and then you can understand how you can design therapeutics and diagnostics devices if you know all three things if you link all three things together all right so finally understanding about biology and medicine will help us to design a novel electronic systems for for curing or for diagnosing cancer that is the idea right now that's why we are understanding this as a introductory class so that we understand how the cell looks like how the tissue looks like and how can we take how can we fabricate devices fabricate microchips fabricate electronic systems or integrate electronic systems all together to understand the tissue properties so if you see the the where exactly the cell originated in nineteen in 1665 a Robert Hooke used a microscope to examine a thin slice of cork dead plant cells and what he saw looked like small boxes you can see here right in this particular image it looks like small boxes placed together isn't it and at that time the the monk used to live in in a small area which is very similar to this kind of boxes and they used to call them cells and that's how hook came up with the naming of these small boxes as cells as they look like the small rooms that monks lived all right so that's how the name originated when you look at the details of the of a single cell what you will find you will find a micro filaments inside the cells you can find centriole you can find a nucleus you can understand ribosomes there are lysosome there is Golgi apparatus there is endoplasmic reticulum right there is macro country on there is smooth endoplasmic reticulum so lot of structure formulates herself all right the the interesting is the nucleus how we will know if I if I take the number of cells let's say if I take number of cells and I place on the glass slide how do you know whether all these dot looking structures our cells are not right suppose I take using cytology okay so if you remember the five minutes introduction class I told about a word called Saito law a studying of cells right so if you want to study let's say oral cancer then you need to take out cells from thee from the mouth when you take out the cells and you smear the cells what do you do smear s m e a are when you take out the cells and smears just smear the cells you will see like this okay now the question is how you are sure that all these dots are cells or there are de breeze or there are bacteria how we'll delineate the cells from the debris x' and other things all right that's where the nuclear staining helps us alright so you can do a nuclear staining and you will see that when you stain the nucleus of a cell with a marker called DP d AP I you will see that this nucleus within the cell this nucleus will turn blue okay you can see a red dot because my pen is red but when you stain the cell with Dappy you will see that the nucleus turns to blue that means that that if I have a glass slide with some dots and if I stay in these cells with the P then I would distinguish or delineate these cells from the breeze and other organisms right because I can see clearly the cells who amongst these other particles would the nucleus would turn blue in color will turn blue in color okay so that is something that we need to understand when you talk about the cells now let's go to the next slide right so the point is that when you open the cell you can see lot of things within the cell then the most important thing from engineering perspective is that what we will do if cell consists of so complex things right what we want to do is what we are to understand is that yes the cell constitutes of lot of this particular technical names microfilament our nucleus and i BOS ohms and a lot of the things but the chemical composition within the cell sodium potassium right that if the cell is lized like this when the cell dies when the cell ruptures right then this chemical comes out and these chemicals are conductive that's what our interest lies so let let me give an example why why it is really important from engineering perspective okay so if I have a material and I can measure impedance right impedance or resistance let's say resistance is inversely inverse of conductivity correct more conductive material is the less is resistance value right or higher the resistance value less the conductivity so what I want to tell you is that if you have cells all right and if the cell ruptures if the cell lies what will happen the chemical within the cell will come out when the chemical within the cell comes out the conductivity increases so how can we use it what what is there for us right so the interesting thing is if I load a drug on group of cells and if the drug is effective then the cells would lies and the conductivity would increase so if I can design a sensor which can measure the conductivity of cells and when the cell is niced then I can understand whether the drug is effective or not that means I can understand the efficacy of a drug that means that I can do a drug screening for drug screening using the conductivity we can design a device right that we will see as a part of this course and I'll tell you how quickly we can design this drug skimming device very easy a simple property of conductivity right now you cannot measure resistance in this case because the cells are capped in a drug and if you understand that it's not real Sisseton snow because there is a double layer capacitance involved when designer device on which you are putting the cells you cannot just rely on DC the current our resistance you had to rely on impedance because lot of parasitic effect would come into picture so we'll see coming back to our cell theory so the beginning of the cell theory in 1839 a German zoologist named Theodor Schwann concluded that all animals were made up of cells and he also co-founded the cell theory right what he founded all the animals right you talk from humans chimpanzees snake frog fish talk about anything hey we're made up of cells ok good so what happened in 1855 in 1855 a german medical doctor right named rude love observed under the microscope cells dividing all right very interesting observation and he reasoned that all cells comes from other pre-existing cells by the phenomenon called cell division all right so the cell division is responsible for forming other cells so from where the cell comes from the pre-existing cells all right so this was the observation by do love which ow a German medical doctor in 1855 okay so if you further understand if you take a cell which is right shown here all living things are made up of cells right cells are the basic unit of structure of a function in an organism and the basic unit of life cells comes from the reproduction of existing cells and that is you've with the cell division when you understand within the cell you will see that there are hydrophobic region of protein there are hydrophilic region of protein there is a phospholipid bilayer and molecules in the cell membranes are constantly moving and changing additionally those proteins also help more larger molecules are aiding cell recognition now within the proteins we divide proteins into two sub division the first one we call peripheral proteins and second one we call integral proteins so what are peripheral proteins and what are integral proteins peripheral proteins are attached on the surface inner or outer while the integral proteins are embedded completely through the membrane so recently if you read research papers you'll find that lot of groups are working on introducing the drug within the cell or they say nano particle loaded drugs nano particle loaded drug alright so what's the purpose of this it's very interesting idea and like I said lot of research groups are working on this so the point is here you see when a drug enters the cell alright how much time a drug can stay within the cell how much time a drug can stay within the cell is called influx the time at which they say the drug is thrown out of the cell is called a flux influx efflux right now why drugs is drug is thrown out of the cell because drug is not the part of a cell right so how fast the drug is thrown out now the drug is thrown out quickly so the efflux is faster then the effect of the drug onto the cell would be minimal right but if I create a drug within and I know particle and then nanoparticle is made up of lipid or phospholipid so I cover the phospholipid around the drug and I introduce that nano particle loaded drug into the cell what will happen ba-bye lipid or phospholipid is a part of the cell right so now this say the efflux will reduce the time that is thrown out right is now less that means that more time a drug can stay within the cell the more time the duct can stay within the cell it will start acting on the cell and it will start rupturing the cell and thus the treatment becomes more effective that's what I meant by nanoparticle loaded drug see interesting right same thing very interesting now in the brain there is something called blood-brain barrier okay so the drug cannot pass through lot of the through this barrier and that's why we do reduce the size of the drug to nanoparticles so that it can diffuse through the to the gaps available in this particular blood-brain barrier but the question is how to improve the influx or how to reduce their flux right so very interesting point here is that brain consists of what it consists of stem cells all the star all the things starts from the stem cells right so it's a brain stem cells or we can say neural stem cells neurons right so a group of neurons so neural stem cells neural stem cells causes a new formation of new neurons with an axon and further there are lot of subdivisions within a brain also there's a different topic of research right now what we are talking is if I can lower the neural stem cells with drug and I introduce those neural stem cells loaded with drug for treating the disease related to brain like brain cancer can we improve the influx or can we reduce their flux that means the time that the drug can stay more time within that neural stem nuanced question right and that can be a neural stem cells as a novel drug delivery mechanism for treating brain cancer can we use that right and if we can how can we do that so anything boils down finally to what these cells and that's why we need to understand cells and that's why this particular module so if you come back to the PBT what we find is we have seen cell theory we have seen how the beginning of cell theory was there we have seen the structure of the cells and we have seen the how the cell and tissue culture can be used right now in our next module what we learn we learn what are the cell culture or what is the cell culture now we understand basic thing which is what it sells or what ourselves right a little bit of cell theory and I told you to three different words remember it in flux F flux in vivo ex vivo in vitro right and we saw that the conductivity of these cells right or the the media or would increase if you lies the cell if the cell dies and that phenomenon we can use for drug screening to understand efficacy of a drug we also discussed that we can use we can lower the drug within a biological sample or against a nanoparticle such that the efflux would decrease all the time that a dog can spend within the cell would increase in the next module let us see what is the cell culture and what are the techniques or equipment used for cell culture till then you take care have fun see