Given the rise of peptide and protein therapeutics in the pharmaceutical landscape, identifying the right delivery strategies that are patient-friendly and can be used over broad dose ranges has always been important considerations for the discovery and development of these therapeutic modalities. In recent years, polymeric hydrogels have emerged as potential drug delivery vehicles for peptides and proteins owing to their advantageous properties, including high water content, tunable viscoelasticity, and biocompatibility, which allow bioactive molecules to be protected against degradation and released from the hydrogel matrix in a controlled manner over an extended period of time.

Dr Yingkai Laing from Merck & Co discusses this further and shares some examples of his groups work. In this study, a series of injectable, thermo-responsive hydrogel formulations were evaluated as controlled delivery systems for peptides and proteins. These hydrogel formulations were prepared using concentrated solutions of thermo-gelling PEG/polyester block copolymers, which can undergo temperature-induced sol-gel transitions and spontaneously solidify into hydrogel near the body temperature. Additionally, the thermal gelation of these polymers was also combined with covalent crosslinking to develop in situ forming yet highly stable hydrogels for extended release of macromolecular cargos. Utilizing insulin peptide analogues as model proteins, the delivery and therapeutic efficacy of these formulations in vivo were also studied in diabetic minipig and mouse models via subcutaneous administration. Taken together, these injectable, thermo-responsive hydrogel formulations presented a promising approach for the controlled and sustained delivery of biomacromolecules, which suggests significant potential in developing long-acting parenteral formulations of protein therapeutics to improve patient’s comfort, convenience, and compliance.