Bioactive agents are delivered to a body site in need of the same by providing a first aliquot portion of a reaction mixture which includes an aldehydic polymer solution, and a second aliquot portion of a reaction which includes a cross-linking hydrazide and a bioactive agent. The first and second aliquot portions may be mixed (e.g., by expelling such portions from respective syringe barrels) to form the reaction mixture thereof. The thus formed reaction mixture may then be installed at the body site whereby the reaction mixture is allowed to solidify in situ within about 1 to 10 minutes into a reaction product comprised of a hydrazide cross-linked oxidized aldehydic polymer matrix with the bioactive agent entrapped therein.
