A timed-release tensioned core-shell fiber comprises a core positioned within a shell. The shell is configured to hold the core under said tension or compression. The shell is at least partially removable and releases at least a portion of the tension or compression of the core in response to the shell being removed. The shell is at least partially removable by erosion or degradation due to mechanical, chemical, electrical, physical, or thermal processes, or combinations thereof. In some embodiments, the erosion or degradation of the shell may include biodegradation, bioerosion, photooxidation, or photodegradation. A fiber mesh comprised of core-shell fibers may be tuned for timed release of contraction or expansion forces in response to timed release of tension or compression of the core. The fiber mesh may be used in a medical device, bandage, implant, tissue construct, or sling. A suture may also comprise a core-shell fiber.