UGM Researchers Develop Crack-Resistant Biomaterial Innovation for Bone Tissue Engineering
The demand for biomimetic materials for bone tissue engineering continues to rise due to the increasing complexity of clinical cases, such as severe trauma, bone tumors, and osteomyelitis. In such conditions, the human body cannot naturally regenerate bone, necessitating the use of bone scaffolds—biocompatible support structures designed to mimic real bone tissue.
Scaffold technology plays a vital role in treating complex bone injuries by enabling precise reconstruction of bone shape and function. One of the most promising approaches in scaffold development is the use of a composite of hydroxyapatite (HA) and collagen. HA is the primary inorganic component of bone. At the same time, collagen is a natural organic polymer that supports cell adhesion and proliferation. However, printing scaffolds with these materials often results in microcracks after the drying process.
To address this issue, an interdisciplinary research team from the Department of Mechanical and Industrial Engineering, Faculty of Engineering, Universitas Gadjah Mada (FT UGM), consisting of Dr. M. Kusumawan Herliansyah, Professor Alva Edy Tantowi, and Dr. Maria G. Widiastuti from the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry (FKG UGM), along with doctoral student Nurbaiti, developed an innovative material by adding nanocrystalline cellulose (NCC) to the HA mixture.
NCC is a nano-sized cellulose-based material known for its high mechanical strength and biocompatibility. The team’s findings were published in the Q1-ranked International Journal of Engineering in February 2025, in an article titled “Effect of Adding Nanocrystalline Cellulose on Reducing Micro-Crack of Three-Dimensional Printed Hydroxyapatite/Collagen Composite.”
Professor Tantowi, one of the researchers, stated that NCC holds great potential as it not only strengthens the structure but also maintains material homogeneity in 3D-printed forms.
“Adding NCC is expected to reduce the risk of cracking and improve scaffold quality,” he explained.
The experiment employed extrusion-based 3D bioprinting using an optimal composition of 70% HA, 15% collagen, and 15% NCC. The results showed no cracking after the printing and drying processes. Professor Tantowi noted that NCC significantly improved interlayer cohesion and structural stability during manufacturing.
“Shrinkage on the X, Y, and Z axes was only around 14%, 15.1%, and 20.5%, respectively, indicating good dimensional stability,” he said.
In terms of mechanical properties, the composite material demonstrated a hardness value between 0.002 and 0.003 HV. This hardness is sufficient to meet strength requirements under light pressure during the bone healing process. Additionally, FTIR and XRD characterization confirmed the presence of key functional groups. It showed a reduction in crystallinity index to 28%, indicating enhanced material flexibility—a beneficial trait in tissue regeneration. This decrease in crystallinity also improves the material’s ability to adapt to dynamic biological environments.
“The resulting scaffold is not only sturdy but also more responsive to new tissue formation processes,” added Professor Tantowi.
Electron microscopy analysis (SEM and TEM) revealed a uniformly formed scaffold surface, with spherical HA particles, fibrous collagen, and rod-shaped NCC. This consistent morphological distribution indicates good material mixing and the absence of phase segregation, a common cause of structural weakness in printed composites. Moreover, particle bonding within the 3D network demonstrated solid, biomimetic integration. EDX analysis showed the dominant elements to be oxygen (47.77%), calcium (36.62%), and phosphate (12.8%), all of which are significant components in new bone formation.
“This structure closely resembles the morphology of natural bone tissue, which is a key indicator of a successful biomimetic scaffold,” Professor Tantowi elaborated.
In terms of thermal resistance, the material withstood temperatures of up to 650°C, resulting in a mass loss of only 23.46%. The addition of NCC also reduced the thermal degradation rate compared to NCC-free materials, indicating better overall thermal stability. This durability is crucial to ensuring that the scaffold remains intact during high-temperature fabrication or sterilization processes.
“With strong thermal resistance, this scaffold is not only suitable for clinical applications but also safe for high-temperature medical sterilization,” said Professor Tantowi.
This research not only provides a technical solution to the issue of microcracks in bone scaffolds but also opens up new opportunities for the development of locally sourced, biomimetic materials. Furthermore, it reflects FT UGM’s strong commitment to advancing science and technology that directly addresses real-world challenges.
“We hope this technology can be further developed on an industrial scale to meet clinical needs in hospitals while also supporting national independence in medical device production,” Professor Tantowi concluded.
Author: Triya Andriyani
Post-editor: Lintang Andwyna
Photograph: Freepik