A delivery system comprising a covering containing at least a first substance for release to a surgical site is provided. The covering includes an elongated containment portion having at least one compartment, wherein the covering retains the first substance for mixing with a second substance prior to delivery at a surgical site. The covering may be a single or multi compartment structure capable of retaining at least partially the mixture of the at least first and second substances until the covering is placed at the surgical site. The elongated containment portion of the covering includes a first end and second end opposite each other, wherein at least one end defines an access port configured to receive a device capable of delivering a second substance into the elongated containment portion for mixing with the first substance prior to or during the surgical procedure.
