# Unicondylar Resurfacing in an Ovine Osteoarthritis Disease Model

> **NIH NIH SB1** · CYTEX THERAPEUTICS INC. · 2024 · $399,998

## Abstract

Abstract
Osteoarthritis (OA) is a leading cause of disability in the developed world, affecting over 30 million adults in the
US with an economic burden of over $486 billion per year. Advanced OA is most commonly treated with total
joint replacement, but this is suboptimal for younger patients, especially those under 55 who lead an active
lifestyle, because of the high occurrence of multiple revision surgeries. For this growing patient population,
Cytex is developing implants pairing a patented 3D weaving technology with additive manufacturing to facilitate
cartilage and bone regeneration in the joint. The implant is designed to support joint loading immediately at the
time of implantation and to allow integration and development of osteochondral tissue. Both an acellular
implant and a tissue engineered implant that combines the acellular scaffold with autologous cells have
demonstrated in large animal models of OA the capability of repairing osteochondral lesions and restoring
pain-free joint function for extended durations. The tissue engineered implant is particularly desirable for
patients without a potent endogenous cell source to repopulate the acellular implant and synthesize a mature
extracellular matrix in vivo. Cytex has chosen femoroacetabular impingement (FAI) in the hip as a lead
indication for a pilot clinical study with the acellular implant. FAI presents in active, young patients, with no
good option to repair the resulting osteochondral lesions, which progress into more severe OA. The tissue
engineered implant will follow the acellular product into clinical study. Autologous cells, as used in our pre-
clinical studies, require time-consuming cell isolation and expansion steps. Instead, Cytex will use allogeneic
mesenchymal stem cells (MSCs) derived from bone marrow, which express very low levels of major
histocompatibility complex (MHC) class I and class II antigens. To prepare the allogeneic tissue engineered
implants for clinical study, Cytex must further develop the tissue engineered implant to overcome specific
commercialization hurdles. The goal of this proposal is to address these hurdles: 1) Cytex must identify and
develop potency assays that measure the biological activity of the seeded cells and set acceptance criteria for
those assays. 2) Cytex will identify cryopreservation and storage conditions for the implants to be available off-
the-shelf because surgeons and patients are unlikely to wait several weeks for an implant to be made-to-order.
3) manufacturing of the tissue engineered implants will be transferred to a contract manufacturer that follows
the current good manufacturing practices (cGMPs) required for regulatory approval. 4) Cytex, with an
experienced regulatory consulting firm, will engage with the US FDA to discuss requirements for clinical study
approval. The culmination of this project will be an off-the-shelf tissue engineered implant for cartilage repair
that will enable Cytex to broaden its implant po...

## Key facts

- **NIH application ID:** 10898914
- **Project number:** 5SB1AR066439-06
- **Recipient organization:** CYTEX THERAPEUTICS INC.
- **Principal Investigator:** Bradley T Estes
- **Activity code:** SB1 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $399,998
- **Award type:** 5
- **Project period:** 2015-09-08 → 2026-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10898914

## Citation

> US National Institutes of Health, RePORTER application 10898914, Unicondylar Resurfacing in an Ovine Osteoarthritis Disease Model (5SB1AR066439-06). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10898914. Licensed CC0.

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