Design and development of microformulations for rapid release of small molecules and oligonucleotides

•A protocol for micro-formulation of both small molecules and biologics is introduced.•Increased loading of the therapeutics compared to liquid formulations is achieved.•Full release occurs within 7 h and is repeatable.•The procedure is suitable for conventional micro-dosing or micro-robotic delivery. A systemic delivery of therapeutics frequently results in sub-optimal exposure of the targeted locus and undesired side effects. To address these challenges, a platform for local delivery of diverse therapeutics by remotely controlled magnetic micro-robots was introduced. The approach involves micro-formulation of active molecules using hydrogels that exhibit wide range of loading capabilities and predictable release kinetics. This work introduces two specific hydrogels based on thiol-maleimide and PEG-PLA-diacrylate chemistries that afford high, reliable and reproducible loading and release of several model molecules including doxorubicin, 25-mer poly-dT oligonucleotide and a 5.4 kBp GFP DNA plasmid. The described formulations are suitable for micro-dosing using both conventional or remote delivery devices. [Display omitted]