the present invention provides a monodisperse polymer particles adapted to release alkoxy groups by means of a hydrolyser , such that monodisperse bioactive polymer particles are obtained in vivo . the mbpp are characterized by at least one naturally occurring or synthetic long molecular chain consisting of biologically stable backbones optionally crosslinked , further characterized by a molecular weight of at least 1 kd , comprising between 10 to 1 , 000 , 000 repeated covalently - linked small molecules with a functionality of at least one alkoxy releasing group per molecule ; a long dimension between 0 . 1 and 10 micrometers ; and , a zeta potential value of 30 to 130 mv at ph of about 7 . 0 . the mbpp alter , inhibit , activate , induce or otherwise affect biological or chemical events in vivo .