• Multiple laser energies were usted to generate and compare distinct LIPSS properties. • Low-power LIPSS reduced the inflammatory profile and enhanced osteogenesis while inhibiting adipogénesis. • HA incorporation was achieved while preserving surface patterns, but no biological benefit was observed. Despite its widespread use in orthopedic implants, titanium exhibits limited bioactivity, which hinders effective osseointegration. To enhance its biological performance, laser-induced periodic surface structures (LIPSS) have emerged as a promising strategy, providing nanoscale topographies that influence cell behavior. In this study, we systematically evaluated the effect of femtosecond laser power (50–150 mW) on LIPSS formation on titanium surfaces, with and without concurrent hydroxyapatite (HA) incorporation, and examined their impact on inflammatory and differentiation responses in C3H10T1/2 mesenchymal stem cells. All laser powers generated well-defined LIPSS, with increasing surface roughness and particulate deposition at higher powers. Biologically, the surfaces generated using a laser power of 50 mW attenuated excessive inflammatory responsiveness under LPS stimulation (mean fold change of inflammatory markers 0.61) compared with weaker attenuation at higher powers (0.72–0.80) or HA-treated surfaces (0.93). Importantly, the 50 mW surface also promoted the most robust osteogenic differentiation, increasing the mean expression of osteogenic markers by 1.66-fold at day 7 and 1.43-fold at day 14 relative to controls, while maintaining adipogenic marker expression slightly below control levels (mean fold change of adipogenic markers 0.94). In contrast, higher laser powers and HA incorporation induced modest but consistent increases in adipogenic marker expression. These findings indicate that low-power LIPSS effectively balance immune modulation and osteogenesis, providing an advantageous surface modification strategy for titanium implant optimization. Overall, this study establishes a mechanistic link between laser power, surface topography, and cellular responses, highlighting low-power LIPSS as a promising approach to enhance implant integration.
Pazos-Perez et al. (Sun,) studied this question.