Nanofilm biomaterials: localized cross-linking to optimize mechanical rigidity and bioactivity

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Cell Biology

Background:

• Nanofilm biomaterials are crucial for cell-contacting applications.
• Mechanical rigidity and bioactivity are key properties influencing cell behavior.
• Simultaneously achieving rigidity and bioactivity in nanofilms is challenging due to cross-linking methods impacting bioactivity.

Purpose of the Study:

• To develop a strategy to decouple mechanical rigidity and bioactivity in nanofilm biomaterials.
• To create nanofilms with a rigid outer layer for enhanced cell attachment while preserving inner bioactivity.
• To demonstrate a method for producing simultaneously rigid and bioactive nanofilm biomaterials.

Main Methods:

• Utilized layer-by-layer assembly of charged macromolecules to form nanofilms.
• Employed N-hydroxysulfosuccinimide (sulfo-NHS) activated poly(L-glutamic acid) as a terminal layer for selective outer region cross-linking.
• Characterized film assembly and cross-linking using quartz crystal microbalance with dissipation monitoring (QCMD), FTIR-ATR, and LSCM.
• Assessed cell attachment and metabolic activity of preosteoblastic MC3T3-E1 cells.

Main Results:

• Demonstrated selective cross-linking primarily occurring at the film surface.
• Observed enhanced cell attachment and metabolic activity on the modified nanofilms compared to native films.
• Confirmed the decoupling of mechanical rigidity and bioactivity through surface cross-linking.

Conclusions:

• The proposed method successfully creates nanofilm biomaterials that are both mechanically rigid and bioactive.
• Selective surface cross-linking offers a promising approach to overcome limitations of traditional cross-linking methods.
• This strategy enables the development of advanced biomaterials for diverse biomedical applications.