• Child between 8 and 17 years of age (inclusive) at the time the parent/guardian signs the ICF or adult between 18 and 29 years of age (inclusive) at the time of signing the ICF. Note, the implantations of AUR-201 will initially be staggered based on age and completion of specified DSMB evaluations;

• Diagnosed with Grade II, III, or IV congenital unilateral microtia requiring complete auricular reconstruction;

• Naïve to microtia surgery or have had prior failed microtia surgery not involving the TPF flap;

• Able and willing to adhere to the post-operative wound care instructions (including, but not limited to, wearing protective devices specified by the PI) and the protocol specified follow-up schedule;

• Willing to refrain from non-contact sports and contact sports (e.g., football, soccer, rugby, boxing, karate) for 6 and 12 weeks, respectively, following the first implantation surgery, or longer if deemed necessary for healing by the PI. If the PI opts to implant the AUR-201 wedge at a separate subcutaneous location on Day 0 and then 12 weeks ± 28 days later implants the wedge in the final location, these periods of refraining from non-contact and contact sports will also apply to the second implantation surgery;

• PI deems the subject an appropriate candidate for the planned AUR-201 biopsy and implantation procedure (i.e., either TPF flap or pocket technique) and that the subject meets the following criteria:

∙ Healthy auricular cartilage donor site (e.g., conchal bowl site) on contralateral (non-microtic) ear available for biopsy;

‣ Healthy skin tissue at site of planned microtia repair;

• Healthy (other than for microtia) as determined by the PI based on medical history, physical examinations, body weight, vital signs, 12-lead electrocardiogram (ECG), and safety laboratory tests at screening/pre-biopsy baseline;

• Negative test results for human immunodeficiency virus 1 (HIV-1), human immunodeficiency virus 2 (HIV-2), hepatitis B virus (HBV), hepatitis C virus (HCV), Treponema pallidum (i.e., syphilis), and West Nile virus 1 (WNV-1) within seven days prior to the biopsy for harvesting auricular cartilage from the contralateral ear;

• Body weight ≥ 30 kg at time of screening;

⁃ Able to understand English or Spanish language;

⁃ Subject or parent/guardian able to understand the ICF and give informed consent, and for subjects \<18 years of age, subject able to understand the ICF and give assent;

⁃ Subject or parent/guardian signed the ICFs for both this study (Protocol No. AUR-201-05) and the long-term follow-up (LTFU) study (Protocol No. AUR-201-06), and for subjects \<18 years of age, the subject provided assent for both studies;

⁃ Women of childbearing potential (WCBP) must have a negative serum pregnancy test at screening and a negative urine pregnancy test at the pre-biopsy baseline visit;

⁃ WCBP must agree to abstain from sex or use an adequate method of contraception\* from the time of informed consent through the Final Study Visit (24 weeks ± 14 days after the first implantation surgery);

⁃ Males must abstain from sex with WCBP or use an adequate method of contraception\* from the time of informed consent through the Final Study Visit (24 weeks ± 14 days after the first implantation surgery).

∙ Adequate contraceptive methods include those with a low failure rate, i.e., less than 1% per year, when used consistently and correctly, such as some double barrier methods (condom with spermicide) in conjunction with use by the partner of an intrauterine device, diaphragm with spermicide, oral contraceptives, birth control patch or vaginal ring, or injectable or implanted contraceptives. Abstinence is acceptable only as true abstinence: when this is in line with the preferred and usual lifestyle of the subject. Periodic abstinence (e.g., calendar, ovulation, symptothermal, post-ovulation methods) and withdrawal are not acceptable methods of contraception. A woman that is postmenopausal (≥2 years since last menstrual period) or permanently sterilized (e.g., tubal occlusion, hysterectomy, bilateral salpingectomy) is not considered a WCBP.