(3 + 2) Cycloaddition reaction between azomethine ylides and π-deficient alkenes leads to densely substituted L- and D-unnatural prolines. These (3 + 2) cycloadducts in turn catalyse the preparation of an offspring of unnatural endo- and exo-L-proline derivatives. These latter compounds are also efficient catalysts of aldol reactions and yield aldol adducts with the opposite stereochemistry obtained under natural L-Pro organocatalysis.

The mimesis of biological systems has been demonstrated to be an adequate approach to obtain tissue engineering scaffolds able to promote cell attachment, proliferation, and differentiation abilities similar to those of autologous tissues. Bioceramics are commonly used for this purpose due to their similarities to the mineral component of hard tissues as bone. Furthermore, biomimetic scaffolds are frequently loaded with diverse therapeutic molecules to enhance their biological performance, leading to final products with advanced functionalities. In this review, we aim to describe the already developed bioceramic-based biomimetic systems for drug loading and local controlled release. We will discuss the mechanisms used for the inclusion of therapeutic molecules on the designed systems, paying special attention to the identification of critical parameters that modulate drug loading and release kinetics on these scaffolds.