: Osteoporosis is a pathological loss of bone mass due to an imbalance in bone remodeling where osteoclast-mediated bone resorption exceeds osteoblast-mediated bone formation resulting in skeletal fragility and fractures. Anti-resorptive agents such as bisphosphonates and SERMs, and anabolic drugs that stimulate bone formation, including PTH analogues and sclerostin inhibitors, are current treatments for osteoporosis. Despite their efficacy, severe side effects and loss of potency may limit the long term usage of a single drug. Sequential and combinational use of current drugs, such as switching from an anabolic to an anti-resorptive agent, may provide an alternative approach. Moreover, there are novel drugs being developed against emerging new targets such as Cathepsin K and 17β-HSD2 that may have less side effects. This review will summarize the molecular mechanisms of osteoporosis, current drugs for osteoporosis treatment, and new drug development strategies.

We have studied the influence of matrix materials on the self-organization of InAs nanostructures grown on InP substrates by molecular-beam epitaxy. Our results show that InAs quantum dots are formed on InAlGaAs, whereas quantum-wire-like structures are produced on InAlAs and InGaAs. Tuning from vertical anticorrelation in InAs/InAlAs superlattices to vertical correlation in InAs/InGaAs and InAs/InAlGaAs superlattices is observed, which is explained by the size effects in the nanostructure–nanostructure interaction.

High-density InAs nanowires embedded in an In0.52Al0.48As matrix are fabricated in situ by molecular beam epitaxy on (100) InP. The average cross section of the nanowires is 4.5×10 nm2. The linear density is as high as 70 wires/μm. The spatial alignment of the multilayer arrays exhibit strong anticorrelation in the growth direction. Large polarization anisotropic effect is observed in polarized photoluminescence measurements.