A method of producing a polymer scaffold composition, comprising: a) electrospinning a first polymer solution comprising a first polymer and a second polymer solution comprising a second polymer onto a collector to form a polymer fiber comprising a shell and a core, the electrospinning comprising: i) applying a first voltage to the first polymer solution in a first emitter and ejecting the first polymer solution through a first emitter outlet, the first emitter further comprising a first tube with a first interior, and ii) applying a second voltage to a second polymer solution in a second emitter and ejecting the second polymer solution through a second emitter outlet, the second emitter further comprising a second tube with a second interior, the second tube being disposed within the first interior of the first tube; b) electrospraying a plurality of cells on to at least one of the collector and the polymer fiber; and c) crosslinking the polymer fiber to produce the polymer scaffold composition, wherein the shell comprises the first polymer and the core comprises the second polymer; wherein the first polymer is less likely than the second polymer to cause a host immune response when implanted in host tissue; wherein the core increases strength of the polymer fiber relative to a polymer fiber consisting of the first polymer; and wherein the core increases strength of the polymer scaffold composition relative to a polymer scaffold composition consisting of a crosslinked polymer fiber consisting of the first polymer. a) electrospinning a first polymer solution comprising a first polymer and a second polymer solution comprising a second polymer onto a collector to form a polymer fiber comprising a shell and a core, the electrospinning comprising: i) applying a first voltage to the first polymer solution in a first emitter and ejecting the first polymer solution through a first emitter outlet, the first emitter further comprising a first tube with a first interior, and ii) applying a second voltage to a second polymer solution in a second emitter and ejecting the second polymer solution through a second emitter outlet, the second emitter further comprising a second tube with a second interior, the second tube being disposed within the first interior of the first tube; i) applying a first voltage to the first polymer solution in a first emitter and ejecting the first polymer solution through a first emitter outlet, the first emitter further comprising a first tube with a first interior, and ii) applying a second voltage to a second polymer solution in a second emitter and ejecting the second polymer solution through a second emitter outlet, the second emitter further comprising a second tube with a second interior, the second tube being disposed within the first interior of the first tube; b) electrospraying a plurality of cells on to at least one of the collector and the polymer fiber; and c) crosslinking the polymer fiber to produce the polymer scaffold composition, wherein the shell comprises the first polymer and the core comprises the second polymer; wherein the first polymer is less likely than the second polymer to cause a host immune response when implanted in host tissue; wherein the core increases strength of the polymer fiber relative to a polymer fiber consisting of the first polymer; and wherein the core increases strength of the polymer scaffold composition relative to a polymer scaffold composition consisting of a crosslinked polymer fiber consisting of the first polymer. <EOS>