Compositions and methods for delivering a siRNA, dsRNA, or miRNA polynucleotide into a target cell comprising contacting the target cell with a mesenchymal stem cell, which mesenchymal stem cell comprises an exogenous DNA sequence expressing the siRNA or dsRNA polynucleotide, thereby delivering the siRNA, dsRNA, or miRNA polynucleotide to the target cell through a cellular protrusion or a microvesicle.