RPI ID:
2019-013-401 / 2019-013-601

Innovation Summary:
A poly(pro‑drug) platform constructs biodegradable polymers in which the therapeutic molecule itself—such as estradiol, curcumin, or fingolimod—forms the repeating backbone, linked by cleavable ester, carbonate, or urethane groups and separated by hydrocarbyl or PEG‑based spacers. These high‑molecular‑weight polymers (≈80–90 kDa, n > 25) degrade under physiological conditions to release the active agent at near zero‑order rates (~0.01–0.25%/day), enabling implants that last months to years with minimal burst. Processing routes including casting and electrospinning yield films, fibers, and scaffolds suitable for localized drug delivery in neurological repair, hormone therapy, oncology, and veterinary treatments. By tuning linker chemistry and polymer architecture, release profiles can be customized for indication‑specific regimens while maximizing drug loading and minimizing excipients.

Challenges / Opportunities:
Translation of long‑acting implants requires rigorous validation of biocompatibility, degradation products, sterilization compatibility, and batch‑to‑batch reproducibility in molecular weight and composition. Indication‑specific calibration is necessary to ensure the desired multi‑month or multi‑year release rates in vivo. Market opportunities include expanding to additional small‑molecule drugs, developing combination scaffolds that pair structural support with sustained therapy, and differentiating from existing depot systems through true zero‑order kinetics and drug‑as‑polymer architecture. Manufacturing optimization and regulatory positioning will be key for commercial viability.
Key Benefits / Advantages:
✔ Years‑scale, near zero‑order drug release
✔ High drug loading due to “drug‑as‑polymer” design
✔ Significantly reduced burst release and excipient burden
✔ Tunable linker chemistry for indication‑specific kinetics
✔ Fabrication versatility (films, fibers, electrospun scaffolds)
✔ Suitable for local, long‑acting therapeutic delivery

Applications:
• CNS injury repair and neuroprotective delivery
• Long‑acting hormone therapy and contraception
• Localized anti‑cancer delivery and tumor‑bed prophylaxis
• Veterinary sustained‑release implants

Keywords:
poly(pro‑drug), long‑acting implant, zero‑order release, biodegradable linker, PEG spacer, electrospun scaffolds

Intellectual Property:
US issued patent no. 11,202,834; US published patent application no. US17/515,861