Methods for reaction electrospinning are provided to form collagen fibers. The method can include: acidifying a collagen in an acidic solvent to form an acidic collagen solution; electrospinning the acidic collagen solution within an alkaline atmosphere (e.g., including ammonia vapor) to form collagen fibers; and collecting the collagen fibers within a salt bath (e.g., including ammonium sulfate). The acidic solvent can include water and an alcohol, and can have a pH of about 2 to about 4 (e.g., including a strong acid, such as HCl). An albumin rubber is also provided, which can include albumin crosslinked with glutaraldehyde.