A composite scaffold for use as a tissue engineering implant A composite scaffold for use in tissue engineering applications comprises a porous scaffold matrix comprising at least an organic material, a first microparticle preparation distributed in the scaffold matrix, and a second microparticle preparation distributed in the scaffold matrix. The first microparticle preparation comprises microparticles having a first polymeric microparticle matrix and a first active agent within the matrix such that the first active agent is capable of being released from the microparticle matrix/scaffold at a controlled rate. The second microparticle preparation comprises microparticles having a second microparticle matrix and a second active agent within the matrix such that the second active agent is capable of being released from the second microparticle matrix/scaffold at a controlled rate.

A microparticle preparation suitable for pulmonary delivery of an active agent comprises solid particles having a three-dimensional matrix structure and an active agent entrapped and dispersed throughout the three dimensional matrix structure. The particles having a Mass Median Aerodynamic Diameter (MMAD) of from 1 to 5[mu]m, and the three-dimensional matrix comprises a cross-linked polymer susceptible to degradation by human neutrophil elastase. The three dimensional matrix may comprise an interpenetrating network of a polymeric protein and a cross-linked polysaccharide polymer. Methods for producing the microparticles are also described.