Synthetic biology in healthcare and conservation: II. successful formulation of a synthetic spermatozoa cryopreservation medium

Abstract

Present-day Embryo Culture (ECM), Cell, Gamete and Embryo Cryoprotectant (CM), Stem Cell Culture (SCCM), Cell-based Vaccine Production Media (VPM), etc contain donor serum proteins (DSPs) which carry risk of disease transmission to patients/their babies/healthcare workers. The dependence on DSPs proved difficult to overcome. The European Union recommends avoidance of non-uniform biologicals in healthcare products (EU Tissue Directive No.2004/23/EU) by April 2007. However to-date most manufacturers of healthcare products have not fully complied with this directive. The pioneering research of this author in Australia led to development of synthetic human embryo culture media devoid of DSPs. A clinical trial was performed successfully [Ali, 1997, 2004; Ali et al., 2000] and patented in USA (US Patent 8415094)/PCT protected in Canada/ EU/ Australia/ Russia/ Israel/ worldwide and licensed to Cellcura ASA Norway (www.cellcura.com). The present communication reports development of synthetic spermatozoa cryopreservation medium (SCM). The nature of this intellectual property is proprietary. Patent application is pending. Therefore it shall not be described in detail here but events leading to its development will be presented. In the SCM the mean% +1SD spermatozoa motility pre- and post- freeze-thaw was similar 55.7+17.4 vs 54.9+13.3; n=10 (p>0.05). In previous studies after freezethaw using DSP-containing CM the pre and post-thaw spermatozoa motility was significantly different 45+11 Vs 23+12, p=0.047; n=64 that showed a loss of 22% in motility (p=0.047). A prospective study found SCM statistically similar to DSP containing-CM. Proof of principle was demonstrated following human pregnancy after generation of human embryos by intracytoplasmic spermatozoa injection (ICSI) using SCM frozen-thawed testicular spermatozoa. An efficacious SCM for human, possibly mammalian spermatozoa was formulated that may be regulation-compliant, and very safe. The availability of SCM eliminates batch variation and potential for disease transmission in routine spermatozoa cryopreservation in medicine, meat and dairy industries, and species conservation.