Working At Ossium

Who We Are

At Ossium, we believe that science is humanity’s best weapon in the fight against disease, and we embrace the challenge of mobilizing the world’s healthcare ecosystem to win that fight. In pursuit of this goal, we empower our employees, maintain the highest standards of excellence, and are a force for good.

Kevin Caldwell

CEO, Co-Founder & President

Listen to Kevin Speak About Our Vision


The values we live by


We are mission-driven and results-oriented. We believe that a healthier world is a better one and that our work should drive positive change.


Embracing the truth empowers us to learn from both our successes and our mistakes. We follow the data wherever it leads.


We hold ourselves and each other to the highest bar. We care deeply about the work we do and know that even the smallest details can make a difference.

Inside Look

Day in the Life

Donor Field Services Managers

These donor tissue recovery experts work with our OPO partners to continuously improve our tissue recovery processes.  They are masters of Ossium’s recovery protocols and practices.

Cell Therapy Associates

These processing experts make our cell therapy products. They are skilled in tissue processing, cell processing, and cryopreservation.

Words from the Team

I really appreciate that Ossium has challenged me in ways that totally throw me out of my comfort zone. It's a wonderful place to learn and grow.

Brian Johnstone

Vice President, Research

Brian Johnstone

Vice President, Research

For the past 20 years, Dr. Johnstone has been actively involved in translating adult stem cell therapies into treatments for a host of diseases affecting the major organs of the body. In 2004, he co-authored one of the first studies demonstrating the potential for treating cardiovascular diseases with novel adult stem cells isolated from fat.

Since then, Dr. Johnstone has continued to develop and test new medical uses for adult stem cells as part of his own research as well as in collaboration with international academic centers and pharma / biotech firms.

Outside of the research setting, Dr. Johnstone co-founded NeuroFx, an early-stage biotech firm developing a novel therapy for neurological disorders. Dr. Johnstone led the R&D program at NeuroFx for two years, where he was directly responsible for preclinical and chemistry, manufacturing, and controls development activities. He continues to act as an advisor for NeuroFx. Additionally, Dr. Johnstone has formed two other biotech companies, Chemigen, which is developing a small molecule drug for treating Lou Gehrig’s disease, and EmphyMab Biotech (now Allinaire), which is developing biologics to treat serious lung diseases.

Before becoming an entrepreneur, Dr. Johnstone was an early employee at Sangamo Biosciences for 6 years, where he managed the preclinical development program for their lead gene therapy candidate for cardiovascular diseases, which is currently in Phase II clinical testing. Dr. Johnstone received his Ph.D. from the University of Maryland, College Park, and completed a postdoctoral fellowship at the University of California, Los Angeles.

From the first day I started at Ossium, we had a clear goal to save lives. I come to work every day with that in mind. Getting to work on such a critical cause with the wonderful folks at Ossium makes this an incredible place to be.

Margie Mathewson

Senior Vice President, Business Operations

Margie Mathewson

Senior Vice President, Business Operations

Dr. Mathewson’s career has focused primarily on helping start-ups and small businesses build out robust operations, from internal structures and systems to external partnerships. Prior to joining Ossium, Dr. Mathewson was the 7th team member at Point, a FinTech start-up offering non-traditional options for home equity funding, where she led Business Operations. While there, she drove development of an underwriting process for nontraditional, complicated customers that allowed funding of Point’s initial set of homeowners, including the first to successfully exit the investment. She also communicated complex mathematical concepts to homeowners to educate them on the Point investment model and how their equity sale would work.

Dr. Mathewson also worked as a consultant for McKinsey & Company, where, among other projects, she helped develop a rapid growth strategy for a successful health system, overhauled a sales and supply chain planning process to improve communication and ensure every customer got what they ordered on time, and restructured the international sales team for a major global telecom. Dr. Mathewson completed her PhD at the University of California, San Diego, where she was an NSF Fellow and founded a successful mentorship program for first generation college students in engineering.

I was initially drawn to Ossium by Kevin's vision of changing the way we think about healthcare, and the potential to positively impact so many people. As I got to know the team, my desire to be a part of Ossium only grew! Every day I come to work energized by the passion and knowledge of those around me.

Jay Gardner

Senior Director, Talent & People Operations

Jay Gardner

Senior Director, Talent & People Operations

Ms. Gardner is a hands-on People leader with deep experience supporting high-growth startups across SaaS, cleantech, and fintech. Her focus is building scalable People and Talent infrastructure that emphasizes connection and engagement across multiple locations, teams, and levels.

Before joining Ossium, Ms. Gardner established the People team as employee #18 at Turntide Technologies, a cleantech electric motor startup with backing from Jeff Bezos, Bill Gates, and Robert Downey Jr. During her tenure, she cemented the People team as the connective tissue for a before-its-time hybrid model of 6 offices and 40% remote staff, and drove 555% headcount growth across the company. At Turntide she rolled out multiple people-focused initiatives including introducing OKRs, creating a recruiting playbook, founding a DEBI (Diversity, Equity, Belonging, & Inclusion) team, and building out the onboarding program Turntide 101. Ms. Gardner also spent 4 years in HR Consulting, working with startups across the nation to implement HR systems and best practices. Her team supported between 30-40 clients at any given time to onboard companies’ first hires, create a foundational HR base, and set the company up for future success with a focus on proactive consultative HR.

Prior to finding her calling in the People space, Ms. Gardner worked in guest operations at San Francisco’s two science museums: The California Academy of Sciences (where she presented public engagement shows underwater as a scuba diver) and the Exploratorium. Ms. Gardner received her BA in Feminist Studies from Stanford University, where she won a national championship as a member of the women’s water polo team and was named to the All-American team all four years. She also spent six months playing professional water polo overseas in Greece.

Open Positions

At Ossium, we’re always looking for talented, mission-driven people.