Multifunctional nanoparticles for intracellular drug delivery and photoacoustic imaging of mesenchymal stem cells.

Strategies that control the differentiation of mesenchymal stem cells (MSC) and enable image-guided cell implantation and longitudinal monitoring could advance MSC-based therapies for bone defects and injuries. Here we demonstrate a multifunctional nanoparticle system that delivers resveratrol (RESV) intracellularly to improve osteogenesis and enables photoacoustic imaging of MSCs. RESV-loaded nanoparticles (RESV-NPs), formulated from poly (lactic-co-glycolic) acid and iron oxide, enhanced the stability of RESV by 18-fold and served as photoacoustic tomography (PAT) contrast for MSCs.

Localized and sustained release of brain-derived neurotrophic factor from injectable hydrogel/microparticle composites fosters spinal learning after spinal cord injury.

Damaged axons in the adult mammalian central nervous system (CNS), including those of the spinal cord, have extremely limited endogenous capacity to regenerate. This is the result of both the intrinsic and extrinsic inhibitory factors that limit the regeneration of adult neurons. Despite attempts to limit or eliminate the extrinsic inhibitory components, regeneration of adult neurons in the CNS is still limited.