• -Leveraging precision synthesis and transfer technology for next-generation MoS₂ nanomaterials to establish customized theragenerative biomaterials
• -Research findings published in the internationally renowned journal Nano Convergence (IF: 13.8, JCR: Top 8.8%)
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• Figure caption: (From left) Co-corresponding authors Professor Minho Kang of the Department of Biomedical Chemical Engineering at The Catholic University of Korea and Professor Hyundo Jeong of the School of Materials Science and Engineering at Hanyang University, and co-first authors Inho Choi, M.S. candidate in the Department of Biomedical Chemical Engineering at The Catholic University of Korea, and Jonghwa Seo, Ph.D. candidate in the School of Materials Science and Engineering at Hanyang University.
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  A research team led by Professor Minho Kang of the Department of Biomedical Chemical Engineering at The Catholic University of Korea, in collaboration with Professor Hyundo Jeong's research team from the School of Materials Science and Engineering at Hanyang University, has developed a new biomaterial platform that uniformly modifies the surface of patient-specific 3D-printed implants with the next-generation nanomaterial molybdenum disulfide (MoS₂) without causing damage.
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  This study is particularly significant because it not only applies MoS₂, a representative semiconductor material, to biomedical applications but also introduces a proprietary process that enables high-quality two-dimensional (2D) nanomaterials to be transferred onto complex three-dimensional (3D) polymer implant surfaces without defects.
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  Polyether ether ketone (PEEK), widely used as an orthopedic implant material, possesses an elastic modulus similar to that of bone and excellent mechanical stability. However, its inherently low bioactivity limits its ability to promote cell adhesion and bone integration. Although MoS₂, which generates heat or reactive oxygen species upon light irradiation, has attracted attention as a next-generation therapeutic material, two major challenges have hindered its practical application to implants. The first was the need to produce large-area, highly uniform MoS₂ with precisely controlled thickness and crystallinity. The second was the challenge of coating the resulting MoS₂ uniformly onto heat-sensitive 3D polymer PEEK surfaces without causing damage.
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  To overcome the first challenge, the research team employed the MoO₂ nanoseed-initiated APCVD process. This novel synthesis method utilizes highly crystalline MoO₂ nanoparticles as "seeds" for MoS₂ crystal growth, enabling precise control over crystal orientation and uniformity. The team uniformly coated MoO₂ precursor particles onto a sapphire wafer, followed by a sulfurization process. As a result, they successfully achieved uniform growth of a monolayer MoS₂ film with a thickness of approximately 6 Å (equivalent to a single atomic layer) across an entire 2-inch wafer.
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  To address the second challenge, the researchers applied a polymer-assisted transfer process to transfer the synthesized monolayer MoS₂ onto the surface of 3D-printed PEEK implants. In this process, a thin layer of polystyrene (PS), serving as a support film, was coated onto the MoS₂ grown on the wafer. The PS-supported MoS₂ film was then gently detached from the wafer using water, transferred onto the PEEK surface, and finally freed from the PS layer. This proprietary transfer technology enabled the stable integration of monolayer MoS₂ onto PEEK implant surfaces, which cannot withstand direct high-temperature processing. Notably, the study demonstrated the uniform coating of monolayer MoS₂ over a large-area 3D-printed scaffold featuring complex surface roughness, curvature, and microstructural irregularities rather than a simple flat substrate, highlighting the platform's technological innovation.
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  The resulting MoS₂@PEEK platform was designed to reconstruct irregular bone defects following osteosarcoma resection using patient-specific implants while simultaneously suppressing residual cancer cells and bacterial infections through phototherapy. By introducing a monolayer MoS₂ surface coating, the researchers successfully overcame the limited bioactivity of conventional PEEK, transforming it from a passive structural scaffold into an active platform capable of both therapy and tissue regeneration.
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  Upon irradiation with 650 nm light, the platform generates reactive oxygen species to induce photodynamic therapy for cancer cell elimination. Exposure to 808 nm near-infrared light produces localized heat, enabling photothermal therapy. The combined photodynamic and photothermal effects significantly enhance both residual osteosarcoma cell eradication and antibacterial activity. Furthermore, precise control of the 808 nm photothermal stimulation promotes the adhesion, proliferation, and differentiation of osteoblasts and vascular endothelial cells, thereby facilitating vascularized bone regeneration.
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  Professor Minho Kang of the Department of Biomedical Chemical Engineering at The Catholic University of Korea stated, "The platform developed through this collaborative research represents a next-generation theragenerative strategy capable of simultaneously preventing recurrence after osteosarcoma resection, controlling infection, and promoting bone regeneration within a single implant system. It is particularly meaningful because it successfully integrates next-generation nanomaterial technology into polymer implant materials, which have long faced barriers to clinical application. We will continue to advance follow-up studies aimed at maximizing both anticancer efficacy and bone regenerative performance."
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  This research was supported by the Nano and Materials Technology Development Program and the Basic Research Program of the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT, the Korea Institute of Marine Science & Technology Promotion (KIMST) funded by the Ministry of Oceans and Fisheries, the Korean Fund for Regenerative Medicine (KFRM), and the National Research Facilities and Equipment Center (NFEC) of the Korea Basic Science Institute (KBSI).
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Figure caption

(Figure 1) The research team synthesized large-area, highly crystalline monolayer MoS₂ using the MoO₂ nanoseed-initiated APCVD process and successfully achieved uniform surface modification by transferring it onto the surface of patient-specific 3D-printed PEEK scaffolds through a polymer-assisted transfer process.

The developed MoS₂@PEEK platform simultaneously induces tumor suppression and antibacterial effects through 650 nm photodynamic therapy and 808 nm photothermal therapy, while enhancing the activity of osteoblasts and vascular endothelial cells to promote vascularized bone regeneration.

(Figure 2) After dispersing the MoO₂ solution onto a wafer, the researchers grew MoS₂ on the wafer using the nanoseed-initiated APCVD method with the MoO₂-coated wafer and sulfur powder.

Subsequently, polystyrene was spin-coated onto the MoS₂-grown wafer, and the MoS₂ was transferred onto the surface of a 3D-printed PEEK scaffold through a polymer-assisted transfer process.

(Figure 3) Photothermal performance of MoS₂@PEEK under 808 nm near-infrared (NIR) irradiation at different power densities and irradiation times, and photodynamic performance evaluated by the time-dependent generation of singlet oxygen under 650 nm irradiation based on SOSG fluorescence intensity.

Images showing the antibacterial effects against E. coli and osteosarcoma cell killing following different dual-photoirradiation treatments.

(Figure 4) Representative SEM and fluorescence images showing the adhesion of preosteoblasts on different 3D-printed PEEK specimens after 6 hours of culture.

Cell proliferation evaluated using the CCK-8 assay.

Alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining results for osteogenic differentiation after 7 and 14 days of culture.