Researchers use stem cells from fat to repair bone
New source for bone? Fat chance
Bone grafting is done to strengthen joint replacements, fuse vertebrae, improve healing of bad fractures or replace bone loss. It involves removing healthy bone from either the patient who needs the graft or from a donor, living or dead. But bone tissue isn’t always available and grafts don’t always work, so scientists have been hunting for techniques to improve or replace the procedure.
The UCSF team first found that cartilage cells, when grafted instead of bone cells into a shin fracture in mice, promoted healing. The cartilage cells encouraged bone growth, plus the cells themselves eventually turned into bone.
The scientists believe that someday doctors may be able to implant a scaffold structure that releases growth factors in the area that needs repairing and transforms stem cells from fat – which is much easier to access than bone or cartilage – into bone.
The research was published online April 22 in the Journal of Bone and Mineral Research.
- Erin Allday
Skin cells manipulated into sperm
Stanford scientists took skin cells from infertile men, transformed them into stem cells and implanted them into mice, where they turned into a type of cell that eventually becomes sperm, according to a new paper.
The procedure could help researchers better understand a type of genetic infertility called azoospermia, in which men cannot make mature sperm. It also could reveal new techniques for helping men who have become infertile to produce sperm and become biologic fathers.
The research started with five men – three who weren’t able to produce sperm – who provided samples of skin tissue. The scientists manipulated the skin cells to become induced pluripotent stem cells, which are capable of becoming many other kinds of cells in the body.
The scientists transplanted the stem cells into the seminiferous tubules – where sperm is produced – in mice, and they automatically transformed into germ cells, which become sperm. In the mice, the germ cells did not fully transform into sperm, likely because of significant differences in reproduction between humans and the animals.
Stem cells taken from the infertile men produced far fewer germ cells than those taken from the fertile men. But the fact that any germ cells came from the infertile men at all was remarkable, the scientists said.
The research was published May 1 in the journal Cell Reports.
- Erin Allday