The present disclosure relates to fibers implantable in the body of a human or animal and processes for manufacturing such a fiber. The fiber undergoes a reduction in surface area to volume ratio of a factor of 1.05-10 upon injection in the human or animal body. In an embodiment, a process for manufacturing a fiber comprises extruding a biodegradable polymer into a fiber capable of fitting in a syringe needle of at least 25 Gauge, and cooling the fiber below its dry glass transition temperature while the fiber is under tension.
