Two-Dimensional Metal–Organic Framework-Based Cellular Scaffolds with High Protein Adsorption, Retention, and Replenishment Capabilities

Abstract

Metal–organic frameworks (MOFs) are porous materials with adsorption, storage, and separation capabilities due to their high specific surface areas and large pore volumes. MOFs are thus used in biomedical applications, and MOF nanoparticles have been widely studied as nanocarriers for drug delivery systems. Several research groups recently reported that specific MOF nanoparticles can adsorb and retain proteins, suggesting to us that MOF nanoparticles may have advantages as novel cell culture scaffolds. However, MOF nanoparticles cannot be used as two-dimensional scaffolds for cells. We therefore established a bottom-up technique to construct two-dimensional MOFs [MIL-53 (Al)] on polymer films. The developed two-dimensional MIL-53 (Al) film [fMIL-53 (Al)] exhibited high serum protein adsorption, retention, and replenishment capabilities as compared to conventional cell culture scaffolds. β-Galactosidase, used as a model protein, adsorbed on fMIL-53 (Al) exhibited original enzymatic activity, indicating that proteins are not denatured during the adsorption process. The viability of mouse myoblast cells (C2C12) cultured on fMIL-53 (Al) was 100%, indicating the cell compatibility of fMIL-53 (Al). Importantly, C2C12 cells cultured on serum protein-preadsorbed fMIL-53 (Al) exhibited excellent long-term adhesion, morphology, and proliferation even in a medium lacking serum proteins, demonstrating an important advantage of fMIL-53 (Al) as a cell culture scaffold, given that conventional cell culture scaffolds typically require a serum-containing medium to support stable cell adhesion and proliferation. To our knowledge, this is the first report regarding the application of MOFs as cell culture scaffolds and will serve as a starting point for studying two- and three-dimensional MOF-based cellular scaffolds for cell culture systems and for in vitro and in vivo tissue engineering.

In Situ Preparation of Tannic Acid-Modified Poly(N-isopropylacrylamide) Hydrogel Coatings for Boosting Cell Response

“…The dominant reason for the high protein retention may be π-π stacking and hydrophobic interactions of TA with hydrophobic amino acid residues of proteins [ 43 , 44 ]. The retention rate of protein on PNIPAAm-APTES coatings (sample V–VIII) decreased monotonously with time during the entire protein retention period, which was consistent with the report by Nagahama [ 45 ]. The protein retention rates of PNIPAAm 2000 -APTES-TA and PNIPAAm 1300 -APTES-TA in the first 12 h were 37.5% and 38.9%, respectively.…”

Synergistic effect of hierarchical topographic structure on 3D-printed Titanium scaffold for enhanced coupling of osteogenesis and angiogenesis

“…The adsorption of proteins is influenced by various surface physicochemical properties, including surface wettability, roughness, topography, charge, and chemistry [ 55 ]. While a hydrophobic surface promotes protein absorption, it may also cause denaturation of the absorbed proteins [ 57 ].…”

“…Therefore, the mesopore created by AHT effectively improved protein absorption. Additionally, recent research has demonstrated that certain types of MOFs, such as UiO-66, possess remarkable protein adsorption and retention properties due to their large specific surface areas and pore volumes [ 55 , 56 ]. This is significant as protein adsorption serves as the primary stage in the implantation of scaffolds within living organisms and is crucial for subsequent biological processes [ 78 ].…”

“…Furthermore, the binding of integrin-mediated by surface topography can lead to the reorganization of the cytoskeleton, subsequently affecting the shape of the nucleus and potentially the orientation of chromosomes, a phenomenon known as direct mechanotransduction [ 89 ]. Additionally, the introduction of UiO-66 as an additional modification to the nano-topography resulted in enhanced absorption of serum proteins [ 55 ]. Superior expression of integrin β1 and reorganization of the cytoskeleton were both observed in 1/2UiO-66/AHT.…”

“…Consequently, the integration of UiO-66 onto the titanium scaffold provides a basis for introducing additional biological factors, such as immunomodulators and antibiotics [ 53 , 54 ]. Moreover, it is demonstrated that some specific types of MOFs, including UiO-66, exhibit remarkable protein absorption and retention properties [ 55 , 56 ], which serve as the basis for cell adhesion and cell-topography interaction [ 57 ]. While the osteogenesis promotive function of UiO-66 has been established, its potential effects on angiogenesis have yet to be determined [ 54 ].…”