# MD simulation of polymer-drug complex

**URL:** <https://gromacs.bioexcel.eu/t/md-simulation-of-polymer-drug-complex/5024>\
**Category:** User discussions\
**Tags:** mdrun\
**Created:** [October 14, 2022, 6:54pm UTC](https://gromacs.bioexcel.eu/t/md-simulation-of-polymer-drug-complex/5024 "2022-10-14T18:54:24Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![merry](https://avatars.discourse-cdn.com/v4/letter/m/e480ec/32.png) [@merry](https://gromacs.bioexcel.eu/u/merry)\
**Post date:** [October 14, 2022, 6:54pm UTC](https://gromacs.bioexcel.eu/t/md-simulation-of-polymer-drug-complex/5024/1 "2022-10-14T18:54:24Z")

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GROMACS version: 2019  
GROMACS modification: Yes/No

Hi gromacs users,

Can I use gromacs for MD simulation of polymer (such as chitosan)-drug complex? Is there suitable force field for that in default gromacs force fields?

Thanks

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**Author:** ![rpsingh](https://avatars.discourse-cdn.com/v4/letter/r/c57346/32.png) [@rpsingh](https://gromacs.bioexcel.eu/u/rpsingh)\
**Post date:** [October 16, 2022, 12:55pm UTC](https://gromacs.bioexcel.eu/t/md-simulation-of-polymer-drug-complex/5024/2 "2022-10-16T12:55:56Z")

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What are you trying to simulate? A drug covalently-linked with the polymer or interactions between a drug and a polymer. Both types of molecules can be studies.

What is important here is if the polymer and the drug have been parameterized and what you intend to study as the end result?

RPS

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**Author:** ![merry](https://avatars.discourse-cdn.com/v4/letter/m/e480ec/32.png) [@merry](https://gromacs.bioexcel.eu/u/merry)\
**Post date:** [October 17, 2022, 7:47am UTC](https://gromacs.bioexcel.eu/t/md-simulation-of-polymer-drug-complex/5024/3 "2022-10-17T07:47:58Z")

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Hi Rpsingh, thanks for your answer.

I want to investigate the interaction between drug and polymer in different concentration of drug. The drug does not covalently-linked with the polymer. Is there suitable force field parameters for both of drug and polymer in gromacs package?

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**Author:** ![jalemkul](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/jalemkul/32/18_2.png) [@jalemkul](https://gromacs.bioexcel.eu/u/jalemkul)\
**Post date:** [October 17, 2022, 2:36pm UTC](https://gromacs.bioexcel.eu/t/md-simulation-of-polymer-drug-complex/5024/4 "2022-10-17T14:36:47Z")

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> [@merry](#):
>
> Is there suitable force field parameters for both of drug and polymer in gromacs package?

Out of the box, no. There are no force fields that comprehensively cover everything automatically. But you can parametrize your species for use with any of the available force fields in GROMACS.

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**Author:** ![rpsingh](https://avatars.discourse-cdn.com/v4/letter/r/c57346/32.png) [@rpsingh](https://gromacs.bioexcel.eu/u/rpsingh)\
**Post date:** [October 18, 2022, 9:40am UTC](https://gromacs.bioexcel.eu/t/md-simulation-of-polymer-drug-complex/5024/5 "2022-10-18T09:40:31Z")

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Depends on your polymer and drug. CHARMM-GUI enables creating several common polymers. If yours is not there, look in literature else start parameterizing yourself.