This week: Blind mice see again and hydrogel drug vehicle bypasses toxic immune system to repair muscle damage.
The news highlights:
Platelet-rich plasma does not promote MSC-mediated cartilage repair
Mouse vision restored through activation of retinal stem cells
Drug delivery via hydrogel protects stem cells from aggressive immune system
Platelet-rich plasma (PRP) is commonly used in commercially available regenerative medicine treatments, often for degenerative joint indications. However, a new study led by Jr-Jium Liou, Benjamin Rothrauff, Peter Alexander and Rocky Tuan, University of Pittsburgh School of Medicine (PA, USA), has demonstrated that PRP does not act by promoting proliferation of stem cells or the cartilage formation capabilities of mesenchymal stem cells. Conversely, their research has shown that long term treatment of joints with PRP impaired cartilage formation.
“This article presents a systematic study to elucidate the effects of PRP on the chondrogenic differentiation of adult human MSCs and its potential mechanism of action as a therapeutic adjunct for the treatment of joint diseases,” says Tissue Engineering Co-Editor-in-Chief Antonios G. Mikos, Louis Calder Professor at Rice University (TX, USA).
In a world first, the vision of blind mice was restored through activation of retinal stem cells. In the study, dormant stem cells were activated through gene transfer, before a second gene transfer promoted differentiation of the stem cells into rod photoreceptor cells. Rod photoreceptor cells are the most abundant type of cell in the retina and the new photoreceptors were found to integrate into the native retinal structure.
“This study opens a new pathway for potentially treating blinding diseases by manipulating our own regenerative capability to self-repair,” explained lead investigator Bo Chen, Associate Professor of Ophthalmology and Director of the Ocular Stem Cell Program at the Icahn School of Medicine at Mount Sinai (NY, USA). “If this works, this could transform the way we treat patients with retinal disease and possibly learn how to cure other types of eye disease like glaucoma.”
An engineered hydrogel, developed by researchers at the Georgia Institute of Technology (GA, USA), has been used to help therapeutic stem cells bypass an hostile immune system and target muscle injuries. In a murine model, the hydrogel delivered muscle satellite cells to injured muscle tissue which successfully boosted the healing process.
“Any muscle injury is going to attract immune cells. Typically, this would help muscle stem cells repair damage. But in aged or dystrophic muscles, immune cells lead to the release a lot of toxic chemicals like cytokines and free radicals that kill the new stem cells,” explained Young Jang, an assistant professor in Georgia Tech’s School of Biological Sciences and one of the study’s principal investigators.
“With this system we engineered, we think we can introduce donor cells to enhance the repair mechanism in injured older patients,” commented Woojin Han, a postdoctoral researcher in Georgia Tech’s School of Mechanical Engineering and the paper’s first author. “We also want to get this to work in patients with Duchene muscular dystrophy.”
For more weekly cell therapy news, read previous editions of the cell therapy weekly.