# Bone‐Mimetic Osteon Microtopographies on Poly‐ε‐Caprolactone Enhance the Osteogenic Potential of Human Mesenchymal Stem Cells

## TL;DR

A new bone-like surface design improves the bone-forming ability of stem cells, which could lead to better bone implants.

## Contribution

A novel biomimetic osteon-like microtopography is developed and shown to significantly enhance hMSC osteogenic potential.

## Key findings

- Osteon-like microtopography increases cell attachment threefold compared to a blank surface.
- Proliferation of hMSCs is fourfold higher on osteon-like structures.
- ALP activity is threefold higher at day 7 and fivefold higher at day 14 on osteon-like surfaces.

## Abstract

The attributes of implant surfaces are pivotal for successful osseointegration. Among surface engineering strategies, microtopography stands out as a promising approach to promote early cellular interactions. This study aims to design and craft a novel biomimetic osteon‐like surface modification and to compare its impact on human mesenchymal stem cells (hMSCs) with four established topographies: blank, inverted pyramids, protrusions, and grooves. Poly‐ε‐caprolactone samples are fabricated using 2‐photon‐polymerization and soft lithography, prior to analysis via scanning electron microscopy (SEM), water contact angle (WCA), and protein adsorption assays. Additionally, cellular responses including cell attachment, proliferation, morphology, cytoskeletal organization, and osteogenic differentiation potential are evaluated. SEM confirms the successful fabrication of microtopographies, with minimal effect on WCA and protein adsorption. Cell attachment experiments demonstrate a significant increase on the osteon‐like structure, being three times higher than on the blank. Proliferation assays indicate a fourfold increase with osteon‐like microtopography compared to the blank, while ALP activity is notably elevated with osteon‐like microtopography at days 7 (threefold increase over blank) and 14 (fivefold increase over blank). In conclusion, the novel biomimetic osteon‐like structure demonstrates favorable responses from hMSCs, suggesting potential for promoting successful implant integration in vivo.

The implant surface is crucial for osseointegration, with microtopography as a promising tool. This study designs a novel biomimetic osteon‐like surface and compares its impact on human mesenchymal stem cells with four topographies. Osteon‐like structure significantly enhances cell attachment, proliferation, and osteogenic differentiation. Combined with other techniques like nanoimprint lithography, osteon‐like microtopography has the potential to be used for future bone implants.