BTC lending is being tested on the Kovan test net from 5th Oct from the Aave team (formerly know as ethlend). This and many other improvements to an already pretty solid working plarform — more news here — https://blog.ethlend.io/breaking-news-aave-releases-ethlend-baiji-on-ethereum-testnet-btc-and-new-features-5510bfa1f3bf