I would like to change my section titles into sentence case just like the solution here: How to make sections into sentence case
The titlesec package is already included in my document to modify section title formatting, so this seems like a good solution. The problem is that I am using a book class and require the chapterbib package. When I include the biblatex package to use the \MakeSentenceCase macro, it tells me that it's incompatible with chapterbib and fails to compile.
Is there an alternative method I can use to access \MakeSentenceCase or create a similar macro for use in the \titleformat command?

\MakeSentenceCaseis for uniformizing titles in a bibliography. For your section titles, just type them as you want them to appear. – egreg Jan 30 '14 at 22:40