The non-invasive high-resolution spatial mapping of cell metabolism within tissues could provide substantial advancements in assessing the efficacy of stem cell therapy and understanding tissue development. Here, using two-photon excited fluorescence microscopy, we elucidate the relationships among endogenous cell fluorescence, cell redox state, and the differentiation of human mesenchymal stem cells into adipogenic and osteoblastic lineages. Using liquid chromatography/mass spectrometry and quantitative PCR, we evaluate the sensitivity of an optical redox ratio of FAD/(NADH + FAD) to metabolic changes associated with stem cell differentiation. Furthermore, we probe the underlying physiological mechanisms, which relate a decrease in the redox ratio to the onset of differentiation. Because traditional assessments of stem cells and engineered tissues are destructive, time consuming, and logistically intensive, the development and validation of a non-invasive, label-free approach to defining the spatiotemporal patterns of cell differentiation can offer a powerful tool for rapid, high-content characterization of cell and tissue cultures.

Adults aged 55 to 80 years participated voluntarily in a wait-list control study during in-patient physical therapy following first stroke. All participants (N = 15) received conventional physical therapy gait training throughout 30 treatment sessions. Rhythmic auditory stimulation (RAS)-enhanced gait training was nested within conventional treatments in three conditions: (1) RAS throughout 30 treatments (N = 5); (2) RAS in the last 20 treatments (N = 5); and (3) RAS in the last 10 treatments (N = 5). Cadence and balance outcome measurements were taken at baseline, and following 10, 20, and 30 treatment sessions. Improvements across time were statistically significant in all conditions for one-limb stance, cadence, velocity, stride length, and posture head tilt with no statistically significant improvements for the Timed Up and Go Test and the Functional Reach Test. Statistically significant gains were made in the one-limb stance and cadence with earlier implementations of RAS. Results of the study demonstrate the feasibility of RAS to enhance gait training that warrants further investigation of the protocol to demonstrate the effects of RAS in stroke rehabilitation.

Ceramic scaffolds such as biphasic calcium phosphate (BCP) have been widely studied and used for bone regeneration, but their brittleness and low mechanical strength are major drawbacks. We report the first systematic study on the effect of silk coating in improving the mechanical and biological properties of BCP scaffolds, including 1) optimisation of the silk coating process by investigating multiple coatings, and 2) in vitro evaluation of the osteogenic response of human mesenchymal stem cells (hMSCs) on the coated scaffolds. Our results show that multiple silk coatings on BCP ceramic scaffolds can achieve a significant coating effect to approach the mechanical properties of native bone tissue and positively influence osteogenesis by hMSCs over an extended period. The silk coating method developed in this study represents a simple yet effective means of reinforcement that can be applied to other types of ceramic scaffolds with similar microstructure to improve osteogenic outcomes.

Patterned silk protein films possess desirable characteristics for corneal tissue engineering, including optical transparency, biocompatibility, cell alignment, and tunable mechanical properties, but current fabrication protocols do not provide adequate degradation rates to match the regeneration properties of the human cornea. This novel processing protocol makes silk films more suitable for the construction of human corneal stroma tissue and a promising way to tune silk film degradation properties to match corneal tissue regeneration.

Stimuli-responsive materials enabling the behavior of the cells that reside within them to be controlled are vital for the development of instructive tissue scaffolds for tissue engineering. Herein, we describe the preparation of conductive silk foam-based bone tissue scaffolds that enable the electrical stimulation of human mesenchymal stem cells (HMSCs) to enhance their differentiation toward osteogenic outcomes.