Knowledge Base

Recorded Webinar: Generating PLGA particles for controlled drug delivery


This webinar introduces you to Dolomite’s approach to drug encapsulation in precisely controlled, monodisperse, PLGA particles. This is a practical session showing how you can create particles using a microfluidics approach and explain the benefits over traditional batch methods. By the end of the session, you’ll not only see the benefits but also realise how you can easily validate and then scale-up production with Dolomite.

Questions and Answers

1. What Kind of Gels do you use for Cell Encapsulation?

For cell encapsulation we use an aqeuous phase with a flourocarbon oil (biocompatible) as a carrier phase. Drugs can be encapsulated in agarose and other hydrogels using other Dolomite systems.

2. How do you Prepare Alginate?

We can use a different style of chip (2 reagent chip).

3. Can essential oils be encapsulated?

Yes, this can be achieved. We’d need to know the solvent and the specific oil to advise you accordingly.

4. What minimum size of PLGA nanoparticles can be achieved using 5 input chip?

This depends on the surfactant and flow rates, but it’s possible to achieve a minimum size of 50nm.

5. Are the microfluidic chips disposable or do they last for some time?

Our chips are made of glass, which provides extended lifetime and longer particle production.

6. What is the largest chip size you have?

The largest droplet chip has a channel diameter of 190 microns, but if required we can produce custom made chips in larger sizes.

7. How do you remove solvents like DCM or acetone from nanoparticles solutions and what impact this process have on the final size of the nanoparticles?

DCM and acetone can be gently removed by evaporation. This doesn’t affect the size of the particle if done following a specific method.

8. Can the precipitation method be used with dichloromethane?

DCM and water are almost insoluble and you’ll need to use an antisolvent such as chloroform.

9. What is the smallest droplet size you can produce with this system. And with that droplet size, what size you estimate the PLGA beads would have?

Using the droplet method, the smallest droplet size we can achieve is 5 microns which shrinks to 1 micron after evaporation. We can achieve smaller sizes using nanoprecipitation (the other method we discussed during the webinar).

10. Is it possible to use syringe pumps to produce nanoparticles and PLGA beads as well?

Yes, it is possible to use syringe pumps. However, we use pressure pumps because they have smoother flow.

11. You mentioned using Helium in the pumps. Why would you do that?

To prevent out-gassing and consequent particle precipitation within the channel.

12. Can the Droplet method be adapted to produce 2 to 8 µm particles?

Yes, we could use a different diameter chip and adjust the flow rates, as demonstrated in the pc interface, to achieve your desired particle size.

13. How can hydrophilic drugs be encapsulated by microfluidics?

You could can make ‘core-shell particles’ by double emulsion technique to produce ‘water + drug’/PLGA/water particles. Please contact us for the detailed answer to this question.

14. Can two different size monospheres be created by connecting two different microfluidic chips?

Double emulsions can be created by connecting two chips in series. We have a predefined system to achieve this result.
Janus particles can be created by using a 2 Reagent Chip.
If two similar particles of different sizes are required, then this can be achieved by connecting two different chips to the pumps.

15. Can the double emulsion be done with the droplet method? If yes, how many pumps would be necessary?

Yes, this can be achieved with the droplet method. First, you’ll have to create water/oil emulsion using a hydrophobic chip and two pumps. Then flow these droplets into a second hydrophilic chip using a third pump to produce a final water/oil/water double emulsion.

16. What’s the maximum amount of parallel microfluidic chips that can be used at one time?

You’re able to run 10 chips in parallel, each with 7 junctions totalling to 70 junctions.

17. What is the biggest Telos system you can make? Can this realistically be scaled for industrial purposes, for example 1000 parallel channels?

Each chip has 7 junctions and we can put together 10 slots into the ‘cassette’. This totals to 70 junctions running in one process. Of course, you can use multiple systems simultaneously.

18. Can this system be used for GMP manufacturing?

Currently the system is not GMP certified, but we are looking into getting the system certified.