Utah Startup Claims Lab-Grown Sperm Success, Creates Embryos in Early Test

Paterna Biosciences, a Salt Lake City-based startup, reports successful production of functional human sperm from testicular stem cells in laboratory conditions and has created embryos as proof of concept for the technology. The company's claims, reported by Wired, have not yet undergone peer review or independent verification.

The process isolates spermatogonial stem cells from testicular tissue biopsies and develops them into mature, functional sperm entirely outside the human body. Co-founder and CEO Dr. Alexander Pastuszak, a male reproductive urologist, states that early testing indicates the lab-grown sperm appear effectively identical to naturally produced gametes across cellular morphology and functional parameters.

Technical Approach and Claims

Paterna's methodology targets the nearly century-old challenge of in vitro spermatogenesis by focusing on endogenous stem cell populations rather than induced pluripotent stem cell approaches pursued by other research groups. The company reports high success rates across dozens of tissue samples, with the goal of generating thousands of sperm from a standard testicular biopsy.

According to the company's documentation, their gametes have completed all cellular processes of DNA intermixing, meiotic division, and maturation necessary for fertilization use. The startup created embryos specifically as a viability test rather than for reproductive purposes—the procedure remains far from clinical deployment for pregnancy initiation.

Worth flagging: The company has reached what it describes as a critical milestone in reproductive biotechnology, but the absence of peer-reviewed validation leaves fundamental questions about reproducibility, safety, and efficacy unanswered.

Commercial and Clinical Timeline

Paterna secured $6.4 million in seed funding led by SpringTide Ventures in October 2024, following an earlier $6 million round. The company projects pricing between $5,000 and $12,000 for the eventual therapeutic procedure, positioning it within existing assisted reproductive technology cost structures.

Clinical plans include a larger study involving men with infertility, followed by a pivotal trial incorporating in vitro fertilization protocols with lab-generated gametes and standard embryo transfer procedures. The startup received recognition at the Mayo Clinic and ASU MedTech Accelerator, winning the Disruption Award in March 2025.

Scientific Foundation and Team

The company brought on Dr. Kyle Orwig, a reproductive biology researcher, as co-founder in January 2024. Additional collaboration includes Bradley Cairns, a University of Utah professor specializing in chromatin and sperm biology. The team published research indicating that sperm from infertile, oligozoospermic men exhibit 1.34 to 2.01-fold increases in age-adjusted mutation frequencies compared to fertile populations.

This mutation data underscores Paterna's broader thesis that male infertility treatment lags significantly behind female-focused IVF technologies. The company notes that no FDA-approved therapeutics currently exist specifically for male factor infertility, despite male factors contributing to roughly half of the estimated one-in-six couples affected by fertility challenges.

Market Context and Applications

The technology could address multiple patient populations beyond conventional infertility cases. Men with non-obstructive azoospermia—those who produce no sperm but retain spermatogonial stem cells—represent a primary target demographic. Additionally, the approach could benefit prepubescent boys undergoing chemotherapy, as sperm-forming stem cells are present from birth and could theoretically be preserved and later developed.

Analysis: We have seen this pattern before, when reproductive technologies initially emerged as solutions for specific medical conditions before expanding into broader applications. IVF, originally developed for tubal factor infertility, now produces over 500,000 births annually across diverse patient populations and indications.

External perspective comes from Dr. Ryan Flannigan, a sperm retrieval surgeon at Vancouver Prostate Centre, who acknowledges the potential significance while emphasizing the need for rigorous validation. Other research groups pursue parallel approaches using induced pluripotent stem cells derived from skin or blood cells reprogrammed to embryonic-like states.

Technical Challenges and Validation Requirements

The transition from laboratory proof-of-concept to clinical application faces substantial regulatory and safety hurdles. Gamete production involves complex epigenetic programming, chromosomal organization, and quality control mechanisms that must be precisely replicated in vitro. Even minor deviations in spermatogenesis can result in chromosomal abnormalities, DNA fragmentation, or functional defects not apparent in morphological analysis.

Regulatory pathways for lab-generated gametes remain largely uncharted territory, requiring extensive safety studies, multi-generational outcome tracking, and standardized quality metrics. The field must also address ethical considerations around embryo creation for research purposes and long-term offspring health monitoring.

Industry Implications

In this author's view, Paterna's claims, if validated, represent a meaningful advance in addressing male factor infertility—a field that has indeed received less therapeutic innovation compared to female reproductive medicine. The technology could potentially eliminate the need for surgical sperm extraction procedures in certain patient populations and expand treatment options for men with severe spermatogenic failure.

However, the gap between laboratory demonstration and clinical deployment remains substantial. The company's embryo creation serves primarily as a proof-of-viability milestone rather than evidence of safety or efficacy for reproductive use. Independent replication, peer review, and extensive safety studies will ultimately determine whether this approach can deliver on its therapeutic promise.

The broader implications extend beyond individual treatment options to questions of gamete banking, fertility preservation, and reproductive autonomy—particularly for young cancer patients facing gonadotoxic treatments. Success in this domain could reshape approaches to fertility preservation across pediatric oncology and other medical specialties affecting reproductive function.