Coupled effects of sintering temperature and spacer particle size on properties of powder-metallurgy Mg–Zn–GO–Bredigite scaffolds
Year: 2026
Type: article
Abstract: Magnesium scaffolds face rapid degradation that may impair early cell response. Here, magnesium–zinc–graphene oxide–Bredigite (Mg–Zn–GO–Bredigite) composite scaffolds were fabricated by powder metallurgy using urea (35 vol.%) as spacer, varying sintering temperature (520, 540, 560 °C) and spacer particle size (A: <150 µm; B: 150–250 µm; C: 250–600 µm). Pore architecture, wettability, compression, corrosion, and cytocompatibility using human osteoblast-like MG-63 cells were evaluated. Scanning electron microscopy (SEM) showed homogeneous microstructure at 540 °C, while 560 °C caused excessive sintering. Larger spacers increased macropore size from A to C. Contact angle was lowest for B (∼31–32°), higher for A and C (∼92–99°). The highest compressive strength (∼8 MPa) was achieved for the scaffold sintered at 540 °C with the largest spacer size (250–600 µm), highlighting the combined influence of sintering temperature and pore architecture on mechanical performance. Electrochemical impedance spectroscopy (EIS) indicated improved short-term electrochemical corrosion resistance for the scaffold sintered at 540 °C. The methyl thiazolyl tetrazolium (MTT) assay at 72 h showed metabolic activity 49–55% of control (A: 55.5% > B: 51.3% > C: 49.2%). Live/Dead staining confirmed >77% viable cells (A: ∼90%, B: 83%, C: 77%). Alkaline phosphatase (ALP) activity supported osteogenic differentiation, reaching 1.916 U/mg protein in group A (day 14). Overall, sintering at 540 °C provided the most favorable consolidation window for corrosion resistance and mechanical integrity, while smaller pores (A) promoted the most favorable early MG-63 cell response under the present in vitro conditions. The spacer size-dependent trade-off between load-bearing capability and biological performance highlights the importance of architectural optimization. The achieved compressive strength falls within the lower range reported for cancellous bone, indicating potential suitability for low-load-bearing bone applications.
Source: Results in Engineering
Institution: Urmia University
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,940
OpenAlex ID: W7213909089