Bioactivation of 3D Cell-Imprinted Polydimethylsiloxane Surfaces by Bone Protein Nanocoating for Bone Tissue Engineering

Abstract

Physical and chemical parameters that mimic the physiological niche of the human body have an influence on stem cell fate by creating directional signals to cells. Micro/nano cell-patterned polydimethylsiloxane (PDMS) substrates, due to their ability to mimic the physiological niche, have been widely used in surface modification. Integration of other factors such as the biochemical coating on the surface can achieve more similar microenvironmental conditions and promote stem cell differentiation to the target cell line. Herein, we investigated the effect of physical topography, chemical functionalization by acid bone lysate (ABL) nanocoating, and the combined functionalization of the bone proteins’ nanocoated surface and the topographically modified surface. We prepared four distinguishing surfaces: plain PDMS, physically modified PDMS by 3D cell topography patterning, chemically modified PDMS with bone protein nanocoating, and chemically modified nano 3D cell-imprinted PDMS by bone proteins (ABL). Characterization of extracted ABL was carried out by Bradford staining and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis, followed by the MTT assay for evaluation of cell viability on ABL-coated PDMS. Moreover, field emission scanning electron microscopy and profilometry were used for the determination of optimal coating thickness, and the appropriate coating concentration was identified and used in the study. The binding and retention of ABL to PDMS were confirmed by Fourier transform infrared spectroscopy and bicinchoninic acid assay. Sessile drop static water contact angle measurements on substrates showed that the combined chemical functionalization and nano 3D cell-imprinting on the PDMS surface improved surface wettability by 66% compared to plain PDMS. The results of ALP measurement, alizarin red S staining, immunofluorescence staining, and real-time PCR showed that the nano 3D cell-imprinted PDMS surface functionalized by extracted bone proteins, ABL, is able to guide the fate of adipose derived stem cellss toward osteogenic differentiation. Eventually, chemical modification of the cell-imprinted PDMS substrate by bone protein extraction not only improved the cell adhesion and proliferation but also contributed to the topographical effect itself and caused a significant synergistic influence on the process of osteogenic differentiation.

Molecularly Imprinted Chalcone-Branched Polyimide-Based Chemosensors with Stripe Nanopatterns for the Detection of Melittin

“…After O 2 plasma treatment, the PDMS surface was successively functionalized with APTES and GA. 51 Finally, MEL was immobilized on the GA−PDMS surface through imine formation between the amine groups of MEL and the aldehyde groups of GA. As shown in Figure S4, the FT-IR spectrum of the MEL-immobilized PDMS surface showed C�N stretching and N−H bending vibration peaks at 1653 and 1530 cm −1 , respectively. 54,55 Thus, this spectrum indicated that MEL molecules used as templates for molecular imprinting were successfully immobilized on the GA−PDMS surface. For the formation of the S-MIP film, after the MIP precursor solution was dropped on QC substrates, microcontact printing was performed using the MEL-immobilized PDMS mold to photochemically crosslink CB-PI.…”

Regulation of cell fate by cell imprinting approach in vitro

“…Babaei et al, showed improvement in cell adhesion, proliferation and osteogenic differentiation by coating the osteoblast imprinted substrates with bone extracted proteins. 164 In another recently published report, it was found that small molecules such as β-carotene can enhance the differentiation capacity of cell imprinting. 216 …”

“… 115 The results of previous studies indicate that PDMS, at a 1:10 ratio of curing agent, induces more osteogenicity in stem cells than polystyrene plates. 163 , 164 In some studies, engineering approaches such as lithography have been used to generate substrates with 3D features that mimic physiological shapes and patterns similar to native tissues. For example, aligned microgrooves are fabricated by photolithography to resemble the physiological dimensions of the ECM structure in tendons, muscles, nervous and cartilage tissues.…”

How Mechanical and Physicochemical Material Characteristics Influence Adipose-Derived Stem Cell Fate

“…Keyhanvar et al and Mashinchian et al obtained comparable results using keratinocytes [ 139 , 140 ]. Babaei et al demonstrated this effect for osteoblast-imprinted PDMS [ 141 ]. In this study, the effect was further enhanced by chemical modification with bone lysate.…”