Aliso Viejo-based Focal Therapeutics Inc. has raised about $3.8 million in venture capital, according to a Securities and Exchange Commission filing.

Focal makes a tissue-marking device called BioZorb. BioZorb is intended to help surgeons, oncologists and other clinicians clearly identify and delineate in three dimensions a surgical site for tissue removal.

The device maker’s filing said 28 investors participated in the funding but did not disclose names or plans for use of the proceeds. The filing indicated Focal is seeking about $1.2 million more funding for a total of $5 million in this round.

It raised $3.5 million in Series C money in August 2014 from Okapi Venture Capital in Laguna Beach and Emergent Medical Partners in Portola Valley, according to CrunchBase.