Current advanced reproductive techniques, such as in-vitro or in-vivo fertilization and somatic cell nuclear transfer require a large number of high-quality, matured oocytes to produce a few healthy offsprings. However, obtaining such a large number of good quality oocytes is a challenging task in most of the mammalian species. Occasionally, the oocyte collection procedure inflict serious, irreversible injuries to the donor animals.

As a solution to this problem, our novel approach, oocyte-free preimplantation embryo production by bioprinting, does not require eggs from female animals. In this approach, Embryonic Stem Cells (ESC) and/or induced Pluripotent Stem Cells (iPSC) generated from the animal of interest are the major biomaterial required to de-novo bioprint embryos. This method helps in production of true clones of a donor animal with 100% genomic identity including mitochondrial genome, and production of a large number of identical offsprings from a single embryo (monozygotic multiples).

Extraembryonic shell of a preimplantation embryo is bioprinted using Trophoblast Stem Cells, and Extraembryonic and Visceral Endoderm Cells. These shells can be used as the general structure across different breeds and strains within a species. By depositing pluripotent stem cells derived from the animal of interest inside these shells, cloned offsprings can be produced.