A low-cost fabrication method could make advanced tissue-engineering materials easier to produce in Thailand

Researchers at Walailak University, led by Assistant Professor Dr. Aruna Prasopthum of the School of Pharmacy, have developed a three-dimensional tissue scaffold that mimics the natural transition from cartilage to bone, offering a potential new approach to repairing damaged knee joints. The work is still at the preclinical stage but has already attracted interest from several companies.

Knee injuries that cross both cartilage and the bone beneath it are especially difficult to treat. Bone has a good blood supply and can repair itself reasonably well, but cartilage heals poorly. “Cartilage has very little blood supply, so once it is badly damaged, its ability to heal is limited,” Dr. Aruna explained. Existing options such as microfracture and mosaicplasty each have limitations, including less durable repair tissue and a limited supply of donor tissue. 

The researchers set out to create a single implant that supports cartilage at the surface and bone underneath. “A simple analogy is a two-storey house, where each floor is built for a different purpose,” Dr. Aruna said.

Rather than joining separate layers, which can create weak interfaces, the scaffold is a single continuous piece. Its upper region has smaller pores and a fine, nanofiber-like surface suited to cartilage formation. Moving downward, the pores become larger and the content of bioactive glass rises, reaching approximately 70–90% by weight in the deepest region, which encourages bone formation and blood-vessel growth.

In laboratory studies, human mesenchymal stem cells, adult stem cells that can develop into bone, cartilage and other cell types, responded differently depending on their position. Cartilage-related markers were strongest in the upper and middle regions, while bone-related markers and blood-vessel formation were higher near the bone-like zone. These findings are reported in a 2025 paper, “Facile fabrication of cartilage-bone interface-mimicking ductile scaffolds for zone-specific stem cell differentiation and angiogenesis,” published in ACS Applied Bio Materials.

Bioactive glass is normally brittle. The researchers overcame this by holding the glass particles within a flexible polymer framework, adding a suitable amount of polyethylene glycol (PEG), an additive that helps the material stay flexible, and controlling the pore structure. “A scaffold that can bend slightly without breaking can be trimmed and shaped to fit an irregular defect, whereas a brittle material may crack or fragment during implantation,” Dr. Aruna said. The flexibility has been confirmed in laboratory tests; its benefit in real surgery has yet to be shown.

While 3D printing and bioprinting offer great precision, they depend on costly equipment and specialist operators. This scaffold is made using a simpler approach. “Our scaffold achieves a similarly complex cartilage-to-bone architecture through a much simpler process based on controlled cooling, polymer phase separation, and removable pore-forming particles, without requiring an advanced 3D printer,” Dr. Aruna said. This could lower manufacturing barriers and support future production in Thailand. Even though this work does not rely on 3D printing, the research group has also established a 3D printing laboratory at Walailak University and is pursuing advanced fabrication and bioprinting research in parallel.

In related work published in 2025 in the Journal of Biomedical Materials Research Part A, “Silver-doped mesoporous bioactive glass nanoparticles with core–shell architecture: enhanced in vitro bioactivity, antibacterial efficacy, and biocompatibility,” the researchers developed nanoparticles that release silver gradually at very low concentrations. The particles showed strong antibacterial activity against E. coli and methicillin-resistant Staphylococcus aureus (MRSA) while still supporting the survival and bone-forming behavior of human stem cells.

“Our research is still preclinical,” Dr. Aruna said. “We have demonstrated the proof-of-concept in laboratory and simulated biological models, but not yet in a large-animal or human knee.”

The next steps include large-animal testing in a load-bearing knee, along with studies of durability, sterilization, manufacturing consistency and safety. If therapeutic stem cells are incorporated, the product could fall under the Advanced Therapy Medicinal Product (ATMP) framework, and commercial products would require Thai FDA registration. In an optimistic scenario, first-in-human use could be around three to five years away. The technology was submitted for a Thai petty patent in April 2025 and has drawn interest from several companies for due diligence on its commercial potential.

The research was carried out through collaboration among researchers from Walailak University (School of Pharmacy), Chulalongkorn University (Faculty of Engineering), Burapha University (Faculty of Science) and Nanchang University, China. It was supported by the National Research Council of Thailand (NRCT) through the Research Grant for Talented Young Researchers (Grant No. N42A650219), awarded to Dr. Aruna in 2022.

Photos courtesy of Assistant Professor Dr. Aruna Prasopthum
News by Settaboot Onphakdee, Division of Corporate Communications