New research has shown that microbubble-enhanced therapeutic gene delivery could be utilized as an alternative to bone grafts. The research which was led by scientist from Cedars-Sinai Medical Center (CA, USA) was recently published in Science Translational Medicine.
Bone grafts are made by either harvesting bone from the patient, which can be painful, or by utilizing donated grafts from tissue banks which often fail to integrate. There are more than 2 million bone grafts performed worldwide every year.
The researchers surgically created a critical-sized bone fracture in the tibiae of Yucatán mini-pigs before adding a collagen scaffold to the site of the break to provide a welcoming niche for bone progenitor cells. They then injected microbubbles mixed with genetic material as a bone growth factor. Pulses of sound from an ultrasound wand promoted uptake of the growth factor DNA by progenitor cells, which stimulated bone growth. Eight weeks after the surgery, the fracture was healed in all Yucatán mini-pigs that received the treatment.
Unlike other gene therapies that rely on viral vectors to deliver their cargo, the ultrasound and microbubbles didn't appreciably trigger inflammation, and expression of the introduced gene was undetectable after 10 days.
"This study is the first to demonstrate that ultrasound-mediated gene delivery to an animal's own stem cells can effectively be used to treat nonhealing bone fractures," commented the studies co-senior author and assistant professor of surgery Gadi Pelled (Cedars-Sinai Medical Centre). "It addresses a major orthopedic unmet need and offers new possibilities for clinical translation."
Sources: Bez M, Sheyn D, Tawackoli W et al. In situ bone tissue engineering via ultrasound-mediated gene delivery to endogenous progenitor cells in mini-pigs. Sci. Transl. Med. 9:390 (2017); https://www.sciencedaily.com/r...;
Written by- Adam Tarring