Evaluating in Vitro Calcium Phosphate Formation on the Surfaces of Synthesized Silanated Polymethylmethacrylate Microspheres

Mohammadi, Fatemeh; Hesaraki, Saeed; Naghizadeh, Rahim; Nezafati, Nader; Beygzadeh, Mojtaba

doi:10.30501/acp.2025.538730.1182

Evaluating in Vitro Calcium Phosphate Formation on the Surfaces of Synthesized Silanated Polymethylmethacrylate Microspheres

Document Type : Original Research Article

Authors

Fatemeh Mohammadi ¹

Saeed Hesaraki ²

Rahim Naghizadeh ³

Nader Nezafati ⁴

Mojtaba Beygzadeh ⁵

¹ MSc Student, School of Materials and Metallurgical Engineering Iran University of Science and Technology, Tehran, Iran.

² Professor, Department of Nanotechnology and Advanced Materials, Materials and Energy Research Center, Karaj, Iran.

³ Associate Professor, School of Materials and Metallurgical Engineering Iran University of Science and Technology, Tehran, Iran.

⁴ Associate Professor, Department of Nanotechnology and Advanced Materials, Materials and Energy Research Center, Karaj, Iran.

⁵ Assistant Professor, Department of Energy, Materials and Energy Research Center, Karaj, Iran.

10.30501/acp.2025.538730.1182

Abstract

Poly(methyl methacrylate) (PMMA) bone cement is widely used in orthopedic applications such as kyphoplasty and prosthesis fixation due to its favorable mechanical properties. However, its inherent bioinertness limits direct bonding with bone tissue. This study presents a novel approach to enhance the bioactivity of PMMA through surface chemical modification of the powder phase. PMMA microspheres were synthesized using the solvent evaporation emulsification method, which involved optimizing the surfactant type and concentration, as well as process parameters, to achieve morphological stability. Surface hydrolysis with sulfuric acid was conducted to introduce carboxylic functional groups. Subsequently, chemical functionalization was performed using varying concentrations of silane coupling agents, GPTMS and TEOS. FTIR spectroscopy and SEM analyses confirmed successful surface modification while preserving microsphere morphology. Bioactivity was evaluated by immersing the samples in simulated body fluid (SBF) for 1, 7, and 14 days. A gradual formation of a hydroxyapatite layer was observed on the modified surfaces, as evidenced by SEM imaging, FTIR spectra, and XRD patterns. The results demonstrate that surface silanization considerably improves the bioactivity of PMMA microspheres. This surface modification strategy shows strong potential for developing PMMA-based implant materials with enhanced osseointegration capability.

Keywords

Polymethyl Methacrylate

Y-Glycidoxypropyltrimethoxysilane

Tetraethylorthosilcate

Simulated Body Fluid

Bioactivity

Subjects

Biomaterials

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