Our Leadership Team

Our compassion for patients drives our passion for science 


John Maslowski
Chief Executive Officer

John Maslowski is Chief Executive Officer of Castle Creek Biosciences, Inc.  Previously, he served as President and Chief Executive Officer of Fibrocell Science, Inc., leading the company through a commercialization agreement and eventual acquisition by Castle Creek Holdings, Inc. in 2019.  He also served as a member of Fibrocell’s Board of Directors. 

Formerly, Mr. Maslowski was Fibrocell’s Senior Vice President, Scientific Affairs and Vice President, Operations, driving the U.S. FDA approval of LAVIV® (azficel-T), an autologous fibroblast cell therapy for improving the appearance of nasolabial folds in adults. Prior to Fibrocell, Mr. Maslowski held various positions at Wyeth Pharmaceuticals (now Pfizer), Merck & Co., and Teva Pharmaceutical Industries. He earned a B.S. in biology from Ursinus College and an M.S. in microbiology from Villanova University.

Mr. Maslowski currently serves on the Board of Directors of the Alliance for Regenerative Medicine and is Chairman of the Board of Falcon Therapeutics, a private Durham, N.C. company focused on the development of cell therapy products for oncology.


Mary Spellman, MD, FAAD
Chief Medical Officer

Mary Spellman, M.D., is Chief Medical Officer and Senior Vice President of Research & Development of Castle Creek Biosciences, Inc. Dr. Spellman is a board‑certified dermatologist with more than 30 years of clinical research experience. She directed the clinical research group in dermatology at the University of California, San Diego and has held various leadership positions in research and development at Menlo Therapeutics, Revance Therapeutics, Biogen Idec, Connetics Corporation, and Novartis. Dr. Spellman earned an M.D. from the Medical College of Wisconsin and is a diplomate of the American Board of Dermatology and a fellow of the American Academy of Dermatology.

Greg Wujek
Chief Commercial Officer

Greg Wujek is Chief Commercial Officer of Castle Creek Biosciences, Inc.  Mr. Wujek has more than 30 years of industry experience in executive management, sales, market access, marketing, and business development. Previously, Mr. Wujek served as Chief Executive Officer of Castle Creek Pharmaceuticals. Prior to joining Castle Creek, he managed and developed successful strategies for Zimmer Biomet/ Biologics Division’s first prescription injectable product, Gel-One®. Prevously, Mr.Wujek led the build out of Savient’s biologics arm taking responsibility for Operations, Sales and Managed Care in support of EUFLEXXA®, the company’s first biologic launch. Prior to Savient, Mr. Wujek was responsible for managing the team that successfully launched ALTOPREV® and FORTAMET® at Andrex Laboratories. Mr. Wujek began his career at Forest Laboratories where he quickly elevated himself and took responsibility for the Managed Care department in support of the company’s first blockbuster, TIAZAC®.  He graduated from Illinois State University with a B.S. in political science.

Babar Ghias
Chief Operating Officer

Babar Ghias is Chief Operating Officer of Castle Creek Biosciences, Inc. Mr. Ghias has nearly 20 years of experience in investment banking, investing and operations in the healthcare industry. In addition to his role at Castle Creek, Mr. Ghias also serves as Executive Vice President of Portfolio Management at Paragon Biosciences, a life science innovator, where he is responsible for building and growing emerging biotech companies. Previously, he held several executive positions at Marathon Pharmaceuticals where he was the Chief Financial Officer and head of corporate development. He was also a senior member of the mergers and acquisitions team at Credit Suisse where he advised on over $60 billion in biopharma transactions. Mr. Ghias started his career as an investment banking analyst at UBS Securities Asia. Mr. Ghias earned his M.B.A. from Washington University in St. Louis and holds a B.S. in economics from Lahore University of Management Sciences in Pakistan.

Sean Buckley
Chief Business Officer

Sean Buckley is Chief Business Officer of Castle Creek Biosciences, Inc. Mr. Buckley has over 15 years of experience in the biotech industry, including both clinical and commercial stage products. Previously, Mr. Buckley led Fibrocell’s accounting, finance, legal, IT, governance and PMO departments through a $135M out-licensing transaction, multiple follow-on offerings and the sale to Castle Creek Pharmaceutical Holdings, Inc. Prior to that he held various leadership roles at Fibrocell. Mr. Buckley is a Certified Management Accountant, Project Management Professional and earned an M.B.A. from the University of Maryland.