To prepare most of the biopolymeric nanoparticles through cross-linking chemistry, the rough idea is to  add very slowly the solution of the polymer into large volume of the cross-linker solution under very high stirring rates..

Therefore, the polymeric solution, here chitosan should be of very less concentration , say like, 0.1% solution, (higher concentrations will result in larger particles), and the cross linker solution should be in considerably higher concentration than polymeric solution.. typical , TPP as 1% solution.. This is because once the polymeric solution comes in contact , there will be strong cross-linking and immediately particles will be formed.

Further, regarding volume ratios, you should providing less volume of polymer , so that particles remain as nanoparticles and they do not clump or aggregate. Therefore it should be like, 1ml of polymer solution into 10 ml of TPP solution.. 

This is just a rough idea and you need to optimise from these..

you can refer this work

http://www.sciencedirect.com.sci-hub.org/science/article/pii/S0144861709003129

better way is to find out the interaction between the two and fnd out the exact how many moles are required for each mole of chitosan and to play aorund with it..

Thank You Sir...

Chitosan is a polymer how we can find out the interaction ?

what will be the difference between taking volume ratio and molar ratio for formulating nanoparticles.?

TPP is an ionic cross-linker for chitosan.. The phosphate groups in TPP serves as a linker for amine groups in different chains/units of chitosan through ionic interaction. 

https://www.google.co.in/search?q=chitosan+and+TPP+cross+linking&es_sm=122&source=lnms&tbm=isch&sa=X&ved=0CAgQ_AUoAmoVChMIwO_lk9ruxwIVxQeOCh2JkQuP&biw=1364&bih=707#imgrc=dM8N8ORZMV-tOM%3A

Molar ratios will help you determine exactly how many TPP molecules are required for for crosslinking two units of chitosan...  but its kind of very elaborate to explain here for chitosan and TPP... migh be some people who knows to explain in easy ways can explain.. 

volume ratios, lets consider we are doing chitosan beads using TPP .. you are adding 1 ml of chitosan solution to 10 ml of TPP..  and then once the bead are formed, you can remove those.. now again you could use this same TPP solution for another  0.5 or 1 ml of chitosan, because still there will be free phosphate ions to link the chitosan chains. but sometimes softer beads will be formed... once the the phosphate ions are exhausted you cant use that solution any more.. so which means that  you could addaround 1.5 to 2ml of chitosan into 10 ml of your TPP solution..  these volumes are just an example.

But what usually most of do is, once that 1 ml is added to 10 ml, we just throw off the TPP and prepare a new batch... so it might result of waste of TPP..

But, if you really calculate how many moles of TPP are required for cross-linking one mole of chitosan, then we can minimise the wastages of the solutions..

Thank you sir,

I will go through the articles that you have attached.

 You are always welcome. good luck

Sir how the concentration and volume of polymer and cross linker are dependent ?

If i varying the concentration ratio by keeping volume constant is this affect the encapsulation efficiency or other parameters ? because in all articles they have used very less volume( like 3 ml, 1.2 ml) so whats the logic of using less volume ?

Hi, 

Ok now lets suppose you take 1ml of  1% chitosan solution and add it to 10 ml of TPP solution. Now you take 1 ml of 2% chitosan solution and add it to same 10 ml of TPP. The second solution will have double the amount the chitosan molecules. Now if TPP solution has only enough molecules to cross link 1ml of 1% solution, now when you add 1ml of 2% solution, you wont get the same strength of cross-linking.. it will either result in cross-linking of  only 0.5ml of 2% solution or a weak cross-linking of 1ml of 2% solution.. it depends on how you added the chitosan solution into TPP.

Yes obviously most of the parameters will vary. 

Thank You sir.

Sir I prepared chitosan nanoparticles using 0.1% chitosan and 0.1% TPP with varying volume ration.. I got product (very little). and particles are settling very fast.. even particle size I m not getting.

IS IT NECESSARY TO MAINTAIN THE pH of chitosan solution to 4.6-4.8 ?

Hi Ashvini, 

My gut feeling is that, your TPP concentration is way too low. I would try at 1% TPP concentration and, also drop  the chitosan solution using insulin needle syringes under very high stirring rate

Hi Sir,

Thank You sir.

Sir I am doing trials by varying chitosan and TPP ratio. I tried with 1% TPP also i got the product. As the TPP Conc. increases from 1 volume to 4 volume yield was low like in decreasing order, particles we are getting in micro range. I think i need to increase the RPM..

Sir which RPM you suggest for getting nano sized particles?

Hi Ashvini, 

You can very well address me by my name. 

I had messaged you some details. check your inbox.

keep the highest RPM that you can achieve in your stirrer and also try to reduce the chitosan percentage. Also as i suggested use a very thin gauge needle (ideally an insulin syringe will work.) to drop the chitosan solution into TPP.  and add drop by drop and as slowly as possible. (if you got a syringe pump, you can fine control and automate this).  

Thank you Sir,

Sir we are adding TPP to chitosan. what difference will make if we add Chitosan to TPP or TPP to chitosan. Formation of particle is mainly based on cross linking know. ?

the idea is you need to control the amount of precursors which comes in contact with the crosslinker. So only only when you drop (slow addition drop wise, with time gaps between drops- atleast  for 1ml should take around 3-5 mins)  chitosan solution into TPP , the small droplet alone will get crosslinked and form particle. But if you drop TPP into chitosan solution, then , there will be lot of chitosan particles around, you will end up with either large particles or irregular masses of cross-linked chitosan.  Hope you understood. 

Yes the basic strategy is cross-linking, but different forms can be synthesized, by altering or controlling the rate of cross-linking and by controlling the amount of precursors.

Sir if drug is soluble in chitosan solution(water insoluble drug), then also we need to add chitosan to tpp ?

Hi,

A bit deviated problem from the one being discussed in this thread.

I am currently preparing chitosan nanoparticles. I was able to get chitosan particles with

@ashvini: i think you would have already trie something regarding that .. sorry for the late reply. If the drug is water insoluble, i doubt its solubility in chitosan solution... because chitosan solution is also mostly water only.

@apurva agrawal,

There are lot of factors that can be modified for a nanoparticle to be upatken, like adjusting the zeta, functionalisation with some group or peptides, and even size.. Only certain sized particles will be readily uptaken by cells.etc... Kindly refer some of the articles in this link.

https://scholar.google.co.jp/scholar?q=chitosan+nanoparticles+cell+uptake+jayakumar&btnG=&hl=en&as_sdt=0%2C5&as_vis=1

Dear All,

For getting fine chitosan nano particles, chitosan concentration or its volume must be less than TPP so that a good amount of zeta potential can be archived and that may also help you to uptake the NPs into cells.Other important thing is the DD of chitoan, .DD must have at higher end as much as possible.

You may read our following publications

Chapter Synthesis of Chitosan-Based Nanomaterials

Book Chitosan Based Nanomaterials in Plant Growth and Protection

Nice conversation, Dr Arun, I have a question, if I want to prepare a chitosan Nanoparticles based on your methodology with a final concentration equals to 2mg/mL, how would I do that ? How many volume and how much concentration of both, TPP and chitosan shall I begin with to end up with my desire concentration ?

Good question and nice conversation!

Nice discussion and very helpful to me for synthesis of chitosan nanoparticles.

please, I want to get the lowest nanosize from chitosan nangel, I tried with different preparation by ionic gelation method, but the size all the time is more than 300 nm, I want it to be less than 100 nm? what should I do?

@

Samah Algharib Results indicated that NPs dispersed in a saline solution showed higher stability and a smaller particle size in the presence of sodium chloride, which may be caused by the monovalent sodium salt screening out the electrostatic repulsion between the positively charged amine groups on the CH backbone. The presence of salt may enhance the flexibility within the polymer chain as well as its stability (Ilium, 1998).