Novel collagen-mimetic peptides are disclosed comprising the formula (Xaa-Yaa-Gly)n, where the amino acid at one of the Xaa positions is substituted with a homocysteine residue. Also disclosed are multi-stranded novel collagen-mimetic peptides comprising a first strand as described above that is covalently bonded with a disulfide bridge to a second strand comprising the formula (Xaa-Yaa-Gly)m, where the amino acid at one of the Yaa positions is substituted with a cysteine residue. Disulfide formation between the terminal thiol sulfur of the homocysteine residue of the first strand and the terminal thiol sulfur of the cysteine residue of the second strand reveals unstrained bridges that enhance the structure and substantially improve the stability of collagen triple helices as compared to other possible disulfide or thioether bridges. Thus, the disclosed collagen mimetic peptides have improved stability, and can be used to produce optimized collagen-like fibrillar assemblies for wound healing and other biomedical applications.