This POSTECH Injectable Hydrogel Could Replace Painful Bone Grafts

This POSTECH Injectable Hydrogel Could Replace Painful Bone Grafts

Watchdoq May 29, 2025
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A South Korean breakthrough may eliminate painful bone graft surgeries. POSTECH’s injectable hydrogel rebuilds bone using mussel-inspired adhesion and light.

This Gel Could Replace Painful Bone Grafts: The New Hope from POSTECH’s Injectable Hydrogel

It could’ve been another routine breakthrough buried in a lab paper. But this time, it’s different—because the hope it offers is deeply human.

In late 2024, a group of researchers from South Korea’s POSTECH (Pohang University of Science and Technology) quietly unveiled something extraordinary: a light-activated injectable hydrogel that may one day replace invasive bone graft surgeries. For millions worldwide—whether accident victims, osteoporosis patients, or the elderly—this discovery is a glimpse of a future with less pain, less surgery, and more dignity.

At the center of this innovation is Professor Hyung Joon Cha, along with Dr. Jinyoung Yun and PhD student Hyun Taek Woo, who together have reimagined what bone regeneration can look like. Their work, published in the journal Biomaterials in early 2025, has now gained traction not just among scientists, but among patients, caregivers, and doctors hungry for safer, smarter solutions.

A Gel That Grows Bone

What sounds like science fiction is actually a brilliant combination of nature and nanoscience.

The hydrogel is made of:

  • Alginate, a seaweed-derived substance used in wound dressings and food.
  • RGD peptide-rich mussel adhesive proteins, inspired by how mussels cling to rocks underwater.
  • Calcium ions and phosphonodiols, which help create the mineral matrix of bones.
  • A visible-light photoinitiator, which hardens the gel into a porous scaffold when exposed to safe light.

Here’s how it works: The gel is injected into a bone defect and exposed to visible light. Within seconds, it hardens and mineralizes simultaneously, becoming a biodegradable scaffold. This scaffold attaches firmly to irregular bone surfaces—even in wet conditions like inside the human body—and begins supporting the natural growth of osteoblasts, or bone-forming cells. Over time, the scaffold dissolves, replaced by healthy bone.

Why This Matters: The Human Cost of Bone Grafts

Each year, 2.2 million bone graft surgeries are performed globally. The traditional method involves harvesting bone from the patient’s own body—usually the leg or hip. This isn’t just painful; it creates a second injury site, increasing infection risks and recovery time.

For older patients, those with chronic illness, or trauma survivors, these surgeries can be debilitating. That’s where POSTECH’s gel offers a profound alternative: no cutting, no harvesting, no secondary pain.

What the Tests Showed

In animal studies—specifically a rat femur bone defect model—researchers found:

  • Strong adhesion to jagged bone surfaces without additional adhesives.
  • Rapid bone regrowth within weeks.
  • The hydrogel was fully replaced by new bone tissue, without complications.

In lab (in vitro) settings, osteoblasts not only thrived but proliferated and mineralized inside the gel, proving it wasn’t just a filler—it actively supported regeneration.

Why It Feels Like a Turning Point

This isn’t POSTECH’s first foray into healing through biology. The university previously developed:

  • 3D-printed scaffolds using polycaprolactone (2014),
  • Light-activated wound adhesives (2015),
  • And mussel protein-inspired scaffolds for cardiac and skeletal repair (2021–2022).

But this injectable hydrogel brings everything together—strength, safety, simplicity—in a format that could soon be used in outpatient clinics or emergency trauma units.

What Happens Next?

As of May 2025, the hydrogel hasn’t reached clinical trials, but it’s on the radar. More animal testing, regulatory approvals, and partnerships are required before human use. But experts believe it’s a matter of "when," not "if."

In India—where over 4.6 lakh road accidents were reported in 2022 (NCRB) and osteoporosis silently affects millions of aging women and men—a non-invasive, affordable option like this could be transformative. Particularly when public health spending is just 1.3% of GDP, cost-effective innovations become critical.

Imagine the possibilities: A woman in a Tier-2 Indian town, suffering a spinal fracture due to age, getting treated with a gel and a light, rather than enduring surgery in a distant metro. That’s the kind of change this research could deliver.

A Word to Caregivers and NRIs

If you're caring for aging parents in India or have loved ones recovering from accidents, keep this on your radar. While it’s not available in clinics yet, innovations like these often appear in clinical trials or global partnerships in the next 2–5 years.

Talk to your orthopedic doctors. Keep an eye on developments from POSTECH. Platforms like EurekAlert, ScienceDaily, and even New Atlas are covering this breakthrough because it matters to real people.

This is more than a scientific milestone. It’s a story of empathy meeting engineering—of researchers who looked at surgical pain and said, "There must be a better way." And perhaps, just perhaps, this tiny gel is the better way we’ve been waiting for.

? Sources:

  • Biomaterials, Volume 315, 2025 (DOI: 10.1016/j.biomaterials.2024.122948)
  • EurekAlert (Dec 30, 2024)
  • ScienceDaily (Dec 31, 2024)
  • The Engineer (Jan 2, 2025)
  • New Atlas (Jan 4, 2025)

NCRB India Road Accident Report 2022