The Tigers moved level on points with leaders Cardiff on Friday night after beating the Rams 2-1 at Pride Park.
Goalkeeper David Stockdale returned to Fulham this week and playmaker David Meyler will now go back to Sunderland, while Manchester United duo Ben Amos and Robbie Brady and Sunderland's Ahmed Elmohamady remain with the Tigers until the New Year.
Bruce hopes he can keep them all at the KC Stadium until at least the end of the campaign as he sees them as pivotal to the Tigers' chances of returning to the Premier League.
"I don't want to have to make too many changes to the squad so I hope we can keep them," said Bruce.
"I want to keep them all. Hopefully we can keep the group together and secure the loan deals until the end of the season, or even make some of them permanent. But it's a difficult time in January so we will have to wait and see."
On joining Cardiff at the top of the table, the former Manchester United captain said: "There's a long way to go but we're doing well.
"We were 33/1 (for promotion) at the start of the season so we've come under the radar a bit, which is what I wanted.
"Hopefully we can keep it going but, as I say, much will depend on what happens with the loan players."