Key Employees

The Mesogen team includes Michael Riddle Jr., MD, Interim CEO and Chief Scientific Officer and team members with expertise in tissue engineering, bioreactor design, genetics, molecular biology, embryology and mammalian stem cell and tissue culture.

Michael Riddle Jr., MD
CEO, Chief Scientific Officer

Raymond Drude Jr.
Vice President of Business Development

Scientific Advisory Board

John V. Phelps III, MD
Advance Reproductive Endocrinologist Physician

Michael Hiles, PhD
Frm. Senior Vice President for R&D and Chief Scientific Officer of Cook Biotech Inc.

Joaquin Cortiella, MD
Director of the University of Texas
Medical Branch Regenerative and Nano-medicine Laboratory

Sarmila Sarkar, MS
Scientist III/Team Lead for the NIH RPE Patch Project for the National Eye Institute

Stephen Fadem, MD
Medical Director – Houston Kidney Center Integrated Service Network at DaVita

Jaafar El Annan, MD
The University of Texas Medical Branch at Galveston Retinal Surgeon and Clinical Associate Professor of Ophthalmology

Business Advisory Board

Paul Frison
Senior Life Sciences Executive, Founder Houston Technology Center

John Ramsey
Entrepreneur, Investor and Philanthropist from Dallas, Texas

Don Benson
Senior Life Sciences Executive, Chairman of CHR Solutions

Andrew Nat Jr.
Life Sciences Venture Capitalist Managing Partner Thirdwave Partners

General Larry Wyche
Retired 3 Star US Army
(Lieutenant General)
Global Logistics, Technology and Leadership Expert

A Cure Is Coming

Take The First Step Towards Your Future

Take control of your future and get in touch with us today to explore how Mesogen can assist you. Whether you’re a physician or a patient, we’re actively engaged in different stages of development and would love to discuss how we can support your goals. Don’t hesitate, reach out today!

Michael Riddle, MD

Michael Riddle, MD graduated from the University of Texas Medical Branch.

He developed a human lung bioreactor which was sold to Harvard Apparatus.

Dr. Riddle also invented a pediatric heart valve bioreactor that was sold to Harvard Apparatus and is currently being used at the Mayo Clinic.

Dr. Riddle Developed a stem cell exosome based wound care treatment that was sold through Plasvacc Veterinarian Pharmaceutical company.

He specializes in designing and building custom bioreactors for regenerative medicine applications and other medical technology devices.

He has an extensive laboratory background at the University of Texas, MD Anderson, and the US Navy in clinical and molecular laboratories with over 15 years of laboratory experience.

Research projects include lung, kidney, heart and heart valve regenerative medicine research.

His publications include:

  • Giving New Life to Old Lungs: Methods to Produce and Assess Whole Human Pediatric Bioengineered Lungs in the Journal of Tissue Engineering and Regenerative Medicine
  • Production and Assessment of Decellularized Pig and Human Lung Scaffolds in Tissue Engineering Part A

Dr. Riddle has several patents in the life sciences technology arena.

Raymond Drude Jr.

Raymond spent 27 years in the franchising industry opening offices throughout the Gulf Coast Region for the world’s largest commercial cleaning franchise. He was promoted to VP of Business Development overseeing the U.S. and it’s 21 corporate offices. Raymond currently serves as Vice President of Business Development for Mesogen, Inc.

Dr. John Phelps

Dr. John Phelps is an obstetrician-gynecologist in League City, Texas and is affiliated with multiple hospitals in the area, including Houston Methodist Clear Lake Hospital and University of Texas Medical Branch

He received his medical degree from Georgetown University School of Medicine and has been in practice for more than 20 years

Dr. Phelps’ Specialty / Subspecialties: Obstetrics & Gynecology / General Obstetrics & Gynecology, Minimally Invasive / Endoscopic Surgery, Reproductive Endocrinology & Infertility

Michael Hiles, PhD

Michael Hiles, PhD. recently stepped down as the Senior Vice President for R&D and Chief Scientific Officer of Cook Biotech Inc., a medical device firm specializing in the development of extracellular matrix and resorbable biomaterial technologies for medical purposes.

Prior to moving to Cook Biotech, Mike investigated these same materials for vascular grafts, ligaments, and bladder repair as an Associate Research Scholar in the Hillenbrand Biomedical Engineering Center at Purdue University. Before that, he completed his graduate education through the same Biomedical Center.

He received his BS and MS degrees in Electrical Engineering from Purdue and his Ph.D. in Veterinary Physiology and Pharmacology from the Veterinary Medical School at Purdue. He has published articles on catheter-based medical instrumentation, cardiac fibrillation, pharmacological intervention in acute animal disease, biomaterials, tissue engineering, and biomechanics of soft tissues.

Mike is an inventor on more than 50 issued or pending U.S. patents, serves in an advisory capacity to several industry and academic groups, lectures at multiple academic institutions, and is an Adjunct Professor in both Biomedical Engineering and Veterinary Clinical Sciences at Purdue. He lives with his wife in rural Lafayette, IN.

Dr. Joaquin Cortiella

Dr. Joaquin Cortiella is the Director of the University of Texas Medical Branch Regenerative and Nano-medicine Laboratory

Colonel serving with the 399th Combat Support Hospital in Massachusetts

M.D. from Boston University Medical School, B.A. from Harvard.

Extensive expertise in tissue engineering including production of skin, lung, cartilage

Extensive expertise in the isolation and characterization of adult stem cell populations

Experience using adult and embryonic stem cells as well as tissue engineering techniques to produce human ex-vivo organoids/tissue constructs

Sarmila Sarkar, MS

Senior Scientist  and Team Lead at the Clinical Center of the National Institutes of Health in Bethesda, MD. 

Her expertise in stem cell banking, differentiation and isolation led her to develop and implement robust process methods for the differentiation of iPSC-derived retinal pigmented epithelium cells for the first Phase I/IIa clinical trial in the USA. 

She was the scientist who developed the GMP protocol and grew the first RPE patch transplanted into a human in the USA, August 2022.

Prior to working at the National Institutes of Health, she led a group in a stem cell company for banking of umbilical cord-derived mesenchymal stem cells.

Dr. Stephen Fadem

Dr. Stephen Fadem is a practicing Houston nephrologist. He began practice in 1978 after completing a renal fellowship at The University of Texas Health Science Center in San Antonio.

He is a graduate of the University of Oklahoma College of Medicine, and The University of Texas and MD Anderson Hospital in Houston.

He is a Clinical Professor of Medicine at Baylor College of medicine.

He is also a member of the American Society of Nephrology, International Society of Nephrology, Renal Physicians Association, and the National Kidney Foundation

He was a founding member, and first president of the Gulf Coast Kidney Society. He is the Medical Advisory Board Chairman of the National Kidney Foundation Serving Texas

Jaafar El Annan, MD

Jaafar El Annan, MD, is a Clinical Associate Professor of Ophthalmology at the University of Texas Medical Branch and MD Anderson Cancer Center.

Dr. El Annan attended medical school at the American University of Beirut, and was nominated to receive the Suad Al Sabah award for cultural and scientific manuscript. He then pursued a post-doctoral research fellowship in cell biology and ocular immunology at Harvard Medical School.

During his internship at Greater Baltimore Medical Center he received the GBMC IRB House Staff Research Contest Award. He then pursued his residency at the University of Louisville where he was nominated to receive the Alpha Omega Alpha honor medical society and the resident research award for best presentation/research work. He then completed a 2 year fellowship in Diseases and Surgery of the Retina and Vitreous at the Cullen Eye Institute, Baylor College of Medicine.

Dr. El Annan’s research interests pertain to angiogenesis and retinal vascular diseases, including age-related macular degeneration, diabetic retinopathy, and venous occlusive diseases. Dr. El Annan has written and published more than 45 peer-reviewed scientific manuscripts, national meeting presentations and abstracts. Dr. El Annan is a member of the AAO, ARVO, and ASRS. He is board certified in ophthalmology and was recently selected to be among America’s top Ophthalmologists.

Paul Frison

Paul Frison has been President and/or CEO of three public companies: LifeMark (1975 – 1984 NYSE) ComputerCraft (1984 – 1986 NASDAQ) and LifeCell (1986 – 1999 NASDAQ), each technology based.

He has been involved in four other start-ups by serving on their boards of directors. His experience includes numerous mergers and acquisitions. He has raised multiple rounds of venture capital, two IPOs, and more than a dozen follow-on rounds of public financing.

In 1999, Paul became the initial employee and was elected President and CEO of the Houston Technology Center (HTC), a business incubator and accelerator. He served as CEO/Chairman until February 2007, when he became Executive Vice Chairman. He received the 2004 Ernst & Young Entrepreneur of the Year Award for Entrepreneurship Supporter.

John Ramsey

John Ramsey is an entrepreneur, investor and philanthropist from Dallas, Texas.  With ventures in technology, real estate, education, consumer packaged goods, sports, beauty and entertainment, John spends most of his time creating, building and manufacturing branded products in the health and beauty sector.       

Along with his business activity, John is involved in various charitable and non-profit organizations, all of which are designed to promote a more free and prosperous society.  John is the co-founder of a non-profit organization that is dedicated to returning lost or sex trafficked children with their families thru scientific DNA testing.  John regularly speaks at conferences, educational institutions and politically affiliated organizations about the virtues of a society based upon entrepreneurial expansion and creativity.

Don Benson

Don Benson has an extensive senior management and Board of Directors experience including CHR Solutions, Inc. where he has served as Chairman.

His background in life sciences management includes roles as President and CEO of Methodist Office Building Company, Senior VP of Methodist Healthcare System, and Senior VP of National Nephrology Associates

He has an extensive background in insurance, having served as Senior VP of CIGNA, VP of Aetna, and Board Member of Employer Direct Healthcare, Inc.

Mr. Benson has been involved in approximately 100 major acquisitions, mergers and divestitures exceeding $20 billion in combined value.


Andrew Nat

Andrew Nat is an experienced life sciences and energy executive and Board Member that has closed over $2.6 billion of transactions

He currently serves as the Managing Partner of Thirdwave Partners and is focused on corporate strategy, business development, mergers and acquisitions, and private equity

Principal and CFO, Vesalius Ventures

He has been a Principal at Nexos Resource Partners, Executive Vice President of Texas Bioalliance, Executive Director of the Commercial Review Council for the Cancer Prevention and Research Institute, and Executive Director, Member of the Board of Directors for the Texas Life Science Center.

Andrew has an MBA from Yale and a BA from Columbia University

General Larry Wyche

General Larry Wyche is currently Founder and Chief Executive Officer of Wyche Consulting which provides strategic support for his clients’ international business development strategy and leadership.

Formerly Larry served for 35+ years in the US Army, retiring as a Lieutenant General responsible for 120,000 military personnel in 152 countries, with an annual budget of $58 billion.

He is a member of the National Association of Corporate Directors and serves as a Board Member for the Houston Food Bank

He graduated from the National Defense University, the Florida Institute of Technology, Texas A&M and the National Association for Corporate Directors Leadership Program.