POS8-0833
Injectable Soft Nanogel for Sustained Drug Release
Topic
S8. Frontiers of Functional Polymers in Biology and Medicine
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
YOUNGJUN LEE (Seoul National University)
Co-Author(s)
Abstract
Injectable hydrogels have emerged as promising platforms for localized drug delivery, offering minimally invasive, in situ formation of drug depots directly at target sites. Nevertheless, achieving sustained local release of small molecule drugs from hydrogels remains challenge.
Small molecule drugs generally diffuse rapidly in hydrogels because of their high diffusion coefficients and the relatively large mesh size of conventional polymer networks. To address this limitation, we propose soft and compressible PEG-based nanogels as an injectable colloidal hydrogel system. Owing to their deformability, the nanogels were concentrated to 50 wt% polymer content, forming a jammed suspension that is self-supporting at rest but flows under applied stress. This shear-responsive behavior allows injection while preserving a densely packed structure after administration. The confined interparticle spaces in this jammed nanogel matrix are expected to hinder the diffusion of small-molecule drugs.
To evaluate molecular transport within the concentrated nanogel matrix, fluorescence recovery after photobleaching (FRAP) was used to measure the diffusion coefficient of a small fluorescent molecule. The molecule showed an apparent diffusion coefficient approximately 100-fold lower than that in free water, indicating strongly restricted diffusion within the densely packed nanogel system.
These results suggest that compressible PEG nanogel colloids can be used as an injectable hydrogel platform for sustained local release of small-molecule drugs.
Small molecule drugs generally diffuse rapidly in hydrogels because of their high diffusion coefficients and the relatively large mesh size of conventional polymer networks. To address this limitation, we propose soft and compressible PEG-based nanogels as an injectable colloidal hydrogel system. Owing to their deformability, the nanogels were concentrated to 50 wt% polymer content, forming a jammed suspension that is self-supporting at rest but flows under applied stress. This shear-responsive behavior allows injection while preserving a densely packed structure after administration. The confined interparticle spaces in this jammed nanogel matrix are expected to hinder the diffusion of small-molecule drugs.
To evaluate molecular transport within the concentrated nanogel matrix, fluorescence recovery after photobleaching (FRAP) was used to measure the diffusion coefficient of a small fluorescent molecule. The molecule showed an apparent diffusion coefficient approximately 100-fold lower than that in free water, indicating strongly restricted diffusion within the densely packed nanogel system.
These results suggest that compressible PEG nanogel colloids can be used as an injectable hydrogel platform for sustained local release of small-molecule drugs.
