Ultrasound contrast agents are micron-sized bubbles coated with lipids/proteins to stabilize them in the bloodstream. Apart from enhancing the contrast of the image, they have been implicated in numerous harmful and beneficial bioeffects. I will present an overview of our research emphasizing recent efforts on microbubbles-based non-invasive pressure estimation and ultrasound-assisted bone and cartilage tissue engineering in 3D printed scaffolds. Low-intensity pulsed ultrasound (LIPUS) in conjunction with microbubbles has been shown in our lab to facilitate bone and cartilage formation from mesenchymal stem cells. We will discuss nonlinear shape oscillations of microbubbles and acoustic microstreaming that are responsible for such bioeffects. We studied them using boundary element (BEM) simulation and perturbative analysis of an encapsulated microbubble near a vessel wall. For the BEM solution, the coating of the microbubble is modeled as a viscoelastic interface using an in-house developed strain-softening model (exponential elasticity model). The influence of the shell model on the stability of the numerical simulation during the microbubble jet formation has been investigated. The effects of ultrasound excitation parameters and mechanical properties of the coating, i.e., shell viscosity and elasticity, on the bubble behaviors and the velocity and pressure in the surrounding fluid, have been studied.