The cash will be used to offer more secured loans and property finance to growing and start-up businesses.
Nucleus already has £50m in funding from Paragon specifically for its property finance product.
The new deal provides further room to grow secured lending at competitive rates amid growing demand, Nucleus said.
The specialist lender now has more than £175m of funding lines to extend in loans to companies that could struggle to borrow from high street banks.
Committed to multiple funding options
Chirag Shah, chief executive of Nucleus Commercial Finance, said: “Working with Paragon Bank, a specialist in property lending, highlights our strength in this space and is a testament to the strong sourcing, underwriting and execution capability we have at Nucleus.
“We are committed to offering multiple funding options to best suit the needs of SMEs across the UK. Every business has different financial needs and our range of products reflects this.”
Adam Daniels, managing director of structured lending at Paragon, added: “We are delighted to be able to provide funding for Nucleus.
“The opportunities that Nucleus provide for UK business owners reflects our passion for driving the growth of UK SMES and supporting high-quality lending business.”
Nucleus said it has provided £1.3bn of funding to more than 2,100 small businesses across the country.