Flexible biodegradable polymeric step-index optical fiber

A biocompatible and biodegradable polymeric step-index optical fiber, comprising:

• at least one core made from at least one core material, the at least one core material comprising a first polymeric material having a citric acid bonded with at least a first monomer, the core having an initial modulus and a biodegradation rate;
• and
• at least one cladding around the at least one core, the at least one cladding made from at least one cladding material, the at least one cladding material comprising a second polymeric material having the citric acid bonded with at least a second monomer, the at least second monomer being different from the at least first monomer, the cladding having an initial modulus and a biodegradation rate;
• wherein the core has a refractive index higher than that of the cladding;
• wherein a difference between the initial modulus of the core and the cladding is less than a predetermined threshold and a difference between the biodegradation rates of the core and cladding is less than a predetermined threshold;
• and
• wherein optical properties of the core and cladding are tunable by adjusting monomer ratios, choices of monomers or cross-linking degrees,
• wherein the cladding is poly(octamethylene citrate) (POC) and the core is poly(octamethylene maleate citrate) (POMC).

A method of making a biocompatible and biodegradable polymeric step-index optical fiber, the method comprising the steps of:

• providing a first pre-polymer material having a citric acid bonded with at least a first monomer, the core material;
• providing a second pre-polymer material having the citric acid bonded with at least a second monomer, the second monomer being different from the first monomer;
• providing a surface-polished cylindrical mold;
• coating the cylindrical mold with the second pre-polymer material and crosslinking the coated second pre-polymer;
• removing the cylindrical mold by swelling the coating to form a cladding;
• and
• injecting the first pre-polymer into the cladding and crosslinking the first pre-polymer to form a core;
• wherein the core has a refractive index higher than that of the cladding;
• wherein a difference between the initial modulus of the core and the cladding is less than 30% and a difference between the biodegradation rates of the core and cladding is less than 30% after about 4 weeks;
• and
• wherein optical properties of the core and cladding are tunable by adjusting monomer ratios, choices of monomers or cross-linking degrees.