Reactjs: How to put HTML into primaryText of a list item?

I would like to have a span inside the ListItem like this:

<ListItem
    primaryText={"<span class='inner'>Some important info</span>" + item.title}
/>

When this is rendered, I don't get an HTML span element, but a text <span class='inner'>Some important info</span>Title of the list item. How to make HTML render as HTML?